ClickHouseAI Observability
Langfuse
Langfuse traces and evaluates LLM apps and agents. It versions prompts on Langfuse Cloud or self-hosted under the MIT license. ClickHouse acquired it in January 2026.
The 30-Second Take
Pick Langfuse for tracing, evals and prompt versioning when trace data must stay in your own infrastructure.
ClickHouse has owned the MIT-licensed platform since January 2026. Pinterest and Khan Academy trace production agents in it.
- Best fit
- Teams shipping LLM apps or agents that want tracing, evals, and prompt versioning in one open-source platform they can self-host.
- Main constraint
- Self-hosting requires ClickHouse, PostgreSQL, Redis, and S3. Cloud counts each trace and observation as a unit, plus each score.
- First move
- Trace one production service with the v4 SDKs or OpenTelemetry on Langfuse Cloud Core, with a spend alert set.
Why
Watch the stack: self-hosting means ClickHouse, Redis and S3 with an owner, and on Cloud every trace, observation and score bills as a unit. Langfuse Cloud moves to v4 on November 16, 2026, and old SDKs will not survive it.
26 practitioners, 103 sources reviewed, Updated Oct 30, 2026How this is measured
- Operating stack
- AI Application Platform
Comparisons
How does Langfuse compare with the alternatives?
Langfuse vs LangSmith
- AI Observability
Pick Langfuse when trace data must stay on your servers without a contract: its MIT-licensed core self-hosts free, and Cloud bills units of traces, observations, and scores. Pick LangSmith, billed per seat and per trace, for one vendor that traces and hosts LangGraph agents; it self-hosts only on Enterprise.
Langfuse vs Arize
- AI Observability
bbv left Arize Phoenix for Langfuse over Phoenix's license, and Bayes Impact moved to Phoenix for a lighter stack. Pick Langfuse to self-host free under the MIT license with prompt management included. Pick Arize AX when the same team also monitors classification or ranking models for drift and performance.
Langfuse vs Braintrust
- AI Observability
CREATE SOMETHING retired Braintrust for Langfuse in July 2026. Pick Langfuse to run the whole platform yourself; at 200,000 traces a month GILD's calculation from published rates puts its Pro plan at US$369 against US$474 on Braintrust Pro. Pick Braintrust for a managed eval product when scores per trace stay few.
Operator Insights
What are teams learning from building on Langfuse and running it in production?
Ryan and DavidRamp engineersRamp
Agents across expense, close and an internal coding agent, on self-hosted Langfuse with ClickHouse Cloud.
ClickHouse on YouTube, published Watch the talk (opens ClickHouse on YouTube in a new tab)
Observation
Ramp's Reflect agent scores and clusters traces in self-hosted Langfuse and proposes fixes that owners accept.
- Takeaway
- Once traces are complete, an agent that reads them can propose the fixes; keep a human owner accepting each one.
- What happened
- Ramp runs its agent tracing on self-hosted Langfuse. Its Reflect agent scores and clusters those traces and proposes fixes for an owner to accept. Reflect covers 12 agents and more than 120 merged suggestions; on the Research agent alone, 60 or more merged suggestions cut tokens 10 to 20%, tool calls 15% and session time 30% (talk on ClickHouse's YouTube channel, Sep 17, 2026).
- Vendor customer story (talk on the YouTube channel of ClickHouse, which owns Langfuse)
- Token and latency changes reported
Deployment details
Agents across expense, close and an internal coding agent, on self-hosted Langfuse with ClickHouse Cloud.
- Vendor customer story (talk on the YouTube channel of ClickHouse, which owns Langfuse)
- Token and latency changes reported
- Team
- Ramp engineering and data platform
- Workload
- 12 production agents
- Product version
- Self-hosted Langfuse on S3, Redis, Postgres, ECS and ClickHouse Cloud
- Measurement
- Tokens, tool calls and session time before and after accepted fixes
In SignalsNot counted. ClickHouse, which owns Langfuse, published the talk, so its record is listed and counts toward no figure.
