0db7657 feat(host): select remote transport with host add --transport · vev

M AGENTS.md +1 -1


@@ -82,6 +82,6 @@ Typed messages and negotiated version live in `internal/protocol`. Remote discov
82	82		- A live unit whose teardown aborts before destructive ownership stays registered, and its snapshot-coordinator quarantine is rolled back so the surviving session resumes checkpoint scheduling and its attached clients are unfrozen.
83	83		- Each connection has a 15-second handshake budget from connect through the initial committed publication.
84	84		- Local and remote attach use the same typed `Hello`/`Welcome` session protocol. `sessionwire` translates typed traffic to Protobuf envelopes carried by IPC, QUIC, or SSH stdio.
85		-	- Remote attach bootstraps an authenticated direct QUIC connection by default; `VEV_REMOTE_TRANSPORT=stdio` explicitly selects an SSH-only carriage.
	85	+	- Remote attach bootstraps an authenticated direct QUIC connection by default; `vev host add --transport ssh <host>` explicitly selects an SSH-only carriage.
86	86		- A session owns shared PTYs, VT state, tabs, panes, PTY content geometry selected by the latest valid attachment claim, and ordered mutations. Each attachment owns its window/view, copy and overlay state, rendering/output state, and reconnect lifecycle; when the latest claimant detaches, the most recently claimed remaining attachment becomes authoritative.
87	87		- Command requests have a 10-second result deadline and are tracked per connection.


@@ -82,6 +82,6 @@ Typed messages and negotiated version live in `internal/protocol`. Remote discov
82		- A live unit whose teardown aborts before destructive ownership stays registered, and its snapshot-coordinator quarantine is rolled back so the surviving session resumes checkpoint scheduling and its attached clients are unfrozen.	82		- A live unit whose teardown aborts before destructive ownership stays registered, and its snapshot-coordinator quarantine is rolled back so the surviving session resumes checkpoint scheduling and its attached clients are unfrozen.
83		- Each connection has a 15-second handshake budget from connect through the initial committed publication.	83		- Each connection has a 15-second handshake budget from connect through the initial committed publication.
84		- Local and remote attach use the same typed `Hello`/`Welcome` session protocol. `sessionwire` translates typed traffic to Protobuf envelopes carried by IPC, QUIC, or SSH stdio.	84		- Local and remote attach use the same typed `Hello`/`Welcome` session protocol. `sessionwire` translates typed traffic to Protobuf envelopes carried by IPC, QUIC, or SSH stdio.
85	-	- Remote attach bootstraps an authenticated direct QUIC connection by default; `VEV_REMOTE_TRANSPORT=stdio` explicitly selects an SSH-only carriage.	85	+	- Remote attach bootstraps an authenticated direct QUIC connection by default; `vev host add --transport ssh <host>` explicitly selects an SSH-only carriage.
86		- A session owns shared PTYs, VT state, tabs, panes, PTY content geometry selected by the latest valid attachment claim, and ordered mutations. Each attachment owns its window/view, copy and overlay state, rendering/output state, and reconnect lifecycle; when the latest claimant detaches, the most recently claimed remaining attachment becomes authoritative.	86		- A session owns shared PTYs, VT state, tabs, panes, PTY content geometry selected by the latest valid attachment claim, and ordered mutations. Each attachment owns its window/view, copy and overlay state, rendering/output state, and reconnect lifecycle; when the latest claimant detaches, the most recently claimed remaining attachment becomes authoritative.
87		- Command requests have a 10-second result deadline and are tracked per connection.	87		- Command requests have a 10-second result deadline and are tracked per connection.

M README.md +1 -1


@@ -23,7 +23,7 @@
23	23		\| Remote \| `vev attach user@host` \| Sessions on a server, rendered there and sent as small diffs over SSH + QUIC. \|
24	24		\| Hybrid \| `vev host add user@host` \| Local and remote sessions in one picker; switch between them without leaving vev. \|
25	25
26		-	Remote and hybrid need vev installed on the remote host. Set `VEV_REMOTE_TRANSPORT=stdio` to use SSH only. See [remote sessions](docs/remote-resilience.md).
	26	+	Remote and hybrid need vev installed on the remote host. Use `vev host add --transport ssh user@host` for SSH only. See [remote sessions](docs/remote-resilience.md).
27	27
28	28		## Features
29	29


@@ -23,7 +23,7 @@
23		\| Remote \| `vev attach user@host` \| Sessions on a server, rendered there and sent as small diffs over SSH + QUIC. \|	23		\| Remote \| `vev attach user@host` \| Sessions on a server, rendered there and sent as small diffs over SSH + QUIC. \|
24		\| Hybrid \| `vev host add user@host` \| Local and remote sessions in one picker; switch between them without leaving vev. \|	24		\| Hybrid \| `vev host add user@host` \| Local and remote sessions in one picker; switch between them without leaving vev. \|
25			25
26	-	Remote and hybrid need vev installed on the remote host. Set `VEV_REMOTE_TRANSPORT=stdio` to use SSH only. See [remote sessions](docs/remote-resilience.md).	26	+	Remote and hybrid need vev installed on the remote host. Use `vev host add --transport ssh user@host` for SSH only. See [remote sessions](docs/remote-resilience.md).
27			27
28		## Features	28		## Features
29			29

M cmd/vev-perf-harness/launcher.go +11 -11


@@ -194,18 +194,17 @@ func (l *cliLauncher) Launch(m processMapping, role roleCommand) (launchedProces
194	194		// a role working directory: daemon-owned subprocess cleanup may otherwise
195	195		// treat the evidence directory as its working tree and remove a preallocated
196	196		// trace while a later repetition is being merged.
197		-	cmd.Env = append(withoutEnv(os.Environ(), "VEV", "VEV_PERF_TRACE", "VEV_PERF_PROCESS_ID", "VEV_PERF_SCENARIO", "VEV_PERF_RUN", "VEV_PERF_BIN", "VEV_REMOTE_TRANSPORT", "XDG_RUNTIME_DIR", "XDG_STATE_HOME", "XDG_CONFIG_HOME"), traceEnvironment(m)...)
	197	+	cmd.Env = append(withoutEnv(os.Environ(), "VEV", "VEV_PERF_TRACE", "VEV_PERF_PROCESS_ID", "VEV_PERF_SCENARIO", "VEV_PERF_RUN", "VEV_PERF_BIN", "XDG_RUNTIME_DIR", "XDG_STATE_HOME", "XDG_CONFIG_HOME"), traceEnvironment(m)...)
198	198		cmd.Env = append(cmd.Env, "XDG_RUNTIME_DIR="+runtimeDir,
199	199		"XDG_STATE_HOME="+filepath.Join(runDir, "state"), "XDG_CONFIG_HOME="+filepath.Join(runDir, "config"), "TERM=xterm-256color", "SHELL=/bin/sh", "VEV_PERF_BIN="+bin)
200	200		l.mu.Lock()
201	201		peer, routed := l.peers[runDir]
202	202		l.mu.Unlock()
203	203		if routed && (m.Role == "client" \|\| m.Role == "daemon") {
204		-	mode, err := remoteMode(peer.command.Transport)
205		-	if err != nil {
	204	+	if _, err := hostTransport(peer.command.Transport); err != nil {
206	205		return nil, err
207	206		}
208		-	cmd.Env = append(withoutEnv(cmd.Env, "PATH", "VEV_REMOTE_TRANSPORT"), "PATH="+runDir+":"+os.Getenv("PATH"), "VEV_REMOTE_TRANSPORT="+mode)
	207	+	cmd.Env = append(withoutEnv(cmd.Env, "PATH"), "PATH="+runDir+":"+os.Getenv("PATH"))
209	208		}
210	209		if err := safedir.EnsurePrivate(filepath.Join(runDir, "state")); err != nil {
211	210		return nil, err

@@ -231,12 +230,12 @@ func (l *cliLauncher) Launch(m processMapping, role roleCommand) (launchedProces
231	230		peer, routed := l.peers[runDir]
232	231		l.mu.Unlock()
233	232		if routed {
234		-	mode, modeErr := remoteMode(peer.command.Transport)
235		-	if modeErr != nil {
236		-	return nil, modeErr
	233	+	transportName, transportErr := hostTransport(peer.command.Transport)
	234	+	if transportErr != nil {
	235	+	return nil, transportErr
237	236		}
238		-	p.configureCommand = exec.Command(bin, "host", "add", "harness@127.0.0.1")
239		-	p.configureCommand.Env = append(withoutEnv(cmd.Env, "PATH", "VEV_REMOTE_TRANSPORT"), "PATH="+runDir+":"+os.Getenv("PATH"), "VEV_REMOTE_TRANSPORT="+mode)
	237	+	p.configureCommand = exec.Command(bin, "host", "add", "--transport", transportName, "harness@127.0.0.1")
	238	+	p.configureCommand.Env = append(withoutEnv(cmd.Env, "PATH"), "PATH="+runDir+":"+os.Getenv("PATH"))
240	239		peerStart := exec.Command(bin, "--daemon")
241	240		peerStart.Env = append(withoutEnv(os.Environ(), "VEV", "VEV_PERF_TRACE", "VEV_PERF_PROCESS_ID", "VEV_PERF_SCENARIO", "VEV_PERF_RUN", "XDG_RUNTIME_DIR", "XDG_STATE_HOME", "PATH"),
242	241		"PATH="+runDir+":"+os.Getenv("PATH"),

@@ -455,10 +454,11 @@ esac
455	454		return peer, nil
456	455		}
457	456
458		-	func remoteMode(t transport) (string, error) {
	457	+	// hostTransport maps a harness transport to the `vev host add --transport` value.
	458	+	func hostTransport(t transport) (string, error) {
459	459		switch t.Kind {
460	460		case "ssh_stdio":
461		-	return "stdio", nil
	461	+	return "ssh", nil
462	462		default:
463	463		return "", fmt.Errorf("transport %q cannot route through a remote peer", t.ID)
464	464		}

 	// a role working directory: daemon-owned subprocess cleanup may otherwise
 	// treat the evidence directory as its working tree and remove a preallocated
 	// trace while a later repetition is being merged.
-	cmd.Env = append(withoutEnv(os.Environ(), "VEV", "VEV_PERF_TRACE", "VEV_PERF_PROCESS_ID", "VEV_PERF_SCENARIO", "VEV_PERF_RUN", "VEV_PERF_BIN", "VEV_REMOTE_TRANSPORT", "XDG_RUNTIME_DIR", "XDG_STATE_HOME", "XDG_CONFIG_HOME"), traceEnvironment(m)...)
+	cmd.Env = append(withoutEnv(os.Environ(), "VEV", "VEV_PERF_TRACE", "VEV_PERF_PROCESS_ID", "VEV_PERF_SCENARIO", "VEV_PERF_RUN", "VEV_PERF_BIN", "XDG_RUNTIME_DIR", "XDG_STATE_HOME", "XDG_CONFIG_HOME"), traceEnvironment(m)...)
 	cmd.Env = append(cmd.Env, "XDG_RUNTIME_DIR="+runtimeDir,
 		"XDG_STATE_HOME="+filepath.Join(runDir, "state"), "XDG_CONFIG_HOME="+filepath.Join(runDir, "config"), "TERM=xterm-256color", "SHELL=/bin/sh", "VEV_PERF_BIN="+bin)
 	l.mu.Lock()
 	peer, routed := l.peers[runDir]
 	l.mu.Unlock()
 	if routed && (m.Role == "client" || m.Role == "daemon") {
-		mode, err := remoteMode(peer.command.Transport)
+		if _, err := hostTransport(peer.command.Transport); err != nil {
-		if err != nil {
 			return nil, err
 		}
-		cmd.Env = append(withoutEnv(cmd.Env, "PATH", "VEV_REMOTE_TRANSPORT"), "PATH="+runDir+":"+os.Getenv("PATH"), "VEV_REMOTE_TRANSPORT="+mode)
+		cmd.Env = append(withoutEnv(cmd.Env, "PATH"), "PATH="+runDir+":"+os.Getenv("PATH"))
 	}
 	if err := safedir.EnsurePrivate(filepath.Join(runDir, "state")); err != nil {
 		return nil, err
 		peer, routed := l.peers[runDir]
 		l.mu.Unlock()
 		if routed {
-			mode, modeErr := remoteMode(peer.command.Transport)
+			transportName, transportErr := hostTransport(peer.command.Transport)
-			if modeErr != nil {
+			if transportErr != nil {
-				return nil, modeErr
+				return nil, transportErr
 			}
-			p.configureCommand = exec.Command(bin, "host", "add", "harness@127.0.0.1")
+			p.configureCommand = exec.Command(bin, "host", "add", "--transport", transportName, "harness@127.0.0.1")
-			p.configureCommand.Env = append(withoutEnv(cmd.Env, "PATH", "VEV_REMOTE_TRANSPORT"), "PATH="+runDir+":"+os.Getenv("PATH"), "VEV_REMOTE_TRANSPORT="+mode)
+			p.configureCommand.Env = append(withoutEnv(cmd.Env, "PATH"), "PATH="+runDir+":"+os.Getenv("PATH"))
 			peerStart := exec.Command(bin, "--daemon")
 			peerStart.Env = append(withoutEnv(os.Environ(), "VEV", "VEV_PERF_TRACE", "VEV_PERF_PROCESS_ID", "VEV_PERF_SCENARIO", "VEV_PERF_RUN", "XDG_RUNTIME_DIR", "XDG_STATE_HOME", "PATH"),
 				"PATH="+runDir+":"+os.Getenv("PATH"),
 	return peer, nil
 }
-func remoteMode(t transport) (string, error) {
+// hostTransport maps a harness transport to the `vev host add --transport` value.
+func hostTransport(t transport) (string, error) {
 	switch t.Kind {
 	case "ssh_stdio":
-		return "stdio", nil
+		return "ssh", nil
 	default:
 		return "", fmt.Errorf("transport %q cannot route through a remote peer", t.ID)
 	}

M docs/configuration.md +6 -3


@@ -154,11 +154,14 @@ rm -rf .dev/dev
154	154		## Remote hosts
155	155
156	156		```sh
157		-	vev host add user@host # add a host
158		-	vev host rm user@host # remove it
159		-	vev host list # show hosts and their status
	157	+	vev host add user@host # add a host (QUIC, the default)
	158	+	vev host add --transport ssh user@host # add a host that uses SSH only
	159	+	vev host rm user@host # remove it
	160	+	vev host list # show hosts and their status
160	161		```
161	162
	163	+	- `--transport quic\|ssh` selects the carriage. `quic` (default) opens a direct QUIC connection bootstrapped over SSH; `ssh` carries everything over SSH, for networks that block UDP.
	164	+	- A host keeps the transport it was added with. To change it, run `vev host rm` and then `vev host add` again; adding it with a different transport is refused.
162	165		- The broker stores hosts in `~/.local/state/vev/broker/state/state.json`.
163	166		- Hosts connect over SSH, so your SSH config (aliases, keys) applies.
164	167		- Remote sessions appear as `session@host` in `vev ls --all` and in the picker.

