langfuse-api

Original：🇺🇸 English

Translated

Interact with the Langfuse API. Use when user wants to query traces, fetch prompts, create datasets, manage scores, or do anything else via the Langfuse REST API.

1installs

Sourcelangfuse/skills

Added on2026-02-04

NPX Install

npx skill4agent add langfuse/skills langfuse-api

SKILL.md Content

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Langfuse API

Help users interact with Langfuse via the REST API.

When to Use

User wants to query or export traces
User wants to manage prompts programmatically
User wants to create/update datasets or dataset items
User wants to fetch or create scores
User wants to manage projects or API keys
Any other Langfuse API interaction

Workflow

1. Check Credentials

Before making any API call, verify credentials are available:

bash

echo $LANGFUSE_PUBLIC_KEY   # pk-...
echo $LANGFUSE_SECRET_KEY   # sk-...
echo $LANGFUSE_HOST         # https://cloud.langfuse.com (or self-hosted/EU/US URL)

If not set, ask user:

"I need your Langfuse API credentials. You can find them in Settings → API Keys in the Langfuse UI."
"Which Langfuse host are you using? (cloud.langfuse.com, us.cloud.langfuse.com, eu.cloud.langfuse.com, or self-hosted URL)"

2. Fetch Fresh API Reference

Always fetch the current API reference before making calls. The API may have new endpoints or changed parameters.

Fetch: https://api.reference.langfuse.com

Look for the specific endpoint needed for the user's request. The reference contains:

All available endpoints
Required and optional parameters
Request/response schemas
Authentication details

3. Make the API Call

Authentication: Basic Auth with

LANGFUSE_PUBLIC_KEY

as username and

LANGFUSE_SECRET_KEY

as password.

Base URL:

{LANGFUSE_HOST}/api/public

Example:

bash

curl -X GET "${LANGFUSE_HOST}/api/public/traces" \
  -u "${LANGFUSE_PUBLIC_KEY}:${LANGFUSE_SECRET_KEY}" \
  -H "Content-Type: application/json"

4. Handle Pagination

Many endpoints return paginated results. Check for:

```
page
```
and
```
limit
```
parameters
```
meta.totalItems
```
and
```
meta.totalPages
```
in response
Iterate if user needs all results

Common Use Cases

User Request	Endpoint to Look Up
"Get my recent traces"	GET /traces
"Export traces from last week"	GET /traces with date filters
"Fetch a specific prompt"	GET /prompts/{name}
"Create a dataset"	POST /datasets
"Add items to dataset"	POST /dataset-items
"Get scores for a trace"	GET /scores with traceId filter
"List all prompts"	GET /prompts

Important Notes

Always fetch fresh docs - Don't rely on cached knowledge of the API
Check rate limits - The API has rate limits; handle 429 responses
Validate responses - Check for errors before processing data
Large exports - For bulk data, use pagination and consider streaming to file

OpenAPI Spec

For programmatic access or generating types:

https://cloud.langfuse.com/generated/api/openapi.yml