Jérémie DoucyContributor, bayes-platformBayes Impact
Bayes Impact's bayes-platform, in staging and production, exporting LLM traces over OpenTelemetry.
GitHub (bayesimpact/bayes-platform), published Read the write-up (opens GitHub (bayesimpact/bayes-platform) in a new tab)
Observation
Bayes Impact is leaving Langfuse: a merged pull request has its platform emit plain OpenTelemetry, and a collector sends LLM traces to Arize Phoenix.
- Takeaway
- Export plain OpenTelemetry and let a collector pick the backend, so leaving Langfuse is a collector change, and plan the replacement's production database and authentication before you move.
- What happened
- A pull request merged on September 29, 2026 deleted the platform's 673-line Langfuse exporter, the langfuse packages and two Google Cloud OpenTelemetry exporters. The platform now emits standard OTLP and knows no trace backend; an OpenTelemetry Collector maps spans to OpenInference and sends them to Phoenix. The plan keeps Langfuse up, read-only, for 30 days, until both hold the same trace history, and the Cloud Run production environment has no gateway yet and exports nothing with this version. The same pull request notes that the Phoenix bundled in its Helm chart is documented as not production ready, with no authentication and SQLite by default.
“…the platform emits standard OTLP and knows no trace backend. The OpenTelemetry Collector does the mapping to OpenInference and sends the LLM traces to Phoenix.”
Jérémie Doucy - Public engineering write-up (GitHub pull request)
- Code change merged
Deployment details
Bayes Impact's bayes-platform, in staging and production, exporting LLM traces over OpenTelemetry.
- Public engineering write-up (GitHub pull request)
- Code change merged
- Team
- Bayes Impact platform engineering
- Workload
- LLM traces from the bayes-platform services
- Product version
- Langfuse exporter and langfuse packages, removed on September 29, 2026
In SignalsCounted once, as the contributor's own pull request. In the record
Buying and deployment
What a team building on it should verify before production traffic grows.
Sourced from Langfuse documentation
Signals
What is the current evidence saying about Langfuse?
Named teams at Pinterest, Cresta, Khan Academy and SuperDial trace production agents in Langfuse, while Bayes Impact and one self-hoster moved to Phoenix to run less infrastructure. Each finding links to its public sources, and the problem-first research records added on Oct 28, 2026 take no side.
Practitioner sentiment, teams and leaders
+46 Positive net
of 26 sources that take a side, each author counted once. Small sample.
How this figure is madeCurrent sentiment
Positive, mixed and negative sources
No source is negative.
Team accounts lean positive, and 26 team and leadership sources give an opinion. All 4 discussing open source and self-hosting praise it. Upgrades draw the most concern, in 5 of 6 sources discussing them. Eight use OpenTelemetry to keep the backend replaceable. Platform choice now splits evenly, 5 to 5, since Apify moved its evals to Langfuse.
Run a pilot on one production app to measure which failures it surfaces and how long tracing them takes.
Evidence field. All 103 sources, one mark each.
Arrange by
Each mark is one source: positive, mixed, negative, no opinion stated, or documentation (not counted).
| Group | Sources | Positive | Mixed | Negative | No opinion stated and not counted in the score | Documentation, checked and not counted |
|---|---|---|---|---|---|---|
| Positive | 12 | 12 | 0 | 0 | 0 | 0 |
| Mixed | 14 | 0 | 14 | 0 | 0 | 0 |
| Negative | 0 | 0 | 0 | 0 | 0 | 0 |
| Not counted | 5 | 0 | 0 | 0 | 5 | 0 |
| Documentation | 15 | 0 | 0 | 0 | 0 | 15 |
| Outside this group | 57 | 17 | 16 | 10 | 14 | 0 |
| Quarter | Sources |
|---|---|
| Q1 2025 | 3 |
| Q2 2025 | 6 |
| Q3 2025 | 10 |
| Q4 2025 | 6 |
| Q1 2026 | 15 |
| Q2 2026 | 8 |
| Q3 2026 | 26 |
| Q4 2026 | 14 |
| Documentation, checked | 15 |
By sentiment
15 documentation pages check facts and are not counted; 57 sit outside this group.
