--- url: 'https://adk.nht.io/api/@nhtio/adk/types/interfaces/DispatchContext.md' description: Context object for a single LLM execution call. --- # Interface: DispatchContext Defined in: [lib/contracts/dispatch\_context.ts:326](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L326) Context object for a single LLM execution call. ## Remarks Mirrors the surface of [@nhtio/adk!TurnContext](TurnContext.md) but is path-agnostic — it knows nothing about a parent context. Mutations apply to local Sets immediately, call persistence callbacks immediately, and fire the corresponding mutation hook (`storedMemory`, `mutatedMemory`, `deletedMemory`, etc.) in both standalone and derived dispatches. The [@nhtio/adk!DispatchRunner](../../dispatch_runner/classes/DispatchRunner.md) is the only thing that creates a context with a parent relationship: when dispatched with a `source: TurnContext`, the runner subscribes to the mutation hooks, queues deltas internally, and flushes them to the parent's Sets at the end of each iteration. The context itself remains unaware of the parent. Middleware/executor signals termination via [DispatchContext.ack](#ack) (clean completion) or [DispatchContext.nack](#nack) (failure). Both set an internal flag the runner reads at end-of-iteration to decide whether to loop or exit. [DispatchContext.isSignalled](#property-issignalled), [DispatchContext.isAcked](#property-isacked), and [DispatchContext.nackError](#property-nackerror) are publicly readable getters so middleware can inspect signal state and bail early. ## Properties | Property | Modifier | Type | Description | Defined in | | ------------------------------------------------------------------------------- | ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------- | | `abort` | `readonly` | (`reason?`: `unknown`) => `void` | Aborts the dispatch's `AbortController` with the supplied reason. Middleware should call this when refusing to proceed — the runner short-circuits cleanly, `dispatchEnd.status` resolves to `'aborted'`, and no `error` event is emitted. | [lib/contracts/dispatch\_context.ts:1067](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1067) | | `aborted` | `readonly` | `boolean` | `true` when the abort controller signal has fired. | [lib/contracts/dispatch\_context.ts:1059](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1059) | | `abortSignal` | `readonly` | `AbortSignal` | The `AbortSignal` from the execution's `AbortController`. | [lib/contracts/dispatch\_context.ts:1061](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1061) | | `deleteMemory` | `readonly` | (`id`: `string`) => `Promise`<`void`> | Removes a memory from the local Set and persistence layer by ID. | [lib/contracts/dispatch\_context.ts:1119](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1119) | | `deleteMessage` | `readonly` | (`id`: `string`) => `Promise`<`void`> | Removes a message from the local Set and persistence layer by ID. | [lib/contracts/dispatch\_context.ts:1131](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1131) | | `deleteRetrievable` | `readonly` | (`id`: `string`) => `Promise`<`void`> | Removes a retrievable record from the local Set and persistence layer by ID. | [lib/contracts/dispatch\_context.ts:1125](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1125) | | `deleteStandingInstruction` | `readonly` | (`v`: `string` | [`Tokenizable`](../../common/classes/Tokenizable.md)) => `Promise`<`void`> | Removes a standing instruction from the local Set and persistence layer. | [lib/contracts/dispatch\_context.ts:1113](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1113) | | `deleteThought` | `readonly` | (`id`: `string`) => `Promise`<`void`> | Removes a thought from the local Set and persistence layer by ID. | [lib/contracts/dispatch\_context.ts:1137](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1137) | | `deleteToolCall` | `readonly` | (`id`: `string`) => `Promise`<`void`> | Removes a tool call from the local Set and persistence layer by ID. | [lib/contracts/dispatch\_context.ts:1143](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1143) | | `dispatchId` | `readonly` | `string` | Stable identifier for the dispatch this context belongs to; set by `DispatchRunner`. | [lib/contracts/dispatch\_context.ts:1055](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1055) | | `emitMessage` | `readonly` | [`EmitMessageFn`](../../turn_runner/type-aliases/EmitMessageFn.md) | Emits a `message` hook; fires