refactor(grain): rewrite API integration based on official Grain docs

[JonasJesus42]

• Fix webhook creation to use correct endpoint (POST //public-api/hooks) with version:2 and view_id (fetched from GET //public-api/views)
• Replace PostgreSQL binding with direct Supabase client integration
• Remove OAuth, use MESH_REQUEST_CONTEXT.authorization for API key
• Add webhook enrichment: fetch full recording details (participants, owners, tags, intelligence notes) from Grain API before indexing
• Implement multi-field search across title, participants, and AI notes
• Add dedicated transcript and summary tools with proper API endpoints
• Handle Grain reachability test on webhook URL creation
• Update all TypeScript types to match official Grain Personal API
• Rewrite README in English with correct setup instructions

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Summary by cubic

Rewrote the Grain MCP against the official Personal API. Fixes webhook setup, adds Supabase indexing and transcript/summary tools, switches auth to the Mesh API key, and includes small fixes for dev webhook override and search input handling.

• New Features

  • Creates webhooks via POST /_/public-api/hooks (version: 2) using a recordings view; only creates when missing and passes Grain’s reachability check.
  • Enriches webhook events by fetching full recording details (participants, owners, tags, notes) before upserting into Supabase; search now matches title, participants, and AI notes, and ignores whitespace‑only queries.
  • Adds GET_TRANSCRIPT (json/txt/srt/vtt) and GET_SUMMARY (md/json/text); LIST_RECORDINGS and GET_RECORDING support cursor pagination and selective fields, including include_calendar_id.
  • Emits grain.recording_indexed after a successful index; updated types to match the Personal API.

• Migration

  • Replace the Postgres binding with Supabase. Set SUPABASE_URL and SUPABASE_ANON_KEY, then run server/db/schema.sql.
  • Use the Grain API key from MESH_REQUEST_CONTEXT.authorization (set the connection’s Token). OAuth was removed.
  • Webhook URL is now {meshUrl}/webhooks/grain/{connectionId}. In dev, set DEVELOPMENT_MODE=true and optionally DEVELOPMENT_WEBHOOK_URL.

^{Written for commit 5356620. Summary will update on new commits.}

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[cubic-dev-ai]

3 issues found across 20 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="grain/server/main.ts">

<violation number="1" location="grain/server/main.ts:41">
P2: Honor DEVELOPMENT_WEBHOOK_URL when DEVELOPMENT_MODE=true so the documented dev override works and avoids rebuilding an already-complete webhook URL.</violation>
</file>

<file name="grain/server/tools/search-indexed-recordings.ts">

<violation number="1" location="grain/server/tools/search-indexed-recordings.ts:69">
P2: Treat whitespace-only queries as empty so the guard blocks unfiltered searches. Otherwise a query like "   " bypasses the guard but is ignored by the DB filter, returning all recordings.</violation>
</file>

<file name="grain/server/lib/grain-client.ts">

<violation number="1" location="grain/server/lib/grain-client.ts:133">
P2: `include_calendar_id` is defined in `ListRecordingsParams` but never serialized into query params, so callers can’t request calendar IDs from the API.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}