agent-client-protocol 3.1.0

# Changelog

## [Unreleased]

## [3.1.0](https://github.com/agentclientprotocol/rust-sdk/compare/v3.0.0...v3.1.0) - 2026-10-07

### Added

- *(acp)* add prepared requests with preselected response handling ([#407](https://github.com/agentclientprotocol/rust-sdk/pull/407))

### Added

- Add `prepare_request` and `prepare_request_to` on raw and v2 connections.
  `PreparedRequest` selects response handling before sending: callbacks and
  forwarding install ordering before publication, while `block_task` and
  `detach` send without holding dispatch. Eager `send_request` APIs are unchanged.
  See [Sending Requests](../../md/sending-requests.md).

## [3.0.0](https://github.com/agentclientprotocol/rust-sdk/compare/v2.2.0...v3.0.0) - 2026-10-06

### Added

- *(acp)* forward unstable subagents schema support ([#402](https://github.com/agentclientprotocol/rust-sdk/pull/402))
- *(config)* [**breaking**] make public configuration APIs extensible ([#403](https://github.com/agentclientprotocol/rust-sdk/pull/403))
- *(acp)* [**breaking**] make native transports and schema support opt-in ([#397](https://github.com/agentclientprotocol/rust-sdk/pull/397))
- *(acp)* [**breaking**] adopt request-scoped MCP binding ([#388](https://github.com/agentclientprotocol/rust-sdk/pull/388))
- *(acp)* make schemars optional ([#373](https://github.com/agentclientprotocol/rust-sdk/pull/373))

### Fixed

- *(acp)* allow singleton role IDs without Default ([#400](https://github.com/agentclientprotocol/rust-sdk/pull/400))
- *(acp)* cancel abandoned function-tool invocations ([#387](https://github.com/agentclientprotocol/rust-sdk/pull/387))
- *(acp)* [**breaking**] preserve connection lifetimes and graceful drain ([#385](https://github.com/agentclientprotocol/rust-sdk/pull/385))
- *(acp)* [**breaking**] preserve protocol-neutral raw JSON-RPC errors ([#384](https://github.com/agentclientprotocol/rust-sdk/pull/384))

### Other

- prepare v3 package metadata and release guidance ([#404](https://github.com/agentclientprotocol/rust-sdk/pull/404))
- slim dependency features and CI validation ([#399](https://github.com/agentclientprotocol/rust-sdk/pull/399))
- reconcile combined breaking release migrations ([#395](https://github.com/agentclientprotocol/rust-sdk/pull/395))
- Simplify logs in example ([#386](https://github.com/agentclientprotocol/rust-sdk/pull/386))

### Changed

- Mark `AcpAgentConfig` non-exhaustive for future configuration extensions.
  Existing private fields, constructors, fluent methods, getters, and JSON
  behavior are unchanged; an executable is still required.
  See the [config API migration guide](../../md/migration-config-api.md).
- **Breaking (unstable MCP):** adopt schema 1.10.1's request-scoped
  `mcp/message(serverId, requestId, method, params)` binding and independent
  inner MCP result/error carriers. Remove MCP connect/disconnect and connection
  IDs. Native MCP supports 2026-07-28 without an initialization prerequisite.
  See the [native binding migration guide](../../md/migration-stateless-mcp.md).
- **Breaking:** `RawJsonRpcMessage::Response` carries `RawJsonRpcResponse` with
  a boxed `RawJsonRpcError`, preserving numeric codes, omitted/null data, and
  error extension fields without ACP interpretation. Raw adapters must use the
  new response type. Typed ACP consumers still receive `Error`; conversion to
  ACP is explicit through `RawJsonRpcError::into_acp_error`.
- **Breaking:** `ConnectTo::into_channel_and_future` now returns
  `(Channel, Option<ConnectionDriver>)` instead of a boxed future. `Some` owns
  connection work; a passive endpoint returns `None`. Custom overrides and
  low-level callers must handle absence explicitly; wrappers should preserve
  the original optional driver rather than erase its lifecycle metadata.
  See the [connection-driver migration guide](../../md/migration-connection-drivers.md).
- **Breaking:** enable no Cargo features by default. JSON Schema generation and
  typed MCP tool helpers require `schemars`; native subprocess support requires
  `process`, and the native `Stdio` adapter requires `stdio`. The two native
  features are independent and expose `LineDirection` with either enabled.
  Protocol serialization and generic transports remain available by default.
  See [Cargo Features](../../md/features.md) for migration examples.
- Request the futures executor only for tests and doctests, not production
  connections. Internal test utilities no longer implicitly enable unrelated
  unstable protocol features or JSON Schema generation.

