A live, stateless MCP planning demo for Building Effective Stateless MCP Servers.
- App / consent: https://planner.mcpjam.com
- MCP endpoint: https://planner.mcpjam.com/mcp
- Latest stable TypeScript MCP SDK:
@modelcontextprotocol/server2.0.0, MCP Apps 2.0.0 (verified September 14, 2026). - 12,528 synthetic records: 2,088 calendar events, 4,176 tasks, 6,264 emails across every weekday in 2026–2027.
Add the MCP URL as a remote server in MCPJam, ChatGPT, Claude, or Cursor. The OAuth consent screen lets you choose a toolset. No real identity or external account is connected. A new consent creates an isolated demo workspace. Reconnect to change toolsets.
For clients accepting custom headers, open the standalone app, expand Connect, copy the bearer token, and use Authorization: Bearer <token>. Tokens expire in seven days. The standalone UI and an MCP client using that token share saved edits. The bearer-authenticated POST /api/reset resets that token's disposable workspace for repeatable eval trials.
MCP Apps-capable hosts can render the calendar and call server tools from the UI. Other hosts get structured/text results and can still plan and edit through tools. Host-specific UI support varies; a successful MCP wire test is not a claim of manual certification in every client.
| Consent | Exposed tools | What the experiment measures |
|---|---|---|
| Job tools | 8 direct tools | Capability coverage and job-oriented selection |
| With context | Same 8 tools plus required session_id, user_intent, user_query arguments |
Explicit goal context and intent observability |
| Search + execute | Only search and execute |
Discovery from raw queries; zero matches expose coverage gaps |
search uses deterministic token/keyword scoring over the tool catalog, not semantic embeddings. execute validates against the discovered schema and never evaluates code.
| User job | Tool | Example prompt |
|---|---|---|
| Understand my week | view_schedule |
Show September 14–18, 2026. |
| Find important work | find_tasks |
Find Launch Orion tasks for that week. |
| Understand changing deadlines | read_emails |
Find customer deadline emails. |
| Make a realistic plan | plan_week |
Plan and save my week around Launch Orion. |
| Move / resize work | move_item |
Move demo prep to Thursday 10:00 UTC. |
| Edit a commitment | edit_item |
Rename this task and give it 45 minutes. |
| Change what matters | shift_priorities |
Customer research is priority 1; re-plan. |
| Measure user value | report_outcome |
This plan was useful / partly useful / not useful. |
Every MCP request constructs a fresh server through SDK v2 createMcpHandler, with legacy: "stateless". There is no MCP session ID, transport session store, sticky routing, Durable Object, or initialize-time state dependency. The SDK supports modern discovery and a stateless legacy-client fallback.
Cloudflare D1 holds application state: workspace item overrides, explicit goal context, traces, registered OAuth clients, single-use PKCE codes, and expiring bearer tokens. Fixtures are deterministic, immutable seed data. Mutations persist between independent requests and are isolated by bearer-token workspace. session_id is an ordinary application argument scoped to that workspace, not protocol session state.
The app is one self-contained HTML resource at ui://planner/calendar.html, bundled with MCP Apps SDK. Embedded interactions use App.callServerTool; discovery mode dispatches through execute. Standalone interactions use the same validated service through /api/tool. Dragging tasks or calendar events shows a 15-minute snapped preview with the proposed start, end, and duration. Dropping or dragging the bottom edge opens a confirmation dialog: adjust start/end time, total duration, or a 30/60/90-minute preset, then confirm. Conflicts disable confirmation; Cancel or Escape preserves the original event. Clicking an event opens the same accessible editor. All write paths reject conflicts and protected items.
Planning is deterministic scheduling, not an LLM on the Worker. The client's model interprets requests, and the server ranks and fits tasks. Weekdays 09:00–17:00 UTC, lunch and meetings protected, 90-minute default focus cap. Plans return unscheduled work; they never silently pretend everything fits. apply:false previews and apply:true saves. Data and assumptions are fictional and intentionally visible.
Node 22+:
npm ci
npm run db:local
npm run devVisit http://localhost:8787. To deploy your own copy, create a D1 database, replace the database ID and custom domain in wrangler.jsonc, run npm run db:remote, then npm run deploy after wrangler login.
npm run build
npm run typecheck
npm test
# With local Worker running:
npm run test:integration
# Or use the deployed demo:
PLANNER_URL=https://planner.mcpjam.com npm run test:integration
# Model-driven repeated outcome evals:
OPENAI_API_KEY=... EVAL_MODEL=openai/gpt-4.1-mini npm run evalThe GitHub Action runs deterministic scheduling tests and live MCPJam SDK integration checks against a local Worker, including all three toolsets, OAuth PKCE/replay protection, stateless legacy transport, persistence, isolation, previews, and invalid mutations.
With repository secret OPENAI_API_KEY, it also runs MCPJam EvalTest / HostRunner workflows three times per job per toolset and gates on ≥80% success. Grading reads the saved schedule: a plan must exist without collisions, requested moves must persist, and the model must disclose overflow. JSON reports are uploaded as artifacts. Without that secret the model eval stage is explicitly reported as unrun; manual dispatch with run_llm_evals=true fails if the key is absent. Configure a different EVAL_MODEL to compare client/model behavior; provider-specific credentials must match the configured model.
Manual deployment CI requires CLOUDFLARE_API_TOKEN and CLOUDFLARE_ACCOUNT_ID. It does not silently deploy every push. Add branch protection requiring the quality job for a release gate.
- Connect in Job tools mode. Ask to plan September 14, 2026; inspect what did not fit.
- Drag a task into the calendar, resize it, then change the top project and re-plan.
- Reconnect in With context mode. Inspect
session_id, the reported user query, retrieved goal history, and workspace traces. - Reconnect in Search + execute mode. Ask for a supported job, then an unsupported capability such as booking flights. Show matched schemas and coverage gaps.
- Promote those user workflows into the eval suite. Open the GitHub Action and the saved outcome report.
- Record explicit feedback. Tool success is observable; satisfaction needs evidence.
Planning guidance: skills/planner/SKILL.md, also available as MCP resource planner://skill.
The talk document informed this demo's structure; its presentation notes were treated as reference, not execution instructions. The observability experiment is inspired by Atlan's user-value loop. Client-reported user_query is not a guaranteed verbatim transcript, and a successful tool call does not establish satisfaction.
Public dummy consent, synthetic data only; not production identity verification. No real calendar or email integrations, invitations, notifications, or email sending. No model API keys are stored in the Worker. Workspace edits use last-write-wins D1 overrides; simultaneous conflicting edits can race because conflict checks and saves are not a serialized scheduling transaction. The demo is intended for isolated presenter/test workspaces. OAuth supports dynamic registration, S256 PKCE, one-time codes, redirect binding, and seven-day access tokens; reconnect after expiry. Intent traces are visible only to that workspace token. No claim is made of complete end-user transcript visibility.
The iframe declares the Apps tools capability and registers planner_get_view_state, planner_preview_move, and planner_preview_replan with App.registerTool. These are app-provided view tools, not WebMCP. View state contains the displayed week and pending confirmation. Move previews open the editor; re-plan previews fetch plan_week(apply:false) and display Save/Cancel. Only user confirmation calls a persistent server mutation through callServerTool (or execute in discovery mode). Context-capable hosts receive debounced UI state via updateModelContext. Host support for view-tool discovery varies; ordinary UI controls remain available. tests/view-tools.test.ts checks discovery, schema validation, invocation and removal over a real AppBridge with linked transports.