Interface: ChatMiddlewareContext<TContext>#

Defined in: packages/ai/src/activities/chat/middleware/types.ts:86

Stable context object passed to all middleware hooks. Created once per chat() invocation and shared across all hooks.

Type Parameters#

TContext#

TContext = unknown

Properties#

abort()#

abort: (reason?) => void;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:115

Abort the chat run with a reason

Parameters#

reason?#

string

Returns#

void

accumulatedContent#

accumulatedContent: string;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:166

Accumulated text content for the current iteration

activity#

activity: "chat";

Defined in: packages/ai/src/activities/chat/middleware/types.ts:133

Which activity this context describes — always 'chat'. Present so the chat context structurally satisfies the base GenerationMiddlewareContext, letting an observe-only middleware authored against the base (e.g. otelMiddleware) run on both chat and media activities.

capabilities#

capabilities: CapabilityRegistry;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:180

Capability bookkeeping for this request. Populated by middleware setup hooks (via provide accessors) and read by later middleware (via get accessors). Prefer the accessors returned by createCapability over using this directly. Orthogonal to context (the user runtime context).

chunkIndex#

chunkIndex: number;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:111

Running count of chunks yielded so far

context#

context: TContext;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:117

Runtime context provided by chat() options

conversationId?#

optional conversationId: string;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:105

Deprecated#

Use threadId instead. Retained as an alias of threadId so middleware written before the AG-UI rename keeps working unchanged. Will be removed in a future major release.

createId()#

createId: (prefix) => string;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:173

Generate a unique ID with the given prefix

Parameters#

prefix#

string

Returns#

string

currentMessageId#

currentMessageId: string | null;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:164

Current assistant message ID (changes per iteration)

defer()#

defer: (promise) => void;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:123

Defer a non-blocking side-effect promise. Deferred promises do not block streaming and are awaited after the terminal hook (onFinish/onAbort/onError).

Parameters#

promise#

Promise<unknown>

Returns#

void

get()#

get: <TValue>(capability) => TValue;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:185

Read a provided capability by its handle. Equivalent to the handle's own get accessor (getX(ctx)); throws if the capability was never provided.

Type Parameters#

TValue#

TValue

Parameters#

capability#

Capability<TValue>

Returns#

TValue

getOptional()#

getOptional: <TValue>(capability) => TValue | undefined;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:190

Read a capability by its handle, returning undefined if it was never provided (never throws).

Type Parameters#

TValue#

TValue

Parameters#

capability#

Capability<TValue>

Returns#

TValue | undefined

hasTools#

hasTools: boolean;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:159

Whether tools are configured

iteration#

iteration: number;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:109

Current agent loop iteration (0-indexed)

messageCount#

messageCount: number;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:157

Number of messages at the start of the request

messages#

messages: readonly ModelMessage<
  | string
  | ContentPart<unknown, unknown, unknown, unknown, unknown>[]
  | null>[];

Defined in: packages/ai/src/activities/chat/middleware/types.ts:171

Current messages array (read-only view)

model#

model: string;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:137

Model identifier (e.g., 'gpt-4o')

modelOptions?#

optional modelOptions: Record<string, unknown>;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:152

Provider-specific model options

options?#

optional options: Record<string, unknown>;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:150

Flattened generation options (metadata)

phase#

phase: ChatMiddlewarePhase;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:107

Current lifecycle phase

provide()#

provide: <TValue>(capability, value) => void;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:195

Provide a capability value. Equivalent to the handle's own provide accessor (provideX(ctx, value)). Typically called from setup.

Type Parameters#

TValue#

TValue

Parameters#

capability#

Capability<TValue>

value#

TValue

Returns#

void

provider#

provider: string;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:135

Provider name (e.g., 'openai', 'anthropic')

requestId#

requestId: string;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:88

Unique identifier for this chat request

runId#

runId: string;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:92

AG-UI run identifier for correlating client and server events

signal?#

optional signal: AbortSignal;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:113

Abort signal from the chat request

source#

source: "server" | "client";

Defined in: packages/ai/src/activities/chat/middleware/types.ts:139

Source of the chat invocation — always 'server' for server-side chat

streamId#

streamId: string;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:90

Unique identifier for this stream

streaming#

streaming: boolean;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:141

Whether the chat is streaming

systemPrompts#

systemPrompts: SystemPrompt[];

Defined in: packages/ai/src/activities/chat/middleware/types.ts:146

System prompts configured for this chat

threadId#

threadId: string;

Defined in: packages/ai/src/activities/chat/middleware/types.ts:99

AG-UI thread identifier — a stable per-conversation ID used to correlate client and server devtools events. Resolves to the caller-provided threadId (or legacy conversationId), or an auto-generated value when neither is supplied.

toolNames?#

optional toolNames: string[];

Defined in: packages/ai/src/activities/chat/middleware/types.ts:148

Names of configured tools, if any