Hover a mark for a quick look, click it or press Enter to open its source.Tap a mark to open its source, then step to its neighbors with Previous and Next.
What practitioners praise
Each mark is a source on it; filled marks praise it.
Most common concerns
Each mark is a source on it; filled marks raise it.
All 103 sources behind these findings
- Comment on: Ask HN: Has anyone used Phoenix, Langfuse, or OpenObserve?jack_bing, Hacker News commenter (self-described: Has used both Langfuse and Pydantic Logfire), Hacker News comment, published Oct 28, 2026
- Comment on: Ask HN: Has anyone used Phoenix, Langfuse, or OpenObserve?Applied_AI, Hacker News commenter (self-described: Traces agents in Langfuse), Hacker News comment, published Oct 28, 2026
- Post on X asking about self-hosted LLM observabilityYash Solanki, X user (self-described: Uses Langfuse and wants a lighter self-hosted tracer on Cloudflare), X post, published Oct 27, 2026
- Reply on X about Phoenix and LangfuseJimothy de la Cruz, Senior Software Engineer (X profile) (self-described: Tried both Phoenix and Langfuse), X post, published Oct 27, 2026
- Best langfuse alternative with evals and governance built in? new customer says no data outside the EUOk-Balance6208, Reddit poster (self-described: Two-person platform team; a new enterprise customer's contract requires EU-only data), Reddit post, r/LangChain, published Oct 26, 2026
- bug: ClickHouse migration 0050 fails on historical Compact scores parts on recommended 26.4Alan Munirji (alanmun), issue author; Codex filed it on his behalf (self-described: Self-hosted Langfuse in production, upgrading from 4.28.1 to 4.70.1 on ClickHouse 26.4), GitHub issue, published Oct 26, 2026
- bug: Graph view freezes the browser for seconds on traces with nested spans (quadratic step adjustment in buildStepData)kumarpriyanshu09, issue author and past contributor to langfuse/langfuse (self-described: Agent traces with thousands of nested observations), GitHub issue, published Oct 26, 2026
- Reply on X about cost tags on agent tracesJack Rudenko, CTO at MadAppGang (X profile) (self-described: MadAppGang's evaluation of agent frameworks), X post, published Oct 23, 2026
- Post on X about self-hosting Langfuse for data residencyHaresh, GenAI Engineer (X profile) (self-described: Client work with data residency requirements, Langfuse self-hosted in the client's Azure tenant), X post, published Oct 21, 2026
- Comment on: Do we really need wrappers like LangChain/LlamaIndex?NatureLucky4912, Reddit commenter (self-described: Built an end-to-end production RAG engine without LangChain), Reddit comment, r/LangChain, published Oct 15, 2026
- Post on X about getting started with evaluation toolsGanesh Iyer, AI payments builder and creator of the Nura family assistant (X profile) (self-described: Tried Arize, Langfuse and Braintrust while building his own apps), X post, published Oct 13, 2026
- PricingLangfuse (Official), Product documentation, checked Oct 12, 2026
- Billable unitsLangfuse (Official), Product documentation, checked Oct 12, 2026
- Self-hosted pricingLangfuse (Official), Product documentation, checked Oct 12, 2026
- Self-host LangfuseLangfuse (Official), Product documentation, checked Oct 12, 2026
- Migrate Langfuse v3 to v4 (self-hosted)Langfuse (Official), Product documentation, checked Oct 12, 2026
- Langfuse v4 is liveLangfuse (Official), Product documentation, checked Oct 12, 2026
- Data retentionLangfuse (Official), Product documentation, checked Oct 12, 2026
- Data regionsLangfuse (Official), Product documentation, checked Oct 12, 2026
- Security and complianceLangfuse (Official), Product documentation, checked Oct 12, 2026
