Context Types

Type definitions for Context, ItemLog, Item variants, and content parts in Noetic.

Context

The execution context threaded through every step.

interface Context<TState = unknown> {
  readonly id: string;
  readonly stepCount: number;
  readonly tokens: TokenUsage;
  readonly elapsed: number;
  readonly cost: number;
  state: TState;
  readonly parent: Context | null;
  readonly depth: number;
  readonly span: Span;
  readonly threadId: string;
  readonly resourceId?: string;
  readonly itemLog: ItemLog;
  readonly lastStepMeta: StepMeta | null;
  recv<T>(channel: Channel<T>, opts?: { timeout?: number }): Promise<T>;
  send<T>(channel: Channel<T>, value: T): void;
  tryRecv<T>(channel: Channel<T>): T | null;
  checkpoint(): Promise<void>;
  complete<T>(value: T): void;
  readonly completed: boolean;
  readonly completionValue: unknown;
  readonly aborted: boolean;
  readonly abortReason?: string;
  abort(reason?: string): void;
}

Field	Type	Description
`id`	`string`	Unique execution identifier
`stepCount`	`number`	Number of steps executed so far
`tokens`	`TokenUsage`	Accumulated token usage
`elapsed`	`number`	Elapsed time in milliseconds
`cost`	`number`	Accumulated cost in USD
`state`	`TState`	Mutable user state
`parent`	`Context \| null`	Parent context (for spawned agents)
`depth`	`number`	Nesting depth (0 for root)
`span`	`Span`	Observability span
`threadId`	`string`	Thread identifier for memory scoping
`resourceId`	`string`	Resource identifier for memory scoping (optional)
`itemLog`	`ItemLog`	Conversation history
`lastStepMeta`	`StepMeta \| null`	Metadata from the last executed step
`completed`	`boolean`	Whether `complete()` has been called
`completionValue`	`unknown`	Value passed to `complete()`
`aborted`	`boolean`	Whether `abort()` has been called
`abortReason`	`string`	Reason passed to `abort()` (optional)

Context Methods

Method	Signature	Description
`recv`	`<T>(channel, opts?) => Promise<T>`	Receive from a channel (blocking)
`send`	`<T>(channel, value) => void`	Send to a channel
`tryRecv`	`<T>(channel) => T \| null`	Non-blocking receive
`checkpoint`	`() => Promise<void>`	Persist current state
`complete`	`<T>(value) => void`	Signal completion with a value
`abort`	`(reason?) => void`	Signal abort

ItemLog

An append-only log of conversation items.

interface ItemLog {
  readonly items: ReadonlyArray<Item>;
  append(item: Item): void;
}

Field	Type	Description
`items`	`ReadonlyArray<Item>`	All items in the log
`append`	`(item: Item) => void`	Append a new item

Item

The Item type is a discriminated union over the type field:

type Item =
  | MessageItem
  | FunctionCallItem
  | FunctionCallOutputItem
  | ReasoningItem
  | ExtensionItem;

ItemBase

All items share this base:

Field	Type	Description
`id`	`string`	Unique item identifier
`status`	`'in_progress' \| 'completed' \| 'incomplete' \| 'failed'`	Item status

MessageItem

Field	Type	Description
`type`	`'message'`	Discriminant
`role`	`'user' \| 'assistant' \| 'system' \| 'developer'`	Message author
`content`	`ContentPart[]`	Message content parts

FunctionCallItem

Field	Type	Description
`type`	`'function_call'`	Discriminant
`call_id`	`string`	Unique call identifier
`name`	`string`	Function name
`arguments`	`string`	JSON-encoded arguments

FunctionCallOutputItem

Field	Type	Description
`type`	`'function_call_output'`	Discriminant
`call_id`	`string`	Matching call identifier
`output`	`string`	JSON-encoded output

ReasoningItem

Field	Type	Description
`type`	`'reasoning'`	Discriminant
`content`	`ContentPart[]`	Reasoning content
`summary`	`ContentPart[]`	Summary of reasoning (optional)
`encrypted_content`	`string`	Encrypted reasoning content (optional)

ExtensionItem

Field	Type	Description
`type`	`x-${string}`	Custom type prefixed with `x-`
`data`	`Record<string, unknown>`	Arbitrary data

ContentPart

type ContentPart =
  | { type: 'output_text'; text: string }
  | { type: 'input_text'; text: string }
  | { type: 'refusal'; refusal: string };

Variant	Fields	Description
`output_text`	`text: string`	Text generated by the model
`input_text`	`text: string`	Text from the user or system
`refusal`	`refusal: string`	Model refusal message

TokenUsage

Field	Type	Description
`input`	`number`	Input tokens consumed
`output`	`number`	Output tokens generated
`total`	`number`	Total tokens

StepMeta

Field	Type	Description
`toolCalls`	`FunctionCallItem[]`	Tool calls made in this step (optional)
`usage`	`{ inputTokens, outputTokens, cachedTokens? }`	Token usage (optional)
`cost`	`number`	Step cost in USD (optional)
`responseItems`	`ReadonlyArray<Item>`	Items produced by this step (optional)

Context Types

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