automation: align catalog state naming

CHANGELOG.md

@@ -23,9 +23,35 @@ changes accumulate. Track in-flight protocol changes via PRs touching
 `NOTIFICATION_INTRODUCED_IN` maps in
 [`types/version/registry.ts`](types/version/registry.ts).
 
-## [1.0.0] — Unreleased
+## [0.9.0] — 2026-08-28
 
-Spec version: `1.0.0`
+Spec version: `0.9.0`
+
+### Added
+
+- Automation catalogue and automation-run channels, including self-contained host-defined event triggers and automation-origin messages, for shared trigger-based agent session workflows.
+- Turn errors are durable response parts, and resumable errors can reopen the same turn through `chat/turnResume`.
+- `InitializeResult._meta` for hosts to advertise implementation-specific extension capabilities in initialize responses.
+
+### Changed
+
+- Annotations now carry an `origin` with a required session URI and optional chat URI and turn ID.
+- Renamed the failed session lifecycle value from `creationFailed` to `failed`.
+- `TerminalSessionClaim` now requires the chat URI that owns the terminal.
+- Terminal state now uses an explicit `running`/`exited` lifecycle that preserves exits without an exit code.
+- Generated clients now preserve unknown values for nonexhaustive protocol enums and their discriminated unions.
+- `SessionToolClientExecutionRequest.toolCall` is narrowed to a running tool-call state.
+- Automation catalogue snapshots now use `AutomationState.entries`, whose items are named `AutomationEntry`.
+
+### Removed
+
+- Removed `error` from `changeset/contentChanged`; changeset failures are represented by `changeset/statusChanged`.
+- Removed session-level forking from `createSession`; use chat forking instead.
+- `ContentNotFound` is no longer an exported AHP error code; `-32006` remains reserved and unassigned.
+
+### Fixed
+
+- Chat reducers now derive `modifiedAt` from turn action data instead of local wall clocks.
 
 ## [0.8.0] — 2026-08-17
 

clients/dotnet/CHANGELOG.md

@@ -477,15 +477,15 @@ this release negotiates.
   receive buffer dropped a frame; the receive loop now grows the buffer after
   copying the previous frame rather than before.
 
-## [0.9.0] — 2026-08-27
+## [0.9.0] — 2026-08-28
 
-Implements AHP 1.0.0.
+Implements AHP 0.9.0.
 
 ### Added
 
 - Automation catalogue and automation-run channels, including self-contained host-defined event triggers and automation-origin messages, for shared trigger-based agent session workflows.
 - Turn errors are durable response parts, and resumable errors can reopen the same turn through `chat/turnResume`.
-- First-party .NET client with generated AHP 1.0 wire types, reducers, JSON-RPC and multi-host clients, and an integrated WebSocket transport targeting `netstandard2.0` and `net8.0`. (#206, #214)
+- First-party .NET client with generated AHP 0.9.0 wire types, reducers, JSON-RPC and multi-host clients, and an integrated WebSocket transport targeting `netstandard2.0` and `net8.0`. (#206, #214)
 - `ClientConfig.TimeProvider` enables deterministic request timeout, keep-alive, reconnect scheduling, and host timestamps.
 - `InitializeResult._meta` for hosts to advertise implementation-specific extension capabilities in initialize responses.
 
@@ -499,6 +499,7 @@ Implements AHP 1.0.0.
 - Generated clients now preserve unknown values for nonexhaustive protocol enums and their discriminated unions.
 - `SessionToolClientExecutionRequest.toolCall` is narrowed to a running tool-call state.
 - The .NET client now ships as the signed `Microsoft.VisualStudioCode.AgentHostProtocol` and `Microsoft.VisualStudioCode.AgentHostProtocol.Abstractions` NuGet packages.
+- Automation catalogue snapshots now use `AutomationState.entries`, whose items are named `AutomationEntry`.
 