- MaskingLangfuse (Official), Product documentation, checked Oct 12, 2026
- OpenTelemetryLangfuse (Official), Product documentation, checked Oct 12, 2026
- Evaluation overviewLangfuse (Official), Product documentation, checked Oct 12, 2026
- Prompt managementLangfuse (Official), Product documentation, checked Oct 12, 2026
- Spend alertsLangfuse (Official), Product documentation, checked Oct 12, 2026
- AlertsLangfuse (Official), Product documentation, checked Oct 12, 2026
- bug: recurring Worker Redis socket timeouts; upstream ioredis reconnect fix not includedklaus-zzz, issue author (self-described: Self-hosted Langfuse Worker in production, after heavy OTLP ingestion), GitHub issue, published Oct 10, 2026
- fix(langfuse): read traces via Observations API v2 before Langfuse Cloud's v4 cutovernimrodbusany, Traigent maintainer (self-described: Traigent SDK's Langfuse connector), GitHub pull request, published Oct 7, 2026
- epic: digitrace rename + self-hosted Langfuse on Cloudflare (cut LangSmith)Chris (chrizefan), owner and approver of tooling decisions at digithings.ai (self-described: digithings.ai LangGraph workloads), GitHub issue, published Oct 1, 2026
- feat(observability): export traces over OTLP and link them to Phoenix instead of LangfuseJérémie Doucy, contributor to the Bayes Impact platform (self-described: Bayes Impact platform, staging and production), GitHub pull request, published Sep 29, 2026
- G11: Temporal replaces ARQ; Langfuse removedamruthvvkp, maintainer of DraftPilot (self-described: Personal project stack), GitHub issue, published Sep 27, 2026
- bug: Data retention mutations accumulate and block async inserts on S3-backed self-hosted ClickHouseNiranchana08, issue author (self-described: Self-hosted Langfuse on S3-backed ClickHouse, several projects writing hundreds of traces a minute), GitHub issue, published Sep 24, 2026
- feat(#126): migrate Langfuse to JS SDK v5 for the v4 observations modelalexosugo, contributor to Medic's cht-agent (self-described: Medic's Community Health Toolkit agent), GitHub pull request, published Sep 23, 2026
- fix(models): migrate Langfuse integration to v4 SDKVimarshDwivedi, contributor to CAMEL (self-described: CAMEL agent framework's Langfuse integration), GitHub pull request, published Sep 21, 2026
- Set up a .NET application w/th OpenTelemetry, and trace/evaluate in LangfuseThang Chung, Engineer at Tiger Tribe (HEINEKEN) (self-described: AI-infused products across the company), dev.to article, published Sep 21, 2026
- How we migrated to Langfuse v4 ahead of the cutoverUttam Kumaran, Founder & CEO, Brainforge (Brainforge agent platform with Mastra agents, chat routes, voice traces, and Cloudflare workers on Langfuse Cloud), Company engineering blog post, Brainforge blog, published Sep 18, 2026
- Maintenance: complete the Langfuse v4 migration (JS SDK v5) before the 2026-11-16 cutover99Yash, maintainer of alfred (self-described: Production on Langfuse Cloud, self-hosted dev stack), GitHub issue, published Sep 17, 2026
- chore(langfuse): migrate tracing and experiments to v4tatoalo, contributor to Sure (self-described: Sure, an open-source personal finance app), GitHub pull request, published Sep 17, 2026
- How Ramp uses Langfuse: Observing, debugging, and continuously improving production AI agentsRyan Delgado and David Traina, Ryan Delgado (Engineering) and David Traina (Data Platform), Ramp (self-described: Ramp, agents across expense, close, and an internal coding agent; self-hosted Langfuse), Conference talk (hosted by ClickHouse, Langfuse's parent company), ClickHouse on YouTube, published Sep 17, 2026