### Added

- Expose the schema's `unstable_subagents` feature, independently and through
  `unstable`. Subagent updates use the existing v1 and draft-v2 session
  notification routes; applications remain responsible for subagent behavior.
- Add reusable native MCP services with request-scoped metadata, notification
  authority, and cancellation. Supervise owned operation cleanup through ACP
  shutdown without changing generic frame queues or task limits.
- Add an owned-only, awaitable `ConnectionDriver`. Passive endpoints have no
  driver, so absence cannot be mistaken for a successful completed future.
- Add `ConnectionDriver::with_finish(future, finish)` and `request_finish()` for
  custom adapters to request graceful shutdown separately from awaiting
  completion. Requests are idempotent; the one-shot hook signals the adapter
  once, and its future must drain, flush, and close accepted output before
  reporting success. Already-requested drivers retain that contract on handoff.
- Add `ConnectionDriver::map_future` for tracing, error annotation, and
  completion cleanup without losing finish capability or requested state.
- Add an opt-in `schemars` feature that forwards JSON Schema support to the
  schema crate and gates the typed MCP tool helpers. Custom MCP servers and
  independently enabled unstable protocol features remain available without it.

### Fixed

- Allow custom roles without a `Default` implementation to construct their
  singleton `RoleId`.
- Keep recoverable session-local runner failures from cancelling unrelated native
  MCP registrations or sealing connection-wide operation admission. Scoped sibling
  runners remain driven through their own cleanup.
- Destroy and acknowledge cancelled queued mutable-tool calls independently of an
  active invocation, so cancelling a call or removing its provider does not wait
  for another registration's unrelated work.
- Cancel running function-backed MCP tool futures when their result receiver is
  dropped, skip cancelled queued calls before invoking the tool closure, and keep
  mutable and concurrent runners usable after a caller leaves or result delivery
  fails. This drops the user future; it does not join operation-level async cleanup.
- Preserve both directions of passive channel bridges after a write
  half-close, allowing a final reverse-direction response.
- Drain accepted output when an owned component finishes, including through
  line and byte-stream adapters, without requiring unrelated remote input to
  close. Ready component and I/O failures remain authoritative during drain.
- Drain routable queued output on successful `Builder::connect_with`
  foreground completion and finish cooperative physical transports without
  starting queued application tasks solely for physical drain. Preserve the
  inherited underway-close-callback cleanup phase. Fail unresolved
  request-readiness gates rather than waiting indefinitely or publishing those
  requests after shutdown.
- Close and drain the incoming producer boundary when owned transport work
  completes, including when escaped senders remain alive.
- Forward physical write-half shutdown through byte-stream adapters so split
  streams can receive a final reverse response after output EOF. Preserve
  partial-write, flush, pending-shutdown, and close-error behavior.
- Discard input to a completed foreground during physical finish, including
  frames already queued at normalization, without losing genuine I/O errors
  or cancelling accepted output.
- Apply one ownership-aware drain rule to protocol connectors and agent/proxy
  routers. Request cooperative finish after initialization rejection or owned
  foreground completion; do not indefinitely join opposed opaque work.
- Do not begin late application delivery or close callbacks after finite
  foreground success. An underway close callback completes before output is
  sealed, so clean EOF during physical drain cannot turn a late callback send
  into a closed-queue failure that cancels accepted output.