 ### Removed
 

clients/dotnet/release-metadata.json

@@ -2,7 +2,7 @@
   "client": "dotnet",
   "packageVersion": "0.9.0",
   "supportedProtocolVersions": [
-    "1.0.0",
+    "0.9.0",
     "0.8.0",
     "0.7.0",
     "0.6.0",

clients/dotnet/src/AgentHostProtocol.Abstractions/Generated/Actions.generated.cs

@@ -2367,10 +2367,10 @@ public sealed record AutomationCreateRequestedAction
 {
     public ActionType Type { get; init; }
 
-    /// <summary>Client-chosen `ahp-automation:` URI that becomes {@link AutomationState.resource}.</summary>
+    /// <summary>Client-chosen `ahp-automation:` URI that becomes {@link AutomationEntry.resource}.</summary>
     public required string Resource { get; init; }
 
-    /// <summary>Complete initial {@link AutomationState.definition}.</summary>
+    /// <summary>Complete initial {@link AutomationEntry.definition}.</summary>
     public required AutomationDefinition Definition { get; init; }
 }
 
@@ -2391,27 +2391,27 @@ public sealed record AutomationUpdateRequestedAction
 {
     public ActionType Type { get; init; }
 
-    /// <summary>Target {@link AutomationState.resource}.</summary>
+    /// <summary>Target {@link AutomationEntry.resource}.</summary>
     public required string Resource { get; init; }
 
     /// <summary>Editable {@link AutomationDefinition} fields to replace.</summary>
     public required AutomationDefinitionPatch Changes { get; init; }
 }
 
 /// <summary>Add or replace one full automation state in
-/// {@link AutomationCatalogState.automations}.
+/// {@link AutomationState.entries}.
 ///
-/// Existing entries are matched by {@link AutomationState.resource} and
+/// Existing entries are matched by {@link AutomationEntry.resource} and
 /// replaced in place. A previously unseen resource is appended.</summary>
 public sealed record AutomationSetAction
 {
     public ActionType Type { get; init; }
 
     /// <summary>Full new or replacement automation state.</summary>
-    public required AutomationState Automation { get; init; }
+    public required AutomationEntry Automation { get; init; }
 }
 
-/// <summary>Remove one automation from {@link AutomationCatalogState.automations}.
+/// <summary>Remove one automation from {@link AutomationState.entries}.
 ///
 /// Clients may dispatch this action only while the target advertises
 /// {@link AutomationOperation.Remove}. The host revalidates that operation
@@ -2423,7 +2423,7 @@ public sealed record AutomationRemovedAction
 {
     public ActionType Type { get; init; }
 
-    /// <summary>{@link AutomationState.resource} to remove.</summary>
+    /// <summary>{@link AutomationEntry.resource} to remove.</summary>
     public required string Resource { get; init; }
 }
 

clients/dotnet/src/AgentHostProtocol.Abstractions/Generated/Commands.generated.cs

@@ -214,7 +214,7 @@ public sealed record InitializeResult
     public TelemetryCapabilities? Telemetry { get; init; }
 
     /// <summary>Host-owned automation support. Presence means clients may subscribe to
-    /// `ahp-automations://` for {@link AutomationCatalogState}; absence means the
+    /// `ahp-automations://` for {@link AutomationState}; absence means the
     /// host does not expose an automation catalogue or automation commands.</summary>
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
     public AutomationCapabilities? Automations { get; init; }
@@ -278,7 +278,7 @@ public sealed record ClientCapabilities
 /// restrictions.
 ///
 /// Capabilities describe implementation support.
-/// {@link AutomationState.operations} remains authoritative for which
+/// {@link AutomationEntry.operations} remains authoritative for which
 /// definition mutations are currently allowed on a particular automation.</summary>
 public sealed record AutomationCapabilities
 {
@@ -295,7 +295,7 @@ public sealed record AutomationCapabilities
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
     public AutomationRunCancellationCapability? RunCancellation { get; init; }
 
-    /// <summary>Maximum terminal entries retained in {@link AutomationState.runs}. Active
+    /// <summary>Maximum terminal entries retained in {@link AutomationEntry.runs}. Active
     /// runs are not counted toward the limit. Absence means the retention limit is
     /// implementation-defined.</summary>
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
@@ -1612,7 +1612,7 @@ public sealed record RunAutomationParams
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
     public Dictionary<string, JsonElement>? Meta { get; init; }
 