 ## Remote hosts
 ```sh
-vev host add user@host   # add a host
+vev host add user@host                    # add a host (QUIC, the default)
-vev host rm user@host    # remove it
+vev host add --transport ssh user@host    # add a host that uses SSH only
-vev host list            # show hosts and their status
+vev host rm user@host                     # remove it
+vev host list                             # show hosts and their status
 ```
+- `--transport quic|ssh` selects the carriage. `quic` (default) opens a direct QUIC connection bootstrapped over SSH; `ssh` carries everything over SSH, for networks that block UDP.
+- A host keeps the transport it was added with. To change it, run `vev host rm` and then `vev host add` again; adding it with a different transport is refused.
 - The broker stores hosts in `~/.local/state/vev/broker/state/state.json`.
 - Hosts connect over SSH, so your SSH config (aliases, keys) applies.
 - Remote sessions appear as `session@host` in `vev ls --all` and in the picker.

M docs/protocol.md +1 -1


@@ -251,7 +251,7 @@ acceptance. Local carriage requires the preamble + `Hello`/`Welcome`
251	251		inside the 15-second budget; a failed handshake closes the exact
252	252		connection. Broker-owned remote carriage uses QUIC (`internal/adapters/quic`,
253	253		TLS 1.3, ALPN `vev/1`, exact SHA-256 pin, one bidirectional stream,
254		-	no 0-RTT); `VEV_REMOTE_TRANSPORT=stdio` selects SSH stdio instead.
	254	+	no 0-RTT); a host added with `vev host add --transport ssh` uses SSH stdio instead.
255	255		For the QUIC route the broker starts one short-lived `_broker-mux-quic-bootstrap --production` over SSH
256	256		which spawns a detached `_broker-mux-quic-proxy` (ephemeral listener +
257	257		certificate, 32-byte token, ≤4 KiB readiness with host-independent


@@ -251,7 +251,7 @@ acceptance. Local carriage requires the preamble + `Hello`/`Welcome`
251		inside the 15-second budget; a failed handshake closes the exact	251		inside the 15-second budget; a failed handshake closes the exact
252		connection. Broker-owned remote carriage uses QUIC (`internal/adapters/quic`,	252		connection. Broker-owned remote carriage uses QUIC (`internal/adapters/quic`,
253		TLS 1.3, ALPN `vev/1`, exact SHA-256 pin, one bidirectional stream,	253		TLS 1.3, ALPN `vev/1`, exact SHA-256 pin, one bidirectional stream,
254	-	no 0-RTT); `VEV_REMOTE_TRANSPORT=stdio` selects SSH stdio instead.	254	+	no 0-RTT); a host added with `vev host add --transport ssh` uses SSH stdio instead.
255		For the QUIC route the broker starts one short-lived `_broker-mux-quic-bootstrap --production` over SSH	255		For the QUIC route the broker starts one short-lived `_broker-mux-quic-bootstrap --production` over SSH
256		which spawns a detached `_broker-mux-quic-proxy` (ephemeral listener +	256		which spawns a detached `_broker-mux-quic-proxy` (ephemeral listener +
257		certificate, 32-byte token, ≤4 KiB readiness with host-independent	257		certificate, 32-byte token, ≤4 KiB readiness with host-independent

M docs/remote-resilience.md +4 -2


@@ -14,12 +14,14 @@ vev must be installed on the remote host. The remote daemon owns the session: it
14	14
15	15		Terminal traffic then goes over QUIC, not SSH. The token and keys stay in memory only.
16	16
17		-	If UDP is blocked, use SSH only:
	17	+	If UDP is blocked, register the host with SSH only:
18	18
19	19		```sh
20		-	VEV_REMOTE_TRANSPORT=stdio vev attach user@host
	20	+	vev host add --transport ssh user@host
21	21		```
22	22
	23	+	The transport is fixed when the host is added (`quic` by default). To switch, run `vev host rm user@host`, then add it again with the other `--transport`.
	24	+
23	25		## What survives a network problem
24	26
25	27		- The remote session and its shells keep running while you are offline.


@@ -14,12 +14,14 @@ vev must be installed on the remote host. The remote daemon owns the session: it
14			14
15		Terminal traffic then goes over QUIC, not SSH. The token and keys stay in memory only.	15		Terminal traffic then goes over QUIC, not SSH. The token and keys stay in memory only.
16			16
17	-	If UDP is blocked, use SSH only:	17	+	If UDP is blocked, register the host with SSH only:
18			18
19		```sh	19		```sh
20	-	VEV_REMOTE_TRANSPORT=stdio vev attach user@host	20	+	vev host add --transport ssh user@host
21		```	21		```
22			22
			23	+	The transport is fixed when the host is added (`quic` by default). To switch, run `vev host rm user@host`, then add it again with the other `--transport`.
			24	+
23		## What survives a network problem	25		## What survives a network problem
24			26
25		- The remote session and its shells keep running while you are offline.	27		- The remote session and its shells keep running while you are offline.

M internal/app/broker_client_test.go +2 -5


@@ -530,10 +530,9 @@ func startTerminalComposition(t *testing.T, intent uint8, name, remoteTarget str
530	530		// daemon owns daemonSessions even when the catalogue has not observed them.
531	531		func startTerminalCompositionWithDaemon(t testing.T, intent uint8, name, remoteTarget string, snapshot ports.BrokerSnapshot, daemonSessions []string) terminalCompositionRun {
532	532		t.Helper()
533		-	// The ordinary terminal path reads the nested-session and remote-transport
534		-	// environment; a test drives the broker composition with both unset.
	533	+	// The ordinary terminal path reads the nested-session environment; a test
	534	+	// drives the broker composition with it unset.
535	535		t.Setenv("VEV", "")
536		-	t.Setenv(envRemoteTransport, "")
537	536		service := newTerminalCompositionService(snapshot)
538	537		service.daemonSessions = daemonSessions
539	538		terminal := newTerminalCompositionTerminal()

@@ -926,7 +925,6 @@ func TestTerminalCompositionCapturesSessionEnvironmentDefensively(t *testing.T)
926	925		// without opening any stream. It remains live until the terminal ends.
927	926		func TestTerminalCompositionReportsBrokerFailureInThePicker(t *testing.T) {
928	927		t.Setenv("VEV", "")
929		-	t.Setenv(envRemoteTransport, "")
930	928		startupErr := errors.New("broker not reachable")
931	929		previousConnect := connectProductionClientBroker
932	930		terminal := newTerminalCompositionTerminal()

@@ -971,7 +969,6 @@ func TestTerminalCompositionReportsBrokerFailureInThePicker(t *testing.T) {
971	969		// without reaching the broker.
972	970		func TestRunAttachNestedSessionBehavior(t *testing.T) {
973	971		t.Setenv("VEV", "outer")
974		-	t.Setenv(envRemoteTransport, "")
975	972		connectCalls := 0
976	973		previousConnect := connectProductionClientBroker
977	974		previousCreate := createDetachedTerminalSession

 // daemon owns daemonSessions even when the catalogue has not observed them.
 func startTerminalCompositionWithDaemon(t *testing.T, intent uint8, name, remoteTarget string, snapshot ports.BrokerSnapshot, daemonSessions []string) *terminalCompositionRun {
 	t.Helper()
-	// The ordinary terminal path reads the nested-session and remote-transport
+	// The ordinary terminal path reads the nested-session environment; a test
-	// environment; a test drives the broker composition with both unset.
+	// drives the broker composition with it unset.
 	t.Setenv("VEV", "")
-	t.Setenv(envRemoteTransport, "")
 	service := newTerminalCompositionService(snapshot)
 	service.daemonSessions = daemonSessions
 	terminal := newTerminalCompositionTerminal()
 // without opening any stream. It remains live until the terminal ends.
 func TestTerminalCompositionReportsBrokerFailureInThePicker(t *testing.T) {
 	t.Setenv("VEV", "")
-	t.Setenv(envRemoteTransport, "")
 	startupErr := errors.New("broker not reachable")
 	previousConnect := connectProductionClientBroker
 	terminal := newTerminalCompositionTerminal()
 // without reaching the broker.
 func TestRunAttachNestedSessionBehavior(t *testing.T) {
 	t.Setenv("VEV", "outer")
-	t.Setenv(envRemoteTransport, "")
 	connectCalls := 0
 	previousConnect := connectProductionClientBroker
 	previousCreate := createDetachedTerminalSession

M internal/app/broker_composition_test.go +3 -3


@@ -110,7 +110,7 @@ func TestProductionBrokerCompositionLocalAndMutableRemote(t *testing.T) {
110	110		return len(snapshot.Daemons) > 0 && snapshot.Daemons[0].Identity != ""
111	111		}, 10time.Second, 10time.Millisecond, "local observation: %+v", service.Snapshot())
112	112
113		-	registration, err := service.AddHost(ctx, "harness@127.0.0.1", remoteBrokerPolicy("stdio"))
	113	+	registration, err := service.AddHost(ctx, "harness@127.0.0.1", remoteBrokerPolicy(hostTransportSSH))
114	114		require.NoError(t, err)
115	115		require.Equal(t, "harness@127.0.0.1", registration.Endpoint)
116	116		require.Eventually(t, func() bool {

@@ -128,8 +128,8 @@ func TestProductionBrokerRemoteMuxTransports(t *testing.T) {
128	128		for _, tc := range []struct {
129	129		name, helper string
130	130		}{
131		-	{"stdio", brokerMuxStdioCommand},
132		-	{"quic", brokerMuxQUICBootstrapCommand},
	131	+	{hostTransportSSH, brokerMuxStdioCommand},
	132	+	{hostTransportQUIC, brokerMuxQUICBootstrapCommand},
133	133		} {
134	134		t.Run(tc.name, func(t *testing.T) {
135	135		binDir := shortTempDir(t, "vb")


@@ -110,7 +110,7 @@ func TestProductionBrokerCompositionLocalAndMutableRemote(t *testing.T) {
110		return len(snapshot.Daemons) > 0 && snapshot.Daemons[0].Identity != ""	110		return len(snapshot.Daemons) > 0 && snapshot.Daemons[0].Identity != ""
111		}, 10time.Second, 10time.Millisecond, "local observation: %+v", service.Snapshot())	111		}, 10time.Second, 10time.Millisecond, "local observation: %+v", service.Snapshot())
112			112
113	-	registration, err := service.AddHost(ctx, "harness@127.0.0.1", remoteBrokerPolicy("stdio"))	113	+	registration, err := service.AddHost(ctx, "harness@127.0.0.1", remoteBrokerPolicy(hostTransportSSH))
114		require.NoError(t, err)	114		require.NoError(t, err)
115		require.Equal(t, "harness@127.0.0.1", registration.Endpoint)	115		require.Equal(t, "harness@127.0.0.1", registration.Endpoint)
116		require.Eventually(t, func() bool {	116		require.Eventually(t, func() bool {

@@ -128,8 +128,8 @@ func TestProductionBrokerRemoteMuxTransports(t *testing.T) {
128		for _, tc := range []struct {	128		for _, tc := range []struct {
129		name, helper string	129		name, helper string
130		}{	130		}{
131	-	{"stdio", brokerMuxStdioCommand},	131	+	{hostTransportSSH, brokerMuxStdioCommand},
132	-	{"quic", brokerMuxQUICBootstrapCommand},	132	+	{hostTransportQUIC, brokerMuxQUICBootstrapCommand},
133		} {	133		} {
134		t.Run(tc.name, func(t *testing.T) {	134		t.Run(tc.name, func(t *testing.T) {
135		binDir := shortTempDir(t, "vb")	135		binDir := shortTempDir(t, "vb")

