#Diffinery plugins for Claude Code and Codex

A plugin marketplace, kept in the Diffinery repository itself, that makes Claude Code and OpenAI's Codex CLI work smoothly with repositories hosted on Diffinery, the open-source git forge built for AI agents: on diffinery.com or on any instance you deploy yourself (see Any Diffinery instance). It has two plugins: diffinery (Claude Code and Codex) and diffinery-ci (Claude Code), described below.

The plugin adds:

diffinery-ci is a Claude Code mod that shows the branch's pull request and its CI checks live, and tells Claude when CI settles:

It reads the GraphQL API of the Diffinery instance in DIFFINERY_URL, the plugin's Diffinery URL setting or the CLI's saved URL (in that order, else diffinery.com), with the token from DIFFINERY_TOKEN, diffinery login, or gh signed in to the host (diffinery auth setup-gh), and sends a token only to the instance it belongs to. It needs Claude Code 2.1.287 or later (the desktop app: 2.1.286). Cloud sessions run its hooks but draw no mod interface, so there it's the note to Claude and the /diffinery-ci text.

Nothing here is needed just to use git: clone, fetch and push work with any git client (diffinery auth setup-git or a token as the HTTPS password). The plugin is for pull requests, CI and issues.

#Install

codician/diffinery is public, so adding the marketplace needs no sign-in. The plugin works through the diffinery CLI, so install it and sign in once per machine:

curl -fsSL https://diffinery.com/install | bash      # Windows: irm https://diffinery.com/install.ps1 | iex
diffinery login
diffinery auth setup-git

#Claude Code

claude plugin marketplace add https://diffinery.com/codician/diffinery.git
claude plugin install diffinery@diffinery

Or inside a session: /plugin marketplace add https://diffinery.com/codician/diffinery.git, then /plugin install diffinery@diffinery, then /reload-plugins (or restart).

Add claude plugin install diffinery-ci@diffinery for the live CI band.

#claude.ai, cloud sessions and projects

claude.ai can't read this repository, so upload the plugins as files: download https://diffinery.com/-/claude/diffinery.zip and https://diffinery.com/-/claude/diffinery-ci.zip, then in claude.ai open Customize → Plugins → Add → Upload plugin for each. They reach your cloud sessions at their next start. For a project's threads, also add them under Project settings → Plugins. Build the same zips from a checkout with python3 scripts/pack-plugins.py at the repository root (they land in dist/).

#Codex

codex plugin marketplace add https://diffinery.com/codician/diffinery.git
codex plugin add diffinery@diffinery

Check with codex plugin list and codex mcp list. Codex runs plugin hooks only after you review and trust them: open /hooks in the Codex TUI and trust the diffinery SessionStart hook (optional; the skill works without it).

#Any Diffinery instance

Diffinery is open source, and every plugin here works with any instance, not only diffinery.com. Both Claude Code plugins have a Diffinery URL setting (userConfig.url, default https://diffinery.com). It sets the MCP server's address (.mcp.json uses ${user_config.url}/mcp), the instance the SessionStart hook recognises in a clone (it gets the value as CLAUDE_PLUGIN_OPTION_URL), and the instance diffinery-ci reads.

• diffinery setup --url https://git.example.com sets it for you, in pluginConfigs in ~/.claude/settings.json, for the copies it installs (diffinery@inline) and for marketplace installs alike. Install the CLI from the instance itself: curl -fsSL https://git.example.com/install | bash.
• Claude Code asks for it when you enable a marketplace install; change it later in /config.
• The zips an instance serves at /-/claude/<name>.zip default the setting to that instance (apps/diffinery/src/docs/claude-plugins.ts), so uploads to claude.ai need nothing else.
• The hook also knows DIFFINERY_URL and the URL diffinery login saved; DIFFINERY_URL takes precedence for the hook and for diffinery-ci, as it does for the CLI.

Codex substitutes no plugin settings, so the Codex manifest reads its own codex.mcp.json, which names https://diffinery.com/mcp. A server of your own named diffinery replaces it, and diffinery setup --url adds one when Codex is installed: codex mcp add diffinery --url https://git.example.com/mcp. The skills and the hook work with any instance in Codex too.

#Sign in

The MCP server signs you in with OAuth in the browser:

• Claude Code: run /mcp, pick plugin:diffinery:diffinery, choose Authenticate.
• Codex: codex mcp login diffinery.

