Langfuse
The open-source default for LLM tracing, MIT-licensed with 79 MCP tools out of the box, and you pay for it in operations: v3 means Postgres plus ClickHouse plus Redis plus S3, and ClickHouse now owns the company.
PRICING
| Self-hosted Open Source | $0 | MIT licence, unlimited units, unlimited users, all core platform features and APIs, enterprise SSO and organisation RBAC, Docker Compose, Helm and Terraform templates for AWS, Azure and GCP. Can run fully air-gapped. You operate Postgres, ClickHouse, Redis and S3 yourself |
| Cloud Hobby | $0 | 50,000 units per month, 30 days of data access, 2 users, 1 annotation queue, 2 monitors, 1,000 req/min ingestion, community support via GitHub. No credit card |
| Cloud Core | $29/mo | 100,000 units included then $8 per 100k, 90 days of data, unlimited users, 3 annotation queues, 20 monitors, 4,000 req/min ingestion, in-app support. Discounts for startups, research and open-source projects |
| Cloud Pro | $199/mo | 3 years of history, data retention management, unlimited annotation queues, 50 monitors, 20,000 req/min, SOC 2 Type II and ISO 27001 reports, HIPAA BAA available, prioritised support |
| Teams add-on | $300/mo | On top of Pro: enterprise SSO (Okta, EntraID), SSO enforcement, project-level RBAC, protected deployment labels, scheduled blob-storage export, dedicated Slack channel, 24h response SLO |
| Cloud Enterprise | $2,499/mo | Everything in Pro plus Teams, audit logs, SCIM API, custom rate limits, uptime and support SLA, dedicated support engineer. Yearly commitment adds custom volume pricing, architecture reviews, AWS Marketplace or invoice billing |
| Self-hosted Enterprise | Quote only | Adds management APIs, project-level RBAC, data retention policies and audit logs to the OSS build. Bundled with ClickHouse Cloud, BYOC or Private, and priced additively on top of your ClickHouse commercial plan |
Two things to know. First, the free self-host is real: MIT, unlimited usage and users, the same codebase that runs Langfuse Cloud, with only management APIs, project-level RBAC, data retention policies and audit logs held back for the commercial licence. Even SSO and organisation RBAC are in the free build, which is unusual. Second, the Cloud unit is an event, not a request: traces, observations and scores are each billed separately, so a deeply nested agent generates many billable units per user action. That makes Langfuse very cheap at low volume and less so for verbose multi-step agents, which is the opposite of a per-byte meter. Euro figures converted from published USD at roughly 0.92.
checked 2026-08-10 · vendor pricing page
Element scores
Strengths
Langfuse is the answer to "what do I self-host", and it earns the position rather than just claiming it. The core is MIT with no usage limits and no feature flags to untangle, it is the same codebase that runs Langfuse Cloud, and you can move between OSS, self-hosted Enterprise and Cloud without a migration. Both SDKs are built natively on OpenTelemetry, so instrumentation you already have keeps working and swapping Langfuse out is a URL change, which is a real answer to lock-in rather than a slogan. On capability the platform is broad: hierarchical traces with agent graphs, sessions and user tracking, prompt management with versioning, release labels, composability and caching that is genuinely better than most dedicated eval tools, datasets and experiments from both UI and SDK, LLM-as-judge and code evaluators, annotation queues, custom dashboards, monitors and alerts. Multimodal is thorough, with an unusually long list of supported MIME types and self-hosted support as long as you bring your own bucket. Protocol support is the standout: a native MCP server exposing 79 tools, read and write, on all four cloud regions and on self-hosted instances, plus a separate public docs MCP server, which means Langfuse can be driven by your coding agent instead of only being looked at. Compliance is respectable for an open-source project, with SOC 2 Type II, ISO 27001, annual penetration tests, GDPR, a DPA, and EU, US, Japan and HIPAA data regions.
Honest dings
The cost is operational. Langfuse v3 replaced a Postgres-only deployment with four services (Postgres, ClickHouse, Redis or Valkey, and S3-compatible storage) and the Helm chart installs ClickHouse and Redis whether you want them or not. The v2 to v3 migration has a long public tail of stuck-migration issues, including a cursor bug where legacy traces all share one created_at timestamp and the migration loops forever, Prisma deadlocks on multi-million-row observation tables with no built-in retry, and clustered ClickHouse setups that the team explicitly does not support. None of this is hidden, the docs and issue tracker are honest about it, but "self-host is free" is a licence statement, not an effort estimate. Second, the ownership question: ClickHouse acquired Langfuse in January 2026, and security, privacy and legal contacts now route to clickhouse.com. The team says the product continues and self-hosting stays, and the technical logic is sound because Langfuse already ran on ClickHouse, but anyone buying today is making a multi-year bet on a database vendor's roadmap. Third, the AI layer is Cloud-only: the Langfuse Assistant shows as unavailable on both self-hosted Open Source and self-hosted Enterprise, so the users who chose Langfuse specifically to keep data in-house get the least AI-assisted product. Fourth, no synthetic-data generation and no turnkey CI regression gate, so for full regression testing you assemble more of the pipeline yourself. Finally, watch the billing unit on Cloud: traces, observations and scores each count, so nested agents multiply your bill in a way a raw request count will not predict.
