spec/v0.6.0 v0.6.0
microsoft/agent-host-protocolJul 20, 2026 → Jul 20, 20260 days between releases
What's New
v0.6.0 is the Swift implementation of the same AHP 0.6.0 spec, adding client-side ping, OAuth client metadata, and terminal command factories.
Breaking Changes
- The `changeset/filesReviewedChanged` event is renamed to `changeset/filesReviewChanged`, with its `fileIds` field renamed to `files`.
- Input requests now travel in a turn's `responseParts`, which changes how input state must be persisted.
- Tool calls can now enter an `AuthRequired` state, so consumers must handle pause/resume rather than assuming terminal completion.
New Features
- `AHPClient.ping()` exposes connection liveness checking directly on the client, complementing the spec's `AHPCommands.ping(id:)`.
- `McpAuthRequirement.oauthClient` carries metadata for pre-registered OAuth clients during MCP tool authentication.
- `AHPCommands.createTerminal` and `disposeTerminal` request factories are provided for terminal lifecycle management.
- `Changeset.capabilities` advertises per-file review support up-front via a `review` presence flag.
- `SystemNotificationResponsePart` gains an optional `_meta` slot following the MCP convention for machine-readable notification descriptors.
Improvements
- Chat turns now carry `startedAt` on start and elapsed `duration` on completion, cancellation, or error.
- Asynchronous tool-call risk assessments return a model-provided explanation and normalized safety score.
- MCP tool calls can pause mid-execution on an OAuth challenge and resume after client authentication.
- `AuthenticateParams` accepts an optional `scopes` field and resources discovered from live auth-required states.
Upgrade Notes
Both artifacts are the same 0.6.0 line, so the delta is implementation surface rather than protocol change; pinning either still requires handling the 0.6.0 renames and the move of input requests into `responseParts`. Update event handlers and any persisted input-state serialization before rolling out, and add handling for the new `AuthRequired` tool-call state so paused calls are not treated as failures. No migration tooling is described in these notes, so validate against a staging host first.
The Two Releases
AHP Spec v0.6.0
Jul 20, 2026· 3 months ago
Defines the protocol specification for AHP 0.6.0, mirroring the Swift package implementation with support for changeset reviews, tool authentication, and notification metadata.
Full release notesAHP Swift Package v0.6.0
Jul 20, 2026· 3 months ago
Implements AHP 0.6.0, introducing changeset review capabilities, asynchronous tool-call risk assessments, and a full OAuth authentication flow for MCP tools.
Full release notes