M internal/app/broker_host_upgrade_test.go +2 -2


@@ -22,7 +22,7 @@ func TestUpgradeBrokerHostVersions(t *testing.T) {
22	22		{
23	23		name: "older build policy is upgraded and identity kept",
24	24		policy: func() ports.BrokerPolicy {
25		-	p := remoteBrokerPolicy("")
	25	+	p := remoteBrokerPolicy(hostTransportQUIC)
26	26		p.ProtocolVersion--
27	27		return p
28	28		},

@@ -30,7 +30,7 @@ func TestUpgradeBrokerHostVersions(t *testing.T) {
30	30		},
31	31		{
32	32		name: "current policy is left untouched",
33		-	policy: func() ports.BrokerPolicy { return remoteBrokerPolicy("") },
	33	+	policy: func() ports.BrokerPolicy { return remoteBrokerPolicy(hostTransportQUIC) },
34	34		wantRevision: 0,
35	35		},
36	36		}


@@ -22,7 +22,7 @@ func TestUpgradeBrokerHostVersions(t *testing.T) {
22		{	22		{
23		name: "older build policy is upgraded and identity kept",	23		name: "older build policy is upgraded and identity kept",
24		policy: func() ports.BrokerPolicy {	24		policy: func() ports.BrokerPolicy {
25	-	p := remoteBrokerPolicy("")	25	+	p := remoteBrokerPolicy(hostTransportQUIC)
26		p.ProtocolVersion--	26		p.ProtocolVersion--
27		return p	27		return p
28		},	28		},

@@ -30,7 +30,7 @@ func TestUpgradeBrokerHostVersions(t *testing.T) {
30		},	30		},
31		{	31		{
32		name: "current policy is left untouched",	32		name: "current policy is left untouched",
33	-	policy: func() ports.BrokerPolicy { return remoteBrokerPolicy("") },	33	+	policy: func() ports.BrokerPolicy { return remoteBrokerPolicy(hostTransportQUIC) },
34		wantRevision: 0,	34		wantRevision: 0,
35		},	35		},
36		}	36		}

M internal/app/broker_offline_local_test.go +1 -1


@@ -618,7 +618,7 @@ func TestProductionRegistryOwnsMutableMembershipWithZeroHosts(t *testing.T) {
618	618		startLocalRegistry(t, registry)
619	619
620	620		require.Empty(t, registry.Snapshot().Daemons[0].Registration, "the local entry carries no configured registration")
621		-	registration, err := registry.AddHost(context.Background(), "user@example.com", remoteBrokerPolicy("quic"))
	621	+	registration, err := registry.AddHost(context.Background(), "user@example.com", remoteBrokerPolicy(hostTransportQUIC))
622	622		require.NoError(t, err, "a zero-host production run must admit a first host")
623	623		require.Equal(t, "user@example.com", registration.Endpoint)
624	624


@@ -618,7 +618,7 @@ func TestProductionRegistryOwnsMutableMembershipWithZeroHosts(t *testing.T) {
618		startLocalRegistry(t, registry)	618		startLocalRegistry(t, registry)
619			619
620		require.Empty(t, registry.Snapshot().Daemons[0].Registration, "the local entry carries no configured registration")	620		require.Empty(t, registry.Snapshot().Daemons[0].Registration, "the local entry carries no configured registration")
621	-	registration, err := registry.AddHost(context.Background(), "user@example.com", remoteBrokerPolicy("quic"))	621	+	registration, err := registry.AddHost(context.Background(), "user@example.com", remoteBrokerPolicy(hostTransportQUIC))
622		require.NoError(t, err, "a zero-host production run must admit a first host")	622		require.NoError(t, err, "a zero-host production run must admit a first host")
623		require.Equal(t, "user@example.com", registration.Endpoint)	623		require.Equal(t, "user@example.com", registration.Endpoint)
624			624

M internal/app/broker_production.go +7 -5


@@ -51,15 +51,17 @@ func ensureProductionBrokerConfig() error {
51	51		return errors.Join(fmt.Errorf("vev: close broker configuration: %w", closeErr), removeErr)
52	52		}
53	53
	54	+	// remoteBrokerPolicy builds the remote host policy for a CLI transport name
	55	+	// (hostTransportQUIC or hostTransportSSH). Callers pass a parsed value, so an
	56	+	// unknown name is a programming error.
54	57		func remoteBrokerPolicy(transport string) ports.BrokerPolicy {
55		-	if transport == "stdio" {
56		-	transport = "ssh-stdio"
57		-	} else {
58		-	transport = "ssh-quic"
	58	+	route, ok := hostTransportRoutes[transport]
	59	+	if !ok {
	60	+	panic(fmt.Sprintf("vev: unknown host transport %q", transport))
59	61		}
60	62		return ports.BrokerPolicy{
61	63		ProtocolVersion: protocol.Version, CatalogSchemaVersion: catalogue.RemoteCatalogSchemaVersion,
62		-	EnvironmentPolicy: protocol.EnvironmentPolicyDaemonOwned, Transport: transport,
	64	+	EnvironmentPolicy: protocol.EnvironmentPolicyDaemonOwned, Transport: string(route),
63	65		Trust: "openssh-config-v1", Launch: broker.DaemonLaunchAuthority, Isolation: "per-user",
64	66		}
65	67		}

 	return errors.Join(fmt.Errorf("vev: close broker configuration: %w", closeErr), removeErr)
 }
+// remoteBrokerPolicy builds the remote host policy for a CLI transport name
+// (hostTransportQUIC or hostTransportSSH). Callers pass a parsed value, so an
+// unknown name is a programming error.
 func remoteBrokerPolicy(transport string) ports.BrokerPolicy {
-	if transport == "stdio" {
+	route, ok := hostTransportRoutes[transport]
-		transport = "ssh-stdio"
+	if !ok {
-	} else {
+		panic(fmt.Sprintf("vev: unknown host transport %q", transport))
-		transport = "ssh-quic"
 	}
 	return ports.BrokerPolicy{
 		ProtocolVersion: protocol.Version, CatalogSchemaVersion: catalogue.RemoteCatalogSchemaVersion,
-		EnvironmentPolicy: protocol.EnvironmentPolicyDaemonOwned, Transport: transport,
+		EnvironmentPolicy: protocol.EnvironmentPolicyDaemonOwned, Transport: string(route),
 		Trust: "openssh-config-v1", Launch: broker.DaemonLaunchAuthority, Isolation: "per-user",
 	}
 }

M internal/app/broker_routes_test.go +2 -2


@@ -40,7 +40,7 @@ func TestBrokerRoutesDurableFirstAddAndRestart(t *testing.T) {
40	40		registry, err := broker.NewRegistryWithConfig(1, store, probe, clock.New(), nil, broker.RegistryConfig{MembershipMode: broker.MembershipMutable})
41	41		require.NoError(t, err)
42	42		routes.Hosts = registry
43		-	policy := remoteBrokerPolicy("stdio")
	43	+	policy := remoteBrokerPolicy(hostTransportSSH)
44	44		reg, err := registry.AddHost(ctx, "user@example.test", policy)
45	45		require.NoError(t, err)
46	46		request := ports.BrokerOpenStreamRequest{Endpoint: reg.Endpoint, Registration: reg, Policy: policy, StartMode: ports.BrokerDaemonExistingOnly}

@@ -110,7 +110,7 @@ func TestProductionBrokerFirstHostAdd(t *testing.T) {
110	110		socket := awaitSandboxReady(t, ready, done)
111	111		service, err := brokeripc.NewConnector(socket, brokeripc.Config{}).Connect(ctx)
112	112		require.NoError(t, err)
113		-	reg, err := service.AddHost(ctx, "user@127.0.0.1:1", remoteBrokerPolicy("stdio"))
	113	+	reg, err := service.AddHost(ctx, "user@127.0.0.1:1", remoteBrokerPolicy(hostTransportSSH))
114	114		require.NoError(t, err)
115	115		if i == 0 {
116	116		registered = reg


@@ -40,7 +40,7 @@ func TestBrokerRoutesDurableFirstAddAndRestart(t *testing.T) {
40		registry, err := broker.NewRegistryWithConfig(1, store, probe, clock.New(), nil, broker.RegistryConfig{MembershipMode: broker.MembershipMutable})	40		registry, err := broker.NewRegistryWithConfig(1, store, probe, clock.New(), nil, broker.RegistryConfig{MembershipMode: broker.MembershipMutable})
41		require.NoError(t, err)	41		require.NoError(t, err)
42		routes.Hosts = registry	42		routes.Hosts = registry
43	-	policy := remoteBrokerPolicy("stdio")	43	+	policy := remoteBrokerPolicy(hostTransportSSH)
44		reg, err := registry.AddHost(ctx, "user@example.test", policy)	44		reg, err := registry.AddHost(ctx, "user@example.test", policy)
45		require.NoError(t, err)	45		require.NoError(t, err)
46		request := ports.BrokerOpenStreamRequest{Endpoint: reg.Endpoint, Registration: reg, Policy: policy, StartMode: ports.BrokerDaemonExistingOnly}	46		request := ports.BrokerOpenStreamRequest{Endpoint: reg.Endpoint, Registration: reg, Policy: policy, StartMode: ports.BrokerDaemonExistingOnly}

@@ -110,7 +110,7 @@ func TestProductionBrokerFirstHostAdd(t *testing.T) {
110		socket := awaitSandboxReady(t, ready, done)	110		socket := awaitSandboxReady(t, ready, done)
111		service, err := brokeripc.NewConnector(socket, brokeripc.Config{}).Connect(ctx)	111		service, err := brokeripc.NewConnector(socket, brokeripc.Config{}).Connect(ctx)
112		require.NoError(t, err)	112		require.NoError(t, err)
113	-	reg, err := service.AddHost(ctx, "user@127.0.0.1:1", remoteBrokerPolicy("stdio"))	113	+	reg, err := service.AddHost(ctx, "user@127.0.0.1:1", remoteBrokerPolicy(hostTransportSSH))
114		require.NoError(t, err)	114		require.NoError(t, err)
115		if i == 0 {	115		if i == 0 {
116		registered = reg	116		registered = reg

M internal/app/remote_hosts.go +44 -4


@@ -24,6 +24,18 @@ const (
24	24		hostActionList = "list"
25	25		)
26	26
	27	+	// Remote carriages selectable with `host add --transport`.
	28	+	const (
	29	+	hostTransportQUIC = "quic"
	30	+	hostTransportSSH = "ssh"
	31	+	)
	32	+
	33	+	// hostTransportRoutes maps each CLI transport to the broker policy transport.
	34	+	var hostTransportRoutes = map[string]ports.BrokerRouteKind{
	35	+	hostTransportQUIC: ports.BrokerRouteSSHQUIC,
	36	+	hostTransportSSH: ports.BrokerRouteSSHStdio,
	37	+	}
	38	+
27	39		type remoteHostDeps struct {
28	40		connect func(context.Context) (ports.BrokerService, error)
29	41		connectExisting func(context.Context) (ports.BrokerService, error)

@@ -66,11 +78,13 @@ func runHostCommand(ctx context.Context, cmd command, deps remoteHostDeps) error
66	78		if err := domain.ValidateRemoteHostTarget(cmd.hostTarget); err != nil {
67	79		return err
68	80		}
69		-	transport, err := remoteTransportModeFromEnv(os.Getenv(envRemoteTransport))
70		-	if err != nil {
71		-	return err
	81	+	policy := remoteBrokerPolicy(cmd.hostTransport)
	82	+	_, err = service.AddHost(ctx, cmd.hostTarget, policy)
	83	+	if isHostConflict(err) {
	84	+	if stored := storedHostTransport(service.Snapshot(), cmd.hostTarget); stored != "" && stored != cmd.hostTransport {
	85	+	return fmt.Errorf("vev: host %q is already registered with transport %q; run `vev host rm %s` first, then add it again: %w", cmd.hostTarget, stored, cmd.hostTarget, err)
	86	+	}
72	87		}
73		-	_, err = service.AddHost(ctx, cmd.hostTarget, remoteBrokerPolicy(transport))
74	88		return err
75	89		case hostActionRm:
76	90		if err := domain.ValidateRemoteHostTarget(cmd.hostTarget); err != nil {

