Updates

Updates and announcements about the Agent Client Protocol

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February 4, 2025

Session Config Options RFD moves to Completed

The RFD for adding more generic Session Config Options to the protocol has been stabilized and is now a part of the protocol. Please review the documentation for more information.

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February 4, 2026

session/delete moves to Draft stage

The RFD for allowing clients to delete a given session has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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February 4, 2026

Logout method moves to Draft stage

The RFD for allowing clients to logout from an agent connection has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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January 15, 2026

Rust SDK based on SACP RFD moves to Draft stage

The RFD for basing the Rust SDK on SACP has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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January 15, 2025

Session Config Options RFD moves to Preview stage

The RFD for adding more generic Session Config Options to the protocol has been moved to Preview stage. Please review the RFD for more information on the current proposal and provide feedback before the feature is stabilized.

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January 14, 2026

Authentication Methods RFD moves to Draft stage

The RFD for creating additional types of authentication methods has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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January 1, 2026

Agent Registry RFD moves to Draft stage

The RFD for creating an Agent Registry has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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January 1, 2026

Session Usage RFD moves to Draft stage

The RFD for adding a new usage_update variant on the session/update notification and usage field on prompt responses in the protocol has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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December 31, 2025

Proxy Chains RFD moves to Draft stage

The RFD for adding proxy chain functionality in the protocol has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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December 11, 2025

Agent Telemetry Export RFD moves to Draft stage

The RFD for providing more guidance on how agents should export telemetry has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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December 3, 2025

session_info_update notification RFD moves to Draft stage

The RFD for adding a new session_info_update variant on the session/update notification in the protocol has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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December 3, 2025

_meta Propagation RFD moves to Draft stage

The RFD for providing more guidance on how the _meta parameter should be used within the protocol has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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November 26, 2025

session/resume RFD moves to Draft stage

The RFD for adding a “session/resume” method to the protocol has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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November 20, 2025

$/cancelRequest RFD moves to Draft stage

The RFD for adding a ”$/cancelRequest” method to the protocol has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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November 20, 2025

session/fork RFD moves to Draft stage

The RFD for adding a “session/fork” method to the protocol has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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November 3, 2025

Session Config Options RFD moves to Draft stage

The RFD for adding more generic Session Config Options to the protocol has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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October 31, 2025

session/list RFD moves to Draft stage

The RFD for adding a “session/list” method to the protocol has been moved to Draft stage. Please review the RFD for more information on the current proposal and provide feedback as work on the implementation begins.

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October 24, 2025

Implementation Information for Agents and Clients

Agents and Clients are now able to provide information about themselves to the other party. The InitializeRequest message now includes an optional clientInfo field and the InitializeResponse message includes an optional agentInfo field.

This information can be used by Clients to show users which Agent is running and what version, by both sides to track usage metrics of which agents and clients are most popular among their users, and also to help track down if any issues are encountered with particular implementation version. This follows the existing pattern laid out in the Model Context Protocol.

This is being introduced as an optional field for now for backwards compatibility. It is possible it will be made into a required field in a future version of the protocol, like MCP, so that both sides can count on this information being available.