---
title: "Messages API MCP connector — MCP compatibility"
description: "The thinnest Anthropic client by design: tool calls only, one bearer token per server, and no local servers. Anthropic documents that you obtain and refresh the token before the API call."
canonicalUrl: "https://zuplo.com/learn/mcp/compatibility/clients/messages-api-mcp-connector"
pageType: "mcp-client"
kind: "API"
verified: "2026-07-31"
---

# Messages API MCP connector

> The thinnest Anthropic client by design: tool calls only, one bearer token per server, and no local servers. Anthropic documents that you obtain and refresh the token before the API call.

_API. Protocol revision: `2025-11-25`._

## Support

- **stdio** — No
- **Streamable HTTP** — Yes
- **Legacy HTTP+SSE** — Yes
- **Protocol revision** — `2025-11-25`
- **Runs the OAuth flow** — No
- **Registration (RFC 7591)** — No
- **Metadata document** — No
- **Pre-registered client ID** — No
- **Sends resource (RFC 8707)** — No
- **Validates iss (RFC 9207)** — No
- **Custom headers** — No

**Protocol revision.** `2025-11-25`. The connector documentation cites that revision's authorization specification for token semantics.

## Caveats and sources

Each one names the column it qualifies and cites the page it comes from, which is often not the page in the row's primary source.

### Runs the OAuth flow

Documented as the caller's job: API consumers handle the flow, obtain the access token before the call, and refresh it as needed. The only credential field is `authorization_token`.

[Source](https://platform.claude.com/docs/en/agents-and-tools/mcp-connector)

### Protocol features

Of the specification's feature set, only tool calls are supported. The documented workaround for resources and prompts is the SDK's client-side MCP helpers, which run your MCP client rather than Anthropic's.

[Source](https://platform.claude.com/docs/en/agents-and-tools/mcp-connector)

[Primary source](https://platform.claude.com/docs/en/agents-and-tools/mcp-connector)

_This row was last verified 2026-07-31 against the 2026-07-28 revision._

- **Clients** — [every client in the matrix](/learn/mcp/compatibility/clients)