## [2.2.0](https://github.com/agentclientprotocol/rust-sdk/compare/v2.1.0...v2.2.0) - 2026-09-18

### Added

- *(acp)* update schema dependency to 1.9.0 ([#366](https://github.com/agentclientprotocol/rust-sdk/pull/366))
- *(acp)* update schema to 1.8 ([#360](https://github.com/agentclientprotocol/rust-sdk/pull/360))

### Fixed

- *(acp)* preserve stderr when shutdown drain times out ([#365](https://github.com/agentclientprotocol/rust-sdk/pull/365))
- *(acp)* support JavaScript-hosted WebAssembly ([#308](https://github.com/agentclientprotocol/rust-sdk/pull/308))

### Other

- *(cookbook)* demonstrate v2 session coordination ([#364](https://github.com/agentclientprotocol/rust-sdk/pull/364))
- *(acp)* exercise v2 example projection semantics ([#363](https://github.com/agentclientprotocol/rust-sdk/pull/363))
- *(cookbook)* demonstrate ordered application dispatch ([#362](https://github.com/agentclientprotocol/rust-sdk/pull/362))
- *(deps)* bump actions-rust-lang/setup-rust-toolchain from 1.17.0 to 2.0.0 ([#356](https://github.com/agentclientprotocol/rust-sdk/pull/356))

### Added

- Update `agent-client-protocol-schema` to 1.8.0, stabilizing optional
  programmatic tool-call names in v1 and draft v2. Remove the
  `unstable_tool_call_name` feature; v2 still requires `unstable_protocol_v2`.

### Fixed

- Preserve already-captured stderr in nonzero process-exit errors when the
  bounded shutdown wait expires before stderr EOF. The capture limit and
  process-group cleanup behavior are unchanged.
- Support JavaScript-hosted `wasm32-unknown-unknown` builds through the opt-in
  `wasm_js` feature, which selects Web Crypto through `wasm-bindgen` as the UUID
  randomness backend. WASI builds continue to work without an additional
  feature. ([#308](https://github.com/agentclientprotocol/rust-sdk/pull/308))

## [2.1.0](https://github.com/agentclientprotocol/rust-sdk/compare/v2.0.0...v2.1.0) - 2026-09-04

### Added

- *(acp)* add stable session restore builders ([#347](https://github.com/agentclientprotocol/rust-sdk/pull/347))
- *(acp)* update schema to 1.7 ([#331](https://github.com/agentclientprotocol/rust-sdk/pull/331))
- *(unstable-v2)* Add runnable v2 quickstart examples ([#330](https://github.com/agentclientprotocol/rust-sdk/pull/330))
- *(unstable-v2)* add v2 resume session builder ([#329](https://github.com/agentclientprotocol/rust-sdk/pull/329))
- *(acp)* add proxy protocol router for v2 ([#324](https://github.com/agentclientprotocol/rust-sdk/pull/324))
- *(acp)* Add v2 proxy MCP attachment ([#314](https://github.com/agentclientprotocol/rust-sdk/pull/314))
- *(acp)* Add v2 session MCP attachment ([#303](https://github.com/agentclientprotocol/rust-sdk/pull/303))
- *(conductor)* add v2 proxy initialization ([#302](https://github.com/agentclientprotocol/rust-sdk/pull/302))
- *(acp)* expose unstable LLM provider methods ([#298](https://github.com/agentclientprotocol/rust-sdk/pull/298))
- *(unstable-v2)* Better v2 session builders ([#295](https://github.com/agentclientprotocol/rust-sdk/pull/295))
- *(acp)* expose unstable plan operations ([#297](https://github.com/agentclientprotocol/rust-sdk/pull/297))
- *(acp)* expose unstable tool-call names ([#296](https://github.com/agentclientprotocol/rust-sdk/pull/296))

### Fixed

- *(acp)* Preserve session config options ([#332](https://github.com/agentclientprotocol/rust-sdk/pull/332))
- *(acp)* box handler chain links to bound dispatch stack use ([#306](https://github.com/agentclientprotocol/rust-sdk/pull/306))
- *(acp)* Allow v2 initialize with future params ([#304](https://github.com/agentclientprotocol/rust-sdk/pull/304))
- *(acp)* preserve same-version initialize fields ([#299](https://github.com/agentclientprotocol/rust-sdk/pull/299))
- *(acp)* Support WASI builds ([#294](https://github.com/agentclientprotocol/rust-sdk/pull/294))

### Added

- Add stable-v1 `load_session*` and `resume_session*` builders that produce a
  `RestoredSession` containing an `ActiveSession` and the exact operation
  response. Session routing is active before either restore request is
  published, preserving required `session/load` replay, and provisional routing
  is removed after failed restores or dropped in-flight blocking starts.
  ([#323](https://github.com/agentclientprotocol/rust-sdk/issues/323))
- *(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](https://github.com/agentclientprotocol/rust-sdk/issues/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](https://github.com/agentclientprotocol/rust-sdk/issues/262))

## [2.0.0](https://github.com/agentclientprotocol/rust-sdk/compare/v1.3.0...v2.0.0) - 2026-07-23

Version 2.0 keeps the stable ACP v1 wire schema unchanged while making coordinated breaking
changes to the Rust SDK APIs and low-level transport boundary.

