chore: release

[acp-release-bot]

🤖 New release

• agent-client-protocol-derive: 2.0.0 -> 2.1.0
• agent-client-protocol: 2.0.0 -> 2.1.0 (✓ API compatible changes)
• agent-client-protocol-polyfill: 2.0.0 -> 2.1.0 (✓ API compatible changes)
• agent-client-protocol-rmcp: 3.0.0 -> 3.1.0 (✓ API compatible changes)
• agent-client-protocol-trace-viewer: 2.0.0 -> 2.1.0 (✓ API compatible changes)
• agent-client-protocol-conductor: 2.0.0 -> 2.1.0 (✓ API compatible changes)
• agent-client-protocol-http: 2.0.0 -> 2.1.0 (✓ API compatible changes)
• agent-client-protocol-cookbook: 2.0.0 -> 2.1.0 (✓ API compatible changes)

Changelog

agent-client-protocol-derive

2.0.0 - 2026-07-23

Breaking changes

• Generated implementations now target agent-client-protocol 2.x and must not be mixed with
  core SDK 1.x types.

Added

• Support generic request, notification, and response types in the JSON-RPC derive macros, and
  accept any Rust type expression—including generic types such as Option<Response>—in a
  request's response attribute. (#267)

Changed

• Harden macro expansion with collision-resistant identifiers and fully qualified SDK paths.
  (#267)

agent-client-protocol

2.1.0 - 2026-08-20

Added

• (acp) update schema to 1.7 (#331)
• (unstable-v2) Add runnable v2 quickstart examples (#330)
• (unstable-v2) add v2 resume session builder (#329)
• (acp) add proxy protocol router for v2 (#324)
• (acp) Add v2 proxy MCP attachment (#314)
• (acp) Add v2 session MCP attachment (#303)
• (conductor) add v2 proxy initialization (#302)
• (acp) expose unstable LLM provider methods (#298)
• (unstable-v2) Better v2 session builders (#295)
• (acp) expose unstable plan operations (#297)
• (acp) expose unstable tool-call names (#296)

Fixed

• (acp) Preserve session config options (#332)
• (acp) box handler chain links to bound dispatch stack use (#306)
• (acp) Allow v2 initialize with future params (#304)
• (acp) preserve same-version initialize fields (#299)
• (acp) Support WASI builds (#294)

Added

• (unstable-v2) Add runnable draft-v2 agent and one-shot client examples. The
  agent implements the complete baseline session lifecycle; the client handles
  permissions, projects chunk and snapshot updates by message ID, and waits for
  the matching idle state. Add a compiled cookbook recipe and mdbook quickstart
  for the same lifecycle.
• (unstable-v2) Add Proxy::protocol_router and ProxyProtocolRouter to
  compose strict v1 and v2 proxy implementations behind one connection.
  Routing requires the exact version selected by the conductor and preserves
  the complete initial transport frame.
• (unstable) Expose programmatic tool-call names through the
  unstable_tool_call_name feature.
• (unstable) Expose v1 and draft-v2 plan operations through the
  unstable_plan_operations feature.
• (unstable-v2) Add high-level protocol v2 session builders and handles with
  independent prompt-acceptance requests, create, resume, and feature-gated
  fork setup responses, cloneable command handles, configuration, close, and
  session-wide cancellation. Client.v2() and Agent.v2() callbacks receive
  a V2ConnectionTo whose unversioned build_session*, resume_session*, and
  feature-gated fork_session* methods expose only the v2 lifecycle. Resume
  and fork return V2ResumeSessionBuilder and V2ForkSessionBuilder, so their
  requests are not published until start_session or
  on_proxy_session_start is called. Session updates and interactive requests
  remain on typed connection handlers. With unstable_mcp_over_acp, all
  available session builders support native per-session MCP attachment while
  preserving independent response consumption. MCP routes are installed and
  runners begin executing before the setup request is published; successful
  attachments remain active for the connection lifetime while setup failures,
  including cancellation error responses, clean up pending state. The
  builders' on_proxy_session_start helpers forward the complete setup
  response and cancellation, install routing before later inbound traffic, and
  then spawn user work with the OpenedV2Session. New and fork builders use
  the response session ID for the installed route and returned command handle;
  resume routing is ready before request publication so replay can precede the
  response as required by the protocol.
• (unstable-v2) Add Proxy::v2() as the draft-v2-only proxy builder while
  keeping Proxy::builder() on stable v1. With unstable_mcp_over_acp,
  Proxy.v2().with_mcp_server(...) injects a connection-scoped MCP server
  declaration into v2 new, resume, and feature-gated fork setup requests while
  preserving unrelated fields. Version-neutral routing infrastructure can
  continue to use Builder::without_acp_version_guard when it owns raw
  version selection and validation.
• (unstable-v2) Expose protocol-neutral dynamic handler registration on
  V2ConnectionTo.
• (unstable-v2) Add ConnectionTo::spawn_connection_with_context for raw
  parents that need the context selected by a child builder.
  V2ConnectionTo::spawn_connection also returns that natural typed context.
  The existing ConnectionTo::spawn_connection::<Role> API remains
  source-compatible and returns a raw ConnectionTo, including when the v2
  child builder's callbacks receive V2ConnectionTo.
• (unstable-v2) Add a version-correct
  schema::v2::InitializeProxyRequest for _proxy/initialize. Proxy
  forwarding now preserves same-version raw initialize fields and raw session
  creation fields instead of interpreting v2 messages as permissive v1
  payloads. Add the low-level
  Builder::without_acp_version_guard escape hatch for routing infrastructure
  that performs its own raw version selection, plus
  Builder::with_v2_protocol_guard for raw-context links after v2 is selected.
• (unstable) Add typed v1 and draft-v2 JSON-RPC routing for configurable LLM
  provider methods behind unstable_llm_providers.