@@ -101,6 +115,32 @@ func runHostCommand(ctx context.Context, cmd command, deps remoteHostDeps) error
101	115		}
102	116		}
103	117
	118	+	// isHostConflict matches a host conflict both in-process and after it crossed
	119	+	// broker IPC, where only the error code survives.
	120	+	func isHostConflict(err error) bool {
	121	+	if errors.Is(err, ports.ErrBrokerHostConflict) {
	122	+	return true
	123	+	}
	124	+	var brokerErr ports.BrokerError
	125	+	return errors.As(err, &brokerErr) && brokerErr.Code == ports.BrokerErrorHostConflict
	126	+	}
	127	+
	128	+	// storedHostTransport returns the CLI transport name registered for target,
	129	+	// or "" when it cannot be determined.
	130	+	func storedHostTransport(snapshot ports.BrokerSnapshot, target string) string {
	131	+	for _, daemon := range snapshot.Daemons {
	132	+	if daemon.Local \|\| daemon.Endpoint != target {
	133	+	continue
	134	+	}
	135	+	for name, route := range hostTransportRoutes {
	136	+	if daemon.Policy.Transport == string(route) {
	137	+	return name
	138	+	}
	139	+	}
	140	+	}
	141	+	return ""
	142	+	}
	143	+
104	144		// listDisconnectedHosts reads configured endpoints without dialing any remote.
105	145		func listDisconnectedHosts(w io.Writer) error {
106	146		state := productionBrokerLayout().State


@@ -24,6 +24,18 @@ const (
24		hostActionList = "list"	24		hostActionList = "list"
25		)	25		)
26			26
			27	+	// Remote carriages selectable with `host add --transport`.
			28	+	const (
			29	+	hostTransportQUIC = "quic"
			30	+	hostTransportSSH = "ssh"
			31	+	)
			32	+
			33	+	// hostTransportRoutes maps each CLI transport to the broker policy transport.
			34	+	var hostTransportRoutes = map[string]ports.BrokerRouteKind{
			35	+	hostTransportQUIC: ports.BrokerRouteSSHQUIC,
			36	+	hostTransportSSH: ports.BrokerRouteSSHStdio,
			37	+	}
			38	+
27		type remoteHostDeps struct {	39		type remoteHostDeps struct {
28		connect func(context.Context) (ports.BrokerService, error)	40		connect func(context.Context) (ports.BrokerService, error)
29		connectExisting func(context.Context) (ports.BrokerService, error)	41		connectExisting func(context.Context) (ports.BrokerService, error)

@@ -66,11 +78,13 @@ func runHostCommand(ctx context.Context, cmd command, deps remoteHostDeps) error
66		if err := domain.ValidateRemoteHostTarget(cmd.hostTarget); err != nil {	78		if err := domain.ValidateRemoteHostTarget(cmd.hostTarget); err != nil {
67		return err	79		return err
68		}	80		}
69	-	transport, err := remoteTransportModeFromEnv(os.Getenv(envRemoteTransport))	81	+	policy := remoteBrokerPolicy(cmd.hostTransport)
70	-	if err != nil {	82	+	_, err = service.AddHost(ctx, cmd.hostTarget, policy)
71	-	return err	83	+	if isHostConflict(err) {
			84	+	if stored := storedHostTransport(service.Snapshot(), cmd.hostTarget); stored != "" && stored != cmd.hostTransport {
			85	+	return fmt.Errorf("vev: host %q is already registered with transport %q; run `vev host rm %s` first, then add it again: %w", cmd.hostTarget, stored, cmd.hostTarget, err)
			86	+	}
72		}	87		}
73	-	_, err = service.AddHost(ctx, cmd.hostTarget, remoteBrokerPolicy(transport))
74		return err	88		return err
75		case hostActionRm:	89		case hostActionRm:
76		if err := domain.ValidateRemoteHostTarget(cmd.hostTarget); err != nil {	90		if err := domain.ValidateRemoteHostTarget(cmd.hostTarget); err != nil {

@@ -101,6 +115,32 @@ func runHostCommand(ctx context.Context, cmd command, deps remoteHostDeps) error
101		}	115		}
102		}	116		}
103			117
			118	+	// isHostConflict matches a host conflict both in-process and after it crossed
			119	+	// broker IPC, where only the error code survives.
			120	+	func isHostConflict(err error) bool {
			121	+	if errors.Is(err, ports.ErrBrokerHostConflict) {
			122	+	return true
			123	+	}
			124	+	var brokerErr ports.BrokerError
			125	+	return errors.As(err, &brokerErr) && brokerErr.Code == ports.BrokerErrorHostConflict
			126	+	}
			127	+
			128	+	// storedHostTransport returns the CLI transport name registered for target,
			129	+	// or "" when it cannot be determined.
			130	+	func storedHostTransport(snapshot ports.BrokerSnapshot, target string) string {
			131	+	for _, daemon := range snapshot.Daemons {
			132	+	if daemon.Local \|\| daemon.Endpoint != target {
			133	+	continue
			134	+	}
			135	+	for name, route := range hostTransportRoutes {
			136	+	if daemon.Policy.Transport == string(route) {
			137	+	return name
			138	+	}
			139	+	}
			140	+	}
			141	+	return ""
			142	+	}
			143	+
104		// listDisconnectedHosts reads configured endpoints without dialing any remote.	144		// listDisconnectedHosts reads configured endpoints without dialing any remote.
105		func listDisconnectedHosts(w io.Writer) error {	145		func listDisconnectedHosts(w io.Writer) error {
106		state := productionBrokerLayout().State	146		state := productionBrokerLayout().State

A internal/app/remote_hosts_test.go +132 -0

@@ -0,0 +1,132 @@
	1	+	package app
	2	+
	3	+	import (
	4	+	"context"
	5	+	"errors"
	6	+	"testing"
	7	+
	8	+	"github.com/stretchr/testify/mock"
	9	+	"github.com/stretchr/testify/require"
	10	+
	11	+	"github.com/bnema/vev/internal/domain"
	12	+	"github.com/bnema/vev/internal/ports"
	13	+	portsmocks "github.com/bnema/vev/internal/ports/mocks"
	14	+	)
	15	+
	16	+	func TestParseHostArgs(t *testing.T) {
	17	+	tests := []struct {
	18	+	name string
	19	+	args []string
	20	+	wantAction string
	21	+	wantTarget string
	22	+	wantTransport string
	23	+	wantErr string
	24	+	nonUsageErr bool
	25	+	}{
	26	+	{name: "add defaults to quic", args: []string{"add", "arch"}, wantAction: "add", wantTarget: "arch", wantTransport: "quic"},
	27	+	{name: "add explicit quic", args: []string{"add", "--transport", "quic", "arch"}, wantAction: "add", wantTarget: "arch", wantTransport: "quic"},
	28	+	{name: "add ssh", args: []string{"add", "--transport", "ssh", "user@arch"}, wantAction: "add", wantTarget: "user@arch", wantTransport: "ssh"},
	29	+	{name: "add ssh equals form", args: []string{"add", "--transport=ssh", "arch"}, wantAction: "add", wantTarget: "arch", wantTransport: "ssh"},
	30	+	{name: "add flag after target", args: []string{"add", "arch", "--transport", "ssh"}, wantAction: "add", wantTarget: "arch", wantTransport: "ssh"},
	31	+	{name: "add invalid value", args: []string{"add", "--transport", "stdio", "arch"}, wantErr: `want "quic" or "ssh"`},
	32	+	{name: "add invalid equals value", args: []string{"add", "--transport=udp", "arch"}, wantErr: `want "quic" or "ssh"`},
	33	+	{name: "add empty equals value", args: []string{"add", "--transport=", "arch"}, wantErr: `want "quic" or "ssh"`},
	34	+	{name: "add missing value", args: []string{"add", "arch", "--transport"}, wantErr: "requires a value"},
	35	+	{name: "add repeated flag", args: []string{"add", "--transport", "ssh", "--transport", "quic", "arch"}, wantErr: "once"},
	36	+	{name: "add unknown flag", args: []string{"add", "--bogus", "arch"}, wantErr: "unknown flag"},
	37	+	{name: "add missing target", args: []string{"add"}, wantErr: "requires a host target"},
	38	+	{name: "add flag without target", args: []string{"add", "--transport", "ssh"}, wantErr: "requires a host target"},
	39	+	{name: "add extra target", args: []string{"add", "--transport", "ssh", "arch", "extra"}, wantErr: "exactly one host target"},
	40	+	{name: "add invalid target", args: []string{"add", "--transport", "ssh", " bad"}, wantErr: "host", nonUsageErr: true},
	41	+	{name: "rm", args: []string{"rm", "arch"}, wantAction: "rm", wantTarget: "arch"},
	42	+	{name: "rm rejects transport", args: []string{"rm", "--transport", "ssh", "arch"}, wantErr: "unknown flag"},
	43	+	{name: "rm rejects transport after target", args: []string{"rm", "arch", "--transport=ssh"}, wantErr: "exactly one host target"},
	44	+	{name: "rm missing target", args: []string{"rm"}, wantErr: "requires a host target"},
	45	+	{name: "list", args: []string{"list"}, wantAction: "list"},
	46	+	{name: "list rejects transport", args: []string{"list", "--transport", "ssh"}, wantErr: "unknown flag"},
	47	+	{name: "list extra", args: []string{"list", "arch"}, wantErr: "accepts no arguments"},
	48	+	}
	49	+	for _, tt := range tests {
	50	+	t.Run(tt.name, func(t *testing.T) {
	51	+	got, err := parseHostArgs(tt.args)
	52	+	if tt.wantErr != "" {
	53	+	require.Error(t, err)
	54	+	require.Contains(t, err.Error(), tt.wantErr)
	55	+	_, usage := errors.AsType[*usageError](err)
	56	+	require.Equal(t, !tt.nonUsageErr, usage, "error type %T", err)
	57	+	return
	58	+	}
	59	+	require.NoError(t, err)
	60	+	require.Equal(t, kindHost, got.kind)
	61	+	require.Equal(t, tt.wantAction, got.hostAction)
	62	+	require.Equal(t, tt.wantTarget, got.hostTarget)
	63	+	require.Equal(t, tt.wantTransport, got.hostTransport)
	64	+	})
	65	+	}
	66	+	}
	67	+
	68	+	func TestHostAddPolicyFollowsTransport(t *testing.T) {
	69	+	tests := []struct {
	70	+	name string
	71	+	args []string
	72	+	wantPolicy ports.BrokerPolicy
	73	+	}{
	74	+	{name: "default", args: []string{"add", "arch"}, wantPolicy: remoteBrokerPolicy(hostTransportQUIC)},
	75	+	{name: "quic", args: []string{"add", "--transport", "quic", "arch"}, wantPolicy: remoteBrokerPolicy(hostTransportQUIC)},
	76	+	{name: "ssh", args: []string{"add", "--transport", "ssh", "arch"}, wantPolicy: remoteBrokerPolicy(hostTransportSSH)},
	77	+	}
	78	+	for _, tt := range tests {
	79	+	t.Run(tt.name, func(t *testing.T) {
	80	+	cmd, err := parseHostArgs(tt.args)
	81	+	require.NoError(t, err)
	82	+	service := portsmocks.NewMockBrokerService(t)
	83	+	service.EXPECT().AddHost(mock.Anything, "arch", tt.wantPolicy).Return(domain.RemoteRegistration{}, nil).Once()
	84	+	service.EXPECT().Close().Return(nil).Once()
	85	+	deps := remoteHostDeps{connect: func(context.Context) (ports.BrokerService, error) { return service, nil }}
	86	+	require.NoError(t, runHostCommand(context.Background(), cmd, deps))
	87	+	})
	88	+	}
	89	+	}
	90	+
	91	+	func TestHostAddReportsTransportConflict(t *testing.T) {
	92	+	// ipcConflict is the shape a conflict has after crossing broker IPC: only
	93	+	// the code survives, not the sentinel.
	94	+	ipcConflict := ports.BrokerError{Code: ports.BrokerErrorHostConflict, Text: "host registration conflict"}
	95	+	storedSSH := ports.BrokerSnapshot{Daemons: []ports.BrokerDaemonObservation{
	96	+	{Endpoint: "arch", Policy: remoteBrokerPolicy(hostTransportSSH)},
	97	+	}}
	98	+	storedLegacy := ports.BrokerSnapshot{Daemons: []ports.BrokerDaemonObservation{
	99	+	{Endpoint: "arch", Policy: ports.BrokerPolicy{Transport: "stdio"}},
	100	+	}}
	101	+	tests := []struct {
	102	+	name string
	103	+	addErr error
	104	+	snapshot ports.BrokerSnapshot
	105	+	wantHint bool
	106	+	}{
	107	+	{name: "in-process sentinel with other transport", addErr: ports.ErrBrokerHostConflict, snapshot: storedSSH, wantHint: true},
	108	+	{name: "IPC code with other transport", addErr: ipcConflict, snapshot: storedSSH, wantHint: true},
	109	+	{name: "same transport conflicts elsewhere", addErr: ipcConflict, snapshot: ports.BrokerSnapshot{Daemons: []ports.BrokerDaemonObservation{
	110	+	{Endpoint: "arch", Policy: remoteBrokerPolicy(hostTransportQUIC)},
	111	+	}}},
	112	+	{name: "host not in snapshot", addErr: ipcConflict, snapshot: ports.BrokerSnapshot{}},
	113	+	{name: "unrecognised stored transport", addErr: ipcConflict, snapshot: storedLegacy},
	114	+	}
	115	+	for _, tt := range tests {
	116	+	t.Run(tt.name, func(t *testing.T) {
	117	+	service := portsmocks.NewMockBrokerService(t)
	118	+	service.EXPECT().AddHost(mock.Anything, "arch", remoteBrokerPolicy(hostTransportQUIC)).Return(domain.RemoteRegistration{}, tt.addErr).Once()
	119	+	service.EXPECT().Snapshot().Return(tt.snapshot).Once()
	120	+	service.EXPECT().Close().Return(nil).Once()
	121	+	deps := remoteHostDeps{connect: func(context.Context) (ports.BrokerService, error) { return service, nil }}
	122	+	err := runHostCommand(context.Background(), command{kind: kindHost, hostAction: hostActionAdd, hostTarget: "arch", hostTransport: hostTransportQUIC}, deps)
	123	+	require.ErrorIs(t, err, tt.addErr)
	124	+	if !tt.wantHint {
	125	+	require.NotContains(t, err.Error(), "vev host rm")
	126	+	return
	127	+	}
	128	+	require.Contains(t, err.Error(), `transport "ssh"`)
	129	+	require.Contains(t, err.Error(), "vev host rm arch")
	130	+	})
	131	+	}
	132	+	}

