chore: release

[acp-release-bot]

🤖 New release

• agent-client-protocol-derive: 2.2.0 -> 3.0.0
• agent-client-protocol: 2.2.0 -> 3.0.0 (✓ API compatible changes)
• agent-client-protocol-polyfill: 2.2.0 -> 3.0.0 (✓ API compatible changes)
• agent-client-protocol-rmcp: 3.1.1 -> 4.0.0 (✓ API compatible changes)
• agent-client-protocol-trace-viewer: 2.2.0 -> 3.0.0 (✓ API compatible changes)
• agent-client-protocol-conductor: 2.2.0 -> 3.0.0 (✓ API compatible changes)
• agent-client-protocol-http: 2.2.0 -> 3.0.0 (✓ API compatible changes)
• agent-client-protocol-cookbook: 2.2.0 -> 3.0.0 (✓ API compatible changes)

Changelog

agent-client-protocol-derive

2.2.0 - 2026-09-18

Other

• (deps) bump actions-rust-lang/setup-rust-toolchain from 1.17.0 to 2.0.0 (#356)

agent-client-protocol

3.0.0 - 2026-10-02

Added

• (acp) make schemars optional (#373)

Fixed

• (acp) [breaking] preserve connection lifetimes and graceful drain (#385)
• (acp) [breaking] preserve protocol-neutral raw JSON-RPC errors (#384)

Other

• Simplify logs in example (#386)

Changed

• 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.

Added

• 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 a default-enabled schemars feature that forwards JSON Schema support to
  the schema crate and gates the typed MCP tool helpers. Set
  default-features = false to use the core SDK without schemars; custom MCP
  servers and independently enabled unstable protocol features remain available.
  Existing users of default-features = false who need the previous JSON Schema
  or typed MCP tool APIs should add features = ["schemars"].

Fixed

• 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.

agent-client-protocol-polyfill

3.0.0 - 2026-10-02

Fixed

• (acp) [breaking] preserve connection lifetimes and graceful drain (#385)
• (acp) [breaking] preserve protocol-neutral raw JSON-RPC errors (#384)

Fixed

• Preserve raw JSON-RPC error codes, omitted/null data, and error extension
  fields in the MCP HTTP bridge instead of interpreting them as ACP errors.

agent-client-protocol-rmcp

4.0.0 - 2026-10-02

Added

• (rmcp) [breaking] upgrade integration to rmcp 3.4
• (acp) make schemars optional (#373)

Breaking changes

• Upgrade the public rmcp dependency from 2.x to 3.4. This requires the next
  major release of agent-client-protocol-rmcp (4.x), while the core ACP SDK
  remains on 2.x. Services supplied to McpServer::from_rmcp must use rmcp 3.x.
• Adapt tool handlers to rmcp's CallToolResponse, use ServerConfig in place
  of the deprecated ServerInfo alias, and remove legacy tool-execution
  metadata. See the migration guide.

Added

• Integration coverage for MCP 2026-07-28 requests without initialization,
  discovery, per-request metadata/version validation, and MRTR results from
  caller-supplied rmcp services. This dependency upgrade does not replace the
  current unstable MCP-over-ACP wire lifecycle.

agent-client-protocol-trace-viewer

3.0.0 - 2026-10-02

Other

• update Cargo.lock dependencies

agent-client-protocol-conductor

3.0.0 - 2026-10-02

Added

• (deps) bump the minor group with 14 updates (#381)
• (rmcp) [breaking] upgrade integration to rmcp 3.4

Fixed

• (acp) [breaking] preserve connection lifetimes and graceful drain (#385)
• (acp) [breaking] preserve protocol-neutral raw JSON-RPC errors (#384)

Fixed

• Retain raw JSON-RPC error codes, omitted/null data, and error extension
  fields in traced response payloads. Trace method and parameter normalization
  is unchanged.

agent-client-protocol-http

3.0.0 - 2026-10-02

Fixed

• (acp) [breaking] preserve connection lifetimes and graceful drain (#385)
• (acp) [breaking] preserve protocol-neutral raw JSON-RPC errors (#384)

Changed

• Adapt HttpClient's ConnectTo conversion to the core SDK's breaking
  optional ConnectionDriver return type. Channels and HTTP framing remain
  unchanged; no new resource limits are introduced.

Fixed

• Preserve raw JSON-RPC error codes, omitted versus null data, and error
  extension fields across HTTP/SSE and WebSocket transports, using the core
  SDK's new RawJsonRpcResponse representation.
• Preserve HTTP channel pumps when an agent-factory endpoint has no owned
  driver; absence is not agent completion while its transport remains open.
• On active agent completion, reject further output from escaped sender clones
  and drain accepted frames before removing the connection and closing its
  streams, without waiting for those clones to be dropped.
• Keep router cancellation owned while natural cleanup awaits its drain.
  Explicit shutdown no longer detaches a taken router task or retains the
  connection through that orphaned task.

agent-client-protocol-cookbook

3.0.0 - 2026-10-02

Added

• (rmcp) [breaking] upgrade integration to rmcp 3.4

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