Skip to content

LangfuseProcessor

This docs was updated at: 2026-02-23

com.paragon.telemetry.langfuse.LangfuseProcessor  ยท  Class

Extends TelemetryProcessor

Telemetry processor that sends traces to Langfuse via OTLP/HTTP.

Langfuse only supports traces (not metrics or logs), so this processor converts TelemetryEvents into OtelSpans and sends them to the /api/public/otel/v1/traces endpoint.

Authentication uses HTTP Basic Auth with public key as username and secret key as password.

See Also

  • <a href="https://langfuse.com/docs/integrations/opentelemetry">Langfuse OpenTelemetry Docs</a>

Methods

builder

public static @NonNull Builder builder()

Creates a new builder for LangfuseProcessor.

fromEnv

public static @NonNull LangfuseProcessor fromEnv()

Creates a processor from environment variables. Requires LANGFUSE_PUBLIC_KEY and LANGFUSE_SECRET_KEY.

fromEnv

public static @NonNull LangfuseProcessor fromEnv(@NonNull OkHttpClient httpClient)

Creates a processor from environment variables with a custom HTTP client.

convertToSpan

private @NonNull OtelSpan convertToSpan(@NonNull TelemetryEvent event)

Converts a TelemetryEvent to an OtelSpan.

sendToLangfuse

private void sendToLangfuse(@NonNull String json)

Sends JSON payload to Langfuse OTEL endpoint.

httpClient

public @NonNull Builder httpClient(@NonNull OkHttpClient httpClient)

Sets the HTTP client.

endpoint

public @NonNull Builder endpoint(@NonNull String endpoint)

Sets the Langfuse endpoint URL.

publicKey

public @NonNull Builder publicKey(@NonNull String publicKey)

Sets the Langfuse public key.

secretKey

public @NonNull Builder secretKey(@NonNull String secretKey)

Sets the Langfuse secret key.

objectMapper

public @NonNull Builder objectMapper(@NonNull ObjectMapper objectMapper)

Sets the ObjectMapper for JSON serialization.

fromEnv

public @NonNull Builder fromEnv()

Loads configuration from environment variables. Reads LANGFUSE_PUBLIC_KEY, LANGFUSE_SECRET_KEY, and optionally LANGFUSE_HOST.

build

public @NonNull LangfuseProcessor build()

Builds the LangfuseProcessor.