Fixed

• Preserve stable v1 NewSessionResponse::config_options on ActiveSession,
  expose them through ActiveSession::config_options, and include them in
  reconstructed and proxied session responses.
  (#301)
• (unstable-v2) Require native v2 client and agent connections to complete
  their single initialization handshake before sending or accepting other
  protocol traffic. Reject initialization in the wrong direction and reject
  reinitialization after a successful handshake while allowing retries after an
  initialization error. Protocol-level request cancellation remains available
  while initialization is in progress.
• (unstable-v2) Preserve unknown initialize fields when the protocol router
  hands a same-version connection to its selected implementation.
• (unstable-v2) Do not retain unhandled v2 session messages for a dynamic v1
  session route that will never be installed.
• Register framework-owned ordered response handling before outbound requests
  become visible to the peer, preventing fast responses from overtaking session
  routing or proxy forwarding.
• Allow the portable protocol engine and transport abstractions to build for
  the wasm32-wasip1 and wasm32-wasip2 targets. The native process-backed
  AcpAgent, thread-backed Stdio, and associated LineDirection type are not
  exposed on these targets. This crate does not provide a WASI runtime adapter;
  embedders can supply transport through Channel, Lines, or
  futures::io-compatible ByteStreams.
  (#262)

agent-client-protocol-polyfill

2.1.0 - 2026-08-20

Added

• (acp) add proxy protocol router for v2 (#324)
• (acp) Add v2 proxy MCP attachment (#314)
• (polyfill) Support v2 MCP-over-ACP bridge (#305)

Added

• Add an unstable_protocol_v2 feature for using McpOverAcpPolyfill in a
  draft-v2 conductor chain. The polyfill selects the schema during proxy
  initialization, advertises the v2 ACP MCP capability when adapting an
  HTTP-capable agent, and handles v2 session setup and mcp/* messages without
  interpreting them as v1.

Fixed

• Route v1 and v2 initialization through strict version-specific proxy
  builders instead of disabling the ACP version guard.
• Forward MCP request cancellation hop by hop instead of tunneling the
  loopback connection's $/cancel_request ID inside mcp/message.

agent-client-protocol-rmcp

3.1.0 - 2026-08-20

Added

• (unstable-v2) Add runnable v2 quickstart examples (#330)

agent-client-protocol-trace-viewer

2.1.0 - 2026-08-20

Other

• update Cargo.lock dependencies

agent-client-protocol-conductor

2.1.0 - 2026-08-20

Added

• (unstable-v2) Add runnable v2 quickstart examples (#330)
• (unstable-v2) add v2 resume session builder (#329)
• (acp) add proxy protocol router for v2 (#324)
• (acp) Add v2 proxy MCP attachment (#314)
• (polyfill) Support v2 MCP-over-ACP bridge (#305)
• (conductor) add v2 proxy initialization (#302)

Added

• Add opt-in protocol-v2 initialization for agent and nested proxy chains
  through unstable_protocol_v2, including version-aware custom instantiator
  methods, raw v2 session creation routing, and the conductor binary.

agent-client-protocol-http

2.1.0 - 2026-08-20

Added

• (unstable-v2) Add runnable v2 quickstart examples (#330)

Fixed

• (http) Preserve outbound messages for slow streams (#292)

agent-client-protocol-cookbook

2.1.0 - 2026-08-20

Added

• (unstable-v2) Add runnable v2 quickstart examples (#330)
• (unstable-v2) add v2 resume session builder (#329)
• (acp) add proxy protocol router for v2 (#324)
• (acp) Add v2 proxy MCP attachment (#314)

Added

• Add a compiled draft-v2 one-shot prompt recipe that handles initialization,
  permissions, message patch projection, prompt acceptance, idle completion,
  and session close.

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