# Git credentials for dashboard fetch/pull/push (issue #45, part A)

## Problem

The dashboard runs git with no terminal and `GIT_TERMINAL_PROMPT=0`. When no
credential helper on the machine holds a credential for the remote's host, git
wants to prompt, cannot, and fails:
`fatal: could not read Username for 'https://git.smartgift.io.vn': terminal prompts disabled`.
Reproduced with `git -c credential.helper= push --dry-run`.

## Decisions (approved 2026-09-25)

- AgentHub keeps its OWN credentials, shared by everyone using the AgentHub
  install (multi-user login is planned; accounts and settings are shared).
- The dashboard asks for a credential when git needs one, then retries.
- Merge and conflict resolution is part B and gets its own design.

## Design

**Store** — `server/lib/git-credentials.js`, one file
`<CLAUDE_HOME>/agenthub-git-credentials/credentials.json` (dir 0700, file 0600,
written through a temp file), one record per `protocol + host`:
`{protocol, host, username, password, savedAt}`. No route returns `password`;
the list reports `hasToken`. Routes: `GET /api/git-credentials`,
`DELETE /api/git-credentials/:protocol/:host`.

**Delivery** — `server/lib/git-credential-helper.js`, a git credential helper
speaking git's own protocol. For a network action, when AgentHub holds a
credential for one of the repo's remote hosts, or the request carries one, git
runs with `-c credential.helper= -c credential.helper=<ours>`: ONLY our helper.
The machine's helpers are left out on purpose — a stale token there would win
over the one just typed, and git's post-success `store` would copy a
"use once" token into the OS user's own helper. With nothing from AgentHub for
the host, the command is unchanged. The secret never reaches argv: the helper
reads the store file, or `AGENTHUB_GIT_ONCE` in that one git process's env.

**Flow** — an auth failure (`could not read Username|Password`,
`Authentication failed`, `terminal prompts disabled`, `Invalid username or
password`) answers `409 EGITAUTH` with `{protocol, host, username?}`. The git
bar shows a form (username, password/token, "remember for everyone on this
AgentHub", on by default) and resends the action with
`credentials: {protocol, host, username, password, remember}`. The server
accepts it only for a host that is one of the repo's remotes, runs the action,
and saves the credential only after git succeeded and `remember` is set.

**Limits** — one credential per host, so everyone on one AgentHub pushes as
the same account. `fetch --all` over remotes on several hosts: a host with no
AgentHub credential gets no machine helper either while one does. Over plain
HTTP on a LAN the token crosses the network unencrypted; the form says so.

## Testing

Store: save/list/remove, 0600, list never carries the password, bad host
refused. Helper: real `git credential fill` through our helper, stored and
once. Route: a local HTTP remote answering 401 → `EGITAUTH` with the host; a
resend with credentials reaches that server as Basic auth; nothing saved on
failure. Client: the form appears on `EGITAUTH`, resends, never renders a token.