-    /// <summary>Target {@link AutomationState.resource}.</summary>
+    /// <summary>Target {@link AutomationEntry.resource}.</summary>
     public required string Automation { get; init; }
 
     /// <summary>Durable client-generated idempotency key. Retrying with the same key and
@@ -1645,10 +1645,10 @@ public sealed record FetchAutomationRunsParams
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
     public Dictionary<string, JsonElement>? Meta { get; init; }
 
-    /// <summary>Target {@link AutomationState.resource}.</summary>
+    /// <summary>Target {@link AutomationEntry.resource}.</summary>
     public required string Automation { get; init; }
 
-    /// <summary>Cursor previously received as {@link AutomationState.runsNextCursor}.
+    /// <summary>Cursor previously received as {@link AutomationEntry.runsNextCursor}.
     /// Omit to request the first page not already included by the snapshot.</summary>
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
     public string? Cursor { get; init; }

clients/dotnet/src/AgentHostProtocol.Abstractions/Generated/JsonSerializerContext.generated.cs

@@ -33,12 +33,12 @@ namespace Microsoft.AgentHostProtocol;
 [JsonSerializable(typeof(AuthRequiredReason))]
 [JsonSerializable(typeof(AutomationCancelledRunLifecycle))]
 [JsonSerializable(typeof(AutomationCapabilities))]
-[JsonSerializable(typeof(AutomationCatalogState))]
 [JsonSerializable(typeof(AutomationCompletedRunLifecycle))]
 [JsonSerializable(typeof(AutomationCreateCapability))]
 [JsonSerializable(typeof(AutomationCreateRequestedAction))]
 [JsonSerializable(typeof(AutomationDefinition))]
 [JsonSerializable(typeof(AutomationDefinitionPatch))]
+[JsonSerializable(typeof(AutomationEntry))]
 [JsonSerializable(typeof(AutomationEventTrigger))]
 [JsonSerializable(typeof(AutomationFailedRunLifecycle))]
 [JsonSerializable(typeof(AutomationManualRunOrigin))]

clients/dotnet/src/AgentHostProtocol.Abstractions/Generated/State.generated.cs

@@ -584,7 +584,7 @@ public enum ResourceChangeType
 
 /// <summary>Operations the host currently permits for an automation.
 ///
-/// The list on {@link AutomationState.operations} is authoritative and may
+/// The list on {@link AutomationEntry.operations} is authoritative and may
 /// change over time. Clients MUST NOT infer permission from capabilities alone:
 /// capabilities describe what the host implementation can support, while
 /// operations describe what is allowed for this particular automation now.</summary>
@@ -4964,7 +4964,7 @@ public sealed record AutomationSessionOrigin
 {
     public SessionOriginKind Kind { get; init; }
 
-    /// <summary>Owning {@link AutomationState.resource}.</summary>
+    /// <summary>Owning {@link AutomationEntry.resource}.</summary>
     public required string Automation { get; init; }
 
     /// <summary>Owning {@link AutomationRunState.resource}.</summary>
@@ -5155,7 +5155,7 @@ public sealed record AutomationSessionTemplate
 /// A definition combines the initial automation message, the session template
 /// used for each run, and zero or more automatic triggers. Run history,
 /// timestamps, and currently allowed operations live on
-/// {@link AutomationState} rather than in the definition.</summary>
+/// {@link AutomationEntry} rather than in the definition.</summary>
 public sealed record AutomationDefinition
 {
     /// <summary>Human-readable automation name.</summary>
@@ -5216,13 +5216,12 @@ public sealed record AutomationDefinitionPatch
     public Dictionary<string, JsonElement>? Meta { get; init; }
 }
 
