@agentskit/observability-langfuse — for agents

Langfuse tracing adapter — plan / tool / model / HITL spans with token, cost, latency capture and parent linking across multi-agent topologies.

#Install

npm install @agentskit/observability-langfuse langfuse

langfuse is loaded lazily and is a peer install.

#Primary exports

langfuse(config?) — returns an Observer that emits one Langfuse trace per agent run with nested span / generation objects per AgentsKit event.

#Config

Field	Default	Notes
`publicKey`	`LANGFUSE_PUBLIC_KEY`	Required (env or arg).
`secretKey`	`LANGFUSE_SECRET_KEY`	Required (env or arg).
`baseUrl`	`LANGFUSE_HOST` or `https://cloud.langfuse.com`	Self-hosted or EU/US cloud.
`release` / `environment`	`LANGFUSE_RELEASE` / `LANGFUSE_ENVIRONMENT`	Free-form metadata.
`sessionId` / `userId` / `tags`	—	Attached to the trace.
`flushAt` / `flushInterval`	`15` / `1000`	Forwarded to the Langfuse SDK.

#Span model

AgentsKit event	Langfuse object	Notes
`agent:step`	`span`	Top-level loop step (plan / act / observe).
`llm:start` / `llm:end`	`generation`	Model, input message count, output content (truncated), token usage.
`tool:start` / `tool:end`	`span`	Tool name, args, result snapshot, duration.
`memory:load` / `memory:save`	`span`	Message count.
`error`	annotates current span	Sets `level: 'ERROR'` and `statusMessage`.

#Minimal example

import { createRuntime } from '@agentskit/runtime'
import { langfuse } from '@agentskit/observability-langfuse'

const runtime = createRuntime({
  adapter,
  observers: [
    langfuse({
      publicKey: process.env.LANGFUSE_PUBLIC_KEY!,
      secretKey: process.env.LANGFUSE_SECRET_KEY!,
      sessionId: 'demo-session',
      tags: ['agentskit', 'showcase'],
    }),
  ],
})

@agentskit/observability — base createTraceTracker shared by this adapter.
@agentskit/runtime.

#Source

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@agentskit/observability-langfuse — for agents

#Install

#Primary exports

#Config

#Span model

#Minimal example

#Related

#Source

Explore nearby

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