registered handlers synchronously. | [lib/contracts/dispatch\_context.ts:1173](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1173) | | `emitThought` | `readonly` | [`EmitThoughtFn`](../../turn_runner/type-aliases/EmitThoughtFn.md) | Emits a `thought` hook; fires registered handlers synchronously. | [lib/contracts/dispatch\_context.ts:1175](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1175) | | `emitToolCall` | `readonly` | [`EmitToolCallFn`](../../turn_runner/type-aliases/EmitToolCallFn.md) | Emits a `toolCall` hook; fires registered handlers synchronously. | [lib/contracts/dispatch\_context.ts:1177](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1177) | | `emitToolExecutionEnd` | `readonly` | [`EmitToolExecutionEndFn`](../../turn_runner/type-aliases/EmitToolExecutionEndFn.md) | Emits a `toolExecutionEnd` hook; fires registered handlers synchronously. | [lib/contracts/dispatch\_context.ts:1181](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1181) | | `emitToolExecutionStart` | `readonly` | [`EmitToolExecutionStartFn`](../../turn_runner/type-aliases/EmitToolExecutionStartFn.md) | Emits a `toolExecutionStart` hook; fires registered handlers synchronously. | [lib/contracts/dispatch\_context.ts:1179](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1179) | | `fetchMemories` | `readonly` | () => | [`Memory`](../../common/classes/Memory.md)\[] | `Promise`<[`Memory`](../../common/classes/Memory.md)\[]> | Fetches memories; delegates to the callback supplied at construction. | [lib/contracts/dispatch\_context.ts:1093](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1093) | | `fetchMessages` | `readonly` | () => | [`Message`](../../common/classes/Message.md)\[] | `Promise`<[`Message`](../../common/classes/Message.md)\[]> | Fetches messages; delegates to the callback supplied at construction. | [lib/contracts/dispatch\_context.ts:1097](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1097) | | `fetchRetrievables` | `readonly` | () => | [`Retrievable`](../../common/classes/Retrievable.md)\[] | `Promise`<[`Retrievable`](../../common/classes/Retrievable.md)\[]> | Fetches retrievable records; delegates to the callback supplied at construction. | [lib/contracts/dispatch\_context.ts:1095](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1095) | | `fetchThoughts` | `readonly` | () => | [`Thought`](../../common/classes/Thought.md)\[] | `Promise`<[`Thought`](../../common/classes/Thought.md)\[]> | Fetches thoughts; delegates to the callback supplied at construction. | [lib/contracts/dispatch\_context.ts:1099](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1099) | | `fetchToolCalls` | `readonly` | () => | [`ToolCall`](../../forge/classes/ToolCall.md)\[] | `Promise`<[`ToolCall`](../../forge/classes/ToolCall.md)\[]> | Fetches tool calls; delegates to the callback supplied at construction. | [lib/contracts/dispatch\_context.ts:1101](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1101) | | `fetchTools` | `readonly` | () => | [`Tool`](../../forge/classes/Tool.md)<[`SpooledArtifact`](../../spooled_artifact/classes/SpooledArtifact.md)>\[] | `Promise`<[`Tool`](../../forge/classes/Tool.md)<[`SpooledArtifact`](../../spooled_artifact/classes/SpooledArtifact.md)>\[]> | Fetches tools; delegates to the callback supplied at construction. | [lib/contracts/dispatch\_context.ts:1103](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1103) | | `id` | `readonly` | `string` | Unique identifier for this execution context, generated as UUIDv6 at construction time. | [lib/contracts/dispatch\_context.ts:1053](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1053) | | `isAcked` | `readonly` | `boolean` | `true` when the context was signalled via [DispatchContext.ack](#ack). | [lib/contracts/dispatch\_context.ts:1071](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1071) | | `isSignalled` | `readonly` | `boolean` | `true` once [DispatchContext.ack](#ack) or [DispatchContext.nack](#nack) has been called. | [lib/contracts/dispatch\_context.ts:1069](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1069) | | `iteration` | `readonly` | `number` | 0-based iteration count within the current dispatch; updated by `DispatchRunner`. | [lib/contracts/dispatch\_context.ts:1057](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1057) | | `mutateMemory` | `readonly` | (`v`: [`Memory`](../../common/classes/Memory.md)) => `Promise`<`void`> | Updates an existing memory in the local Set and