Free for one developer with up to 25 source-built services, 50,000 tool calls a month, then $0.20 per thousand. Team plan is $25 per developer per month with 100,000 tool calls per developer a month, pooled, then $0.20 per thousand. Enterprise from $1,500 per month.
Key features
Hierarchical traces capture every LLM call, tool invocation, and retrieval step
LLM-as-a-judge, heuristic functions, or human review evaluations
Prompt management with one-click deployments and rollbacks
Playground to test prompts on real production inputs and compare models
Experiments with test cases and side-by-side comparison
Human annotation and collaborative human-in-the-loop workflows
Cost and latency monitoring with dashboards and alerts
REST APIs and Query SDK for data access
Langfuse Assistant to automate the AI engineering loop
Source-built servers with TypeScript or Python projects
Remote MCP, OpenAPI, npm package, and container image support
Per-tool and per-argument access control policies
Tool definition review and approval workflow
Content scanning with literal and regex detectors
Activity tracking and audit trails
OIDC and SAML 2.0 single sign-on
SCIM 2.0 provisioning
Workspace-specific data encryption
Custom domain publishing with DNS and Cloudflare certification
What makes it different
MIT licensed open source platform with no data lock-in
Enterprise scale architecture handling billions of monthly events
Works with any language and framework with no framework lock-in
Async by default so tracing never blocks your application
One endpoint replaces every client config, eliminating need for each client to store every server and secret
Coding agent builds the server automatically with no adapter needed
Credentials held once by Rayrun instead of distributed across clients
Built-in security review with published controls and audit trails for compliance teams
Support for multiple service types without writing adapters
Rayrun