openchamber/packages/web/server/lib/project-context/DOCUMENTATION.md

Project Context

Server-owned storage for the Project Notes surface: free-form notes, todos, and plan markdown files.

The managed Chats root (~/.config/openchamber/chats) is also one context owner. Every dated per-session directory beneath it resolves to that root, so Notes, Todo, Plans, pinned knowledge, and project memory are shared across ordinary chats without registering Chats as a user project.

Ownership

Path	Owner	Contents
<projectsDir>/<projectId>.json	shared UI (packages/ui/src/lib/openchamberConfig.ts), plus server-owned version / scheduledTasks	worktree setup, draft starters, project actions
<projectsDir>/<projectId>/context.json	this module, exclusively	notes, todos, plan manifest
<projectsDir>/<projectId>/plans/*.md	this module, exclusively	plan bodies

The split is the point. Both files were previously one, written by the client with a whole-file read-modify-write. Adding a server writer to that file would have made unrelated features (project actions, draft starters) clobber notes across processes, with no lock able to span both sides. Separate files remove the shared resource instead of trying to coordinate access to it.

Nothing outside this module may write context.json or the plans directory.

Storage format

{
  "version": 2,
  "notes": [{
    "id": "", "body": "", "createdAt": 0, "updatedAt": 0,
    "source": "manual | selection | agent",
    "origin": { "sessionId": "", "messageId": "" }
  }],
  "todos": [{ "id": "", "text": "", "completed": false, "createdAt": 0 }],
  "plans": [{ "id": "", "file": "1700000000-title.md", "title": "", "createdAt": 0 }]
}

Notes are entries, not one blob. Version 1 stored a single string; it converts to a single manual note on read (an empty string converts to no notes at all). The conversion lives in the read path rather than a separate migration pass so that every reader — including one racing a writer — sees one shape. Legacy pinned fields may remain in existing files but are ignored; attachment ownership lives in each session's metadata.

source records where a note came from, and origin links it back to the message it was distilled from, so a note taken off a chat selection can be traced to its conversation.

Notes and todos are written through separate routes. That split is what stops a todo toggle from persisting half-typed notes alongside it, and stops an agent-authored note from clobbering a concurrent todo change.

Plan links store a base name, never a path. The file always lives in <projectId>/plans/, so moving the project storage directory cannot invalidate a reference and a caller can never address a file outside it. title is denormalized into the manifest so listing plans costs one read rather than one read per plan; readPlan returns the title parsed from the file, which wins if the two ever disagree.

Routes

Method	Route	Notes
GET	/api/project-context/:projectId	full context; missing file is 200 empty
PUT	/api/project-context/:projectId/todos	replaces the whole list; returns committed context
POST	/api/project-context/:projectId/notes	201; takes {body, source?, origin?}
PATCH	/api/project-context/:projectId/notes/:noteId	patches body; legacy pinned input is ignored by session knowledge; 404 when unknown
DELETE	/api/project-context/:projectId/notes/:noteId	404 when unknown
PATCH	/api/project-context/:projectId/plans/:planId	legacy project pin state only; session attachment uses session knowledge; 404 when unknown
GET	/api/project-context/:projectId/plans/:planId	404 when the link or its markdown is gone
POST	/api/project-context/:projectId/plans	201; takes {title, body}, never a path
PUT	/api/project-context/:projectId/plans/:planId	takes the whole {raw} document; 404 when the link or its markdown is gone
DELETE	/api/project-context/:projectId/plans/:planId	404 when unknown

Body parsing is attached per route. This server has no global JSON parser: core-routes parses only an allowlist of /api path prefixes so the generic OpenCode proxy keeps an unread request stream, and every other /api request passes through untouched. A write route that forgets express.json() therefore sees req.body as undefined and rejects every request as a malformed body — which is exactly how this shipped once. routes.http.test.js mounts the routes on a bare express app so that failure mode fails the suite instead of the user.

projectId is validated against /^[a-zA-Z0-9._:-]+$/, which rejects separators and traversal. Validation failures are 400; malformed stored data and I/O failures are 500.

Invariants

• Missing is not malformed. A missing context.json is authoritative empty data. Unparseable JSON is a failure that propagates as 500, so the client preserves what it already has instead of rendering an empty panel over intact data on disk.
• Writes are serialized per project through an in-process lock, and land via write-to-temp + rename so a crash cannot leave a half-written file.
• readContext never takes the lock. Every mutator calls it while already holding the lock, so locking there would deadlock. The legacy migration it can trigger is safe unlocked: both writes are atomic renames of identical content.
• Plan create writes markdown before the manifest entry; delete removes the manifest entry before the file. Either partial failure leaves an unreferenced markdown file, which is inert. The reverse order would leave a manifest entry that renders as a plan and fails to open.
• Plan update takes the raw document, not title + body. The editor owns the file verbatim; reassembling it from parsed parts would rewrite the heading and reformat what the user typed. The manifest title is re-derived from the saved content, and the file name never changes with the title — it is the stable identity behind the link.
• Plan update refuses to recreate a deleted file. If the markdown vanished underneath an open editor the link is already dead; writing would resurrect content the user believes was discarded, so it returns 404 instead.
• A note patch touches only the fields it names. Pinning sends pinned alone, so it cannot roll back an edit that landed between the two requests, and editing does not reset a pin. Editing bumps updatedAt; pinning does not, because a pin is not a change to what the note says.
• A note body can be clamped but never blanked. An empty body is rejected rather than stored, since a note with nothing in it is indistinguishable from a delete the user did not ask for.
• Notes are capped at 200 per project. Past that, creation fails loudly instead of silently evicting the oldest entry.
• Per-entry sanitization never fails the whole read. A malformed todo or plan link is dropped; the rest of the context still loads.

Legacy migration

projectNotes, projectTodos, and projectPlanFiles originally lived in <projectId>.json. On the first read with no context.json, those three keys are moved out and deleted from the client-owned file; every other key is preserved untouched.

Plan links carried absolute paths. Migration converts each to a base name. A file already in the plans directory is used in place; one referenced from elsewhere — a stale path left by an earlier project id — is copied in rather than dropped. A link whose markdown cannot be found at all is discarded, since it could not have been opened either way.

The legacy keys are removed only after context.json is durably written, so any failure simply leaves the migration to run again on the next read. Repeat and concurrent reads converge on identical content.

Cross-module contract

packages/web/server/lib/opencode/settings-runtime.js merges project storage when a project id changes. Its mergeProjectContextFiles step must run before moveDirectoryContents, because that mover only renames into a free destination and would otherwise discard the old context.json whenever the destination already had one.

mergeProjectContextFiles merges every list by identity and deliberately does not convert a version 1 string note: this module owns that conversion, and doing it in two places would mean two definitions of the same migration.

mergeProjectConfigData still merges the legacy projectNotes / projectTodos / projectPlanFiles keys. That is deliberate: a project whose context has not been migrated yet keeps its data in <projectId>.json, and the migration picks it up from the merged destination afterwards.

Tests

• runtime.test.js — storage, sanitization, migration, locking, plan lifecycle.
• routes.test.js — status-code mapping, payload validation, failure surfacing.