-/// <summary>Authoritative state of one automation in the
-/// {@link AutomationCatalogState.automations} catalogue.
+/// <summary>Authoritative state of one automation in {@link AutomationState.entries}.
 ///
 /// The host owns trigger evaluation, run claims, run retention, and operation
 /// availability. Clients render this state and submit actions or commands; they
 /// never run a fallback scheduler for a host-owned definition.</summary>
-public sealed class AutomationState
+public sealed class AutomationEntry
 {
     /// <summary>Stable `ahp-automation:/&lt;id&gt;` resource identifier.</summary>
     public required string Resource { get; set; }
@@ -5236,7 +5235,7 @@ public sealed class AutomationState
 
     /// <summary>Newest-first retained run summaries. This is a bounded window; use
     /// {@link FetchAutomationRunsParams | fetchAutomationRuns} when
-    /// {@link AutomationState.runsNextCursor} is present.</summary>
+    /// {@link AutomationEntry.runsNextCursor} is present.</summary>
     public required List<AutomationRunSummary> Runs { get; set; }
 
     /// <summary>Opaque cursor passed as {@link FetchAutomationRunsParams.cursor} for the next older run-history page.</summary>
@@ -5265,10 +5264,10 @@ public sealed class AutomationState
 /// Subsequent {@link AutomationSetAction | `automation/set`} and
 /// {@link AutomationRemovedAction | `automation/removed`} actions keep the
 /// catalogue synchronized and participate in normal reconnect replay.</summary>
-public sealed class AutomationCatalogState
+public sealed class AutomationState
 {
-    /// <summary>Full automation states keyed by {@link AutomationState.resource}.</summary>
-    public required List<AutomationState> Automations { get; set; }
+    /// <summary>Full automation entries keyed by {@link AutomationEntry.resource}.</summary>
+    public required List<AutomationEntry> Entries { get; set; }
 
     /// <summary>Opaque host-defined catalogue metadata.</summary>
     [JsonPropertyName("_meta")]
@@ -5434,7 +5433,7 @@ public sealed class AutomationRunState
     /// <summary>URI of this automation-run channel.</summary>
     public required string Resource { get; set; }
 
-    /// <summary>Owning `ahp-automation:` URI matching {@link AutomationState.resource}.</summary>
+    /// <summary>Owning `ahp-automation:` URI matching {@link AutomationEntry.resource}.</summary>
     public required string Automation { get; set; }
 
     /// <summary>Immutable provenance describing how this run was created.</summary>
@@ -6283,7 +6282,7 @@ public sealed class SnapshotState
     public AnnotationsState? Annotations { get; set; }
 
     /// <summary>Automation catalogue state variant, when populated.</summary>
-    public AutomationCatalogState? Automations { get; set; }
+    public AutomationState? Automations { get; set; }
 
     /// <summary>Automation run state variant, when populated.</summary>
     public AutomationRunState? AutomationRun { get; set; }
@@ -6303,9 +6302,9 @@ public override SnapshotState Read(ref Utf8JsonReader reader, Type typeToConvert
         {
             result.AutomationRun = root.Deserialize(AhpJsonTypeInfo.Get<AutomationRunState>(options));
         }
-        else if (root.TryGetProperty("automations", out _))
+        else if (root.TryGetProperty("entries", out _))
         {
-            result.Automations = root.Deserialize(AhpJsonTypeInfo.Get<AutomationCatalogState>(options));
+            result.Automations = root.Deserialize(AhpJsonTypeInfo.Get<AutomationState>(options));
         }
         else if (root.TryGetProperty("turns", out _))
         {
@@ -6344,7 +6343,7 @@ public override SnapshotState Read(ref Utf8JsonReader reader, Type typeToConvert
     public override void Write(Utf8JsonWriter writer, SnapshotState value, JsonSerializerOptions options)
     {
         if (value.AutomationRun is not null) { JsonSerializer.Serialize(writer, value.AutomationRun, AhpJsonTypeInfo.Get<AutomationRunState>(options)); return; }
-        if (value.Automations is not null) { JsonSerializer.Serialize(writer, value.Automations, AhpJsonTypeInfo.Get<AutomationCatalogState>(options)); return; }
+        if (value.Automations is not null) { JsonSerializer.Serialize(writer, value.Automations, AhpJsonTypeInfo.Get<AutomationState>(options)); return; }
         if (value.Chat is not null) { JsonSerializer.Serialize(writer, value.Chat, AhpJsonTypeInfo.Get<ChatState>(options)); return; }
         if (value.Session is not null) { JsonSerializer.Serialize(writer, value.Session, AhpJsonTypeInfo.Get<SessionState>(options)); return; }
         if (value.Terminal is not null) { JsonSerializer.Serialize(writer, value.Terminal, AhpJsonTypeInfo.Get<TerminalState>(options)); return; }

