Docs API & Data Platform FeaturesPublic API

Public API

Langfuse is open and meant to be extended via custom workflows and integrations. All Langfuse data and features are available via the API.

/api/public

https://us.cloud.langfuse.com/api/public

https://cloud.langfuse.com/api/public

https://hipaa.cloud.langfuse.com/api/public

References:

API Reference:https://api.reference.langfuse.com
OpenAPI spec:https://cloud.langfuse.com/generated/api/openapi.yml
Postman collection:https://cloud.langfuse.com/generated/postman/collection.json

There are 3 different groups of APIs:

This page -> Project-level APIs: CRUD traces/evals/prompts/configuration within a project
Organization-level APIs: provision projects, users (SCIM), and permissions
Management API: administer organizations on self-hosted installations

Authentication

Authenticate with the API usingBasic Auth.The API keys are available in the Langfuse project settings.

Username: Langfuse Public Key
Password: Langfuse Secret Key

Example:

curl -u public-key:secret-key https://cloud.langfuse.com/api/public/projects

Access via SDKs

Both the LangfusePython SDK and theJS/TS SDK provide a strongly-typed wrapper around our public REST API for your convenience. The API methods are accessible via theapi property on the Langfuse client instance in both SDKs.

You can use your editor’s Intellisense to explore the API methods and their parameters.

When fetchingprompts, please use theget_prompt (Python) /getPrompt (JS/TS) methods on the Langfuse client to benefit from client-side caching, automatic retries, and fallbacks.

When using thePython SDK:

from langfuseimport get_clientlangfuse= get_client()...# fetch a tracelangfuse.api.trace.get(trace_id)# async client via asyncioawait langfuse.async_api.trace(trace_id)# explore more endpoints via Intellisenselangfuse.api.*await langfuse.async_api.*

import { LangfuseClient }from '@langfuse/client';const langfuse = new LangfuseClient();...// fetch a traceawait langfuse.api.trace.get(traceId);// explore more endpoints via Intellisenselangfuse.api.*

Install Langfuse by adding the following to yourpom.xml:

<dependencies>  <dependency>    <groupId>com.langfuse</groupId>    <artifactId>langfuse-java</artifactId>    <version>0.0.1-SNAPSHOT</version>  </dependency></dependencies><repositories>  <repository>    <id>github</id>    <name>GitHub Package Registry</name>    <url>https://maven.pkg.github.com/langfuse/langfuse-java</url>  </repository></repositories>

Instantiate and use the Java SDK via:

import com.langfuse.client.LangfuseClient;import com.langfuse.client.resources.prompts.types.PromptMetaListResponse;import com.langfuse.client.core.LangfuseClientApiException;LangfuseClient client= LangfuseClient.builder()  .url("https://cloud.langfuse.com")// 🇪🇺 EU data region  // .url("https://us.cloud.langfuse.com") // 🇺🇸 US data region  // .url("http://localhost:3000") // 🏠 Local deployment  .credentials("pk-lf-...","sk-lf-...")  .build();try {  PromptMetaListResponse prompts= client.prompts().list();}catch (LangfuseClientApiExceptionerror) {  System.out.println(error.getBody());  System.out.println(error.getStatusCode());}