@@ -0,0 +1,132 @@
	1	+	package app
	2	+
	3	+	import (
	4	+	"context"
	5	+	"errors"
	6	+	"testing"
	7	+
	8	+	"github.com/stretchr/testify/mock"
	9	+	"github.com/stretchr/testify/require"
	10	+
	11	+	"github.com/bnema/vev/internal/domain"
	12	+	"github.com/bnema/vev/internal/ports"
	13	+	portsmocks "github.com/bnema/vev/internal/ports/mocks"
	14	+	)
	15	+
	16	+	func TestParseHostArgs(t *testing.T) {
	17	+	tests := []struct {
	18	+	name string
	19	+	args []string
	20	+	wantAction string
	21	+	wantTarget string
	22	+	wantTransport string
	23	+	wantErr string
	24	+	nonUsageErr bool
	25	+	}{
	26	+	{name: "add defaults to quic", args: []string{"add", "arch"}, wantAction: "add", wantTarget: "arch", wantTransport: "quic"},
	27	+	{name: "add explicit quic", args: []string{"add", "--transport", "quic", "arch"}, wantAction: "add", wantTarget: "arch", wantTransport: "quic"},
	28	+	{name: "add ssh", args: []string{"add", "--transport", "ssh", "user@arch"}, wantAction: "add", wantTarget: "user@arch", wantTransport: "ssh"},
	29	+	{name: "add ssh equals form", args: []string{"add", "--transport=ssh", "arch"}, wantAction: "add", wantTarget: "arch", wantTransport: "ssh"},
	30	+	{name: "add flag after target", args: []string{"add", "arch", "--transport", "ssh"}, wantAction: "add", wantTarget: "arch", wantTransport: "ssh"},
	31	+	{name: "add invalid value", args: []string{"add", "--transport", "stdio", "arch"}, wantErr: `want "quic" or "ssh"`},
	32	+	{name: "add invalid equals value", args: []string{"add", "--transport=udp", "arch"}, wantErr: `want "quic" or "ssh"`},
	33	+	{name: "add empty equals value", args: []string{"add", "--transport=", "arch"}, wantErr: `want "quic" or "ssh"`},
	34	+	{name: "add missing value", args: []string{"add", "arch", "--transport"}, wantErr: "requires a value"},
	35	+	{name: "add repeated flag", args: []string{"add", "--transport", "ssh", "--transport", "quic", "arch"}, wantErr: "once"},
	36	+	{name: "add unknown flag", args: []string{"add", "--bogus", "arch"}, wantErr: "unknown flag"},
	37	+	{name: "add missing target", args: []string{"add"}, wantErr: "requires a host target"},
	38	+	{name: "add flag without target", args: []string{"add", "--transport", "ssh"}, wantErr: "requires a host target"},
	39	+	{name: "add extra target", args: []string{"add", "--transport", "ssh", "arch", "extra"}, wantErr: "exactly one host target"},
	40	+	{name: "add invalid target", args: []string{"add", "--transport", "ssh", " bad"}, wantErr: "host", nonUsageErr: true},
	41	+	{name: "rm", args: []string{"rm", "arch"}, wantAction: "rm", wantTarget: "arch"},
	42	+	{name: "rm rejects transport", args: []string{"rm", "--transport", "ssh", "arch"}, wantErr: "unknown flag"},
	43	+	{name: "rm rejects transport after target", args: []string{"rm", "arch", "--transport=ssh"}, wantErr: "exactly one host target"},
	44	+	{name: "rm missing target", args: []string{"rm"}, wantErr: "requires a host target"},
	45	+	{name: "list", args: []string{"list"}, wantAction: "list"},
	46	+	{name: "list rejects transport", args: []string{"list", "--transport", "ssh"}, wantErr: "unknown flag"},
	47	+	{name: "list extra", args: []string{"list", "arch"}, wantErr: "accepts no arguments"},
	48	+	}
	49	+	for _, tt := range tests {
	50	+	t.Run(tt.name, func(t *testing.T) {
	51	+	got, err := parseHostArgs(tt.args)
	52	+	if tt.wantErr != "" {
	53	+	require.Error(t, err)
	54	+	require.Contains(t, err.Error(), tt.wantErr)
	55	+	_, usage := errors.AsType[*usageError](err)
	56	+	require.Equal(t, !tt.nonUsageErr, usage, "error type %T", err)
	57	+	return
	58	+	}
	59	+	require.NoError(t, err)
	60	+	require.Equal(t, kindHost, got.kind)
	61	+	require.Equal(t, tt.wantAction, got.hostAction)
	62	+	require.Equal(t, tt.wantTarget, got.hostTarget)
	63	+	require.Equal(t, tt.wantTransport, got.hostTransport)
	64	+	})
	65	+	}
	66	+	}
	67	+
	68	+	func TestHostAddPolicyFollowsTransport(t *testing.T) {
	69	+	tests := []struct {
	70	+	name string
	71	+	args []string
	72	+	wantPolicy ports.BrokerPolicy
	73	+	}{
	74	+	{name: "default", args: []string{"add", "arch"}, wantPolicy: remoteBrokerPolicy(hostTransportQUIC)},
	75	+	{name: "quic", args: []string{"add", "--transport", "quic", "arch"}, wantPolicy: remoteBrokerPolicy(hostTransportQUIC)},
	76	+	{name: "ssh", args: []string{"add", "--transport", "ssh", "arch"}, wantPolicy: remoteBrokerPolicy(hostTransportSSH)},
	77	+	}
	78	+	for _, tt := range tests {
	79	+	t.Run(tt.name, func(t *testing.T) {
	80	+	cmd, err := parseHostArgs(tt.args)
	81	+	require.NoError(t, err)
	82	+	service := portsmocks.NewMockBrokerService(t)
	83	+	service.EXPECT().AddHost(mock.Anything, "arch", tt.wantPolicy).Return(domain.RemoteRegistration{}, nil).Once()
	84	+	service.EXPECT().Close().Return(nil).Once()
	85	+	deps := remoteHostDeps{connect: func(context.Context) (ports.BrokerService, error) { return service, nil }}
	86	+	require.NoError(t, runHostCommand(context.Background(), cmd, deps))
	87	+	})
	88	+	}
	89	+	}
	90	+
	91	+	func TestHostAddReportsTransportConflict(t *testing.T) {
	92	+	// ipcConflict is the shape a conflict has after crossing broker IPC: only
	93	+	// the code survives, not the sentinel.
	94	+	ipcConflict := ports.BrokerError{Code: ports.BrokerErrorHostConflict, Text: "host registration conflict"}
	95	+	storedSSH := ports.BrokerSnapshot{Daemons: []ports.BrokerDaemonObservation{
	96	+	{Endpoint: "arch", Policy: remoteBrokerPolicy(hostTransportSSH)},
	97	+	}}
	98	+	storedLegacy := ports.BrokerSnapshot{Daemons: []ports.BrokerDaemonObservation{
	99	+	{Endpoint: "arch", Policy: ports.BrokerPolicy{Transport: "stdio"}},
	100	+	}}
	101	+	tests := []struct {
	102	+	name string
	103	+	addErr error
	104	+	snapshot ports.BrokerSnapshot
	105	+	wantHint bool
	106	+	}{
	107	+	{name: "in-process sentinel with other transport", addErr: ports.ErrBrokerHostConflict, snapshot: storedSSH, wantHint: true},
	108	+	{name: "IPC code with other transport", addErr: ipcConflict, snapshot: storedSSH, wantHint: true},
	109	+	{name: "same transport conflicts elsewhere", addErr: ipcConflict, snapshot: ports.BrokerSnapshot{Daemons: []ports.BrokerDaemonObservation{
	110	+	{Endpoint: "arch", Policy: remoteBrokerPolicy(hostTransportQUIC)},
	111	+	}}},
	112	+	{name: "host not in snapshot", addErr: ipcConflict, snapshot: ports.BrokerSnapshot{}},
	113	+	{name: "unrecognised stored transport", addErr: ipcConflict, snapshot: storedLegacy},
	114	+	}
	115	+	for _, tt := range tests {
	116	+	t.Run(tt.name, func(t *testing.T) {
	117	+	service := portsmocks.NewMockBrokerService(t)
	118	+	service.EXPECT().AddHost(mock.Anything, "arch", remoteBrokerPolicy(hostTransportQUIC)).Return(domain.RemoteRegistration{}, tt.addErr).Once()
	119	+	service.EXPECT().Snapshot().Return(tt.snapshot).Once()
	120	+	service.EXPECT().Close().Return(nil).Once()
	121	+	deps := remoteHostDeps{connect: func(context.Context) (ports.BrokerService, error) { return service, nil }}
	122	+	err := runHostCommand(context.Background(), command{kind: kindHost, hostAction: hostActionAdd, hostTarget: "arch", hostTransport: hostTransportQUIC}, deps)
	123	+	require.ErrorIs(t, err, tt.addErr)
	124	+	if !tt.wantHint {
	125	+	require.NotContains(t, err.Error(), "vev host rm")
	126	+	return
	127	+	}
	128	+	require.Contains(t, err.Error(), `transport "ssh"`)
	129	+	require.Contains(t, err.Error(), "vev host rm arch")
	130	+	})
	131	+	}
	132	+	}

M internal/app/run.go +74 -31


@@ -88,18 +88,20 @@ type command struct {
88	88		listAll bool
89	89		hostAction string
90	90		hostTarget string
91		-	killAll bool
92		-	killSessions bool
93		-	cmd cmdInvocation
94		-	env envInvocation
95		-	brokerServe brokerServeOptions
96		-	brokerMux brokerMuxOptions
97		-	brokerReady brokerReadyOptions
98		-	uiDriver uiDriverOptions
99		-	uiObserve bool
100		-	uiControl bool
101		-	uiSocket string
102		-	web webOptions
	91	+	// hostTransport is the `host add` carriage: hostTransportQUIC or hostTransportSSH.
	92	+	hostTransport string
	93	+	killAll bool
	94	+	killSessions bool
	95	+	cmd cmdInvocation
	96	+	env envInvocation
	97	+	brokerServe brokerServeOptions
	98	+	brokerMux brokerMuxOptions
	99	+	brokerReady brokerReadyOptions
	100	+	uiDriver uiDriverOptions
	101	+	uiObserve bool
	102	+	uiControl bool
	103	+	uiSocket string
	104	+	web webOptions
103	105		}
104	106
105	107		// usageError is a user-facing argument error; the app prints it (with usage)

@@ -123,7 +125,8 @@ usage:
123	125		vev ls list local sessions
124	126		vev ls <host> list sessions on a known remote host
125	127		vev ls --all list local and remote sessions
126		-	vev host add <host> add a pinned remote host
	128	+	vev host add [--transport quic\|ssh] <host>
	129	+	add a pinned remote host (default transport: quic)
127	130		vev host rm <host> remove a pinned remote host
128	131		vev host list list known remote hosts
129	132		vev kill <name> kill a session

@@ -439,19 +442,27 @@ func parseHostArgs(args []string) (command, error) {
439	442		return command{}, usagef("`host` requires add, rm, or list")
440	443		}
441	444		switch args[0] {
442		-	case hostActionAdd, hostActionRm:
	445	+	case hostActionAdd:
	446	+	return parseHostAddArgs(args[1:])
	447	+	case hostActionRm:
443	448		if len(args) < 2 \|\| args[1] == "" {
444		-	return command{}, usagef("`host %s` requires a host target", args[0])
	449	+	return command{}, usagef("`host rm` requires a host target")
	450	+	}
	451	+	if strings.HasPrefix(args[1], "-") {
	452	+	return command{}, usagef("unknown flag %q for `host rm`", args[1])
445	453		}
446	454		if len(args) > 2 {
447		-	return command{}, usagef("`host %s` accepts exactly one host target", args[0])
	455	+	return command{}, usagef("`host rm` accepts exactly one host target")
448	456		}
449	457		if err := domain.ValidateRemoteHostTarget(args[1]); err != nil {
450	458		return command{}, err
451	459		}
452		-	return command{kind: kindHost, hostAction: args[0], hostTarget: args[1]}, nil
	460	+	return command{kind: kindHost, hostAction: hostActionRm, hostTarget: args[1]}, nil
453	461		case hostActionList:
454	462		if len(args) > 1 {
	463	+	if strings.HasPrefix(args[1], "-") {
	464	+	return command{}, usagef("unknown flag %q for `host list`", args[1])
	465	+	}
455	466		return command{}, usagef("`host list` accepts no arguments")
456	467		}
457	468		return command{kind: kindHost, hostAction: hostActionList}, nil

