npm · #4534

@agentclientprotocol/sdk

1.4.0agentclientprotocol/typescript-sdk ↗

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 7 days ago
20 Aug 2026
Ships fairly regularly
a new release about every 2 weeks
Nearly every release is documented
notes for 50 of 50 stable releases
Nothing withdrawn
no release was ever pulled
10 months old
50 releases · first in 2025

Release timeline

50 releases since 2025

2026

Releases

1.4.020 Aug 2026
Release notes
1.4.0 (2026-08-20)

Features
- Stabilize elicitation APIs (#242) (dc3b0e4)
Bug Fixes
- jsonrpc: report malformed input (#230) (0819dbe)
- server: preserve routed outbound messages (#231) (5f58a95)
- v2: enforce initialization lifecycle (#235) (b7d6e81)
- v2: enforce method contracts (#229) (0101014)
Open source →
Additional notes
Features
- Stabilize elicitation APIs (#242) (dc3b0e4)
Bug Fixes
- jsonrpc: report malformed input (#230) (0819dbe)
- server: preserve routed outbound messages (#231) (5f58a95)
- v2: enforce initialization lifecycle (#235) (b7d6e81)
- v2: enforce method contracts (#229) (0101014)
Open source →
1.3.021 Jul 2026
Release notes
1.3.0 (2026-07-21)

Features
- experimental: Add experimental ACP v2 API (#223) (26cdeb4)
- Update to schema v1.20.0 and v2.0.0-alpha.2 (#225) (cb61107)
Open source →
Additional notes
Features
- experimental: Add experimental ACP v2 API (#223) (26cdeb4)
- Update to schema v1.20.0 and v2.0.0-alpha.2 (#225) (cb61107)
Open source →
1.2.17 Jul 2026
Release notes
1.2.1 (2026-07-07)

Bug Fixes
- http: make SSE close and response delivery deterministic (#209) (2adee0f)
- Preserve extensible union semantics in TS schemas (#215) (e323221)
Open source →
Additional notes
Bug Fixes
- http: make SSE close and response delivery deterministic (#209) (2adee0f)
- Preserve extensible union semantics in TS schemas (#215) (e323221)
Open source →
1.2.06 Jul 2026
Release notes
1.2.0 (2026-07-06)

Features
- Update schema to 1.17.0 (#204) (fa8b5bd)
- Update schema to 1.19.0 (#213) (6599433)
Bug Fixes
- make ndJsonStream receive path linear in message size (#210) (2fc41d2)
- unify JSON-RPC message validation policy across transports (#212) (5e01eb2), closes #211
Open source →
Additional notes
Features
- Update schema to 1.17.0 (#204) (fa8b5bd)
- Update schema to 1.19.0 (#213) (6599433)
Bug Fixes
- make ndJsonStream receive path linear in message size (#210) (2fc41d2)
- unify JSON-RPC message validation policy across transports (#212) (5e01eb2), closes #211
Open source →
1.1.029 Jun 2026
Release notes
1.1.0 (2026-06-29)

Features
- Expose request ids in handler contexts (#202) (eda849c)
Open source →
Additional notes
Features
- Expose request ids in handler contexts (#202) (eda849c)
Open source →
1.0.024 Jun 2026
Release notes
1.0.0 (2026-06-24)

Features
- schema: Update to v1.16.0 of the schema (#199) (de58791)
Miscellaneous Chores
- release 1.0.0 (#201) (008fc28)
Open source →
Additional notes
Features
- schema: Update to v1.16.0 of the schema (#199) (de58791)
Miscellaneous Chores
- release 1.0.0 (#201) (008fc28)
Open source →
0.29.022 Jun 2026
Release notes
0.29.0 (2026-06-22)

Features
- unstable: Add support for request cancellation (#195) (d5197f9)
Open source →
Additional notes
Features
- unstable: Add support for request cancellation (#195) (d5197f9)
Open source →
0.28.119 Jun 2026
Release notes
0.28.1 (2026-06-19)