- v4 backfill (M3): per-part chunking does not bound memory, full_sorting_merge sorts input/outputjokerleee-ctrl, issue author (self-described: Self-hosted production Langfuse running the v4 backfill), GitHub issue, published Sep 16, 2026
- Dual-write Event Propagation Job cursor stuck for 48+ hours, no errors loggedDanielRuVe, issue author (self-described: Self-hosted Langfuse on EKS with the Helm chart, mid-upgrade from v3 to v4 in dual-write mode), GitHub issue, published Sep 14, 2026
- chore(evals): Delete the Phoenix eval runnerJiří Spilka (jirispilka), Engineer at Apify (self-described: Apify MCP server evals), GitHub pull request, published Sep 14, 2026
- Comment on: I've operated petabyte-scale ClickHouse clusters for 5 yearsthreecheese, Hacker News commenter (self-described: Local instance on a laptop), Hacker News comment, published Sep 11, 2026
- Epic: Explore Langfuse (self-hosted) for LLM engineering & observabilitypkuppens, maintainer of healthcare-aigent (self-described: Five-stage CrewAI clinical pipeline), GitHub issue, published Sep 8, 2026
- Cut local stack from ~47 containers to 14; Langfuse → LangSmithTitus Lim, data scientist (self-described: Agent application template), GitHub pull request, published Sep 3, 2026
- ADR: record the Langfuse swap-cost decision with a named revisit triggerTheConnMan, maintainer of Curie (self-described: Curie product shipping Langfuse as its trace store), GitHub issue, published Aug 29, 2026
- observability: the demo box cannot host self-hosted Langfuse (about 6 CPU and 16 GiB marginal, ClickHouse floor 8 GiB)sakibsadmanshajib, maintainer of hive (self-described: Small shared server for the hive project), GitHub issue, published Aug 29, 2026
- Which Bin Goes Out Tonight? Tracing A2A Agents Without Burning Your Free TierHugo Lesta (hugolesta), DevOps engineer, home cluster (self-described: Three-agent A2A bot on a home cluster), dev.to article, published Aug 14, 2026
- bug: v4 unified Tracing table cannot display trace total cost - root SPAN rows show $0.00HectorPascual, developer (issue author) (self-described: LangGraph agent in production), GitHub issue, published Aug 13, 2026
- feat: self-hosted OTel observability (Phoenix/Langfuse) for multi-agent tracing - not LangSmithAndrew Kaszubski, maintainer of the autonomous-dev Claude Code plugin (self-described: Multi-agent coding harness, local-first), GitHub issue, published Aug 6, 2026
- feat(observability): standardise on Phoenix; restore Langfuse v4 as fallbackJordi Martinez, developer (self-described: Own infrastructure, run locally and on an AWS host), GitHub pull request, published Aug 6, 2026
- Architecting AI Systems for the Messy Reality of Enterprises: Why Agentic Compute is the Missing LayerArun Joseph, co-founder & CEO of Masaic, former head of AI engineering at Deutsche Telekom (Enterprise agent platform that exports OpenTelemetry from the collector), Conference talk with transcript, InfoQ Dev Summit Munich 2025, published Aug 3, 2026
- Medic for Apache Spark - First Aid for Failing JobsDrasko Profirovic, Staff Engineer, Pinterest (Pinterest's Medic agent, which diagnoses failing Spark jobs through MCP tools over job logs and metrics), Conference talk with transcript, AI Engineer World's Fair 2026, published Jul 20, 2026
- Retire Braintrust for Langfusecreatesomethingtoday, CREATE SOMETHING repository owner (pull request author) (self-described: CREATE SOMETHING monorepo: evals, telemetry, prompts and MCP services), GitHub pull request, published Jul 6, 2026
- Strands Agents + Langfuse EvaluationsRoger Viñas Alcon, Developer (self-described: Banking assistant agent trial), dev.to article, published Jul 2, 2026
