Interface: StreamChunk

Defined in: providers/types.ts:112

Streaming chunk types

Properties

model?

optional model?: string;

Defined in: providers/types.ts:157

Model that generated this response (only present on ‘done’ chunks)

stopReason?

optional stopReason?: string;

Defined in: providers/types.ts:166

Stop reason (only present on ‘done’ chunks).

• ‘end_turn’: Normal completion
• ‘max_tokens’: Hit max_tokens limit
• ‘refusal’: Model refused the request (Claude 4.5+)
• ‘context_window_exceeded’: Hit context window limit (Claude 4.5+)
• ‘tool_use’: Model wants to call a tool

text?

optional text?: string;

Defined in: providers/types.ts:122

thinking?

optional thinking?: {
  signature?: string;
  thinking?: string;
};

Defined in: providers/types.ts:146

Thinking block data (for thinking_start/thinking_end)

signature?

optional signature?: string;

thinking?

optional thinking?: string;

toolCallId?

optional toolCallId?: string;

Defined in: providers/types.ts:132

Which tool call a tool_use_delta / tool_use_end belongs to.

⚠️ Optional for compatibility, but a provider that can emit two tool calls at once MUST set it: without an id the agent closes whichever call it saw last, so two calls announced before either finishes merge into one slot, the JSON fails to parse, and BOTH are dropped (the turn is then reported as output-limit truncation). Measured on processChunks before this field existed; see tests/agent-parallel-tools.test.ts.

toolUse?

optional toolUse?: {
  id: string;
  input?: Record<string, unknown>;
  name: string;
  signature?: string;
};

Defined in: providers/types.ts:133

id

id: string;

input?

optional input?: Record<string, unknown>;

name

name: string;

signature?

optional signature?: string;

Thought signature for Gemini 3 function calls. Only present on first function call in each step.

type

type: 
  | "text"
  | "tool_use_start"
  | "tool_use_delta"
  | "tool_use_end"
  | "thinking_start"
  | "thinking_delta"
  | "thinking_end"
  | "done";

Defined in: providers/types.ts:113

usage?

optional usage?: LLMUsage;

Defined in: providers/types.ts:153

Token usage (only present on ‘done’ chunks)