persistence layer. | [lib/contracts/dispatch\_context.ts:1117](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1117) | | `mutateMessage` | `readonly` | (`v`: [`Message`](../../common/classes/Message.md)) => `Promise`<`void`> | Updates an existing message in the local Set and persistence layer. | [lib/contracts/dispatch\_context.ts:1129](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1129) | | `mutateRetrievable` | `readonly` | (`v`: [`Retrievable`](../../common/classes/Retrievable.md)) => `Promise`<`void`> | Updates an existing retrievable record in the local Set and persistence layer. | [lib/contracts/dispatch\_context.ts:1123](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1123) | | `mutateStandingInstruction` | `readonly` | (`v`: `string` | [`Tokenizable`](../../common/classes/Tokenizable.md)) => `Promise`<`void`> | Updates an existing standing instruction in the local Set and persistence layer. | [lib/contracts/dispatch\_context.ts:1111](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1111) | | `mutateThought` | `readonly` | (`v`: [`Thought`](../../common/classes/Thought.md)) => `Promise`<`void`> | Updates an existing thought in the local Set and persistence layer. | [lib/contracts/dispatch\_context.ts:1135](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1135) | | `mutateToolCall` | `readonly` | (`v`: [`ToolCall`](../../forge/classes/ToolCall.md)) => `Promise`<`void`> | Updates an existing tool call in the local Set and persistence layer. | [lib/contracts/dispatch\_context.ts:1141](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1141) | | `nackError` | `readonly` | `Error` | `undefined` | The error stored by [DispatchContext.nack](#nack), or `undefined` if not nacked. | [lib/contracts/dispatch\_context.ts:1073](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1073) | | `refreshStandingInstructions` | `readonly` | () => | (`string` | [`Tokenizable`](../../common/classes/Tokenizable.md))\[] | `Promise`<(`string` | [`Tokenizable`](../../common/classes/Tokenizable.md))\[]> | Refreshes and returns standing instructions. | [lib/contracts/dispatch\_context.ts:1105](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1105) | | `standingInstructions` | `readonly` | `Set`<[`Tokenizable`](../../common/classes/Tokenizable.md)> | Standing instructions for this execution, in insertion order. | [lib/contracts/dispatch\_context.ts:1079](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1079) | | `stash` | `readonly` | [`Registry`](../../common/classes/Registry.md) | Arbitrary key-value store for cross-step state. | [lib/contracts/dispatch\_context.ts:1075](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1075) | | `storeMediaBytes` | `readonly` | (`id`: `string`, `bytes`: [`ConduitBytes`](../type-aliases/ConduitBytes.md)) => | [`MediaReader`](../../common/interfaces/MediaReader.md) | `Promise`<[`MediaReader`](../../common/interfaces/MediaReader.md)> | Persists tool-generated media bytes into consumer storage and returns a [@nhtio/adk!MediaReader](../../common/interfaces/MediaReader.md). **Remarks** This is a low-level persistence conduit, NOT a mutation: it does not add to `turnMessages`/ `turnToolCalls` or fire a `stored*` hook. The handler builds a [@nhtio/adk!Media](../../common/classes/Media.md) from the returned reader (`Media.toolGenerated({ reader })`) and stores the owning primitive — a [@nhtio/adk!Message](../../common/classes/Message.md) attachment or [@nhtio/adk!ToolCall](../../forge/classes/ToolCall.md) result — via the relevant `store*` method separately. Persisting bytes without storing the primitive means the framework never sees the media. | [lib/contracts/dispatch\_context.ts:1155](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1155) | | `storeMemory` | `readonly` | (`v`: [`Memory`](../../common/classes/Memory.md)) => `Promise`<`void`> | Stores a new memory in the local Set and persistence layer. | [lib/contracts/dispatch\_context.ts:1115](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1115) | | `storeMessage` | `readonly` | (`v`: [`Message`](../../common/classes/Message.md)) => `Promise`<`void`> | Stores a new message in the local Set and persistence layer. | [lib/contracts/dispatch\_context.ts:1127](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1127) | | `storeRetrievable` | `readonly` | (`v`: [`Retrievable`](../../common/classes/Retrievable.md)) => `Promise`<`void`> | Stores a new retrievable record in the local Set and persistence