### Breaking changes

- `Channel` now carries batch-aware `TransportFrame` values, and custom `Channel` or `ConnectTo`
  relays must preserve frames rather than forwarding individual messages. `Lines` and
  `ByteStreams` fields are private; construct those adapters with `new`.
  ([#275](https://github.com/agentclientprotocol/rust-sdk/pull/275),
  [#280](https://github.com/agentclientprotocol/rust-sdk/pull/280))
- JSON-RPC APIs now reflect protocol roles: notifications are never answered,
  `ResponseRouter` uses `route*` methods, typed request IDs are borrowed, and
  `TypeNotification` is role-independent. ([#272](https://github.com/agentclientprotocol/rust-sdk/pull/272),
  [#277](https://github.com/agentclientprotocol/rust-sdk/pull/277))
- Handler and routing APIs now use explicit ownership and terminology:
  `DynamicHandlerGuard` replaces cloneable registrations, background tasks use `with_runner`,
  combined matchers use `if_dispatch*`, and obsolete low-level helpers have been removed.
  ([#277](https://github.com/agentclientprotocol/rust-sdk/pull/277),
  [#280](https://github.com/agentclientprotocol/rust-sdk/pull/280),
  [#283](https://github.com/agentclientprotocol/rust-sdk/pull/283))
- MCP-over-ACP now uses the feature-gated schema-native `McpServer::Acp`, `mcp/connect`,
  `mcp/message`, and request/response `mcp/disconnect` types. The SDK-local wire types,
  `acp:` HTTP declarations, and legacy accessors are removed; MCP and session accessors now
  borrow typed identifiers and connection state. ([#281](https://github.com/agentclientprotocol/rust-sdk/pull/281))
- `AcpAgent` now uses `AcpAgentConfig`, represents JSON environment variables as an object, and
  no longer provides the deprecated Zed constructors or the Gemini convenience constructor.
  ([#276](https://github.com/agentclientprotocol/rust-sdk/pull/276),
  [#280](https://github.com/agentclientprotocol/rust-sdk/pull/280))
- Response callbacks that select ordered consumption before a response is routed during its
  original dispatch now finish before later inbound messages are dispatched. Already-routed
  responses and locally delivered failures do not add this barrier. Framework session setup is
  ordered, while user session work remains concurrent. An ordered callback must not await later
  inbound traffic on the same connection.
  ([#282](https://github.com/agentclientprotocol/rust-sdk/pull/282))

See the [2.0 migration guide] for exact API replacements and migration examples.

### Added

- Accept incoming JSON-RPC batches on stable v1 and draft v2 connections, process entries
  independently, and group replies into one response array. Typed requests and notifications
  are still sent individually. ([#271](https://github.com/agentclientprotocol/rust-sdk/pull/271),
  [#275](https://github.com/agentclientprotocol/rust-sdk/pull/275))
- Add `SentRequest::map` for transforming a response with one-shot closures without requiring the
  mapped output to implement `JsonRpcResponse`. Values consumed with `block_task` may carry
  non-`'static` lifetimes; callback-style consumption remains `'static`.
  ([#278](https://github.com/agentclientprotocol/rust-sdk/pull/278))

### Changed

- Update `agent-client-protocol-schema` to 1.5.0. The stable v1 wire schema is unchanged; the
  opt-in draft v2 API gains semantic newtypes, revised diff and terminal types, and generic
  fallible conversions. ([#273](https://github.com/agentclientprotocol/rust-sdk/pull/273))

