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# MCP Connector

> For the full documentation index, see: https://docs.mulesoft.com/llms.txt

Anypoint Connector for MCP (MCP Connector) uses the Model Context Protocol (MCP) to enable AI
clients that support MCP to invoke and interact with APIs, connectors, and apps.

Guide: [MCP Connector User Guide](https://docs.mulesoft.com/mcp-connector/latest/)

## 1.7.2

**October 2, 2026**

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.6 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr><tr><td><p>MCP Java SDK</p></td><td><p>2.0.1</p></td></tr><tr><td><p>MCP Protocol</p></td><td><p>2025-06-18</p></td></tr></tbody></table>

### Fixed Issues

<table><colgroup><col> <col></colgroup><thead><tr><th>Issue Resolution</th><th>ID</th></tr></thead><tbody><tr><td><p>The MCP server no longer restores an idle-expired Streamable HTTP session from the L2 Object Store. Subsequent requests for the expired session now return the expected HTTP 404 response.</p></td><td><p>W-24003367</p></td></tr><tr><td><p>Server-initiated elicitation messages over Streamable HTTP now remain associated with the request that initiated them when concurrent requests use the same MCP session.</p></td><td><p>W-23859154</p></td></tr><tr><td><p>The Jackson 2 library is upgraded to version 2.22.3 and the Jackson 3 library is upgraded to version 3.2.3 to address reported security vulnerabilities.</p></td><td><p>W-3300013</p></td></tr></tbody></table>

## 1.7.1

**September 18, 2026**

### What’s New

- The MCP Java SDK is upgraded from 2.0.0 to 2.0.1.

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.6 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr><tr><td><p>MCP Java SDK</p></td><td><p>2.0.1</p></td></tr><tr><td><p>MCP Protocol</p></td><td><p>2025-06-18</p></td></tr></tbody></table>

### Fixed Issues

<table><colgroup><col> <col></colgroup><thead><tr><th>Issue Resolution</th><th>ID</th></tr></thead><tbody><tr><td><p>The Streamable HTTP MCP client no longer fails with <code>MCP:PARSE_ERROR</code> and discards the server’s response when the server sends a keep-alive Server-Sent Events (SSE) frame while a response is pending.</p></td><td><p>W-24045650</p></td></tr><tr><td><p>The <code>reactor-core</code> library is upgraded to version 3.8.7 to address reported security vulnerabilities (CVE-2026-47857 and CVE-2026-47863).</p></td><td><p>W-24143109</p></td></tr></tbody></table>

## 1.7.0

**August 25, 2026**

### What’s New

- The MCP Java SDK is upgraded from 1.0.1 to 2.0.0. Connector operations, sources, configuration,
  and error types are unchanged.

- The MCP SDK’s JSON provider is migrated to Jackson 3. Connector operations, sources,
  configuration, and error types are unchanged.

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.6 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr><tr><td><p>MCP Java SDK</p></td><td><p>2.0.0</p></td></tr><tr><td><p>MCP Protocol</p></td><td><p>2025-06-18</p></td></tr></tbody></table>

### Fixed Issues

<table><colgroup><col> <col></colgroup><thead><tr><th>Issue Resolution</th><th>ID</th></tr></thead><tbody><tr><td><div><div><p>The Streamable HTTP transport no longer leaks resources by holding open a persistent Server-Sent Events (SSE) stream for every non-initialize request. Response framing is now deferred until an outbound message is actually sent: non-eliciting requests (such as <code>tools/call</code>, <code>resources/read</code>, and <code>prompts/get</code>) return a plain <code>application/json</code> response, and an SSE stream is opened only when the server must send a server-initiated message such as an elicitation.</p></div><div><div data-type="NOTE"><div><p>As part of the Streamable HTTP framing change, a request that triggers a server-initiated message (an elicitation) now requires the client to advertise the SSE channel in its <code>Accept</code> header. Clients that call such operations must send:</p></div><div><div><pre>Accept: application/json, text/event-stream</pre></div></div><div><p>A client that sends only <code>Accept: application/json</code> and then triggers an elicitation receives an <code>INVALID_REQUEST</code> error. Spec-conformant MCP clients already send both media types and are unaffected. If you maintain a custom MCP client, ensure it advertises <code>text/event-stream</code> on requests that might elicit.</p></div></div></div></div></td><td><p>W-23293249</p></td></tr></tbody></table>

## 1.6.1

**July 17, 2026**

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.6 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr><tr><td><p>MCP Java SDK</p></td><td><p>1.0.1</p></td></tr><tr><td><p>MCP Protocol</p></td><td><p>2025-06-18</p></td></tr></tbody></table>

### Fixed Issues

<table><colgroup><col> <col></colgroup><thead><tr><th>Issue Resolution</th><th>ID</th></tr></thead><tbody><tr><td><p><code>Session has not been initialized</code> and <code>Response was already initiated</code> errors no longer occur with strict MCP clients that omit the session ID on the request following the initialize response.</p></td><td><p>W-23239922</p></td></tr><tr><td><p>The MCP server no longer accumulates a gradual memory leak in long-running server deployments.</p></td><td><p>W-22555872</p></td></tr><tr><td><p>The Jackson dependencies are upgraded to 2.22.1 to address security vulnerabilities.</p></td><td><p>W-3300013</p></td></tr></tbody></table>

## 1.6.0

**June 8, 2026**

### What’s New

- MCP Connector now includes the **MCP Server - Create Elicitation** operation and the **MCP
  Client - Elicitation Listener** source.