layer. | [lib/contracts/dispatch\_context.ts:1121](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1121) | | `storeRetrievableBytes` | `readonly` | (`id`: `string`, `bytes`: [`ConduitBytes`](../type-aliases/ConduitBytes.md)) => | [`SpoolReader`](../../spooled_artifact/interfaces/SpoolReader.md) | `Promise`<[`SpoolReader`](../../spooled_artifact/interfaces/SpoolReader.md)> | Persists extracted retrievable text bytes into consumer storage and returns a [@nhtio/adk!SpoolReader](../../spooled_artifact/interfaces/SpoolReader.md). **Remarks** Low-level persistence conduit, same posture as [DispatchContext.storeMediaBytes](#property-storemediabytes): returns a value, touches no Sets, fires no hook. Wrap the reader in a [@nhtio/adk!SpooledArtifact](../../spooled_artifact/classes/SpooledArtifact.md) and pass it as `Retrievable.content`, then persist the record via [DispatchContext.storeRetrievable](#property-storeretrievable). | [lib/contracts/dispatch\_context.ts:1168](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1168) | | `storeStandingInstruction` | `readonly` | (`v`: `string` | [`Tokenizable`](../../common/classes/Tokenizable.md)) => `Promise`<`void`> | Stores a new standing instruction in the local Set and persistence layer. | [lib/contracts/dispatch\_context.ts:1109](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1109) | | `storeThought` | `readonly` | (`v`: [`Thought`](../../common/classes/Thought.md)) => `Promise`<`void`> | Stores a new thought in the local Set and persistence layer. | [lib/contracts/dispatch\_context.ts:1133](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1133) | | `storeToolCall` | `readonly` | (`v`: [`ToolCall`](../../forge/classes/ToolCall.md)) => `Promise`<`void`> | Stores a new tool call in the local Set and persistence layer. | [lib/contracts/dispatch\_context.ts:1139](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1139) | | `systemPrompt` | `readonly` | [`Tokenizable`](../../common/classes/Tokenizable.md) | The system prompt for this execution. | [lib/contracts/dispatch\_context.ts:1077](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1077) | | `tools` | `readonly` | [`ToolRegistry`](../../forge/classes/ToolRegistry.md) | Tool registry for this execution. | [lib/contracts/dispatch\_context.ts:1091](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1091) | | `turnMemories` | `readonly` | `Set`<[`Memory`](../../common/classes/Memory.md)> | Memories loaded for this execution. | [lib/contracts/dispatch\_context.ts:1081](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1081) | | `turnMessages` | `readonly` | `Set`<[`Message`](../../common/classes/Message.md)> | Messages loaded for this execution. | [lib/contracts/dispatch\_context.ts:1085](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1085) | | `turnRetrievables` | `readonly` | `Set`<[`Retrievable`](../../common/classes/Retrievable.md)> | Retrievable records loaded for this execution. | [lib/contracts/dispatch\_context.ts:1083](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1083) | | `turnThoughts` | `readonly` | `Set`<[`Thought`](../../common/classes/Thought.md)> | Thoughts loaded for this execution. | [lib/contracts/dispatch\_context.ts:1087](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1087) | | `turnToolCalls` | `readonly` | `Set`<[`ToolCall`](../../forge/classes/ToolCall.md)> | Tool calls loaded for this execution. | [lib/contracts/dispatch\_context.ts:1089](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1089) | | `waitFor` | `readonly` | [`OpenGateFn`](../../turn_runner/type-aliases/OpenGateFn.md) | Opens a gate and suspends until it resolves, rejects, times out, or is aborted. | [lib/contracts/dispatch\_context.ts:1183](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1183) | ## Methods ### \_getHooks() ```ts _getHooks(): Hooks; ``` Defined in: [lib/contracts/dispatch\_context.ts:938](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L938) **`Internal`** Accessor used by [@nhtio/adk!DispatchRunner](../../dispatch_runner/classes/DispatchRunner.md) to register forwarding handlers. #### Returns `Hooks`<[`DispatchContextHooks`](../type-aliases/DispatchContextHooks.md)> *** ### \_setDispatchId() ```ts _setDispatchId(id: string): void; ``` Defined in: [lib/contracts/dispatch\_context.ts:928](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L928) **`Internal`** Set by [@nhtio/adk!DispatchRunner](../../dispatch_runner/classes/DispatchRunner.md) after