clients/dotnet/src/AgentHostProtocol.Abstractions/Generated/Version.generated.cs

@@ -14,11 +14,11 @@ public static class ProtocolVersion
     /// The current protocol version (SemVer MAJOR.MINOR.PATCH) this
     /// generated source speaks.
     /// </summary>
-    public const string Current = "1.0.0";
+    public const string Current = "0.9.0";
 
     private static readonly string[] s_supported =
     {
-        "1.0.0",
+        "0.9.0",
         "0.8.0",
         "0.7.0",
         "0.6.0",

clients/dotnet/src/AgentHostProtocol/Reducers.cs

@@ -2350,7 +2350,7 @@ public static ReduceOutcome ApplyToAnnotations(AnnotationsState state, StateActi
 
     /// <summary>Applies an action to the automation catalogue in place.</summary>
     public static ReduceOutcome ApplyToAutomation(
-        AutomationCatalogState state,
+        AutomationState state,
         StateAction action)
     {
         Guard.ThrowIfNull(state, nameof(state));
@@ -2363,29 +2363,29 @@ public static ReduceOutcome ApplyToAutomation(
                 return ReduceOutcome.NoOp;
             case AutomationSetAction set:
                 {
-                    int index = state.Automations.FindIndex(
+                    int index = state.Entries.FindIndex(
                         automation => automation.Resource == set.Automation.Resource);
                     if (index < 0)
                     {
-                        state.Automations.Add(set.Automation);
+                        state.Entries.Add(set.Automation);
                     }
                     else
                     {
-                        state.Automations[index] = set.Automation;
+                        state.Entries[index] = set.Automation;
                     }
 
                     return ReduceOutcome.Applied;
                 }
             case AutomationRemovedAction removed:
                 {
-                    int index = state.Automations.FindIndex(
+                    int index = state.Entries.FindIndex(
                         automation => automation.Resource == removed.Resource);
                     if (index < 0)
                     {
                         return ReduceOutcome.NoOp;
                     }
 
-                    state.Automations.RemoveAt(index);
+                    state.Entries.RemoveAt(index);
                     return ReduceOutcome.Applied;
                 }
             default:

clients/dotnet/tests/AgentHostProtocol.Tests/FixtureDrivenReducerTests.cs

@@ -79,7 +79,7 @@ public void ReducerMatchesFixture(string name, string path)
                     RunFixture<ChatState>(initial, expected, actions, Reducers.ApplyToChat);
                     break;
                 case "automation":
-                    RunFixture<AutomationCatalogState>(
+                    RunFixture<AutomationState>(
                         initial,
                         expected,
                         actions,

clients/go/CHANGELOG.md

@@ -14,9 +14,9 @@ tag whose matching `## [X.Y.Z]` heading is missing from this file.
 
 ## [Unreleased]
 
-## [0.9.0] — 2026-08-27
+## [0.9.0] — 2026-08-28
 
-Implements AHP 1.0.0.
+Implements AHP 0.9.0.
 
 ### Added
 
@@ -32,6 +32,7 @@ Implements AHP 1.0.0.
 - Terminal state now uses an explicit `running`/`exited` lifecycle that preserves exits without an exit code.
 - Generated clients now preserve unknown values for nonexhaustive protocol enums and their discriminated unions.
 - `SessionToolClientExecutionRequest.toolCall` is narrowed to a running tool-call state.
+- Automation catalogue snapshots now use `AutomationState.entries`, whose items are named `AutomationEntry`.
 
 ### Removed