comet-ml--opik/apps/opik-documentation/documentation/fern/docs-v2/integrations/langserve.mdx

---
description: Configure LangServe host-level OpenTelemetry export for Opik with clear applicability and minimal setup guidance.
headline: LangServe | Opik Documentation
og:description: LangServe has no standalone OTEL bootstrap; instrument the hosting app and export to Opik.
og:site_name: Opik Documentation
og:title: LangServe Integration - Opik
title: Observability for LangServe with Opik
---

[LangServe](https://github.com/langchain-ai/langserve) does not define its own standalone OpenTelemetry bootstrap. Instrumentation is configured at the host app/runtime layer (typically FastAPI + LangChain components).

## When this guide applies

Use this when your LangServe routes run inside a Python web app and you want request + framework spans in Opik.

## Opik OTLP endpoint modes

For full endpoint/header details, see [Opik OpenTelemetry overview](/integrations/opentelemetry).

<Tabs>
    <Tab value="Opik Cloud" title="Opik Cloud">
        ```bash wordWrap
        export OTEL_EXPORTER_OTLP_ENDPOINT=https://www.comet.com/opik/api/v1/private/otel
        export OTEL_EXPORTER_OTLP_HEADERS='Authorization=<your-api-key>,Comet-Workspace=<your-workspace>,projectName=<your-project-name>'
        ```

        Required headers: `Authorization`, `Comet-Workspace`
        Optional headers: `projectName`
    </Tab>
    <Tab value="Enterprise deployment" title="Enterprise deployment">
        ```bash wordWrap
        export OTEL_EXPORTER_OTLP_ENDPOINT=https://<comet-deployment-url>/opik/api/v1/private/otel
        export OTEL_EXPORTER_OTLP_HEADERS='Authorization=<your-api-key>,Comet-Workspace=<your-workspace>,projectName=<your-project-name>'
        ```

        Required headers: `Authorization`, `Comet-Workspace`
        Optional headers: `projectName`
    </Tab>
    <Tab value="Self-hosted instance" title="Self-hosted instance">
        ```bash wordWrap
        export OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:5173/api/v1/private/otel
        export OTEL_EXPORTER_OTLP_HEADERS='projectName=<your-project-name>'
        ```

        Required headers: none by default
        Optional headers: `projectName`, auth headers if enabled
    </Tab>
</Tabs>

## OTEL configuration pattern for LangServe

Intent:
Configure telemetry at the LangServe host boundary so request and framework spans can be exported.

Applies when:
LangServe is mounted in an app you control (for example FastAPI).

Required inputs:
- host runtime instrumentation enabled
- OTLP endpoint
- OTLP headers for your deployment mode

Optional inputs:
- explicit `service.name`
- additional framework or library instrumentors
- route-level filtering/sampling

Minimal valid setup:
- set `OTEL_EXPORTER_OTLP_ENDPOINT`
- set `OTEL_EXPORTER_OTLP_HEADERS`
- enable instrumentation for your host app and LangChain stack

Use canonical host/runtime setup from:
- [OpenTelemetry FastAPI instrumentation](https://opentelemetry-python-contrib.readthedocs.io/en/latest/instrumentation/fastapi/fastapi.html)
- [Opik LangChain integration guide](/tracing/integrations/langchain)

## Validation

1. Send a request through a LangServe endpoint.
2. Confirm a root HTTP/server span is emitted from your host app.
3. Confirm downstream LangChain/LangServe-related spans are exported and visible in Opik.

## Source references

- [LangServe repository](https://github.com/langchain-ai/langserve)
- [OpenTelemetry FastAPI instrumentation](https://opentelemetry-python-contrib.readthedocs.io/en/latest/instrumentation/fastapi/fastapi.html)
- [Opik LangChain integration guide](/tracing/integrations/langchain)
- [Opik OpenTelemetry overview](/integrations/opentelemetry)