construction. #### Parameters | Parameter | Type | | --------- | -------- | | `id` | `string` | #### Returns `void` *** ### \_setIteration() ```ts _setIteration(n: number): void; ``` Defined in: [lib/contracts/dispatch\_context.ts:933](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L933) **`Internal`** Updated by [@nhtio/adk!DispatchRunner](../../dispatch_runner/classes/DispatchRunner.md) on each iteration. #### Parameters | Parameter | Type | | --------- | -------- | | `n` | `number` | #### Returns `void` *** ### ack() ```ts ack(): void; ``` Defined in: [lib/contracts/dispatch\_context.ts:969](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L969) Signals successful completion of this execution. #### Returns `void` #### Remarks Sets the context's internal signal flag. The [@nhtio/adk!DispatchRunner](../../dispatch_runner/classes/DispatchRunner.md) reads the flag at the end of each iteration to decide whether to loop or exit. Calling `ack()` does NOT abort the current iteration — the current pipeline and flush complete first. #### Throws [@nhtio/adk!E\_LLM\_EXECUTION\_ALREADY\_SIGNALLED](../../exceptions/variables/E_LLM_EXECUTION_ALREADY_SIGNALLED.md) when the context has already been signalled (whether via `ack()` or `nack()`). *** ### nack() ```ts nack(error?: Error): void; ``` Defined in: [lib/contracts/dispatch\_context.ts:1027](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1027) Signals failed completion of this execution, optionally with an error. #### Parameters | Parameter | Type | Description | | --------- | ------- | --------------------------------------------------------------------------- | | `error?` | `Error` | Optional error describing the failure. If omitted, a generic Error is used. | #### Returns `void` #### Remarks Sets the context's internal signal flag and stores the error. The [@nhtio/adk!DispatchRunner](../../dispatch_runner/classes/DispatchRunner.md) reads the flag at the end of each iteration and surfaces the error via the `dispatchEnd` observability payload and as the rejection reason of `dispatch()`. Calling `nack()` does NOT abort the current iteration — the current pipeline and flush complete first. #### Throws [@nhtio/adk!E\_LLM\_EXECUTION\_ALREADY\_SIGNALLED](../../exceptions/variables/E_LLM_EXECUTION_ALREADY_SIGNALLED.md) when the context has already been signalled. *** ### onAck() ```ts onAck(handler: () => void): () => void; ``` Defined in: [lib/contracts/dispatch\_context.ts:1008](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L1008) Registers a handler to run when this context completes successfully via [ack](#ack). #### Parameters | Parameter | Type | Description | | --------- | ------------ | ---------------------------------------- | | `handler` | () => `void` | Callback invoked when `ack()` is called. | #### Returns An unsubscribe function that removes the handler. () => `void` #### Remarks The handler does NOT fire on [nack](#nack) — failed executor runs should leave any ack-tied subscriptions alone so the consumer can inspect what was registered when debugging the failure. Returns an unsubscribe function; subscriptions are short-lived and die with the context regardless. The canonical consumer is `ToolRegistry.bindContext(ctx)`, which uses this hook to drop ephemeral tools (notably forged artifact-query tools from `SpooledArtifact.forgeTools(ctx)`) at ctx-completion. Consumers may also register custom handlers here for any per-executor cleanup. #### See * [@nhtio/adk!ToolRegistry.bindContext](../../forge/classes/ToolRegistry.md#bindcontext) * [@nhtio/adk!SpooledArtifact.forgeTools](../../spooled_artifact/classes/SpooledArtifact.md#forgetools) *** ### toolCallCount() ```ts toolCallCount(checksum: string): number; ``` Defined in: [lib/contracts/dispatch\_context.ts:954](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/contracts/dispatch_context.ts#L954) Returns how many times a tool call with the given checksum has been stored in this execution. #### Parameters | Parameter | Type | Description | | ---------- | -------- | ----------------------------------------- | | `checksum` | `string` | The `ToolCall.checksum` value to look up. | #### Returns `number` #### Remarks Checksums are computed over `tool + args` (see [@nhtio/adk!ToolCall.checksum](../../forge/classes/ToolCall.md#property-checksum)). This count lets the executor detect repeat invocations of the same call without scanning the full Set. Returns `0` when the checksum has not been seen.