@@ -460,6 +471,50 @@ func parseHostArgs(args []string) (command, error) {
460	471		}
461	472		}
462	473
	474	+	// parseHostAddArgs parses `host add [--transport quic\|ssh] <host>`.
	475	+	func parseHostAddArgs(args []string) (command, error) {
	476	+	transport, target := "", ""
	477	+	for i := 0; i < len(args); i++ {
	478	+	arg := args[i]
	479	+	switch {
	480	+	case arg == "--transport" \|\| strings.HasPrefix(arg, "--transport="):
	481	+	if transport != "" {
	482	+	return command{}, usagef("`host add` accepts --transport once")
	483	+	}
	484	+	value, hasValue := strings.CutPrefix(arg, "--transport=")
	485	+	if !hasValue {
	486	+	if i+1 >= len(args) {
	487	+	return command{}, usagef("`--transport` requires a value (%s or %s)", hostTransportQUIC, hostTransportSSH)
	488	+	}
	489	+	i++
	490	+	value = args[i]
	491	+	}
	492	+	switch value {
	493	+	case hostTransportQUIC, hostTransportSSH:
	494	+	transport = value
	495	+	default:
	496	+	return command{}, usagef("invalid transport %q (want %q or %q)", value, hostTransportQUIC, hostTransportSSH)
	497	+	}
	498	+	case strings.HasPrefix(arg, "-"):
	499	+	return command{}, usagef("unknown flag %q for `host add`", arg)
	500	+	case target != "":
	501	+	return command{}, usagef("`host add` accepts exactly one host target")
	502	+	default:
	503	+	target = arg
	504	+	}
	505	+	}
	506	+	if target == "" {
	507	+	return command{}, usagef("`host add` requires a host target")
	508	+	}
	509	+	if err := domain.ValidateRemoteHostTarget(target); err != nil {
	510	+	return command{}, err
	511	+	}
	512	+	if transport == "" {
	513	+	transport = hostTransportQUIC
	514	+	}
	515	+	return command{kind: kindHost, hostAction: hostActionAdd, hostTarget: target, hostTransport: transport}, nil
	516	+	}
	517	+
463	518		// performanceTrace creates one serialized timestamp owner for this process.
464	519		// An empty trace environment leaves all production behavior and wire bytes
465	520		// unchanged.

@@ -802,8 +857,8 @@ func runDaemonOwnedWithLogger(ctx context.Context, log *slog.Logger) (retErr err
802	857		}
803	858		binding, err := daemonmux.NewServerBindings(identity, incarnation, []daemonmux.ServerPolicyAdmission{
804	859		{Policy: localDaemonPolicy(), Origin: ports.SessionOriginLocal},
805		-	{Policy: remoteBrokerPolicy("quic"), Origin: ports.SessionOriginRemote},
806		-	{Policy: remoteBrokerPolicy("stdio"), Origin: ports.SessionOriginRemote},
	860	+	{Policy: remoteBrokerPolicy(hostTransportQUIC), Origin: ports.SessionOriginRemote},
	861	+	{Policy: remoteBrokerPolicy(hostTransportSSH), Origin: ports.SessionOriginRemote},
807	862		})
808	863		if err != nil {
809	864		return fmt.Errorf("vev: establish daemon mux authority: %w", err)

@@ -913,7 +968,6 @@ func runAttach(ctx context.Context, intent uint8, name, remoteTarget string) (re
913	968		}
914	969
915	970		const (
916		-	envRemoteTransport = "VEV_REMOTE_TRANSPORT"
917	971		uiRemoteCleanupCommand = "_ui-cleanup"
918	972		// daemonStopCommand is the hidden, environment-scoped graceful stop of
919	973		// this environment's daemon, for harnesses and scripts. Users run

@@ -921,17 +975,6 @@ const (
921	975		daemonStopCommand = "_daemon-stop"
922	976		)
923	977
924		-	func remoteTransportModeFromEnv(value string) (string, error) {
925		-	switch value {
926		-	case "", "quic":
927		-	return "quic", nil
928		-	case "stdio":
929		-	return "stdio", nil
930		-	default:
931		-	return "", fmt.Errorf("vev: invalid remote transport %q (want %q or %q)", value, "quic", "stdio")
932		-	}
933		-	}
934		-
935	978		const daemonStopTimeout = 2 * time.Second
936	979
937	980		var (

 	listAll      bool
 	hostAction   string
 	hostTarget   string
-	killAll      bool
+	// hostTransport is the `host add` carriage: hostTransportQUIC or hostTransportSSH.
-	killSessions bool
+	hostTransport string
-	cmd          cmdInvocation
+	killAll       bool
-	env          envInvocation
+	killSessions  bool
-	brokerServe  brokerServeOptions
+	cmd           cmdInvocation
-	brokerMux    brokerMuxOptions
+	env           envInvocation
-	brokerReady  brokerReadyOptions
+	brokerServe   brokerServeOptions
-	uiDriver     uiDriverOptions
+	brokerMux     brokerMuxOptions
-	uiObserve    bool
+	brokerReady   brokerReadyOptions
-	uiControl    bool
+	uiDriver      uiDriverOptions
-	uiSocket     string
+	uiObserve     bool
-	web          webOptions
+	uiControl     bool
+	uiSocket      string
+	web           webOptions
 }
 // usageError is a user-facing argument error; the app prints it (with usage)
   vev ls              list local sessions
   vev ls <host>       list sessions on a known remote host
   vev ls --all        list local and remote sessions
-  vev host add <host> add a pinned remote host
+  vev host add [--transport quic|ssh] <host>
+                      add a pinned remote host (default transport: quic)
   vev host rm <host>  remove a pinned remote host
   vev host list       list known remote hosts
   vev kill <name>     kill a session
 		return command{}, usagef("`host` requires add, rm, or list")
 	}
 	switch args[0] {
-	case hostActionAdd, hostActionRm:
+	case hostActionAdd:
+		return parseHostAddArgs(args[1:])
+	case hostActionRm:
 		if len(args) < 2 || args[1] == "" {
-			return command{}, usagef("`host %s` requires a host target", args[0])
+			return command{}, usagef("`host rm` requires a host target")
+		}
+		if strings.HasPrefix(args[1], "-") {
+			return command{}, usagef("unknown flag %q for `host rm`", args[1])
 		}
 		if len(args) > 2 {
-			return command{}, usagef("`host %s` accepts exactly one host target", args[0])
+			return command{}, usagef("`host rm` accepts exactly one host target")
 		}
 		if err := domain.ValidateRemoteHostTarget(args[1]); err != nil {
 			return command{}, err
 		}
-		return command{kind: kindHost, hostAction: args[0], hostTarget: args[1]}, nil
+		return command{kind: kindHost, hostAction: hostActionRm, hostTarget: args[1]}, nil
 	case hostActionList:
 		if len(args) > 1 {
+			if strings.HasPrefix(args[1], "-") {
+				return command{}, usagef("unknown flag %q for `host list`", args[1])
+			}
 			return command{}, usagef("`host list` accepts no arguments")
 		}
 		return command{kind: kindHost, hostAction: hostActionList}, nil
 	}
 }
+// parseHostAddArgs parses `host add [--transport quic|ssh] <host>`.
+func parseHostAddArgs(args []string) (command, error) {
+	transport, target := "", ""
+	for i := 0; i < len(args); i++ {
+		arg := args[i]
+		switch {
+		case arg == "--transport" || strings.HasPrefix(arg, "--transport="):
+			if transport != "" {
+				return command{}, usagef("`host add` accepts --transport once")
+			}
+			value, hasValue := strings.CutPrefix(arg, "--transport=")
+			if !hasValue {
+				if i+1 >= len(args) {
+					return command{}, usagef("`--transport` requires a value (%s or %s)", hostTransportQUIC, hostTransportSSH)
+				}
+				i++
+				value = args[i]
+			}
+			switch value {
+			case hostTransportQUIC, hostTransportSSH:
+				transport = value
+			default:
+				return command{}, usagef("invalid transport %q (want %q or %q)", value, hostTransportQUIC, hostTransportSSH)
+			}
+		case strings.HasPrefix(arg, "-"):
+			return command{}, usagef("unknown flag %q for `host add`", arg)
+		case target != "":
+			return command{}, usagef("`host add` accepts exactly one host target")
+		default:
+			target = arg
+		}
+	}
+	if target == "" {
+		return command{}, usagef("`host add` requires a host target")
+	}
+	if err := domain.ValidateRemoteHostTarget(target); err != nil {
+		return command{}, err
+	}
+	if transport == "" {
+		transport = hostTransportQUIC
+	}
+	return command{kind: kindHost, hostAction: hostActionAdd, hostTarget: target, hostTransport: transport}, nil
+}
 // performanceTrace creates one serialized timestamp owner for this process.
 // An empty trace environment leaves all production behavior and wire bytes
 // unchanged.
 	}
 	binding, err := daemonmux.NewServerBindings(identity, incarnation, []daemonmux.ServerPolicyAdmission{
 		{Policy: localDaemonPolicy(), Origin: ports.SessionOriginLocal},
-		{Policy: remoteBrokerPolicy("quic"), Origin: ports.SessionOriginRemote},
+		{Policy: remoteBrokerPolicy(hostTransportQUIC), Origin: ports.SessionOriginRemote},
-		{Policy: remoteBrokerPolicy("stdio"), Origin: ports.SessionOriginRemote},
+		{Policy: remoteBrokerPolicy(hostTransportSSH), Origin: ports.SessionOriginRemote},
 	})
 	if err != nil {
 		return fmt.Errorf("vev: establish daemon mux authority: %w", err)
 }
 const (
-	envRemoteTransport     = "VEV_REMOTE_TRANSPORT"
 	uiRemoteCleanupCommand = "_ui-cleanup"
 	// daemonStopCommand is the hidden, environment-scoped graceful stop of
 	// this environment's daemon, for harnesses and scripts. Users run
 	daemonStopCommand = "_daemon-stop"
 )
-func remoteTransportModeFromEnv(value string) (string, error) {
-	switch value {
-	case "", "quic":
-		return "quic", nil
-	case "stdio":
-		return "stdio", nil
-	default:
-		return "", fmt.Errorf("vev: invalid remote transport %q (want %q or %q)", value, "quic", "stdio")
-	}
-}
 const daemonStopTimeout = 2 * time.Second
 var (

M internal/app/web_daemon_broker_test.go +2 -3


@@ -314,10 +314,9 @@ func startWebGatewayFixture(t testing.T) webGatewayFixture {
314	314		// connector composition, so a test can script the broker without a process.
315	315		func startWebGatewayFixtureOver(t testing.T, broker offlineClientFixture, connector func() ports.BrokerConnector) webGatewayFixture {
316	316		t.Helper()
317		-	// The gateway composition reads the nested-session and transport environment;
318		-	// a test drives the broker client with both unset.
	317	+	// The gateway composition reads the nested-session environment; a test
	318	+	// drives the broker client with it unset.
319	319		t.Setenv("VEV", "")
320		-	t.Setenv(envRemoteTransport, "")
321	320		settings, err := webterm.ParseSettings("", webterm.Origin)
322	321		require.NoError(t, err)
323	322		fixture := &webGatewayFixture{

 // connector composition, so a test can script the broker without a process.
 func startWebGatewayFixtureOver(t *testing.T, broker offlineClientFixture, connector func() ports.BrokerConnector) *webGatewayFixture {
 	t.Helper()
-	// The gateway composition reads the nested-session and transport environment;
+	// The gateway composition reads the nested-session environment; a test
-	// a test drives the broker client with both unset.
+	// drives the broker client with it unset.
 	t.Setenv("VEV", "")
-	t.Setenv(envRemoteTransport, "")
 	settings, err := webterm.ParseSettings("", webterm.Origin)
 	require.NoError(t, err)
 	fixture := &webGatewayFixture{

M scripts/debug-remote-attach.sh +10 -7


@@ -3,7 +3,7 @@ set -euo pipefail
3	3
4	4		usage() {
5	5		cat <<'USAGE' >&2
6		-	Usage: scripts/debug-remote-attach.sh [--mode stdio\|quic\|default] [--session NAME] [--duration 8s] [--vev-bin PATH] user@host
	6	+	Usage: scripts/debug-remote-attach.sh [--mode ssh\|quic\|default] [--session NAME] [--duration 8s] [--vev-bin PATH] user@host
7	7
8	8		Runs a real remote attach smoke/debug attempt under a PTY, captures local and
9	9		remote vev versions, and stores local/remote log tails around the attempt.

