# Langfuse — Open-source, self-hostable tracing and evaluation platform for LLM applications. > Source: The Agents Index — https://theagentsindex.com/langfuse (structured, researched, re-verified) Langfuse is an open-source AI engineering platform for tracing, evaluating, and managing prompts in LLM applications. It combines observability, datasets, experiments, and collaborative human review around production agent data. **Best for:** Teams building and improving production-grade LLM applications | Fact | Value | | --- | --- | | Website | https://langfuse.com/ | | Category | LLM observability & tracing | | Open source | Yes | | Price | Free | | Price source | https://langfuse.com/pricing | | Price checked | 29 October 2026 | | MCP server | Yes | | API | Not stated | | Self-host | Yes | | Facts | 18 facts from 12 sources | | Facts checked | 29 October 2026 | Screenshot of Langfuse: https://theagentsindex.com/img/1920/screenshots/langfuse.webp, captured 31 October 2026 **What we checked** - Pages last read: 29 October 2026 - Facts checked: 18 facts (From 12 sources) - AI answers: Named in 0 of 151 (Our October check) ## What we checked on Langfuse ### How much it does unattended **Agent permissions** · Partly — Halo pauses before changing data or configuration, though a conversation can enable Always approve. > Halo pauses for your approval before changing data or configuration. Always approve lets a tool run without asking again in the current conversation. > — https://langfuse.com/docs/api-and-data-platform/features/halo · Action approvals section, checked 29 October 2026 ### Which models it runs on **Model choice** · Yes — The vendor positions Langfuse as model-agnostic, with integrations spanning providers and agent frameworks. > Langfuse is also open source, based on OpenTelemetry for interoperability, self-hostable at the same scale as Langfuse Cloud, and model- and framework-agnostic. > — https://langfuse.com/pricing · Pricing FAQ, comparison question, checked 29 October 2026 ### Whose machine it runs on **Self-hosted** · Yes — The open-source platform can be deployed on customer infrastructure using Docker and production deployment options. > Langfuse is open source and can be self-hosted using Docker on your own infrastructure. > — https://langfuse.com/self-hosting · Self-host Langfuse introduction, checked 29 October 2026 **Open source** · Yes — Langfuse publishes its platform as open-source software and explicitly presents it as self-hostable and extensible. > Langfuse is open, self-hostable, and extensible. > — https://langfuse.com/docs · Langfuse Overview introduction, checked 29 October 2026 **Licence** · Yes — All product features are MIT licensed, so companies may fork, modify, and contribute to the software. > MIT license — all product features are MIT licensed, scale to billions of monthly events, and you can fork, modify, and contribute. > — https://langfuse.com/ · Open platform, open source section, checked 29 October 2026 ### Building with it **SDK languages** · Yes — Native SDKs are available for Python and JavaScript or TypeScript, with other languages supported through OpenTelemetry. > Python and TypeScript native SDKs, plus Go, Java, .NET, Ruby, PHP, and Swift via OpenTelemetry. > — https://langfuse.com/ · Works with any stack, Languages, checked 29 October 2026 **Tracing and evals** · Yes — The platform traces LLM calls and workflow steps, then evaluates production data with datasets and experiments. > One integrated platform to trace, manage prompts, evaluate, and experiment from prototype to production scale. > — https://langfuse.com/ · Platform features introduction, checked 29 October 2026 ### What it costs to run **How it meters** · Yes — Cloud pricing combines a monthly plan fee with usage measured as ingested traces, observations, and scores. > Langfuse pricing is based on the number of ingested units per billing period. Units are either traces, observations or scores. > — https://langfuse.com/docs/administration/billable-units · Billable Units introduction, checked 29 October 2026 **Free tier** · Yes — The standing Hobby plan is free, requires no credit card, and includes limited platform usage. > Get started, no credit card required. Great for hobby projects and POCs. > — https://langfuse.com/pricing · Cloud Plans, Hobby, checked 29 October 2026 **MCP server** · Yes — A native authenticated MCP server lets AI assistants and agents interact programmatically with project data. > Langfuse includes a native Model Context Protocol (MCP) server that enables AI assistants and agents to interact with your Langfuse data programmatically. > — https://langfuse.com/docs/api-and-data-platform/features/mcp-server · Langfuse MCP Server introduction, checked 29 October 2026 **Bring your own key** · Yes — Self-hosted deployments can connect their own LLM API or gateway, including within a private VPC. > Bring your own LLM API; it can also run in the same VPC or a peered VPC. > — https://langfuse.com/self-hosting · Architecture section, checked 29 October 2026 ### Buying it for a team **A company can buy it** · Yes — Cloud