  These capabilities implement the MCP elicitation protocol so servers can request additional
  structured input from clients during tool and resource execution.

- Elicitation is opt-in through the new **Enable Elicitations** field on the client configuration.

  For multi-worker deployments, use Streamable HTTP server transport and configure an Object Store
  on the server connection so elicitation correlation is preserved across workers. SSE server
  transport is single-worker only.

- Server connection configuration now includes the new **Elicitation Timeout Seconds**,
  **Elicitations Object Store**, and **Elicitation Polling Seconds** fields to route elicitation
  responses across replicas.

- The **MCP Client - List Tools**, **MCP Client - List Resources**, and **MCP Client - List
  Prompts** operations now include the new **Additional Properties** field.

  Pass custom headers, correlation IDs, tenant identifiers, or other metadata on list calls. The
  values are propagated to the corresponding server-side listeners and are accessible from
  `attributes.additionalProperties`.

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.6 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr><tr><td><p>MCP Java SDK</p></td><td><p>1.0.1</p></td></tr><tr><td><p>MCP Protocol</p></td><td><p>2025-06-18</p></td></tr></tbody></table>

### Fixed Issues

<table><colgroup><col> <col></colgroup><thead><tr><th>Issue Resolution</th><th>ID</th></tr></thead><tbody><tr><td><p>The MCP client now refreshes the OAuth bearer token automatically when an outbound request receives an HTTP 401 response, and the resulting error is reclassified as a connectivity error so it is eligible for reconnection.</p></td><td><p>W-22677666</p></td></tr><tr><td><p>Events emitted by the <strong>MCP Server - On New Session Listener</strong> source are no longer counted toward Usage-Based Pricing metering. The source fires as a byproduct of the upstream HTTP listener trigger, so its events were being double-counted.</p></td><td><p>W-21663653</p></td></tr></tbody></table>

## 1.5.0

**May 1, 2026**

### What’s New

- MCP Connector now includes the **MCP Client - Get Prompt** and **MCP Client - List Prompts**
  operations, and the **MCP Server - Prompt Listener** source.

  Expose server-side prompt templates with typed arguments and consume them from clients, with
  responses supporting text, image, embedded resource, and resource link content.

- The **MCP Client - Call Tool** operation now includes the new **Extract Structured Content**
  field.

  Define tool parameter and output schemas using either inline JSON or external files, fully
  supported by robust design-time schema validation. With this, the connector now also includes the
  new `MCP:SCHEMA_VALIDATION_FAILED` error.

- The connector now includes response attributes to support structured client-side error handling
  with HTTP response details. With this, the connector now also includes the new `MCP:UNAUTHORIZED`
  error.

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.6 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr><tr><td><p>MCP Java SDK</p></td><td><p>1.0.1</p></td></tr><tr><td><p>MCP Protocol</p></td><td><p>2025-06-18</p></td></tr></tbody></table>

## 1.4.0

**March 22, 2026**

### What’s New

- The MCP Java SDK is upgraded to the latest release version (1.0.0).

- Both the server and client transports now default to 2025-06-18 as the preferred version of the
  protocol.

- Both the server and client transports now set the `Mcp-Protocol-Version` header to the version
  negotiated upon connection initialization.

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.6 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr><tr><td><p>MCP Java SDK</p></td><td><p>1.0.0</p></td></tr><tr><td><p>MCP Protocol</p></td><td><p>2025-06-18</p></td></tr></tbody></table>

### Fixed Issues

<table><colgroup><col> <col></colgroup><thead><tr><th>Issue Resolution</th><th>ID</th></tr></thead><tbody><tr><td><p>When no audience is defined in the Mule flow, TextContent responses for tool calls no longer serialize an empty audience array in annotations. An empty array could cause some MCP clients to interpret the content as being visible to nobody and filter it out.</p></td><td><p>W-21425262</p></td></tr></tbody></table>

## 1.3.1

**January 16, 2026**

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.6 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr><tr><td><p>MCP Java SDK</p></td><td><p>0.11.2</p></td></tr></tbody></table>

### Fixed Issues

<table><colgroup><col> <col></colgroup><thead><tr><th>Issue Resolution</th><th>ID</th></tr></thead><tbody><tr><td><p>Nested objects are now properly serialized for downstream consumption.</p></td><td><p>W-20405721</p></td></tr><tr><td><p>In the <strong>MCP Server - On New Session Listener</strong> source, a <code>NullPointerException</code> error no longer occurs in the response builder when the header isn’t defined.</p></td><td><p>W-20437648</p></td></tr><tr><td><p>Tool parameters are now validated according to the JSON schema before execution.</p></td><td><p>W-20037056</p></td></tr></tbody></table>

## 1.3.0

**November 13, 2025**

### What’s New

- The **MCP Server - On New Session Listener** source now supports custom rejection headers with the
  new **Reject With Headers** field.

