session/list doesn't conform to the ACP spec: empty params scopes to the launch project instead of all sessions, and cwd filter value is discarded

Summary

Per the ACP session/list spec, an empty params object should return "the first page of sessions," and the optional cwd parameter should filter to "sessions with a matching cwd." In practice, opencode's ACP session/list handler does neither: it silently scopes to the git-derived "project" of wherever the agent process was launched, and discards any cwd value you actually pass.

Repro

$ pwd
/path/to/some-git-repo   # a git repo opencode has never seen before
$ opencode acp
{"jsonrpc":"2.0","id":1,"method":"session/list","params":{}}
{"jsonrpc":"2.0","id":1,"result":{"sessions":[]}}

$ pwd
/home/someuser   # not a git repo
$ opencode acp
{"jsonrpc":"2.0","id":1,"method":"session/list","params":{}}
{"jsonrpc":"2.0","id":1,"result":{"sessions":[ ... dozens of sessions with unrelated cwds,
  e.g. various temp directories and other unrelated project paths ... ]}}

Same method, same empty params, wildly different results depending on the literal directory the agent process happens to be started from — and neither result is "all sessions."

Expected (per spec)

"All parameters are optional. A request with an empty params object returns the first page of sessions."
cwd: "Filter sessions by working directory. Must be an absolute path. Only sessions with a matching cwd are returned."

Actual / root cause

1. Empty params is not unfiltered. Session.list always scopes to the current instance's project id, with no way to opt out:

   // packages/opencode/src/session/session.ts:548-555
   const list = Effect.fn("Session.list")(function* (input?: ListInput) {
     const ctx = yield* InstanceState.context
     return yield* listByProject(db, { projectID: ctx.project.id, ...input })
   })
   

   ctx.project.id comes from ProjectV2.resolve() (packages/core/src/project.ts:110-122), which walks up from the server's own launch directory looking for a git repo. No repo → everything collapses into the shared ID.global bucket (explaining why a non-git launch directory returns a grab-bag of unrelated sessions from every prior non-git invocation). A repo found → a brand-new project id scoped to that repo, which starts out empty even though other sessions exist elsewhere.

2. cwd is treated as a boolean, not a filter value. Even when the ACP layer forwards params.cwd (packages/opencode/src/acp/service.ts:251), the underlying HTTP handler ignores the actual value:

   // packages/opencode/src/server/routes/instance/httpapi/handlers/session.ts:65
   const directory = ctx.query.directory ? yield* InstanceState.directory : undefined
   

   Any truthy directory/cwd is replaced with InstanceState.directory (the running instance's own directory) before the equality filter runs. So session/list { cwd: "/some/other/path" } never actually filters by /some/other/path — it filters by wherever the server itself started.

This looks like the REST endpoint was designed for opencode's own UI/CLI, where a server instance is pinned 1:1 to a workspace and "directory" is really just a "scope to my workspace" toggle — and the ACP bridge is reusing it as if it implemented the protocol's literal cwd filter, which it doesn't.

Suggested fix

• Default (cwd omitted): return sessions across all known projects/directories, not just the launch instance's project.
• When cwd is provided: filter by exact equality against SessionTable.directory/cwd, using the client-supplied value — not InstanceState.directory.