Serve resources over resources/list and resources/read - #1

Stacked on #3 (Prettier). Review only the top two commits.

Summary

Adds the resources capability, so a server can expose documents (including MCP Apps ui:// views) instead of only tools:

resources: {
  list: [{ uri: "ui://demo/chart", name: "chart", mimeType: "text/html;profile=mcp-app" }],
  read: async (ctx, uri, user) => {
    if (uri !== "ui://demo/chart") return null;
    return { contents: [{ uri, mimeType: "text/html;profile=mcp-app", text: html }] };
  },
},

Behavior

• resources is advertised only when options.resources is set, so existing servers behave exactly as before. listChanged: false; no subscribe (2026-07-28 replaced it with subscriptions/listen).
• Three methods in both eras: resources/list, resources/templates/list, resources/read. list and templates are optional and are served as empty when unset: the spec lets UI-only resources stay unlisted, but the advertised capability still promises the methods.
• Entries are opaque and sent as-is, so _meta, title, size and annotations survive untouched.
• Errors:
  • read returning null → Resource not found with the URI in error.data: -32602 on MCP 2026-07-28 (SEP-2164) and -32002 on earlier revisions.
  • A missing or non-string uri → -32602 invalid params (not "not found").
  • A throwing handler → generic -32603; the error is logged, never sent (same policy as tool handlers).
• ttlMs/cacheScope only on the 2026-07-28 path (SEP-2549): the tool-list TTL for the lists, ttlMs: 0 + private for resources/read.
• The existing Mcp-Name header check already covers resources/read in the modern era.
• No scopes on resources. Handlers receive the verified user; access control is theirs, the same as for internal functions. Documented in README and DESIGN.

Out of scope

resources/subscribe, notifications/resources/*, and prompts. This is the read path only.

Testing

src/client/index.test.ts:

• the capability is advertised only when configured, and the methods are -32601 (404 on 2026-07-28) without it
• legacy list/templates/read with no cache hints
• modern ttlMs/cacheScope and -32602 + error.data.uri; legacy -32002
• read-only config serves empty lists
• non-string uri → -32602
• a throwing handler → -32603 without leaking the error

npm test → 68 pass · npm run typecheck · npm run lint

MCP Apps rides on top of this: the tool's _meta.ui.resourceUri (convex#7) points at a resource, and the host fetches it with resources/read. Nothing in this PR knows about ui://; the example lands in the next PR.