- Comment on: AI OSS tool repo goes archived over night after raising $7.3M Seedspmurrayzzz, Hacker News commenter (self-described: Hacker News thread: AI OSS tool repo goes archived over night after raising US$7.3M Seed), Hacker News comment, published Jun 13, 2026
- What I learned using Langfuse in a real AI recruiting agentmarginTop15px, Reddit user, r/LLMDevs (self-described: AI recruiting platform with a Clojure backend and a Python agent layer), Reddit post, published Jun 3, 2026
- Spent 3 months evaluating Galileo, Arize, Langfuse and LangSmith for production LLM monitoring. Notes for anyone doing the same.Total_Listen_4289, Reddit user, r/LLMDevs (self-described: Small team shipping agents, evaluating observability for production), Reddit post, published May 30, 2026
- I ran langfuse, langsmith and helicone in prod for a month and only one of them stuckrafio77, Reddit user, r/LLMDevs (self-described: Production agents, three tools run side by side for a month), Reddit post, published May 20, 2026
- LLM Observability with Self-Hosted Langfuse and vLLMVikram Singh, PyImageSearch author (self-described: Tutorial series tracing a local vLLM app), Tutorial blog post, PyImageSearch, published May 18, 2026
- Langfuse v3 Self-Hosting - Complete LLM Tracing GuideKim Jangwook, web developer (jangwook.net) (self-described: Two personal and client projects, one on Langfuse Cloud and one self-hosted), Personal blog post, jangwook.net, published May 3, 2026
- Prototyping complex LLM agents? DO NOT use LangFuse or LiteLLM - use CLI coding agents or provider-native SDKs.JustZed32, Reddit user, r/LLMDevs (self-described: Coding agent for an enterprise workflow, prototyping stage), Reddit post, published Apr 13, 2026
- One Registry to Rule them AllSonny Merla, Global Data Science & AI Manager, Amplifon (Amplifon's AmplifAI program, co-presented with Quantyca engineers who built its MCP and A2A blueprints), Conference talk with transcript, AI Engineer Europe 2026, published Apr 10, 2026
- Observability for AI Agents: Tracing Multi-Service LLM Pipelines with LangfuseJames Idzik, Software Engineer at Cresta (self-described: Cresta, AI agents for customer conversations, self-hosted Langfuse per Kubernetes cluster), Engineering blog post (co-written with Langfuse), Cresta engineering blog, published Mar 26, 2026
- Allow using
metadatafields (e.g.organizationId) as Breakdown Dimension in Dashboard Widgetstjain1511, developer (issue author) (self-described: Multi-tenant product), GitHub issue, published Mar 16, 2026 - PSA: Check your Langfuse traces. Their SDK intercepts other tools' traces by default and charges you for them.alxdan, Reddit user, r/LocalLLaMA (self-described: Langfuse v3.12 beside DeepEval in the same process), Reddit post, published Mar 12, 2026
- Replace Langfuse with Phoenix, add LiteLLM proxy, add Snowflake Labs MCPMichael Svendsen, developer (self-described: Own self-hosted agent stack with LibreChat and LiteLLM), GitHub pull request, published Mar 4, 2026
- Comment on: Ask HN: What is the "Control Plane" for local AI agents?KurSix, Hacker News commenter (self-described: Hacker News thread: Ask HN: What is the "Control Plane" for local AI agents?), Hacker News comment, published Mar 4, 2026
- feat(aihub): Replace Arize Phoenix with Langfusemfundn, developer on bbvch-ai's AI Hub (self-described: bbvch-ai AI Hub, agent tracing and datasets), GitHub pull request, published Feb 10, 2026
- bug: Filters for traces are not working like expectednzuchna, developer (issue author) (self-described: Self-hosted v3.150.0 with LLM-as-a-judge), GitHub issue, published Feb 4, 2026