Bug Fixes
- Expose peer contexts from app connections (#190) (d657310)
Open source →
Additional notes
Bug Fixes
- Expose peer contexts from app connections (#190) (d657310)
Open source →
0.28.018 Jun 2026
Release notes
0.28.0 (2026-06-18)

Features
- schema: Update to schema v1.14.0 (#185) (3c619a7)
Open source →
Additional notes
Features
- schema: Update to schema v1.14.0 (#185) (3c619a7)
Open source →
0.27.118 Jun 2026
Release notes
0.27.1 (2026-06-18)

Bug Fixes
- node-adapter: Cap HTTP request body size (#186) (3832d4c)
- node-adapter: harden Node adapter request parsing (220eae6)
Open source →
Additional notes
Bug Fixes
- node-adapter: Cap HTTP request body size (#186) (3832d4c)
- node-adapter: harden Node adapter request parsing (220eae6)
Open source →
0.27.018 Jun 2026
Release notes
0.27.0 (2026-06-18)

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.

Features
- Experimental Streamable HTTP & WebSocket Transport (#155) (d6a3d88)
- New SDK design (see MIGRATION_0.26_0.27.md) (#181) (87e2df3)
Open source →
Additional notes
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.

Features
- Experimental Streamable HTTP & WebSocket Transport (#155) (d6a3d88)
- New SDK design (see MIGRATION_0.26_0.27.md) (#181) (87e2df3)
Open source →
0.26.016 Jun 2026
Release notes
0.26.0 (2026-06-16)

Features
- schema: Update to v1.13.7 of the schema (#179) (34885b6)
Open source →
Additional notes
Features
- schema: Update to v1.13.7 of the schema (#179) (34885b6)
Open source →
0.25.113 Jun 2026
Release notes
0.25.1 (2026-06-13)

Bug Fixes
- cleanup zod generation (#170) (be44483)
- Zod type inference errors (#177) (d9fafa2)
Open source →
Additional notes
Bug Fixes
- cleanup zod generation (#170) (be44483)
- Zod type inference errors (#177) (d9fafa2)
Open source →
0.25.05 Jun 2026
Release notes
0.25.0 (2026-06-05)

Features
- schema: stabilize deleteSession (#168) (2cc77af)
Open source →
Additional notes
Features
- schema: stabilize deleteSession (#168) (2cc77af)
Open source →
0.24.02 Jun 2026
Release notes
0.24.0 (2026-06-02)

Features
- Add resilient schema deserialization (#167) (5864e73)
- schema: Stabilize addl dirs and remove unstable model selectors (#165) (fa6e302)
Open source →
Additional notes
Features
- Add resilient schema deserialization (#167) (5864e73)
- schema: Stabilize addl dirs and remove unstable model selectors (#165) (fa6e302)
Open source →
0.23.01 Jun 2026
Release notes
0.23.0 (2026-06-01)

Features
- schema: Stabilize logout and update schema to v0.13.4 (#163) (cfd900a)
Open source →
Additional notes
Features
- schema: Stabilize logout and update schema to v0.13.4 (#163) (cfd900a)
Open source →
0.22.118 May 2026
Release notes
0.22.1 (2026-05-18)

Bug Fixes
- Event ordering (#153) (7b63226)
Open source →
Additional notes
Bug Fixes
- Event ordering (#153) (7b63226)
Open source →
0.22.018 May 2026
Release notes
0.22.0 (2026-05-18)

Features
- unstable: Add session delete handling (#152) (f9384f5)
- Update schema to v0.13.2 (#150) (b15960b)
Open source →
Additional notes
Features
- unstable: Add session delete handling (#152) (f9384f5)
- Update schema to v0.13.2 (#150) (b15960b)
Open source →
0.21.114 May 2026
Release notes
0.21.1 (2026-05-14)

Bug Fixes
- emit .js extensions in generated schema barrel for nodenext consumers (#146) (63b96db)
Open source →
Additional notes
Bug Fixes
- emit .js extensions in generated schema barrel for nodenext consumers (#146) (63b96db)
Open source →
0.21.028 Apr 2026
Release notes
0.21.0 (2026-04-28)