The skill also uses the diffinery CLI, which has its own sign-in:

curl -fsSL https://diffinery.com/install | bash      # Windows: irm https://diffinery.com/install.ps1 | iex
diffinery login                                     # or: diffinery login --device
diffinery auth setup-git                            # optional: git credential helper

#Headless use (CI, cloud sessions): DIFFINERY_TOKEN

The diffinery CLI and diffinery auth setup-git pick up DIFFINERY_TOKEN on their own.

The plugin's MCP server uses OAuth only. Neither client can take a token from the environment when it is set and fall back to OAuth when it is not, from one config:

• Claude Code turns OAuth off as soon as the server config has an Authorization header, even an empty one, and plugin header helpers do not see variables like DIFFINERY_TOKEN.
• Codex's bearer_token_env_var makes the server fail to start when the variable is unset.

So on headless machines, add a token-based server of your own. It takes precedence over the plugin's:

# Claude Code: same URL, so the plugin's OAuth entry is hidden while this one exists
claude mcp add --scope user --transport http diffinery https://diffinery.com/mcp \
  --header 'Authorization: Bearer ${DIFFINERY_TOKEN}'

# Codex: same name, so it replaces the plugin's server
codex mcp add diffinery --url https://diffinery.com/mcp --bearer-token-env-var DIFFINERY_TOKEN
# ...or just for one run, without touching config.toml:
codex -c 'mcp_servers.diffinery.url="https://diffinery.com/mcp"' \
      -c 'mcp_servers.diffinery.bearer_token_env_var="DIFFINERY_TOKEN"' exec "..."

Keep the single quotes in the Claude Code command: Claude Code expands ${DIFFINERY_TOKEN} when it connects, so the token is never written to its config.

#claude.ai and the Claude apps

Settings → Connectors → Add custom connector, with the URL https://diffinery.com/mcp (or your own instance's https://git.example.com/mcp). You sign in with your Diffinery account when you connect it.

#gh

Prefer the diffinery CLI: it knows Diffinery's extras (--intent, auto-merge, run logs). gh works too once you run diffinery auth setup-gh, which signs gh in to the Diffinery host (diffinery.com or yours) as a GitHub Enterprise host. That is also what lets Claude Code show the branch's pull request with its CI status. See https://diffinery.com/docs/agents/github-cli.

#Layout

Paths from the repository root:

.claude-plugin/marketplace.json     Claude Code marketplace
.agents/plugins/marketplace.json    Codex marketplace
plugins/diffinery/
  .claude-plugin/plugin.json        Claude Code manifest
  .codex-plugin/plugin.json         Codex manifest
  .claude-plugin/icon.png           the listing icon (also in diffinery-ci)
  .mcp.json                         the diffinery MCP server (Claude Code: ${user_config.url}/mcp)
  codex.mcp.json                    the diffinery MCP server (Codex: diffinery.com)
  skills/diffinery/SKILL.md         the skill (both clients)
  commands/pr-status.md             /pr-status (Claude Code)
  codex-skills/pr-status/SKILL.md   pr-status skill (Codex has no plugin commands)
  hooks/hooks.json                  SessionStart hook (both clients)
  hooks/session-start.sh            the hook: POSIX sh, no network, silent outside Diffinery repos
plugins/diffinery-ci/                Claude Code only (a mod)
  .claude-plugin/plugin.json        manifest
  hooks/hooks.json                  names the hooks module
  hooks/register.tsx                the mod: band, pane, status line, CI watch
  hooks/lib.ts                      parsing and wording, no engine calls
  types/index.d.ts                  the mod's state contract
  tests/ci.test.tsx                 `claude plugin test plugins/diffinery-ci`
scripts/pack-plugins.py             builds dist/<plugin>-<version>.zip for upload
apps/diffinery/claude-plugins/      the packed zips diffinery.com serves (see its README)

Check changes with claude plugin validate . and claude plugin validate plugins/diffinery from the repository root, and for the mod claude plugin validate plugins/diffinery-ci and claude plugin test plugins/diffinery-ci. Bump version in both plugin manifests and both marketplace entries together.

More: https://diffinery.com/docs/connect

#License

Apache-2.0, like the rest of the repository. See LICENSE.