Turn

TypeScript SDK reference

Defined in: src/genai/turn.ts:92

Extends

• SpanBase

Accessors

agentName

Get Signature

get agentName(): string

Defined in: src/genai/turn.ts:103

Returns

string

---

model

Get Signature

get model(): string

Defined in: src/genai/turn.ts:107

Returns

string

Methods

addEvent()

Deprecated. Record this data via setAttributes instead. OpenTelemetry is phasing out the Span Event API (Span.addEvent). This method still works and existing span-event data stays valid. See https://opentelemetry.io/blog/2026/deprecating-span-events/

addEvent(name, attributes?, startTime?): this

Add a named event to the span. Useful for marking non-span moments such as context compaction, tool-loop detection, or guardrail trips. Warns and no-ops after end(). Mirrors OTel Span.addEvent.

Defined in: src/genai/spanBase.ts:82

Parameters

name

string

attributes?

Attributes

startTime?

TimeInput

Returns

this

Example

span.addEvent('context_compacted', {removedMessages: 12});

Inherited from

SpanBase.addEvent

---

end()

end(opts?): void

Read current field values (to reflect mutations made via record() since start) and close the span. Idempotent. Pass error to mark it as failed; pass endTime to backdate the close.

Defined in: src/genai/turn.ts:241

Parameters

opts?

SpanEndOptions

Returns

void

---

record()

record(opts): this

Bulk-set any subset of the mutable fields. Replaces (does not merge). Useful for assigning everything at once after a provider call returns.

Defined in: src/genai/turn.ts:201

Parameters

opts

agentDescription?

string

agentId?

string

agentName?

string

agentVersion?

string

messages?

Message[]

model?

string

systemInstructions?

string[]

Returns

this

---

setAttribute()

Deprecated. Use setAttributes instead, which mirrors the Python SDK’s set_attributes and OTel’s Span.setAttributes. Retained as a thin alias so existing single-attribute callers keep working. Only Turn carries this — the other emitters never shipped a singular form.

setAttribute(key, value): this

Defined in: src/genai/turn.ts:193

Parameters

key

string

value

AttributeValue

Returns

this

---

setAttributes()

setAttributes(attributes): this

Set multiple attributes on the span at once. Warns and no-ops after end(). Mirrors OTel Span.setAttributes (and the Python SDK’s set_attributes).

Defined in: src/genai/spanBase.ts:63

Parameters

attributes

Attributes

Returns

this

Example

span.setAttributes({'weave.tag': 'prod', 'gen_ai.response.id': id});

Inherited from

SpanBase.setAttributes

---

startLLM()

startLLM(opts): LLM

Start a child LLM span under this Turn.

Defined in: src/genai/turn.ts:161

Parameters

opts

LLMInit

Returns

LLM

---

startSubagent()

startSubagent(opts): SubAgent

Start a child SubAgent span under this Turn.

Defined in: src/genai/turn.ts:179

Parameters

opts

SubAgentInit

Returns

SubAgent

---

startTool()

startTool(opts): Tool

Start a child Tool span under this Turn.

Defined in: src/genai/turn.ts:170

Parameters

opts

ToolInit

Returns

Tool