Features
- unstable: Add providers/* support (#138) (e234c21)
Open source →
Additional notes
Features
- unstable: Add providers/* support (#138) (e234c21)
Open source →
0.20.023 Apr 2026
Release notes
0.20.0 (2026-04-23)

Features
- Stabilize closeSession and resumeSession (#132) (806d307)
Open source →
Additional notes
Features
- Stabilize closeSession and resumeSession (#132) (806d307)
Open source →
0.19.223 Apr 2026
Release notes
0.19.2 (2026-04-23)

Bug Fixes
- Avoid event loop timing causing out of order messages (#130) (8f514f3)
Open source →
Additional notes
Bug Fixes
- Avoid event loop timing causing out of order messages (#130) (8f514f3)
Open source →
0.19.121 Apr 2026
Release notes
0.19.1 (2026-04-21)

Bug Fixes
- avoid spurious unhandledRejection when transport fails mid-sendRequest (#122) (b6b2cb4)
- Flush decoder state at end of NDJSON stream (#119) (4e1b07a)
- Use TypeScript private keyword instead of ES #private fields (#127) (c6e6ee2)
Open source →
Additional notes
Bug Fixes
- avoid spurious unhandledRejection when transport fails mid-sendRequest (#122) (b6b2cb4)
- Flush decoder state at end of NDJSON stream (#119) (4e1b07a)
- Use TypeScript private keyword instead of ES #private fields (#127) (c6e6ee2)
Open source →
0.19.014 Apr 2026
Release notes
0.19.0 (2026-04-14)

Features
- unstable: Initial unstable elicitation support (#113) (bf259e9)
Open source →
Additional notes
Features
- unstable: Initial unstable elicitation support (#113) (bf259e9)
Open source →
0.18.28 Apr 2026
Release notes
0.18.2 (2026-04-08)

Bug Fixes
- propagate input stream errors through ndJsonStream (#111) (f57a8d1)
Open source →
Additional notes
Bug Fixes
- propagate input stream errors through ndJsonStream (#111) (f57a8d1)
Open source →
0.18.16 Apr 2026
Release notes
0.18.1 (2026-04-06)

Bug Fixes
- Handle ACP connection transport failures cleanly (#103) (028ee3f)
Open source →
Additional notes
Bug Fixes
- Handle ACP connection transport failures cleanly (#103) (028ee3f)
Open source →
0.18.01 Apr 2026
Release notes
0.18.0 (2026-04-01)

Features
- unstable: Add initial additionalDirectories and NES support (#104) (43cde3b)
Open source →
Additional notes
Features
- unstable: Add initial additionalDirectories and NES support (#104) (43cde3b)
Open source →
0.17.127 Mar 2026
Release notes
0.17.1 (2026-03-27)

Bug Fixes
- Make sure we use zod/v4 path for imports (#99) (e632d3b)
Open source →
Additional notes
Bug Fixes
- Make sure we use zod/v4 path for imports (#99) (e632d3b)
Open source →
0.17.025 Mar 2026
Release notes
0.17.0 (2026-03-25)

Features
- schema: Update schema to 0.11.3 (#88) (0fe246e)
Open source →
Additional notes
Features
- schema: Update schema to 0.11.3 (#88) (0fe246e)
Open source →
0.16.111 Mar 2026
Release notes
0.16.1 (2026-03-11)

Bug Fixes
- unstable: Fixes for session/close capabilities (#85) (e8721b7)
Open source →
Additional notes
Bug Fixes
- unstable: Fixes for session/close capabilities (#85) (e8721b7)
Open source →
0.16.010 Mar 2026
Release notes
0.16.0 (2026-03-10)

Features
- add unstable session/close (#81) (2c9bc77)
- Stabilize unstable_listSessions to listSessions (#84) (9e89bbc)
Open source →
Additional notes
Features
- add unstable session/close (#81) (2c9bc77)
- Stabilize unstable_listSessions to listSessions (#84) (9e89bbc)
Open source →
0.15.05 Mar 2026
Release notes
0.15.0 (2026-03-05)