@@ -20,6 +20,8 @@ Notes:
20	20		vev/ssh error is captured; inspect the bundle for confirmation.
21	21		- The remote host must be reachable by SSH for log collection.
22	22		- The attach attempt unsets VEV so the smoke test can run from inside vev.
	23	+	- --mode ssh\|quic re-registers the host (vev host rm, then vev host add
	24	+	--transport MODE) before attaching; default keeps the existing registration.
23	25		USAGE
24	26		}
25	27

@@ -53,8 +55,8 @@ if [[ $# -ne 1 ]]; then
53	55		exit 2
54	56		fi
55	57		case "$mode" in
56		-	default\|stdio\|quic) ;;
57		-	*) echo "invalid --mode $mode (want default, stdio, or quic)" >&2; exit 2 ;;
	58	+	default\|ssh\|quic) ;;
	59	+	*) echo "invalid --mode $mode (want default, ssh, or quic)" >&2; exit 2 ;;
58	60		esac
59	61
60	62		target="$1"

@@ -153,10 +155,11 @@ attach_log_raw="$out_dir/.attach.typescript.raw"
153	155		attach_err_raw="$out_dir/.attach.err.raw"
154	156		attach_stdout_raw="$out_dir/.attach.stdout.raw"
155	157		cmd=("$vev_bin" attach "$attach_target")
156		-	if [[ "$mode" == "default" ]]; then
157		-	env_cmd=(env -u VEV -u VEV_REMOTE_TRANSPORT)
158		-	else
159		-	env_cmd=(env -u VEV "VEV_REMOTE_TRANSPORT=$mode")
	158	+	env_cmd=(env -u VEV)
	159	+	if [[ "$mode" != "default" ]]; then
	160	+	# A host keeps the transport it was added with: switching is rm then add.
	161	+	run_capture host-rm "${env_cmd[@]}" "$vev_bin" host rm "$target"
	162	+	run_capture host-add "${env_cmd[@]}" "$vev_bin" host add --transport "$mode" "$target"
160	163		fi
161	164
162	165		set +e

 usage() {
   cat <<'USAGE' >&2
-Usage: scripts/debug-remote-attach.sh [--mode stdio|quic|default] [--session NAME] [--duration 8s] [--vev-bin PATH] user@host
+Usage: scripts/debug-remote-attach.sh [--mode ssh|quic|default] [--session NAME] [--duration 8s] [--vev-bin PATH] user@host
 Runs a real remote attach smoke/debug attempt under a PTY, captures local and
 remote vev versions, and stores local/remote log tails around the attempt.
     vev/ssh error is captured; inspect the bundle for confirmation.
   - The remote host must be reachable by SSH for log collection.
   - The attach attempt unsets VEV so the smoke test can run from inside vev.
+  - --mode ssh|quic re-registers the host (vev host rm, then vev host add
+    --transport MODE) before attaching; default keeps the existing registration.
 USAGE
 }
   exit 2
 fi
 case "$mode" in
-  default|stdio|quic) ;;
+  default|ssh|quic) ;;
-  *) echo "invalid --mode $mode (want default, stdio, or quic)" >&2; exit 2 ;;
+  *) echo "invalid --mode $mode (want default, ssh, or quic)" >&2; exit 2 ;;
 esac
 target="$1"
 attach_err_raw="$out_dir/.attach.err.raw"
 attach_stdout_raw="$out_dir/.attach.stdout.raw"
 cmd=("$vev_bin" attach "$attach_target")
-if [[ "$mode" == "default" ]]; then
+env_cmd=(env -u VEV)
-  env_cmd=(env -u VEV -u VEV_REMOTE_TRANSPORT)
+if [[ "$mode" != "default" ]]; then
-else
+  # A host keeps the transport it was added with: switching is rm then add.
-  env_cmd=(env -u VEV "VEV_REMOTE_TRANSPORT=$mode")
+  run_capture host-rm "${env_cmd[@]}" "$vev_bin" host rm "$target"
+  run_capture host-add "${env_cmd[@]}" "$vev_bin" host add --transport "$mode" "$target"
 fi
 set +e

M scripts/demo/README.md +1 -1


@@ -29,7 +29,7 @@ shell --exec [vev args]`. It sets:
29	29		option, so `.dev/test/bin/ssh` wraps the real client with
30	30		`-F .dev/test/ssh/config`. The key, `known_hosts` and config are generated in
31	31		`.dev/test/ssh/`. `~/.ssh` and your agent are never used.
32		-	- `VEV_REMOTE_TRANSPORT=stdio`: hosts are registered with the SSH-only carriage.
	32	+	- `vev host add --transport ssh`: hosts are registered with the SSH-only carriage.
33	33		QUIC cannot work here. The remote proxy listens on a random UDP port, and
34	34		the client dials that port on the SSH target name (`remote-a`), which does
35	35		not resolve to the loopback port mapping.


@@ -29,7 +29,7 @@ shell --exec [vev args]`. It sets:
29		option, so `.dev/test/bin/ssh` wraps the real client with	29		option, so `.dev/test/bin/ssh` wraps the real client with
30		`-F .dev/test/ssh/config`. The key, `known_hosts` and config are generated in	30		`-F .dev/test/ssh/config`. The key, `known_hosts` and config are generated in
31		`.dev/test/ssh/`. `~/.ssh` and your agent are never used.	31		`.dev/test/ssh/`. `~/.ssh` and your agent are never used.
32	-	- `VEV_REMOTE_TRANSPORT=stdio`: hosts are registered with the SSH-only carriage.	32	+	- `vev host add --transport ssh`: hosts are registered with the SSH-only carriage.
33		QUIC cannot work here. The remote proxy listens on a random UDP port, and	33		QUIC cannot work here. The remote proxy listens on a random UDP port, and
34		the client dials that port on the SSH target name (`remote-a`), which does	34		the client dials that port on the SSH target name (`remote-a`), which does
35		not resolve to the loopback port mapping.	35		not resolve to the loopback port mapping.

M scripts/demo/compose.test.yaml +1 -1


@@ -3,7 +3,7 @@
3	3		#
4	4		# sshd is published on loopback only. QUIC is not published: the remote QUIC
5	5		# proxy listens on a random UDP port per bootstrap and the client dials the
6		-	# SSH target name, so hosts are registered with VEV_REMOTE_TRANSPORT=stdio.
	6	+	# SSH target name, so hosts are registered with `vev host add --transport ssh`.
7	7		# The project name is derived from VEV_ENV/VEV_TEST_ENV so distinct sandbox
8	8		# environments (see scripts/demo/test-remotes.sh) never share one compose
9	9		# project's containers or network.


@@ -3,7 +3,7 @@
3		#	3		#
4		# sshd is published on loopback only. QUIC is not published: the remote QUIC	4		# sshd is published on loopback only. QUIC is not published: the remote QUIC
5		# proxy listens on a random UDP port per bootstrap and the client dials the	5		# proxy listens on a random UDP port per bootstrap and the client dials the
6	-	# SSH target name, so hosts are registered with VEV_REMOTE_TRANSPORT=stdio.	6	+	# SSH target name, so hosts are registered with `vev host add --transport ssh`.
7		# The project name is derived from VEV_ENV/VEV_TEST_ENV so distinct sandbox	7		# The project name is derived from VEV_ENV/VEV_TEST_ENV so distinct sandbox
8		# environments (see scripts/demo/test-remotes.sh) never share one compose	8		# environments (see scripts/demo/test-remotes.sh) never share one compose
9		# project's containers or network.	9		# project's containers or network.

M scripts/demo/test-remotes.sh +4 -4


@@ -52,7 +52,7 @@ port_for() {
52	52		# command launched from inside a real vev pane does not look nested.
53	53		vev_env() {
54	54		env -u VEV -u VEV_ENV_ROOT \
55		-	VEV_ENV="$env_name" VEV_ENV_ROOT="$env_root" VEV_REMOTE_TRANSPORT=stdio \
	55	+	VEV_ENV="$env_name" VEV_ENV_ROOT="$env_root" \
56	56		PATH="$bin_dir:$PATH" "$@"
57	57		}
58	58

@@ -152,7 +152,7 @@ register_hosts() {
152	152		log "host already registered: $host"
153	153		continue
154	154		fi
155		-	vev_env timeout 30 "$vev_bin" host add "$host" \|\| die "vev host add $host failed"
	155	+	vev_env timeout 30 "$vev_bin" host add --transport ssh "$host" \|\| die "vev host add --transport ssh $host failed"
156	156		log "host registered: $host"
157	157		done
158	158		}

@@ -277,7 +277,7 @@ cmd_shell_hint() {
277	277		cat <<EOF
278	278		Sandbox ready. Launch the client from any terminal with:
279	279
280		-	cd $root && env -u VEV VEV_ENV=$env_name VEV_ENV_ROOT=$env_root VEV_REMOTE_TRANSPORT=stdio PATH=$bin_dir:\$PATH ./build/vev
	280	+	cd $root && env -u VEV VEV_ENV=$env_name VEV_ENV_ROOT=$env_root PATH=$bin_dir:\$PATH ./build/vev
281	281
282	282		or: $0 shell --exec
283	283		Plain ssh: $bin_dir/ssh remote-a

@@ -288,7 +288,7 @@ cmd_shell() {
288	288		[[ -x $bin_dir/ssh ]] \|\| die "sandbox is not up; run: $0 up"
289	289		if [[ ${1:-} == --exec ]]; then
290	290		shift
291		-	exec env -u VEV -u VEV_ENV_ROOT VEV_ENV="$env_name" VEV_ENV_ROOT="$env_root" VEV_REMOTE_TRANSPORT=stdio \
	291	+	exec env -u VEV -u VEV_ENV_ROOT VEV_ENV="$env_name" VEV_ENV_ROOT="$env_root" \
292	292		PATH="$bin_dir:$PATH" "$vev_bin" "$@"
293	293		fi
294	294		cmd_shell_hint


@@ -52,7 +52,7 @@ port_for() {
52		# command launched from inside a real vev pane does not look nested.	52		# command launched from inside a real vev pane does not look nested.
53		vev_env() {	53		vev_env() {
54		env -u VEV -u VEV_ENV_ROOT \	54		env -u VEV -u VEV_ENV_ROOT \
55	-	VEV_ENV="$env_name" VEV_ENV_ROOT="$env_root" VEV_REMOTE_TRANSPORT=stdio \	55	+	VEV_ENV="$env_name" VEV_ENV_ROOT="$env_root" \
56		PATH="$bin_dir:$PATH" "$@"	56		PATH="$bin_dir:$PATH" "$@"
57		}	57		}
58			58

@@ -152,7 +152,7 @@ register_hosts() {
152		log "host already registered: $host"	152		log "host already registered: $host"
153		continue	153		continue
154		fi	154		fi
155	-	vev_env timeout 30 "$vev_bin" host add "$host" \|\| die "vev host add $host failed"	155	+	vev_env timeout 30 "$vev_bin" host add --transport ssh "$host" \|\| die "vev host add --transport ssh $host failed"
156		log "host registered: $host"	156		log "host registered: $host"
157		done	157		done
158		}	158		}

@@ -277,7 +277,7 @@ cmd_shell_hint() {
277		cat <<EOF	277		cat <<EOF
278		Sandbox ready. Launch the client from any terminal with:	278		Sandbox ready. Launch the client from any terminal with:
279			279
280	-	cd $root && env -u VEV VEV_ENV=$env_name VEV_ENV_ROOT=$env_root VEV_REMOTE_TRANSPORT=stdio PATH=$bin_dir:\$PATH ./build/vev	280	+	cd $root && env -u VEV VEV_ENV=$env_name VEV_ENV_ROOT=$env_root PATH=$bin_dir:\$PATH ./build/vev
281			281
282		or: $0 shell --exec	282		or: $0 shell --exec
283		Plain ssh: $bin_dir/ssh remote-a	283		Plain ssh: $bin_dir/ssh remote-a

@@ -288,7 +288,7 @@ cmd_shell() {
288		[[ -x $bin_dir/ssh ]] \|\| die "sandbox is not up; run: $0 up"	288		[[ -x $bin_dir/ssh ]] \|\| die "sandbox is not up; run: $0 up"
289		if [[ ${1:-} == --exec ]]; then	289		if [[ ${1:-} == --exec ]]; then
290		shift	290		shift
291	-	exec env -u VEV -u VEV_ENV_ROOT VEV_ENV="$env_name" VEV_ENV_ROOT="$env_root" VEV_REMOTE_TRANSPORT=stdio \	291	+	exec env -u VEV -u VEV_ENV_ROOT VEV_ENV="$env_name" VEV_ENV_ROOT="$env_root" \
292		PATH="$bin_dir:$PATH" "$vev_bin" "$@"	292		PATH="$bin_dir:$PATH" "$vev_bin" "$@"
293		fi	293		fi
294		cmd_shell_hint	294		cmd_shell_hint

