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The Agent Client Protocol (ACP) is a protocol that standardizes communication between *code editors* (interactive programs for viewing and editing source code) and *coding agents* (programs that use generative AI to autonomously modify code).
Last release 2 days ago
02 Oct 2026
Ships fairly regularly
a new release about every 2 weeks
Nearly every release is documented
notes for 55 of 55 stable releases
Nothing withdrawn
no release was ever pulled
11 months old
55 releases · first in 2025
v2: check the extensible-union values you build
One column per month.
update schemas to v1.24.1 and v2.0.0-alpha.7
jsonrpc: report malformed input
make ndJsonStream receive path linear in message size
Expose request ids in handler contexts
unstable: Add support for request cancellation
Expose peer contexts from app connections
schema: Update to schema v1.14.0
node-adapter: Cap HTTP request body size
For now, you will still have the old interfaces available to ease the migration, but they are deprecated and will be removed in a future release.
This is a big release! We have rewritten the SDK to have a more ergonomic design for creating new agents and clients. You can read more in the Migration Guide for how to migrate.
For now, you will still have the old interfaces available to ease the migration, but they are deprecated and will be removed in a future release.
schema: Update to v1.13.7 of the schema
schema: stabilize deleteSession
schema: Stabilize logout and update schema to v0.13.4
## 0.22.1 (2026-05-18) ### Bug Fixes * Event ordering
emit .js extensions in generated schema barrel for nodenext consumers
unstable: Add providers/* support
Stabilize closeSession and resumeSession
Avoid event loop timing causing out of order messages
avoid spurious unhandledRejection when transport fails mid-sendRequest
unstable: Initial unstable elicitation support
propagate input stream errors through ndJsonStream
Handle ACP connection transport failures cleanly
unstable: Add initial additionalDirectories and NES support
Make sure we use zod/v4 path for imports
schema: Update schema to 0.11.3
unstable: Fixes for session/close capabilities
inconsistent bigint vs number in zod and schema
Stabilize Session Config Options
schema: Update to schema v0.10.7
(breaking) no more auto underscoring of extension methods
unstable: add resumeSession support
## 0.10.0 (2025-12-11) ### Features * Update to 0.10.2 of the schema
## 0.9.0 (2025-12-11) ### Features * Update to 0.10.1 of the schema
## 0.8.0 (2025-12-08) ### Features * Update to 0.10 of the schema
## 0.7.0 (2025-12-01) ### Features * Update to v0.9.1 of the schema
Updates to the latest version of the ACP JSON Schema, v0.8.0
Updates to the latest version of the ACP JSON Schema, v0.8.0
This update provides much improved schema interfaces. The migration should be minimal because in TypeScript the interfaces should be functionally equivalent. But there may be some areas where the types are now more informative to the compiler and will hopefully help you catch errors earlier.
Add ability for agents and clients to provide information about their implementation
_meta field on `SetSessionModeResponseFull Changelog: https://github.com/agentclientprotocol/typescript-sdk/compare/v0.5.0...v0.5.1
Update to latest ACP JSON Schema by @benbrandt in https://github.com/agentclientprotocol/typescript-sdk/pull/10
Full Changelog: https://github.com/agentclientprotocol/typescript-sdk/compare/v0.4.9...v0.5.0
AbortSignal and closed promise on connections so you can wait for the connection to close and handle any other cleanup tasks you need for a graceful shutdown. https://github.com/agentclientprotocol/typescript-sdk/pull/11Fix: Correct RPC method call in setSessionModel by @bliuk in https://github.com/agentclientprotocol/typescript-sdk/pull/7
Full Changelog: https://github.com/agentclientprotocol/typescript-sdk/compare/v0.4.8...v0.4.9
Fix: return valid setSessionModel response object by @benbrandt in https://github.com/agentclientprotocol/typescript-sdk/pull/4
Full Changelog: https://github.com/agentclientprotocol/typescript-sdk/compare/v0.4.7...v0.4.8
First publish from the new repo!
First publish from the new repo!
Full Changelog: https://github.com/agentclientprotocol/typescript-sdk/commits/v0.4.7
- No changes
Unstable initial support for model selection.
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