plans include production, scaling, and Enterprise options designed for projects with unlimited users. > For production projects. Longer data access and unlimited users. > — https://langfuse.com/pricing · Cloud Plans, Core, checked 29 October 2026 **Admin controls** · Yes — Role-based controls restrict project configuration, while project API keys can be narrowed to specific permissions. > Choose a set of permissions under Permissions when creating a project API key to limit what the key can do. > — https://langfuse.com/docs/administration/rbac · Project API key permissions section, checked 29 October 2026 **Audit log** · Partly — Immutable, attributed audit trails are available on Enterprise cloud and self-hosted Enterprise Edition only. > Enterprise | Available | Self Hosted | Enterprise Edition > — https://langfuse.com/docs/administration/audit-logs · Audit Logs availability table, checked 29 October 2026 **Single sign-on** · Partly — Enterprise SSO is OIDC-only and requires the Pro Teams Add-on or an Enterprise or self-hosted deployment. > Hobby | Not Available | Core | Not Available | Pro | Teams Add-on required | Enterprise | Available | Self Hosted | Available > — https://langfuse.com/docs/administration/authentication-and-sso · Enterprise SSO & SSO Enforcement availability table, checked 29 October 2026 ### What happens to your code **Data residency** · Yes — Cloud customers choose US, EU, Japan, or HIPAA regions, while self-hosting offers infrastructure control. > US — Oregon (AWS us-west-2); EU — Ireland (AWS eu-west-1); Japan — Tokyo (AWS ap-northeast-1); HIPAA — Oregon (AWS us-west-2). > — https://langfuse.com/security/data-regions · Langfuse Cloud Regions table, checked 29 October 2026 **Getting out** · Yes — Observability data can be batch-exported as CSV or JSON; published pages do not address unused-credit expiry. > Most tables in Langfuse support batch-exports. All filters applied to the table will be applied to the export. > — https://langfuse.com/docs/api-and-data-platform/features/export-from-ui · Export Data from UI introduction, checked 29 October 2026 **Certifications** · Yes — Langfuse documents GDPR compliance across the service, with SOC 2 and ISO 27001 audit coverage. > Langfuse Cloud is SOC 2 Type II certified, ISO 27001 compliant, GDPR compliant, and offers a HIPAA-ready region. > — https://langfuse.com/ · Questions and answers, Is Langfuse secure and compliant?, checked 29 October 2026 ## Langfuse price and terms **Terms** - Free plan: Yes — Hobby is a standing free plan with 50k units per month, two users, and 30 days of data access **What needs a higher plan** - Enterprise: Audit log ## For AI agents - MCP server: Yes Pricing page as we captured it: https://theagentsindex.com/img/1920/screenshots/langfuse/pricing.webp, captured 31 October 2026 Read on https://langfuse.com/pricing, 29 October 2026. ## Langfuse alternatives - [Arize](https://theagentsindex.com/arize) · Free plan, then $50 a month: Managed agent observability and evals with an ELv2-licensed self-hosted Phoenix option. It publishes a price. [1 alternative](https://theagentsindex.com/langfuse/alternatives/) ## Questions about Langfuse ### How much does Langfuse cost? Langfuse is free to use. From langfuse.com/pricing, checked 29 October 2026. ### Does Langfuse have an API or an MCP server? It has an MCP server. ### Is Langfuse open source, and can you host it yourself? It is open source. You can host it yourself. ### What have we checked on Langfuse? 18 facts, under these headings: How much it does unattended, which models it runs on, whose machine it runs on, building with it, what it costs to run, buying it for a team, what happens to your code. ### How do we check Langfuse? We hold 18 facts on Langfuse, quoted from 12 pages. Facts and price last checked 29 October 2026. How we check every listing: https://theagentsindex.com/methodology/ ## Sources and changes Last changed 31 October 2026 **Sources on langfuse.com** (12) - https://langfuse.com/, read 29 October 2026 - https://langfuse.com/pricing, read 29 October 2026 - https://langfuse.com/self-hosting, read 29 October 2026 - https://langfuse.com/docs, read 29 October 2026 - https://langfuse.com/docs/administration/audit-logs, read 29 October 2026 - https://langfuse.com/docs/administration/authentication-and-sso, read 29 October 2026 - https://langfuse.com/docs/administration/billable-units, read 29 October 2026 - https://langfuse.com/docs/administration/rbac, read 29 October 2026 - https://langfuse.com/docs/api-and-data-platform/features/export-from-ui, read 29 October 2026 - https://langfuse.com/docs/api-and-data-platform/features/halo, read 29 October 2026 - https://langfuse.com/docs/api-and-data-platform/features/mcp-server, read 29 October 2026 - https://langfuse.com/security/data-regions, read 29 October 2026 ## Is this yours? AI assistants like ChatGPT and Claude opened The Agents Index pages 2,746 times in September. Claim Langfuse: https://theagentsindex.com/claim/langfuse Report an error if a fact is wrong: hello@theagentsindex.com, subject "Report an error: Langfuse (langfuse)".