M scripts/remote-picker-harness/README.md +6 -5


@@ -16,17 +16,18 @@ lifecycle at return, and a successfully committed navigation action.
16	16		`acceptance.py CLIENT_CONTAINER REMOTE_CONTAINER SCENARIO[@stdio\|@quic]` runs
17	17		the table-driven baseline matrix. Every scenario asserts committed outcomes
18	18		(action IDs, exact lifecycle/session/focus context, observed published
19		-	output); sending a key is never success. Transport selection is forwarded
20		-	into the client container (`docker exec -e VEV_REMOTE_TRANSPORT=stdio`, or
21		-	unset for QUIC); passing it to the `docker` CLI process alone never reached
22		-	the driver. Direct-remote scenarios use `--remote remote --session NAME`
	19	+	output); sending a key is never success. Before each scenario the
	20	+	client container's `remote` host is re-registered with
	21	+	`vev host add --transport quic\|ssh remote` (`@stdio` selects `ssh`; a host
	22	+	keeps the transport it was added with, so the script runs `host rm` first).
	23	+	Direct-remote scenarios use `--remote remote --session NAME`
23	24		against a named fixture session, so the attached target is a named exact
24	25		lifecycle rather than an ephemeral session, and never create a local home
25	26		session as setup. `VEV_ACCEPTANCE_TOPOLOGY=local\|direct` selects which daemon
26	27		serves the client-picker scenario: `local` keeps the attachment and the
27	28		picker rows in the client container, `direct` serves both from the remote
28	29		container. The client needs a pinned `remote` SSH alias and
29		-	`vev host add remote`. Scripts create uniquely named sessions and detach
	30	+	`vev host add remote` (the script then re-registers it per scenario). Scripts create uniquely named sessions and detach
30	31		their clients; the container owner handles session cleanup.
31	32
32	33		Client and daemon debug logging is on (`VEV_LOG=debug`); the remote accepts

 `acceptance.py CLIENT_CONTAINER REMOTE_CONTAINER SCENARIO[@stdio|@quic]` runs
 the table-driven baseline matrix. Every scenario asserts committed outcomes
 (action IDs, exact lifecycle/session/focus context, observed published
-output); sending a key is never success. Transport selection is forwarded
+output); sending a key is never success. Before each scenario the
-into the client container (`docker exec -e VEV_REMOTE_TRANSPORT=stdio`, or
+client container's `remote` host is re-registered with
-unset for QUIC); passing it to the `docker` CLI process alone never reached
+`vev host add --transport quic|ssh remote` (`@stdio` selects `ssh`; a host
-the driver. Direct-remote scenarios use `--remote remote --session NAME`
+keeps the transport it was added with, so the script runs `host rm` first).
+Direct-remote scenarios use `--remote remote --session NAME`
 against a named fixture session, so the attached target is a named exact
 lifecycle rather than an ephemeral session, and never create a local home
 session as setup. `VEV_ACCEPTANCE_TOPOLOGY=local|direct` selects which daemon
 serves the client-picker scenario: `local` keeps the attachment and the
 picker rows in the client container, `direct` serves both from the remote
 container. The client needs a pinned `remote` SSH alias and
-`vev host add remote`. Scripts create uniquely named sessions and detach
+`vev host add remote` (the script then re-registers it per scenario). Scripts create uniquely named sessions and detach
 their clients; the container owner handles session cleanup.
 Client and daemon debug logging is on (`VEV_LOG=debug`); the remote accepts

M scripts/remote-picker-harness/acceptance.py +32 -11


@@ -7,10 +7,12 @@ lifecycle/session/focus context, observed published output). Sending a key
7	7		or accepting a request is never success: every scenario ends on a
8	8		postcondition ``wait`` or a verified capture.
9	9
10		-	Transport selection passes through the client process environment:
11		-	``VEV_REMOTE_TRANSPORT`` unset means QUIC, ``stdio`` means SSH stdio. The
12		-	value is forwarded into the container with ``docker exec -e`` so it actually
13		-	reaches the driver process.
	10	+	Transport selection is host registration state: before each scenario the
	11	+	``remote`` host is re-registered in the client container with
	12	+	``vev host add --transport quic\|ssh remote``. A bare scenario or ``@quic``
	13	+	means QUIC; ``@stdio`` means the SSH stdio carriage (``--transport ssh``).
	14	+	``VEV_ACCEPTANCE_TRANSPORT`` carries the selected name to the scenarios for
	15	+	evidence labels only.
14	16
15	17		Direct-remote scenarios use ``--remote ENDPOINT --session NAME`` against a
16	18		named fixture session: a named exact remote target, never an ephemeral

@@ -369,7 +371,7 @@ def scenario_direct_remote_named(client_container, remote_container, env):
369	371		--session NAME`` attaches to that exact lifecycle instead of creating an
370	372		ephemeral one, so the daemon-owned target is pinned, not inferred.
371	373		"""
372		-	mode = env.get("VEV_REMOTE_TRANSPORT", "quic")
	374	+	mode = env.get("VEV_ACCEPTANCE_TRANSPORT", "quic")
373	375		suffix = uuid.uuid4().hex[:8]
374	376		name = "direct" + suffix
375	377		fixture = Driver(remote_container, ["--session", name])

@@ -416,7 +418,7 @@ def scenario_warm_reuse(client_container, remote_container, env):
416	418		fails the scenario. The remote daemon's attach count is recorded, not
417	419		asserted: each visit is a new logical attachment by design.
418	420		"""
419		-	mode = env.get("VEV_REMOTE_TRANSPORT", "quic")
	421	+	mode = env.get("VEV_ACCEPTANCE_TRANSPORT", "quic")
420	422		suffix = uuid.uuid4().hex[:8]
421	423		local_name = "locl" + suffix
422	424		remote_name = "remt" + suffix

@@ -556,7 +558,7 @@ def commit_target(driver, target, before):
556	558		def scenario_client_picker_navigate(client_container, remote_container, env):
557	559		"""P6.2: client-owned navigation picker end to end, plus its cancel path."""
558	560		topology = picker_topology(env)
559		-	mode = env.get("VEV_REMOTE_TRANSPORT", "quic")
	561	+	mode = env.get("VEV_ACCEPTANCE_TRANSPORT", "quic")
560	562		suffix = uuid.uuid4().hex[:8]
561	563		first, second, entry = (name + suffix for name in ("picka", "pickb", "pickc"))
562	564		# Direct mode is served by the remote daemon: the picker interaction

@@ -601,7 +603,7 @@ def scenario_client_picker_navigate(client_container, remote_container, env):
601	603
602	604		def scenario_hybrid_exact_return(client_container, remote_container, env):
603	605		"""M4/M5: local A -> local B -> remote -> exact local A with committed action."""
604		-	mode = env.get("VEV_REMOTE_TRANSPORT", "quic")
	606	+	mode = env.get("VEV_ACCEPTANCE_TRANSPORT", "quic")
605	607		suffix = uuid.uuid4().hex[:8]
606	608		first, second, remote = (name + suffix for name in ("sample", "second", "other"))
607	609		fixture = Driver(remote_container, ["--session", remote])

@@ -643,6 +645,24 @@ SCENARIOS = {
643	645		}
644	646
645	647
	648	+	REMOTE_HOST = "remote"
	649	+	HOST_TRANSPORT_FLAGS = {"quic": "quic", "stdio": "ssh"}
	650	+
	651	+
	652	+	def register_remote(client_container, transport):
	653	+	"""Re-register the remote host with the requested carriage.
	654	+
	655	+	A host keeps the transport it was added with, so switching requires
	656	+	``host rm`` then ``host add``. The rm may fail when nothing is registered.
	657	+	"""
	658	+	docker_capture(["exec", client_container, "vev", "host", "rm", REMOTE_HOST])
	659	+	result = docker_capture(["exec", client_container, "vev", "host", "add",
	660	+	"--transport", HOST_TRANSPORT_FLAGS[transport], REMOTE_HOST])
	661	+	check(result.returncode == 0,
	662	+	f"vev host add --transport {HOST_TRANSPORT_FLAGS[transport]} failed",
	663	+	{"stdout": result.stdout, "stderr": result.stderr})
	664	+
	665	+
646	666		def main(argv):
647	667		if len(argv) != 4:
648	668		raise SystemExit("usage: acceptance.py CLIENT_CONTAINER REMOTE_CONTAINER SCENARIO[@stdio\|@quic]")

@@ -651,10 +671,11 @@ def main(argv):
651	671		if name not in SCENARIOS:
652	672		raise SystemExit(f"unknown scenario {name}; want one of {sorted(SCENARIOS)}")
653	673		env = {}
654		-	if transport == "stdio":
655		-	env["VEV_REMOTE_TRANSPORT"] = "stdio"
656		-	elif transport and transport != "quic":
	674	+	if transport and transport not in HOST_TRANSPORT_FLAGS:
657	675		raise SystemExit(f"unknown transport {transport}; want stdio or quic")
	676	+	transport = transport or "quic"
	677	+	env["VEV_ACCEPTANCE_TRANSPORT"] = transport
	678	+	register_remote(client_container, transport)
658	679		topology = os.environ.get("VEV_ACCEPTANCE_TOPOLOGY")
659	680		if topology:
660	681		env["VEV_ACCEPTANCE_TOPOLOGY"] = topology

 or accepting a request is never success: every scenario ends on a
 postcondition ``wait`` or a verified capture.
-Transport selection passes through the client process environment:
+Transport selection is host registration state: before each scenario the
-``VEV_REMOTE_TRANSPORT`` unset means QUIC, ``stdio`` means SSH stdio. The
+``remote`` host is re-registered in the client container with
-value is forwarded into the container with ``docker exec -e`` so it actually
+``vev host add --transport quic|ssh remote``. A bare scenario or ``@quic``
-reaches the driver process.
+means QUIC; ``@stdio`` means the SSH stdio carriage (``--transport ssh``).
+``VEV_ACCEPTANCE_TRANSPORT`` carries the selected name to the scenarios for
+evidence labels only.
 Direct-remote scenarios use ``--remote ENDPOINT --session NAME`` against a
 named fixture session: a named exact remote target, never an ephemeral
     --session NAME`` attaches to that exact lifecycle instead of creating an
     ephemeral one, so the daemon-owned target is pinned, not inferred.
     """
-    mode = env.get("VEV_REMOTE_TRANSPORT", "quic")
+    mode = env.get("VEV_ACCEPTANCE_TRANSPORT", "quic")
     suffix = uuid.uuid4().hex[:8]
     name = "direct" + suffix
     fixture = Driver(remote_container, ["--session", name])
     fails the scenario. The remote daemon's attach count is recorded, not
     asserted: each visit is a new logical attachment by design.
     """
-    mode = env.get("VEV_REMOTE_TRANSPORT", "quic")
+    mode = env.get("VEV_ACCEPTANCE_TRANSPORT", "quic")
     suffix = uuid.uuid4().hex[:8]
     local_name = "locl" + suffix
     remote_name = "remt" + suffix
 def scenario_client_picker_navigate(client_container, remote_container, env):
     """P6.2: client-owned navigation picker end to end, plus its cancel path."""
     topology = picker_topology(env)
-    mode = env.get("VEV_REMOTE_TRANSPORT", "quic")
+    mode = env.get("VEV_ACCEPTANCE_TRANSPORT", "quic")
     suffix = uuid.uuid4().hex[:8]
     first, second, entry = (name + suffix for name in ("picka", "pickb", "pickc"))
     # Direct mode is served by the remote daemon: the picker interaction
 def scenario_hybrid_exact_return(client_container, remote_container, env):
     """M4/M5: local A -> local B -> remote -> exact local A with committed action."""
-    mode = env.get("VEV_REMOTE_TRANSPORT", "quic")
+    mode = env.get("VEV_ACCEPTANCE_TRANSPORT", "quic")
     suffix = uuid.uuid4().hex[:8]
     first, second, remote = (name + suffix for name in ("sample", "second", "other"))
     fixture = Driver(remote_container, ["--session", remote])
 }
+REMOTE_HOST = "remote"
+HOST_TRANSPORT_FLAGS = {"quic": "quic", "stdio": "ssh"}
+def register_remote(client_container, transport):
+    """Re-register the remote host with the requested carriage.
+    A host keeps the transport it was added with, so switching requires
+    ``host rm`` then ``host add``. The rm may fail when nothing is registered.
+    """
+    docker_capture(["exec", client_container, "vev", "host", "rm", REMOTE_HOST])
+    result = docker_capture(["exec", client_container, "vev", "host", "add",
+                             "--transport", HOST_TRANSPORT_FLAGS[transport], REMOTE_HOST])
+    check(result.returncode == 0,
+          f"vev host add --transport {HOST_TRANSPORT_FLAGS[transport]} failed",
+          {"stdout": result.stdout, "stderr": result.stderr})
 def main(argv):
     if len(argv) != 4:
         raise SystemExit("usage: acceptance.py CLIENT_CONTAINER REMOTE_CONTAINER SCENARIO[@stdio|@quic]")
     if name not in SCENARIOS:
         raise SystemExit(f"unknown scenario {name}; want one of {sorted(SCENARIOS)}")
     env = {}
-    if transport == "stdio":
+    if transport and transport not in HOST_TRANSPORT_FLAGS:
-        env["VEV_REMOTE_TRANSPORT"] = "stdio"
-    elif transport and transport != "quic":
         raise SystemExit(f"unknown transport {transport}; want stdio or quic")
+    transport = transport or "quic"
+    env["VEV_ACCEPTANCE_TRANSPORT"] = transport
+    register_remote(client_container, transport)
     topology = os.environ.get("VEV_ACCEPTANCE_TOPOLOGY")
     if topology:
         env["VEV_ACCEPTANCE_TOPOLOGY"] = topology