OpenRouter Broadcast Integration

OpenRouter Broadcast sends a trace of each API request you make through OpenRouter to the observability destinations you configure. Traces are sent after the request completes, so Broadcast adds no latency to your API responses. LangWatch receives these traces through OpenRouter’s generic OpenTelemetry Collector destination, which exports to any OTLP/HTTP backend. LangWatch is not a named destination in OpenRouter yet, so you configure that generic destination with the LangWatch endpoint and your API key.

This page is for OpenRouter’s server-side Broadcast. To trace OpenRouter calls from your own Go code instead, see OpenRouter (Go).

Prerequisites

An OpenRouter account. Broadcast can be set up for your user or, by an admin, for an organization.
A LangWatch API key, from your project settings.

Setup

Enable Broadcast in OpenRouter

In OpenRouter, go to Settings > Observability and turn on Enable Broadcast.

Configure the OpenTelemetry Collector destination

Click the edit icon next to OpenTelemetry Collector and enter:

Endpoint: https://app.langwatch.ai/api/otel/v1/traces
Headers:

{
  "Authorization": "Bearer <LANGWATCH_API_KEY>"
}

Replace <LANGWATCH_API_KEY> with your LangWatch API key. OpenRouter encrypts destination credentials before storing them.Self-hosted LangWatch: replace https://app.langwatch.ai with the URL of your own instance, for example https://langwatch.example.com/api/otel/v1/traces. OpenRouter sends traces from its own servers, so the endpoint must be reachable from the public internet.

Test and save

Click Test Connection. OpenRouter only saves the destination when the test passes.

Send a test request

Make a request through OpenRouter:

curl https://openrouter.ai/api/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $OPENROUTER_API_KEY" \
  -d '{
    "model": "openai/gpt-5-mini",
    "messages": [{ "role": "user", "content": "Hello from OpenRouter" }]
  }'

See the trace in LangWatch

Open your project in LangWatch. The trace for the request appears in the traces list.

What OpenRouter sends

According to the Broadcast documentation, each trace includes:

The input messages and the model output, with multimodal content stripped.
Token usage: prompt, completion and total tokens.
The total cost of the request.
Timing: start time, end time and latency.
The model slug and the provider that served the request.
Whether tools were included in the request and whether tool calls were made.

The OpenTelemetry Collector destination sends these as OTLP/HTTP with JSON encoding. Model, token usage and cost use the GenAI semantic conventions (gen_ai.*), and the prompt and completion are on the generation span.

Sessions, users and metadata

OpenRouter reads these optional fields from the request body and adds them to the trace:

Request field	Span attribute	Use
`session_id` (or the `x-session-id` header)	`session.id`	Group related requests, such as a conversation or an agent run. Up to 256 characters.
`user`	`user.id`	Associate the trace with an end user. Up to 128 characters.
`trace`	`trace.metadata.*`	Any JSON object of custom metadata. `environment` becomes `trace.metadata.environment`.

A few keys inside trace have a fixed meaning for the OpenTelemetry Collector destination:

Key	Maps to
`trace_id`	Trace ID. Use the same value across requests to group them into one trace.
`trace_name`	Name of the root span.
`span_name`	Name of intermediate spans.
`generation_name`	Name of the LLM generation span.
`parent_span_id`	Parent span ID, to link the OpenRouter trace to a span from your own tracing.

Example request body:

{
  "model": "openai/gpt-5-mini",
  "messages": [{ "role": "user", "content": "Hello!" }],
  "user": "user_12345",
  "session_id": "session_abc",
  "trace": {
    "trace_name": "Chat Handler",
    "generation_name": "Generate Response",
    "environment": "staging"
  }
}

Destination options

These OpenRouter settings apply per destination:

Privacy Mode removes the input messages and the output from traces. Tokens, cost, timing, model and custom metadata are still sent.
Sampling rate sends a share of traces, for example 0.5 for about half. When you send a session_id, every trace in a session is kept or dropped together.
API key filtering sends only traces from the API keys you select, and never from keys you exclude.

Once traces reach LangWatch, your Data Privacy rules apply to them.

Overview

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Direct Integrations

OpenRouter Broadcast Integration

Prerequisites

Setup

What OpenRouter sends

Sessions, users and metadata

Destination options

​Prerequisites

​Setup

​What OpenRouter sends

​Sessions, users and metadata

​Destination options

Prerequisites

Setup

What OpenRouter sends

Sessions, users and metadata

Destination options