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.6 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr><tr><td><p>MCP Java SDK</p></td><td><p>0.11.2</p></td></tr></tbody></table>

### Fixed Issues

<table><colgroup><col> <col></colgroup><thead><tr><th>Issue Resolution</th><th>ID</th></tr></thead><tbody><tr><td><p>In the <strong>MCP Server - On New Session Listener</strong> source, the <strong>Reject With Status Code</strong> field now correctly returns custom rejection status codes instead of defaulting to 500.</p></td><td><p>W-19387519</p></td></tr><tr><td><p>The connector now properly cleans up tracked inbound requests even when exceptions occur during message processing, preventing memory leaks that could accumulate over time.</p></td><td><p>W-20037035</p></td></tr></tbody></table>

## 1.2.1

**September 11, 2025**

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.6 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr><tr><td><p>MCP Java SDK</p></td><td><p>0.11.2</p></td></tr></tbody></table>

### Fixed Issues

<table><colgroup><col> <col></colgroup><thead><tr><th>Issue Resolution</th><th>ID</th></tr></thead><tbody><tr><td><p>The MCP server now responds with HTTP 404 for expired sessions, and the MCP client now properly handles session expiration by creating a new session when receiving HTTP 404 responses.</p></td><td><p>W-19178802</p></td></tr><tr><td><p>Connection and disconnection handling is now improved because disconnect methods are now properly subscribed and executed.</p></td><td><p>W-19264682</p></td></tr></tbody></table>

## 1.2.0

**August 6, 2025**

### What’s New

- MCP Connector now supports distributed tracing.

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.6 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr><tr><td><p>MCP Java SDK</p></td><td><p>0.10.0</p></td></tr></tbody></table>

## 1.1.0

**July 18, 2025**

### What’s New

- A **Default Request Headers** parameter is added to both the SSE Client and Streamable HTTP Client
  connection types within the MCP Connector’s Client configuration. This parameter lets you specify
  custom headers to send with every request to the MCP server.

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.6 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr><tr><td><p>MCP Java SDK</p></td><td><p>0.10.0</p></td></tr></tbody></table>

### Fixed Issues

<table><colgroup><col> <col></colgroup><thead><tr><th>Issue Resolution</th><th>ID</th></tr></thead><tbody><tr><td><p>Serialization errors with ObjectStore v2 no longer occur.</p></td><td><p>W-19045311</p></td></tr></tbody></table>

## 1.0.0

**June 26, 2025**

### What’s New

- MCP Connector 1.0.0 is not backward-compatible with the 0.1.0-BETA version of this connector. For
  more information, see
  [Upgrading MCP Connector to Version 1.0.0](https://docs.mulesoft.com/mcp-connector/latest/mcp-connector-upgrade-migrate).

- Support for the Streamable HTTP transport method is added.

- You can now add custom response headers on every exposed endpoint (including `/sse`, `/messages`,
  and the new `/mcp`).

- You no longer need to add the `mule.http.service.implementation=NETTY` system property.

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.6 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr><tr><td><p>MCP Java SDK</p></td><td><p>0.10.0</p></td></tr></tbody></table>

## 0.1.0-BETA (Deprecated)

**April 15, 2025**

### What’s New

This is a new connector.

> [!NOTE] MCP Connector is a beta connector that is subject to the Beta Services Terms at
> [Agreements - Salesforce.com](https://www.salesforce.com/company/legal/) or a written Unified
> Pilot Agreement if executed by Customer, and the Non-GA Gen AI and Non-GA Credit Consumption terms
> in the
> [Product Terms Directory](https://ptd.salesforce.com/?_ga=2.247987783.1372150065.1709219475-629000709.1639001992).
> Use of this beta connector with external systems or services consumes
> [Mule messages](https://docs.mulesoft.com/general/usage-metrics) and is at the Customer’s sole discretion.

For more information, see the [MCP Connector User Guide](https://docs.mulesoft.com/mcp-connector/latest/).

### Compatibility

<table><colgroup><col> <col></colgroup><thead><tr><th>Software</th><th>Version</th></tr></thead><tbody><tr><td><p>Mule</p></td><td><p>4.9.3 and later</p></td></tr><tr><td><p>OpenJDK</p></td><td><p>17</p></td></tr></tbody></table>

## See Also

- [MCP Connector User Guide](https://docs.mulesoft.com/mcp-connector/latest/)

- [MCP Connector Reference](https://docs.mulesoft.com/mcp-connector/latest/mcp-connector-reference)

- [Salesforce Help](https://help.salesforce.com)

- [MuleSoft Services](https://www.mulesoft.com/support-and-services)

- [Known Issues](https://help.salesforce.com/s/issues)