1# ermite
2
3A single-user Git forge in one Go binary. ermite hosts bare repositories, serves clone and push over HTTPS, reviews branches as merge requests, and shows everything in a web interface with live updates.
4
5Status: early development. `ermite serve` serves Git over HTTP (clone, fetch, push), the API, `GET /-/health`, and the web: repositories, an expandable file tree with a repository-wide fuzzy file finder, files, commits, refs and merge requests. Visitors read public repositories; the owner signs in with a one-time link from the CLI to see private ones and to review and merge.
6
7## Run
8
9```sh
10export ERMITE_DATA_DIR=/var/lib/ermite
11export ERMITE_PUBLIC_URL=https://git.example.com
12export ERMITE_ADMIN_TOKEN=$(head -c 32 /dev/urandom | base64)
13ermite serve
14```
15
16| Variable | Default | Notes |
17|---|---|---|
18| `ERMITE_DATA_DIR` | required | absolute path of the data root |
19| `ERMITE_PUBLIC_URL` | required | `http(s)` base URL, no path |
20| `ERMITE_ADMIN_TOKEN` | required | at least 32 characters |
21| `ERMITE_ADDR` | `:7341` | listen address |
22| `ERMITE_TRUSTED_PROXIES` | empty | comma-separated CIDRs |
23| `ERMITE_GIT` | `git` | git 2.45 or newer |
24| `ERMITE_GIT_READER` | `ermite-git` | `ermite-git` reads refs, trees, blobs and history with the [ermite-git](https://git.bnema.dev/bnema/ermite-git) library where it is faster than the `git` binary and falls back to `git` elsewhere and for repositories it does not read; `cli` uses the `git` binary for every read (the escape hatch if a read looks wrong: set it and restart) |
25| `ERMITE_SOURCE_URL` | `$ERMITE_PUBLIC_URL/ermite` | link to the source (AGPL) |
26| `ERMITE_LOG_LEVEL` | `info` | `trace`, `debug`, `info`, `warn`, `error` |
27| `ERMITE_LOG_FORMAT` | `json` | `json` or `console` |
28| `ERMITE_COMMITTER_NAME` | `ermite` | committer of squash merges |
29| `ERMITE_COMMITTER_EMAIL` | `ermite@<public host>` | committer email of squash merges |
30| `ERMITE_OWNER` | `owner` | owner login that CI shows in `github.repository` (`<owner>/<repo>`) and `github.repository_owner`; follows the rules of repository names |
31| `ERMITE_CI_LOG_RETENTION` | `90d` | how long CI runs, jobs, checks and logs are kept: `Nd` (days) or a Go duration such as `720h`, at least one hour |
32| `ERMITE_CI_POLL_TIMEOUT` | `50s` | how long the server holds a runner's `FetchJob` call when no job is queued, from `1s` to `55s`; set it below the response timeout of a reverse proxy in front of ermite (Gordon cuts a response that has no headers after 30 s, so use `25s` behind it) |
33
34`ermite version` prints the version (and the server's when a server URL is configured, see Remote CLI).
35
36## Remote CLI
37
38The same binary drives a running server over its API. It reads `ERMITE_URL` (the server address, `http://` or `https://`) and `ERMITE_TOKEN` (a bearer token; optional for public reads). A token sent over plain `http://` to a host that is not loopback triggers a warning on every call.
39
40Each setting comes from the environment or from a config file, the environment first:
41
42| Setting | Environment | Config file key |
43|---|---|---|
44| server address | `ERMITE_URL` | `url` |
45| bearer token (optional for public reads) | `ERMITE_TOKEN` | `token.cmd`, a command that prints it |
46
47The file is `~/.config/ermite/config` (`$XDG_CONFIG_HOME/ermite/config` when set; `~/Library/Application Support/ermite/config` on macOS and `%AppData%\ermite\config` on Windows; `ERMITE_CONFIG` names another file). `ermite config show` prints the path in use. It holds no secret: `token.cmd` is a command line that fetches the token from your secret manager (pass, gopass, op, bw, secret-tool, …).
