An AI communication bus implementing the Model Context Protocol (MCP), the Agent2Agent (A2A) Protocol, and the Universal Memory Protocol (UMP), built with Hono on Val Town.

Three interoperability layers in one service:

• MCP — tools, resources, and prompts for AI clients like Claude Desktop
• A2A — agent-to-agent task management and messaging
• UMP — portable, bi-temporal agent memory with provenance and consent

Rendering mermaid diagram...

• initialize — Capability negotiation with session ID
• notifications/initialized — Client ready notification
• ping — Health check
• tools/list — List available tools
• tools/call — Invoke a tool
• resources/list — List available resources
• resources/read — Read a resource
• prompts/list — List available prompts
• prompts/get — Get a prompt template

• message/send — Send a message, create or update a task
• message/stream — Send a message with SSE streaming response
• tasks/get — Get task by ID
• tasks/list — List tasks with filters
• tasks/cancel — Cancel a task
• ping — Health check

Discovery via /.well-known/agent.json returns the agent's capabilities, skills, and endpoint URL.

working → completed | failed | canceled | rejected | input-required | auth-required

Implements the Standard (L2) conformance level: all six operations, bi-temporal valid_at queries, provenance, scope + consent enforcement, and both MCP and HTTP bindings.

Each record is a typed, scoped, bi-temporal, signed JSON object:

• Kinds: semantic, episodic, procedural, working, identity
• Scope: owner (DID), project, agent, session, visibility (private/shared/public)
• Bi-temporal: valid_from/valid_to (when the fact is true) + created/observed (when the system learned it)
• Provenance: actor, actor_kind, method, source, evidence (W3C PROV-aligned)
• Consent: retention, exportable, redact (JSON-paths stripped on export)
• Lifecycle: confidence, salience, decay, status (active/candidate/tombstoned)
• Supersession: revise creates a successor and links via supersedes/superseded_by

/.well-known/ump.json returns a manifest pointing at the UMP endpoint and advertising conformance level.

main.ts      — Hono HTTP handler, routes for MCP, A2A & UMP
mcp.ts       — MCP protocol handler (tools, resources, prompts)
a2a.ts       — A2A protocol handler (agent card, tasks, messaging, SSE)
ump.ts       — UMP protocol handler (memory records, bi-temporal, supersession)
storage.ts   — SQLite persistence for tasks and messages
types.ts     — Shared TypeScript types for all three protocols

curl -X POST <endpoint>/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"my-client","version":"1.0"}}}'

curl -X POST <endpoint>/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"send_agent_message","arguments":{"text":"Hello from MCP!"}}}'

curl -X POST <endpoint>/a2a \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"message/send","params":{"message":{"role":"user","parts":[{"type":"text","text":"Hello from A2A!"}]}}}'

curl -X POST <endpoint>/ump/remember \
  -H "Content-Type: application/json" \
  -d '{"record":{"kind":"procedural","body":{"text":"Use pnpm for this repo."},"scope":{"owner":"did:key:z6Mk...","project":"github.com/example/app","visibility":"private"},"provenance":{"actor":"did:key:z6Mk...","actor_kind":"user","method":"user_correction"}}}'

curl -X POST <endpoint>/ump/recall \
  -H "Content-Type: application/json" \
  -d '{"query":"package manager","scope":{"owner":"did:key:z6Mk...","project":"github.com/example/app"}}'

curl -X POST <endpoint>/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"ump.remember","arguments":{"record":{"kind":"semantic","body":{"text":"User prefers concise release notes."},"scope":{"owner":"did:key:z6Mk...","project":"github.com/example/app","visibility":"private"},"provenance":{"actor":"did:key:z6Mk...","actor_kind":"user","method":"user_correction"}}}}}'

• Model Context Protocol — v2025-06-18
• Agent2Agent Protocol — v1.0
• Universal Memory Protocol — v0.1 (L2)