Features
- Update to 0.11.0 of the schema (#79) (2763d63)
Bug Fixes
- use npx.cmd on Windows in client example (#68) (fdc7815)
Open source →
Additional notes
Features
- Update to 0.11.0 of the schema (#79) (2763d63)
Bug Fixes
- use npx.cmd on Windows in client example (#68) (fdc7815)
Open source →
0.14.15 Feb 2026
Release notes
0.14.1 (2026-02-05)

Bug Fixes
- inconsistent bigint vs number in zod and schema (#66) (5e3c342)
Open source →
Additional notes
Bug Fixes
- inconsistent bigint vs number in zod and schema (#66) (5e3c342)
Open source →
0.14.04 Feb 2026
Release notes
0.14.0 (2026-02-04)

Features
- Stabilize Session Config Options (#64) (15806a2)
Open source →
Additional notes
Features
- Stabilize Session Config Options (#64) (15806a2)
Open source →
0.13.122 Jan 2026
Release notes
0.13.1 (2026-01-22)

Bug Fixes
- schema: Update to schema v0.10.7 (#58) (ade1b68)
Open source →
Additional notes
Bug Fixes
- schema: Update to schema v0.10.7 (#58) (ade1b68)
Open source →
0.13.013 Jan 2026
Release notes
0.13.0 (2026-01-13)

Features
- (breaking) no more auto underscoring of extension methods (#55) (ec4b095)
- add unstable session config option handling (#56) (ec7bb47)
- Update to 0.10.6 of the schema (#53) (766964e)
Open source →
Additional notes
Features
- (breaking) no more auto underscoring of extension methods (#55) (ec4b095)
- add unstable session config option handling (#56) (ec7bb47)
- Update to 0.10.6 of the schema (#53) (766964e)
Open source →
0.12.016 Dec 2025
Release notes
0.12.0 (2025-12-16)

Features
- unstable: add list sessions method (#47) (2efd404)
- Update to 0.10.4 of the schema (#49) (6c44fb2)
Open source →
Additional notes
Features
- unstable: add list sessions method (#47) (2efd404)
- Update to 0.10.4 of the schema (#49) (6c44fb2)
Open source →
0.11.012 Dec 2025
Release notes
0.11.0 (2025-12-12)

Features
- unstable: add resumeSession support (#41) (721c450)
Open source →
Additional notes
Features
- unstable: add resumeSession support (#41) (721c450)
Open source →
0.10.011 Dec 2025
Release notes
0.10.0 (2025-12-11)

Features
- Update to 0.10.2 of the schema (#39) (0773dde)
Open source →
Additional notes
Features
- Update to 0.10.2 of the schema (#39) (0773dde)
Open source →
0.9.011 Dec 2025
Release notes
0.9.0 (2025-12-11)

Features
- Update to 0.10.1 of the schema (#36) (210392b)
Open source →
Additional notes
Features
- Update to 0.10.1 of the schema (#36) (210392b)
- Unstable: add unstable forkSession support (#37) (16262ef )
Open source →
0.8.08 Dec 2025
Release notes
0.8.0 (2025-12-08)

Features
- Update to 0.10 of the schema (#31) (f026432)
Open source →
Additional notes
Features
- Update to 0.10 of the schema (#31) (f026432)
Open source →
0.7.01 Dec 2025
Release notes
0.7.0 (2025-12-01)

Features
- Update to v0.9.1 of the schema (#28) (6166944)
Open source →
Additional notes
Features
- Update to v0.9.1 of the schema (#28) (6166944)
Open source →
0.6.01 Dec 2025
Release notes
0.6.0 (2025-12-01)

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.

Open source →
Additional notes
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.