48
49```ini
50# ~/.config/ermite/config
51url       = https://git.example.com
52token.cmd = pass show ermite/token
53```
54
55```sh
56ermite config set url https://git.example.com
57ermite config set token.cmd 'pass show ermite/token'   # or: gopass show -o ermite/token, op read op://vault/ermite/token, secret-tool lookup service ermite
58ermite config show [--json]                             # path and stored values; unset removes a key
59```
60
61`token.cmd` runs with `sh -c` (`cmd /C` on Windows) only when a command needs the token, at most once per run, with your environment and, when standard input is a terminal, that terminal (so a pinentry or biometric prompt works; otherwise it reads nothing). On a timeout or when ermite is interrupted or terminated, the command and everything it started are killed (when standard input is a terminal, only the shell is, so that prompts keep working). It must print the token alone on one line, in under 4 KiB, within 60 seconds. It is not run when `ERMITE_TOKEN` is set, nor by `ermite version` or `ermite config`, and not when the config file, or the directory holding it, can be written by other users or the file belongs to another user (`ermite config show` and `set` warn about it). On Windows this check does not exist: keep the file in your own profile, the default place. It belongs to the server of the file: when `ERMITE_URL` names a different server than the file's `url`, it is not run and the call is anonymous (with a notice; set `ERMITE_TOKEN` to authenticate there). A failure is reported in one line without its output. Shell completion never runs it: it is anonymous unless `ERMITE_TOKEN` is set.
62
63```sh
64export ERMITE_URL=https://git.example.com ERMITE_TOKEN=ermite_...
65ermite repo list | show <name> | create <name> [--description …] [--visibility public] | edit <name> [--description …] [--visibility …] [--default-branch …] | delete <name> [--yes]
66ermite token create <label> [--preset cli|agent|ci|runner] [--scope repo:read …] [--repo name …] [--branch-prefix agent/x/ …] [--expires 30d]   # prints the secret once
67ermite token list | revoke <id>
68# a token for an AI agent that cannot touch main:
69ermite token create claude --preset agent --scope repo:read --repo myrepo --branch-prefix agent/claude/
70ermite mr create <repo> --source <branch> --title … | list <repo> | show <repo> <n> [--diff]
71ermite mr comment <repo> <n> -m … [--path … --line … --side old|new] | resolve <repo> <n> <comment>
72ermite mr merge <repo> <n> --head <id> [--squash] [--delete-branch] | close <repo> <n>
73ermite run list <repo> [--workflow …] [--branch …] [--status …] | view <repo> <id> [--attempt n] [--log [--job …]]
74ermite run watch <repo> <id> [--log] | cancel <repo> <id> | rerun <repo> <id> [--failed]
75ermite runner list | remove <id>
76ermite web login                # prints a one-time sign-in link (60 s)
77ermite web logout --all         # signs every browser out
78ermite web passkey list | remove <id>   # the owner's passkeys; removing one signs every browser out
79ermite signing-key show         # public key and allowed_signers line of squash commits
80ermite config show [--json] | set <url|token.cmd> <value> | unset <key>   # the CLI config file
81ermite version                  # client and server, warns about missing server features
82ermite watch [repo] [--json]    # follows events, reconnects and resumes
83```
84
85An agent skill describing the CLI and the forge lives in [`skills/ermite`](skills/ermite/SKILL.md); link or copy that folder into your agent's skills directory.
86
87`--json` on `repo list|show|create|edit`, `token create|list`, `run list|view|cancel|rerun`, `runner list` and `version` prints stable field names, listed in each command's `--help`; `watch --json` prints one object per line. Errors are one line on standard error (`ermite: …`) and exit status 1. `ermite completion bash|zsh|fish` prints a shell completion script that completes repository names from the server.
