Langfuse vs Braintrust (2026): Pricing, Self-Hosting, MCP
I compare Langfuse and Braintrust for LLM tracing and evals: free tiers, paid plans, self-hosting, open source status and their MCP servers.
By agentools
Short answer
Pick Langfuse if you want open source tracing and evals you can self-host for free, or a cloud plan from $0 to $29 per month. Pick Braintrust if you want a hosted eval platform with unlimited users on the free Starter plan and a hosted MCP server that can run evals. Both have MCP; only Langfuse is open source.
- Langfuse: Open source tracing you can self-host
- Braintrust: Hosted evals with unlimited users
Once an agent is in production, I want two things: traces that show what it actually did, and evals that tell me whether a change made it better or worse. Langfuse and Braintrust both cover tracing and evals, so the choice comes down to hosting, pricing model and how much you care about open source.
Langfuse is open source, with an MIT licensed core and a free self-hosted option, plus a cloud priced by billable units. Braintrust is a closed source hosted platform priced by processed data and scores, with on-prem or hosted deployment on Enterprise. Every number below comes from the vendors' pricing pages and docs, checked on October 30, 2026.
At a glance
| Tool | Pricing | Free tier | MCP support | Open source |
|---|---|---|---|---|
 Langfuse | Core $29/mo, Pro $199/mo, Enterprise $2,499/mo. Self-hosting free | Hobby: 50k units/mo, 30 days, 2 users, no card | Yes. Built-in server at /api/public/mcp on every plan | Yes. MIT core, free to self-host |
| Braintrust | Pro $249/mo, Enterprise custom | Starter: $10 credits, 1 GB data, 10k scores, 14 days, unlimited users | Yes. Hosted server at api.braintrust.dev/mcp | No. The autoevals library is MIT |
The 2 picks
1. Langfuse
Open-source tracing and evals for agents
Langfuse does tracing, prompt management and evals for LLM apps and agents. Everything outside its enterprise folders is MIT licensed on GitHub, and self-hosting is free.
The cloud has four plans. Hobby is free with no credit card: 50k units per month, 30 days of data access and 2 users. Core is $29 per month with 100k units, then $8 per extra 100k, 90 days of data access and unlimited users. Pro is $199 per month with 3 years of data access, Teams is a $300 per month add-on, and Enterprise is $2,499 per month. Startups can get 50% off the first year.
Langfuse has a built-in MCP server on every plan, served over Streamable HTTP with Basic Auth from your API keys. In Claude Code, for the EU cloud:
claude mcp add --transport http langfuse https://cloud.langfuse.com/api/public/mcp --header "Authorization: Basic YOUR_BASE64_TOKEN"
There is also a CLI, npx @langfuse/cli.
Caveat: self-hosting is free in license cost, but you run and upgrade the infrastructure yourself.
Pricing: Open sourceObservability platform
2. Braintrust
Evals and observability for AI agents
Braintrust is a hosted platform for evals and observability on AI agents. It is closed source, though its autoevals scoring library is MIT on GitHub.
Starter is $0 per month with $10 in credits, 1 GB of processed data then $4 per GB, 10k scores then $2.50 per 1k, 14 days of retention and unlimited users. Pro is $249 per month with $100 in credits, 5 GB then $3 per GB, 50k scores then $1.50 per 1k and 30 days of retention. Enterprise is custom and adds on-prem or hosted deployment.
Braintrust runs a hosted MCP server at https://api.braintrust.dev/mcp, with OAuth or an API key and nothing to install. An agent can query logs with SQL, create scorers and run evals through it. In Claude Code:
claude mcp add --transport http braintrust https://api.braintrust.dev/mcp
There is also a bt CLI.
Caveat: retention on the free and Pro plans is short (14 and 30 days), so export anything you need to keep longer.
Pricing: Free tierObservability platform
More to consider
Which one should you choose?
I would pick Langfuse if I want to own my traces, need to self-host for data reasons, or want a cheap cloud plan as a solo founder. Hobby is enough to try it, and Core at $29 per month has unlimited users and 90 days of data.
I would pick Braintrust if evals are the main job and I want everything hosted with no infrastructure, plus unlimited users even on the free plan. Its MCP server is useful when a coding agent should read production logs and run evals for me.
If you only need to replay what a coding agent did in a session, a lighter local tool such as AgentPlay may be enough.
How I checked these numbers
I read langfuse.com/pricing, braintrust.dev/pricing, both MCP docs and the GitHub licenses on October 30, 2026. Usage-based plans change often, so confirm the limits before you commit.
Questions
Is Langfuse free?
Yes, in two ways. Self-hosting Langfuse is free, and Langfuse Cloud has a free Hobby plan with 50k units per month, 30 days of data access and 2 users, no credit card required.
Does Braintrust have a free plan?
Yes. Braintrust Starter is $0 per month with $10 in credits, 1 GB of processed data, 10k scores, 14 days of retention and unlimited users.
Is Langfuse or Braintrust open source?
Langfuse is open source: everything outside its enterprise folders is MIT licensed. Braintrust is closed source, though its autoevals library is MIT.
Do Langfuse and Braintrust support MCP?
Yes. Langfuse has a built-in MCP server at /api/public/mcp on every plan, and Braintrust has a hosted MCP server at api.braintrust.dev/mcp that can query logs and run evals.
Can I self-host Braintrust?
Only on Enterprise, which offers on-prem or hosted deployment at a custom price. Langfuse can be self-hosted for free with Docker Compose or Kubernetes.