### Fixed

- Install framework-owned session and proxy routes before later messages, route response-handler
  failures to the pending local request, and prevent handlers from emitting a second response
  after already responding. ([#280](https://github.com/agentclientprotocol/rust-sdk/pull/280),
  [#282](https://github.com/agentclientprotocol/rust-sdk/pull/282))
- Preserve batch boundaries across adapters, routers, and tracing; retain invalid call entries
  without aborting relays; do not reply to malformed response-shaped input; and complete dropped
  batched responders so sibling replies can flush.
  ([#275](https://github.com/agentclientprotocol/rust-sdk/pull/275),
  [#280](https://github.com/agentclientprotocol/rust-sdk/pull/280))
- During protocol negotiation, ignore response-only traffic before initialization, preserve
  response siblings in mixed initialization batches, flush initialization rejections before
  closing, and drop unused protocol probes before falling back to v1.
  ([#280](https://github.com/agentclientprotocol/rust-sdk/pull/280),
  [#285](https://github.com/agentclientprotocol/rust-sdk/pull/285))
- Preserve `MatchDispatchFrom` retry state across chained matchers.
  ([#274](https://github.com/agentclientprotocol/rust-sdk/pull/274))

[2.0 migration guide]: https://agentclientprotocol.github.io/rust-sdk/migration_v2.0.html

## [1.3.0](https://github.com/agentclientprotocol/rust-sdk/compare/v1.2.0...v1.3.0) - 2026-07-20

### Added

- *(unstable-v2)* Add routers for supporting both v1 and v2 at once ([#253](https://github.com/agentclientprotocol/rust-sdk/pull/253))

### Fixed

- *(acp)* preserve builder auto traits for on_close ([#269](https://github.com/agentclientprotocol/rust-sdk/pull/269))
- *(acp)* Handle  incoming EOF correctly ([#261](https://github.com/agentclientprotocol/rust-sdk/pull/261))
- *(acp)* Bound stderr capture memory ([#255](https://github.com/agentclientprotocol/rust-sdk/pull/255))
- kill the agent's whole process group when ChildGuard drops ([#251](https://github.com/agentclientprotocol/rust-sdk/pull/251))
- *(unstable-v2)* Require matching v2 protocol negotiation ([#252](https://github.com/agentclientprotocol/rust-sdk/pull/252))

## [1.2.0](https://github.com/agentclientprotocol/rust-sdk/compare/v1.1.0...v1.2.0) - 2026-07-07

### Added

- *(acp)* add constructors for renamed adapters ([#247](https://github.com/agentclientprotocol/rust-sdk/pull/247))

## [1.1.0](https://github.com/agentclientprotocol/rust-sdk/compare/v1.0.1...v1.1.0) - 2026-07-06

### Added

- *(deps)* bump schema to 1.4.0 ([#243](https://github.com/agentclientprotocol/rust-sdk/pull/243))
- *(acp)* Make request cancellation stable ([#242](https://github.com/agentclientprotocol/rust-sdk/pull/242))

## [1.0.1](https://github.com/agentclientprotocol/rust-sdk/compare/v1.0.0...v1.0.1) - 2026-06-29

### Fixed

- *(acp)* Ignore all unhandled notifications ([#229](https://github.com/agentclientprotocol/rust-sdk/pull/229))

## [1.0.0](https://github.com/agentclientprotocol/rust-sdk/compare/v0.15.1...v1.0.0) - 2026-06-24

### Added

- *(deps)* bump protocol schema to 1.1.0 ([#224](https://github.com/agentclientprotocol/rust-sdk/pull/224))

### Other

- *(acp)* Handle large future sizes in run_until ([#225](https://github.com/agentclientprotocol/rust-sdk/pull/225))

## [0.15.1](https://github.com/agentclientprotocol/rust-sdk/compare/v0.15.0...v0.15.1) - 2026-06-22

### Fixed

- *(acp)* Hide agent stdio windows on Windows ([#215](https://github.com/agentclientprotocol/rust-sdk/pull/215))

## [0.15.0](https://github.com/agentclientprotocol/rust-sdk/compare/v0.14.0...v0.15.0) - 2026-06-18

### Added

- *(deps)* update schema to 0.14.0 ([#211](https://github.com/agentclientprotocol/rust-sdk/pull/211))
- *(acp)* Update schema crate to 0.13.8 ([#210](https://github.com/agentclientprotocol/rust-sdk/pull/210))
- *(transports)* add HTTP/WebSocket transport support ([#162](https://github.com/agentclientprotocol/rust-sdk/pull/162))
- *(acp)* add unstable request cancellation support ([#179](https://github.com/agentclientprotocol/rust-sdk/pull/179))