88
89## Git over HTTP
90
91```sh
92git clone http://git.example.com/<repo>.git          # public repositories need no credentials
93git push http://u:<token>@git.example.com/<repo>.git main
94```
95
96The URL GitHub-shaped clients use, `http://git.example.com/<owner>/<repo>` (`<owner>` is `ERMITE_OWNER`, with or without `.git`), is served too; any other owner is a 404. The token goes as the password of Basic with any user (`x-access-token`), or as `Authorization: Bearer <token>` or `token <token>`.
97
98Use the admin token (`ERMITE_ADMIN_TOKEN`) or a stored token as the password; the username is ignored. Store it in a Git credential helper rather than in the URL. Pushing to a new name creates a private repository. Repository names are lowercase, `[a-z0-9._-]`. TLS is terminated by your proxy; list its network in `ERMITE_TRUSTED_PROXIES` so that failed-login limits see the real client address (`X-Forwarded-For`).
99
100## Branch-limited tokens
101
102For an AI agent that should propose changes, not publish them: `--branch-prefix agent/claude/` (repeatable, up to 8, each ending with `/`) limits a token to the branches under its prefixes.
103
104- It can push, force-push and delete `refs/heads/agent/claude/…`. Any other ref (`main`, other branches, tags, notes, anything outside `refs/heads/`) refuses the whole push, and the message names the ref.
105- It cannot create a repository (push to a new name, or `repo create`), delete one, or change its settings (default branch, visibility, description, merge modes, failing-checks rule): those decide what happens to branches outside its prefixes. It never has the rights of the owner (it cannot open web sessions even with every scope), and can only create tokens whose prefixes lie within its own.
106- It opens, comments on and closes merge requests as usual; with `mr:merge` it can merge only into a branch under its prefixes, and delete only a source branch under them. You review and merge the agent's request.
107- CI: it reads runs, jobs, logs and checks as any token that can read the repository. With `ci:write` it can cancel and re-run only the runs of branches under its prefixes, never those of `main`, other branches or tags. It never manages runners (`runner list|remove`, registration), even with `runner:register`: a runner runs every branch of every repository.
108- `ermite token list` shows a `branches` column (`all` when unlimited); `--json` has `branch_prefixes`.
109- This build stores tokens in storage schema 2. Once it has started on your data, an older ermite refuses to start on it (it would read limited tokens as unrestricted): to go back, restore the backup taken before the upgrade.
110
111## Merge requests
112
113A merge request proposes a branch for its target (the default branch unless set). The merge is refused when the branch moved since the reviewed head (`--head`) or when the target is not an ancestor of it. Fast-forward moves the target; squash writes one commit signed by the server's SSH key (`ermite signing-key show` prints the `allowed_signers` line for `git verify-commit`). `ermite repo edit --merge-modes` limits the modes per repository. `--delete-branch` (a checkbox on the web) deletes the source branch after the merge, unless it is the default branch or another open request uses it. Tokens need `mr:write` to open and comment, and `mr:merge` to merge (and delete the merged branch).
114
115## CI
116
117ermite runs the `.github/workflows/*.yml` workflows of a repository on `push` (a branch or a tag, and the merge of a merge request) and shows each job as a check on the commit, the branch list and the merge request. CI is on once a runner is registered; there is no switch. Before that a push makes no run and no check.
118
119Runs execute on [ermite-runner](https://git.bnema.dev/bnema/ermite-runner) hosts, which call ermite over its API. Create a token for the runner host with `ermite token create <label> --preset runner` (the `runner:register` scope, which also gives access to the code and the secrets of every repository: give it only to runners you operate), then register the runner with it. `ermite runner list` shows the runners and whether they are online; `ermite runner remove <id>` stops one. A job goes to a runner that has every label of its `runs-on`; a job no runner takes within 24 hours fails.
120
121Every job gets a **repository token** (`github.token`, `ermitegh_…`) when a runner takes it: it reads the repository of the run, even a private one, over Git and the REST subset below, writes nothing, and ends with the job (completion, cancel, lost runner) or five minutes after the job's deadline. It is not a stored token: `ermite token list` never shows it and no scope manages it.
