SCM plugins

SCM integrations subclass ScmPluginBase (@coro-ai/plugin-sdk). The runner always needs a tiny native footprint even when ninety percent of automation flows through MCP.

Required lifecycle + native ops

Method	Responsibility
`init(config, deps)`	Validate credentials (Zod-enforced manifest schema)
`cloneInfo({ repo })`	Return HTTPS URL plus `GIT_*` env vars for spawning `git`
`matchesRemote(remoteUrl)`	Decide whether `.git/config` URIs bind to this plugin
`pollPr(ref)`	Poll PR snapshot while no MCP session exists (`PollingTransport`)

Failure to implement accurate pollPr breaks parked jobs in local polling mode.

Optional native PR operations

Traditional REST implementations may override:

createPr, getPrStatus, listPrComments, postPrComment, mergePr, …

MCP-first plugins omit these entirely and expose mcpServer() instead — the shim tools (scm_create_pr) may respond with redirection payload telling the agent to invoke mcp__<provider>__* directly.

`normalizeInbound?(req)`

Converts webhook HTTP envelopes into canonical NormalizedEvent objects { ref, kind, raw, … }. Return null for irrelevant payloads.

`writerCreatePr?(args)`

Self-improvement PRs bypass live MCP sessions — plugins must optionally implement a miniature native opener or refuse proposals gracefully.

Reference implementation

@coro-ai/plugin-gitlab demonstrates MCP-first authoring:

Minimal native methods (cloneInfo, pollPr, matchesRemote).
mcpStdioDescriptor pointing at @modelcontextprotocol/server-gitlab.
allowedMcpTools whitelisting high-value GitLab MCP operations.
Optional snippet under intelligence/snippets/*.md.

Copy its structure when adding self-managed GitLab, Gitea, Forgejo, etc.