### Other

- *(acp)* Replace jsonrpcmsg crate with shared schema types ([#205](https://github.com/agentclientprotocol/rust-sdk/pull/205))
- *(acp)* Remove unused module files ([#204](https://github.com/agentclientprotocol/rust-sdk/pull/204))
- *(deps)* Preserve serde_json object order ([#202](https://github.com/agentclientprotocol/rust-sdk/pull/202))

## [0.14.0](https://github.com/agentclientprotocol/rust-sdk/compare/v0.13.1...v0.14.0) - 2026-06-05

### Added

- Stabilize session/delete, message ids, and context usage ([#199](https://github.com/agentclientprotocol/rust-sdk/pull/199))
- *(acp)* add unstable elicitation support ([#197](https://github.com/agentclientprotocol/rust-sdk/pull/197))

### Fixed

- *(acp)* Serialize proxy metadata as _meta ([#198](https://github.com/agentclientprotocol/rust-sdk/pull/198))

### Other

- Add features to docs.rs ([#190](https://github.com/agentclientprotocol/rust-sdk/pull/190))

### Added

- *(unstable)* Add JSON-RPC support for elicitation requests and notifications.

## [0.13.1](https://github.com/agentclientprotocol/rust-sdk/compare/v0.13.0...v0.13.1) - 2026-06-01

### Added

- *(deps)* bump schema to 0.13.5 ([#188](https://github.com/agentclientprotocol/rust-sdk/pull/188))

## [0.13.0](https://github.com/agentclientprotocol/rust-sdk/compare/v0.12.1...v0.13.0) - 2026-06-01

### Added

- *(acp)* stabilize logout support ([#185](https://github.com/agentclientprotocol/rust-sdk/pull/185))
- *(acp)* Extract all rmcp logic to the rmcp crate ([#180](https://github.com/agentclientprotocol/rust-sdk/pull/180))
- *(acp)* Add unstable (very experimental!) protocol v2 support ([#170](https://github.com/agentclientprotocol/rust-sdk/pull/170))

### Changed

- Move the `rmcp`-backed MCP server builder to `agent-client-protocol-rmcp`, removing `tokio`, `tokio-util`, and `rmcp` from the core crate's normal dependency graph.

## [0.12.1](https://github.com/agentclientprotocol/rust-sdk/compare/v0.12.0...v0.12.1) - 2026-05-17

### Other

- update Cargo.toml dependencies

## [0.12.0](https://github.com/agentclientprotocol/rust-sdk/compare/v0.11.1...v0.12.0) - 2026-05-16

### Added

- *(acp)* add unstable session delete support ([#165](https://github.com/agentclientprotocol/rust-sdk/pull/165))
- extract mcp-over-acp proxy ([#146](https://github.com/agentclientprotocol/rust-sdk/pull/146))
- Stabilize session/close and session/resume ([#147](https://github.com/agentclientprotocol/rust-sdk/pull/147))
- remove direct dependency on tokio  ([#145](https://github.com/agentclientprotocol/rust-sdk/pull/145))

### Fixed

- propagate client connection errors and check capability value truthiness ([#108](https://github.com/agentclientprotocol/rust-sdk/pull/108))

### Other

- Trim dependencies ([#149](https://github.com/agentclientprotocol/rust-sdk/pull/149))
- remove unreachable!() and improve error messages ([#139](https://github.com/agentclientprotocol/rust-sdk/pull/139))

### Breaking Changes

- **Removed `McpAcpTransport`** struct and its `MetaCapability` impl. MCP-over-ACP support is now advertised via `mcpCapabilities.acp` in `InitializeResponse`, not `_meta.symposium.mcp_acp_transport`.
- **Renamed `McpConnectRequest.acp_url` to `acp_id`** to match `McpServerAcp.id` and the MCP-over-ACP RFD.

### Added

- *(unstable)* Add support for `session/delete` method.
- `McpConnectionTo::acp_id()` method.

### Deprecated

- `McpConnectionTo::acp_url()` — use `acp_id()` instead.