Open source →
0.5.124 Oct 2025
Release notes
What's Changed
- Add ability for agents and clients to provide information about their implementation
- Fix incorrectly serialized _meta field on `SetSessionModeResponse
Full Changelog: https://github.com/agentclientprotocol/typescript-sdk/compare/v0.5.0...v0.5.1
Open source →
Additional notes
- Add ability for agents and clients to provide information about their implementation
- Fix incorrectly serialized _meta field on SetSessionModeResponse
Open source →
0.5.024 Oct 2025
Release notes
What's Changed
- Update to latest ACP JSON Schema by @benbrandt in https://github.com/agentclientprotocol/typescript-sdk/pull/10
- Add signal and closed properties to connection classes by @benbrandt in https://github.com/agentclientprotocol/typescript-sdk/pull/11
- Allow more customization of RequestError messages by @benbrandt in https://github.com/agentclientprotocol/typescript-sdk/pull/12
Full Changelog: https://github.com/agentclientprotocol/typescript-sdk/compare/v0.4.9...v0.5.0
Open source →
Additional notes
- Provide access to an 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/11
- Allow for more customization of error messages: https://github.com/agentclientprotocol/typescript-sdk/pull/12
- Update to latest ACP JSON Schema: https://github.com/agentclientprotocol/typescript-sdk/pull/10
Open source →
0.4.921 Oct 2025
Release notes
What's Changed
- Fix: Correct RPC method call in setSessionModel by @bliuk in https://github.com/agentclientprotocol/typescript-sdk/pull/7
New Contributors
- @bliuk made their first contribution in https://github.com/agentclientprotocol/typescript-sdk/pull/7
Full Changelog: https://github.com/agentclientprotocol/typescript-sdk/compare/v0.4.8...v0.4.9
Open source →
Additional notes
- Fix: incorrect method for session/set_model client implementation.
Open source →
0.4.815 Oct 2025
Release notes
What's Changed
- 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
Open source →
Additional notes
- Fix: return valid setSessionModel response object
Open source →
0.4.711 Oct 2025
Release notes
What's Changed

First publish from the new repo!

Full Changelog: https://github.com/agentclientprotocol/typescript-sdk/commits/v0.4.7

Open source →
Additional notes
- New repo: https://github.com/agentclientprotocol/typescript-sdk
Open source →
0.4.610 Oct 2025
Release notes
- No changes
Open source →
0.4.510 Oct 2025
Release notes
- Unstable initial support for model selection.
Open source →

@agentclientprotocol/sdk

Release timeline

Releases

1.4.0 (2026-08-20)

Features

Bug Fixes

Features

Bug Fixes

1.3.0 (2026-07-21)

Features

Features

1.2.1 (2026-07-07)

Bug Fixes

Bug Fixes

1.2.0 (2026-07-06)

Features

Bug Fixes

Features

Bug Fixes

1.1.0 (2026-06-29)

Features

Features

1.0.0 (2026-06-24)

Features

Miscellaneous Chores

Features

Miscellaneous Chores

0.29.0 (2026-06-22)

Features

Features

0.28.1 (2026-06-19)

Bug Fixes

Bug Fixes

0.28.0 (2026-06-18)

Features

Features

0.27.1 (2026-06-18)

Bug Fixes

Bug Fixes

0.27.0 (2026-06-18)

Features

Features

0.26.0 (2026-06-16)

Features

Features

0.25.1 (2026-06-13)

Bug Fixes

Bug Fixes

0.25.0 (2026-06-05)

Features

Features

0.24.0 (2026-06-02)

Features

Features

0.23.0 (2026-06-01)

Features

Features

0.22.1 (2026-05-18)

Bug Fixes

Bug Fixes

0.22.0 (2026-05-18)

Features

Features

0.21.1 (2026-05-14)

Bug Fixes

Bug Fixes

0.21.0 (2026-04-28)

Features

Features

0.20.0 (2026-04-23)

Features

Features

0.19.2 (2026-04-23)

Bug Fixes

Bug Fixes

0.19.1 (2026-04-21)

Bug Fixes

Bug Fixes

0.19.0 (2026-04-14)

Features