122
123An action of `ERMITE_OWNER/<repo>` that exists on this server wins over the same name on github.com. It is resolved **on behalf of whoever pushed the run**: ermite records the pusher with the run (the admin token, the owner's session, or the stored token by its id) and, at every answer, asks whether that pusher can read the action's repository, with the same rule as everywhere else: a public repository, or `repo:read` on a repository of the token's list. The token is looked up again each time, so a token revoked or expired since reads nothing for the run. A repository the pusher cannot read answers like one that does not exist (`repository not found`), whatever the ref, so it does not reveal itself. A job can therefore use an action from another private repository only when its pusher could read it. The runner gets an **archive token** for each such action: it is bound to that repository and that commit and downloads that one archive (`/-/github/api/repos/<owner>/<repo>/tarball/<sha>`) and nothing else. Git over HTTP, the repository endpoint and the rest of the API see it as a caller who can read nothing, not even a public repository. It goes with its job, and with the repository it reads if that is deleted. At most eight archives are written at once for one client address (`429` beyond: a runner host runs several jobs, and all come from one address) and sixteen on the server (`503`); both answers carry `Retry-After: 5`. A client that stops reading is cut after two minutes without progress.
124
125The Actions that run here call a small part of GitHub's REST API, served at `github.api_url` (`/-/github/api`): `GET /repos/{owner}/{repo}`, `/repos/{owner}/{repo}/hash-algorithm` and `/repos/{owner}/{repo}/tarball[/{ref}]` (streamed with 200, not redirected; a `HEAD` answers the headers without building the archive). The owner in these paths and in the Git URLs is matched without regard to case, as on GitHub. Any other path is GitHub's `404 {"message":"Not Found",…}`, so an action that needs more fails as on a GitHub instance without that feature.
126
127Actions from github.com are resolved with `git ls-remote https://github.com/<owner>/<repo>` (no credentials, 20 s, 16 MiB of output, at most four at once, 60 s for a whole call). ermite hands git only the proxy settings of its own environment (`HTTPS_PROXY`, `HTTP_PROXY`, `NO_PROXY`, `ALL_PROXY` and their lower-case forms), so a server that reaches the Internet through a proxy sets them for `ermite serve`; nothing else of its environment, no credential, reaches git.
128
129`ermite run list|view|watch|cancel|rerun` and the `Actions` tab of a repository read and control the runs; `cancel` and `rerun` need the `ci:write` scope. With `failing_checks_block` on (the default, `ermite repo edit --failing-checks-block=false`), a merge is refused while a check of the head failed or has not finished. A workflow that uses a feature ermite does not support yet (reusable workflows, `environment:`, `concurrency`) fails with `not supported yet: <feature>`, never silently. Logs are files under `$ERMITE_DATA_DIR/ci/logs`, and the job summaries (the Markdown a step writes to `GITHUB_STEP_SUMMARY`) under `$ERMITE_DATA_DIR/ci/summaries`; both go with their run (retention, repository deletion). Annotations (`::notice`, `::warning`, `::error`) are kept in the metadata store. The run page shows them in an Annotations box and the job page at their step; the summaries are rendered under the run with the README renderer (raw HTML dropped, `javascript:` links dropped). `ermite run view` prints an ANNOTATIONS section, and `ermite run view --summary` prints the summaries as Markdown.
130
131## Web sign-in
132
133Two ways in, both for the owner, both giving the same session cookie for 12 hours. Neither works over plain `http` except on localhost: the cookie is `Secure`.
134
135- **Passkey** (a phone, a laptop, a security key): open `/-/login` and press "Sign in with a passkey". Nothing to type, no terminal. A passkey is added once from `/-/passkeys` while signed in.
136- **Link**: `ermite web login`, run with the admin token or a token with every scope, prints a link that works once within 60 seconds. Opening it and confirming signs the browser in (never longer than the token that asked for the link). It is also how to sign in the first time, before any passkey exists.