## [0.11.1](https://github.com/agentclientprotocol/rust-sdk/compare/v0.11.0...v0.11.1) - 2026-04-21

### Fixed

- *(acp)* remove `boxfnonce` dependency in favor of `Box<dyn FnOnce>` ([#137](https://github.com/agentclientprotocol/rust-sdk/pull/137))

## [0.11.0](https://github.com/agentclientprotocol/rust-sdk/compare/v0.10.4...v0.11.0) - 2026-04-20

### Added

- Migrate to new SDK design ([#117](https://github.com/agentclientprotocol/rust-sdk/pull/117))
- Migration Guide here: https://agentclientprotocol.github.io/rust-sdk/migration_v0.11.x.html

### Fixed

- *(rpc)* log errors when sending response to peer fails ([#101](https://github.com/agentclientprotocol/rust-sdk/pull/101))
- *(rpc)* handle write failures in handle_io loop ([#99](https://github.com/agentclientprotocol/rust-sdk/pull/99))
- *(rpc)* use RawValue::NULL constant instead of from_string().unwrap() ([#96](https://github.com/agentclientprotocol/rust-sdk/pull/96))

### Other

- Cleanup docs still referencing sacp ([#129](https://github.com/agentclientprotocol/rust-sdk/pull/129))
- Add mdbook build ([#120](https://github.com/agentclientprotocol/rust-sdk/pull/120))
- Add migration guide for next release ([#111](https://github.com/agentclientprotocol/rust-sdk/pull/111))
- remove debug code from rpc_tests ([#100](https://github.com/agentclientprotocol/rust-sdk/pull/100))
- *(test)* add conditional compilation ([#98](https://github.com/agentclientprotocol/rust-sdk/pull/98))

## [0.10.4](https://github.com/agentclientprotocol/rust-sdk/compare/v0.10.3...v0.10.4) - 2026-03-31

### Added

- *(schema)* Update schema to 0.11.4 ([#95](https://github.com/agentclientprotocol/rust-sdk/pull/95))

### Fixed

- add warning logs for silent failures in RPC message handling ([#92](https://github.com/agentclientprotocol/rust-sdk/pull/92))
- Clearer error message when connection is broken before messages are sent ([#89](https://github.com/agentclientprotocol/rust-sdk/pull/89))

### Other

- Fix the rpc_test and example use following the new schema api ([#88](https://github.com/agentclientprotocol/rust-sdk/pull/88))

## [0.10.3](https://github.com/agentclientprotocol/rust-sdk/compare/v0.10.2...v0.10.3) - 2026-03-25

### Added

- *(unstable)* Add logout support ([#84](https://github.com/agentclientprotocol/rust-sdk/pull/84))
- *(schema)* Update schema to 0.11.3 ([#82](https://github.com/agentclientprotocol/rust-sdk/pull/82))

## [0.10.2](https://github.com/agentclientprotocol/rust-sdk/compare/v0.10.1...v0.10.2) - 2026-03-11

### Added

- *(unstable)* Add support for session/close methods ([#77](https://github.com/agentclientprotocol/rust-sdk/pull/77))

## [0.10.1](https://github.com/agentclientprotocol/rust-sdk/compare/v0.10.0...v0.10.1) - 2026-03-10

### Added

- Stabilize session_list and session_info_update ([#74](https://github.com/agentclientprotocol/rust-sdk/pull/74))

### Fixed

- Make examples compile again ([#76](https://github.com/agentclientprotocol/rust-sdk/pull/76))

## [0.10.0](https://github.com/agentclientprotocol/rust-sdk/compare/v0.9.5...v0.10.0) - 2026-03-05

### Added

- Add more unstable feature flags from schema ([#71](https://github.com/agentclientprotocol/rust-sdk/pull/71))
- [**breaking**] Update to schema crate v0.11.0 ([#69](https://github.com/agentclientprotocol/rust-sdk/pull/69))

## [0.9.5](https://github.com/agentclientprotocol/rust-sdk/compare/v0.9.4...v0.9.5) - 2026-03-03

### Fixed

- handle escaped forward slashes in JSON-RPC method names ([#65](https://github.com/agentclientprotocol/rust-sdk/pull/65))

