MCP tools

Settings → MCP servers takes the common mcpServers JSON:

{
  "giphy":  { "command": "npx", "args": ["-y", "mcp-server-giphy"], "env": { "GIPHY_API_KEY": "…" } },
  "remote": { "url": "https://example.com/mcp", "headers": { "Authorization": "Bearer …" } },
  "legacy": { "url": "https://old.example.com/sse", "type": "sse" }
}

• Tools reach the model as mcp_<server>_<tool>. A GIF found by Giphy is sent with send_gif {url}.
• env, headers, args, command and url may use ${NAME} from the environment or .env, so secrets stay out of settings.json.
• Stdio servers run in their own directory, data/mcp/<server>/.
• Reconnect MCP in Settings restarts them; the status lists each server's protocol and tools.

Protocol revisions

Revision	Transport
2026-07-28	Streamable HTTP, stateless	probed first with server/discover
2025-11-25, 2025-06-18, 2025-03-26	Streamable HTTP or stdio	initialize handshake, sessions
2024-11-05	HTTP+SSE (deprecated)	last fallback

 server/discover (2026-07-28)
   ├─ ok ─────────────────────────────▶ stateless
   ├─ -32022 unsupported version ─────▶ switch version
   └─ anything else ─▶ initialize ─┬──▶ session (re-initialize on 404)
                                   └──▶ legacy HTTP+SSE

Elicitation and sampling requests (input_required) are reported to the model as errors.