137
138Passkeys need `ERMITE_PUBLIC_URL` to be `https` (or `http://localhost`) with a **host name, not an IP address**: WebAuthn ties a passkey to that name, and a passkey registered for one name does not work on another. On `http://127.0.0.1:…` the server starts without passkeys (the log says `passkeys disabled`, the routes and links are absent, `ermite version` does not list `passkeys`). Up to 20 passkeys can be registered; each asks for user verification (a fingerprint, a face or a PIN), and the server stores only the public key. A security key that reports a signature counter is checked for cloning; synced passkeys (iCloud, Google, a password manager) report none, so they are not.
139
140`ermite web passkey list` shows them, `ermite web passkey remove <id>` removes one. Removing a passkey, `ermite web logout --all`, or revoking a token with every scope ends every session, on every device. Browser writes require the session and an `Origin` equal to `ERMITE_PUBLIC_URL`. If you lose every device, `ermite web login` still works from a terminal.
141
142The server keeps its runtime files in `$ERMITE_DATA_DIR/run/` (the hook socket and scripts that git calls on each push); the hook socket path must stay under about 100 bytes.
143
144## Run with Docker
145
146```sh
147docker build --build-arg VERSION="$(git describe --tags --always --dirty)" -t ermite .
148token=$(head -c 32 /dev/urandom | base64)   # keep it: it is the root credential
149docker run -d -p 127.0.0.1:7341:7341 -v ermite-data:/data \
150  -e ERMITE_PUBLIC_URL=http://localhost:7341 -e ERMITE_ADMIN_TOKEN="$token" ermite
151```
152
153The image is alpine with git, runs as uid 10001 and keeps its data in the `/data` volume. Logs are JSON by default. The build fetches `bnema.dev/ermite-*` from `git.bnema.dev`, so the host must reach it (NetBird); the build container uses the host's DNS and routes. Behind another route, pass `--build-arg GIT_REWRITE_BASE=http://git.bnema.dev:8088/` with `--network host`, as the CI job does.
154
155## Develop with compose
156
157```sh
158docker compose up
159```
160
161Serves on `http://localhost:7341` with the development admin token in `compose.yaml`. The source is mounted and [air](https://github.com/air-verse/air) (`go tool air`, `.air.toml`) rebuilds and restarts the server on each change to a `.go` or `.templ` file or an embedded web asset; the module and build caches and the data live in named volumes. `docker compose down -v` removes them. The dev container runs as root, which maps to your user under rootless Docker.
162
163## Build
164
165```sh
166go build ./cmd/ermite
167go test ./...
168```
169
170## Architecture
171
172`cmd/ermite` (entry point, calls `app.Run`) → `internal/app` (CLI and composition root: builds the adapters and wires them to the use cases) → `internal/usecase` (use cases), `internal/ports` (interfaces and parameter types that cross layers), `internal/domain` (pure values and rules) and `internal/adapters` (Git, KV store, HTTP, API, web, client implementations of the ports).
173
174- `internal/usecase` imports only `internal/domain` and `internal/ports`.
175- Adapters import `internal/domain`, `internal/ports` and the shared `internal/clientlimit`; never a use case, `internal/app` or another adapter.
176- The web adapter, like the API and Git over HTTP, calls the use cases through `internal/ports` with the principal of the request (anonymous, or the owner with a valid session); it never imports the generated API code.
177- `internal/ports` imports only `internal/domain`; `internal/domain` imports nothing from the module.
178- `internal/config` (environment parsing) is used by `internal/app` only.
179
180`internal/boundary/boundary_test.go` enforces these import rules on production files; `hexcheck` (`.hexcheck.yaml`) checks the layering of types and behaviour. The release version is stamped with `-ldflags "-X bnema.dev/ermite/internal/app.stamped=<version>"`.
181
182## Develop
183
184Tools are pinned in `go.mod`:
185
186```sh
187go tool buf lint
188go tool buf generate        # proto/ -> gen/
189go generate ./...           # mockery mocks of the ports
190go tool hexcheck -fail-on warn ./...
191```
192
193## License
194
195AGPL-3.0-or-later. See [LICENSE](LICENSE).