## [0.9.4](https://github.com/agentclientprotocol/rust-sdk/compare/v0.9.3...v0.9.4) - 2026-02-04

### Added

- Update to 0.10.8 of the schema ([#51](https://github.com/agentclientprotocol/rust-sdk/pull/51))

## [0.9.3](https://github.com/agentclientprotocol/rust-sdk/compare/v0.9.2...v0.9.3) - 2026-01-09

### Other

- update Cargo.toml dependencies

## [0.9.2](https://github.com/agentclientprotocol/rust-sdk/compare/v0.9.1...v0.9.2) - 2025-12-17

### Added

- *(unstable)* Add initial support for session config options ([#36](https://github.com/agentclientprotocol/rust-sdk/pull/36))

## [0.9.1](https://github.com/agentclientprotocol/rust-sdk/compare/v0.9.0...v0.9.1) - 2025-12-17

### Added

- *(unstable)* Add initial support for resuming sessions ([#34](https://github.com/agentclientprotocol/rust-sdk/pull/34))
- *(unstable)* Add initial support for forking sessions ([#33](https://github.com/agentclientprotocol/rust-sdk/pull/33))
- *(unstable)* Add initial support for listing sessions ([#31](https://github.com/agentclientprotocol/rust-sdk/pull/31))

### Other

- Add test for unstable session info feature ([#35](https://github.com/agentclientprotocol/rust-sdk/pull/35))

## [0.9.0](https://github.com/agentclientprotocol/rust-sdk/compare/v0.8.0...v0.9.0) - 2025-12-08

Update to v0.10.0 of agent-client-protocol-schema

## 0.8.0 (2025-12-01)

The types from the Rust crate, `agent-client-protocol-schema` has major breaking changes. All exported type are now marked as `#[non_exhaustive]`. Since the schema itself is JSON, and we can introduce new fields and variants in a non-breaking way, we wanted to allow for the same behavior in the Rust library.

All enum variants are also tuple variants now, with their own structs. This made it nicer to represent in the JSON Schema, and also made sure we have `_meta` fields on all variants.

This upgrade will likely come with a lot of compilation errors, but ideally upgrading will be more painless in the future.

## 0.7.0 (2025-10-24)

- Add ability for agents and clients to provide information about their implementation
- Fix incorrectly serialized `_meta` field on `SetSessionModeResponse`

## 0.6.0 (2025-10-23)

- Provide missing `_meta` fields on certain enum variants.
- More consistent enum usage. Enums are always either newtype or struct variants within a single enum, not mixed.

## 0.5.0 (2025-10-20)

- Export necessary RPC types. Fixes an issue where certain fields weren't public enough.
- Make id types easier to create and add `PartialEq` and `Eq` impls for as many types as possible.
- Export `acp::Result<T, E = acp::Error>` for easier indication of ACP errors.
- Use `acp::Error`/`acp::Result` instead of `anyhow::Error`/`anyhow::Result` for all return types.

## 0.4.7 (2025-10-13)

- Depend on `agent-client-protocol-schema` for schema types

## 0.4.6 (2025-10-10)

### Rust

- Fix: support all valid JSON-RPC ids (int, string, null)

## 0.4.5 (2025-10-02)

- No changes

## 0.4.4 (2025-09-30)

- Provide default trait implementations for optional capability-based `Agent` and `Client` methods.

## 0.4.3 (2025-09-25)

- impl `Agent` and `Client` for `Rc<T>` and `Arc<T>` where `T` implements either trait.

## 0.4.2 (2025-09-22)

**Unstable** fix missing method for model selection in Rust library.

## 0.4.1 (2025-09-22)

**Unstable** initial support for model selection.

## 0.4.0 (2025-09-17)

- Make `Agent` and `Client` dyn compatible (you'll need to annotate them with `#[async_trait]`) [#97](https://github.com/agentclientprotocol/agent-client-protocol/pull/97)
- `ext_method` and `ext_notification` methods are now more consistent with the other trait methods [#95](https://github.com/agentclientprotocol/agent-client-protocol/pull/95)
  - There are also distinct types for `ExtRequest`, `ExtResponse`, and `ExtNotification`
- Rexport `serde_json::RawValue` for easier use [#95](https://github.com/agentclientprotocol/agent-client-protocol/pull/95)