Sources (13) — every claim traceable
Every audit lists the research it rests on — transparency and traceability are the product. Tools evolve: each audit is a snapshot of its audit date, and re-audits supersede older versions (kept below for reference).
- langfuse.com/pricing — Official Cloud pricing verified live 10/08/2026: Hobby $0 / 50k units / 2 users, Core $29, Pro $199, Teams add-on $300, Enterprise $2,499, graduated overage from $8 per 100k units down to below $7 at volume. Also the feature matrix showing SOC 2 and ISO 27001 reports and HIPAA from Pro, SSO and project RBAC only with the Teams add-on, and data regions US, EU, Japan and HIPAA (accessed 2026-08-10)
- langfuse.com/pricing-self-host — Official self-host pricing and the source of the licensing detail: OSS is MIT with unlimited units and users and includes enterprise SSO and RBAC, while management APIs, project-level RBAC, data retention policies and audit logs are Enterprise. Also the source of the finding that Langfuse Assistant is unavailable on BOTH self-hosted tiers (accessed 2026-08-10)
- langfuse.com/press — Official company facts: founded 2023, Y Combinator W23, HQ Berlin for product and engineering with San Francisco for GTM, 16+ full-time employees, MIT licence, $4M seed November 2023 led by Lightspeed, General Catalyst (La Famiglia) and Y Combinator, acquired by ClickHouse January 2026 (accessed 2026-08-10)
- mcp.reference.langfuse.com — Official auto-generated MCP reference and the primary evidence for the Protocols score: server ID langfuse-cloud, 79 discovered tools, connection variants for Cloud EU, Cloud US, Cloud Japan, HIPAA US, self-hosted and local, Basic Auth with project-scoped keys (accessed 2026-08-10)
- langfuse.com/docs/api-and-data-platform/features/mc… — Official MCP server docs: native, stateless, streamableHttp, and the explicit warning that both read and write tools are enabled by default so clients must be allowlisted for read-only access (accessed 2026-08-10)
- langfuse.com/docs/observability/features/multi-moda… — Official multimodal docs: automatic base64 extraction to object storage, full MIME table across images, audio, video, documents and archives, free on Cloud while in beta with pricing reserved, and the self-hosting requirement for a publicly resolvable S3-compatible bucket (accessed 2026-08-10)
- langfuse.com/security — Official security overview: SOC 2 Type II, ISO 27001, annual third-party penetration tests, GDPR and DPA, masking, retention and deletion controls, AWS regions us-west-2, eu-west-1 and ap-northeast-1, and air-gapped self-hosting. Also evidence of the ClickHouse integration, because security, privacy and legal contacts are now @clickhouse.com addresses (accessed 2026-08-10)
- langfuse.com/docs/langfuse-assistant — Official Assistant docs: runs on the Langfuse MCP server, pauses for explicit approval before any write, scoped to the signed-in user's permissions, conversations saved per user and project, and the vendor's own statement that it is beta and may return incomplete results (accessed 2026-08-10)
- orrick.com/en/News/2026/01/Open-source-LLM-Observab… — Independent confirmation of the ClickHouse acquisition (deal counsel, 26/01/2026), founders Marc Klingen, Maximilian Deichmann and Clemens Rawert, prior capital from Y Combinator, Lightspeed and General Catalyst (accessed 2026-08-10)
- github.com/langfuse/langfuse — Official repository: 32,737 stars, 3,515 forks, 759 open issues, created May 2023, built on ClickHouse. Also documents that self-hosted instances report basic usage telemetry to a central PostHog by default, excluding traces, prompts, observations, scores and dataset contents (accessed 2026-08-10)
- github.com/langfuse/langfuse/issues/6198 — Independent user reports of v2-to-v3 migration failure at scale: Prisma deadlocks on the observations migration with 5M and 15M row tables, no built-in retry so failed jobs must be manually reset via SQL, and the maintainer-confirmed root cause that legacy rows share one created_at value so the migration cursor never advances. Corroborated by issues 7117, 7743 and 4662 (accessed 2026-08-10)
- thoughtworks.com/radar/platforms/langfuse — Independent analyst assessment: v3's ClickHouse, Redis and S3 architecture is more scalable but also more complex to self-host, SDKs now natively OpenTelemetry, and Langfuse held at Assess with the explicit caveat that teams should judge whether the infrastructure commitment is justified at their scale (accessed 2026-08-10)
- llmtools.cc/blog/langfuse-vs-braintrust — Independent head-to-head (26/07/2026): confirms self-host is free, MIT and near-complete with only a few features gated, prices the managed option at roughly $101/month at 1M events, and flags both the four-service operational burden and the ClickHouse ownership question as the two things to weigh (accessed 2026-08-10)