- Comment on: ClickHouse acquires Langfuseagsqwe, Hacker News commenter (self-described: Hacker News thread: ClickHouse acquires Langfuse), Hacker News comment, published Jan 18, 2026
- Comment on: ClickHouse acquires Langfuseaxpy906, Hacker News commenter (self-described: Hacker News thread: ClickHouse acquires Langfuse), Hacker News comment, published Jan 18, 2026
- Comment on: ClickHouse acquires Langfuseponywombat, Hacker News commenter (self-described: Hacker News thread: ClickHouse acquires Langfuse), Hacker News comment, published Jan 17, 2026
- Comment on: ClickHouse acquires Langfusedandelionv1bes, Hacker News commenter (self-described: Evaluating for a wider recommendation), Hacker News comment, published Jan 17, 2026
- Comment on: Cursor's latest "browser experiment" implied success without evidenceRoark66, Hacker News commenter (self-described: Personal LLM proxy), Hacker News comment, published Jan 17, 2026
- Comment on: ClickHouse acquires Langfusefloriferous, Hacker News commenter (self-described: Hacker News thread: ClickHouse acquires Langfuse), Hacker News comment, published Jan 17, 2026
- Comment on: Langfuse Joins ClickHouseossa-ma, Hacker News commenter (self-described: Hacker News thread: Langfuse Joins ClickHouse), Hacker News comment, published Jan 16, 2026
- Comment on: Lightpanda migrate DOM implementation to Zighobofan, Hacker News commenter (self-described: EratoLab, MCP server stack), Hacker News comment, published Jan 12, 2026
- Comment on: Ask HN: What agent frameworks are you using, and how well do they work?walpurginacht, Hacker News commenter (self-described: Hacker News thread: Ask HN: What agent frameworks are you using, and how well do they work?), Hacker News comment, published Dec 17, 2025
- Any langfuse user that could help mePast-Today-2642, Reddit user, r/LLMDevs (self-described: LLM-as-a-judge evaluator on existing traces), Reddit post, published Dec 17, 2025
- bug: Experiments and Evaluators fail to parse Anthropic "thinking" block from reasoning modelsabhidadhaniya23, developer (issue author) (self-described: Experiments with Anthropic models), GitHub issue, published Dec 13, 2025
- Langfuse multi-step traces?Repulsive-Memory-298, Reddit user, r/LLMDevs (self-described: Agent with multi-step traces grouped by trace ID), Reddit post, published Nov 20, 2025
- Langfuse vs. MLflowmnze_brngo_7325, Reddit user, r/LLMDevs (self-described: pydantic-ai agents, self-hosted open-source tools only), Reddit post, published Nov 13, 2025
- bug: Incompatibility with Python 3.14corrylc, developer (issue author) (self-described: GitHub repository langfuse/langfuse), GitHub issue, published Oct 8, 2025
- Comment on: LLM Observability in the Wild, Why OpenTelemetry Should Be the Standard7thpower, Hacker News commenter (self-described: Hacker News thread: LLM Observability in the Wild, Why OpenTelemetry Should Be the Standard), Hacker News comment, published Sep 30, 2025
- Comment on: LLM Observability in the Wild, Why OpenTelemetry Should Be the Standardjkisiel, Hacker News commenter (self-described: Small startup), Hacker News comment, published Sep 28, 2025
- LLM Observability: Debugging My Journaling AgentMargarita Sliachina, Data scientist (self-described: AI journaling assistant side project), dev.to article, published Sep 20, 2025
- Comment on: Building your own CLI coding agent with Pydantic-AIbluecoconut, Hacker News commenter (self-described: Hacker News thread: Building your own CLI coding agent with Pydantic-AI), Hacker News comment, published Aug 28, 2025
- Comment on: It is worth it to buy the fast CPUscreye, Hacker News commenter (self-described: Local agent development), Hacker News comment, published Aug 24, 2025
- Comment on: Open SWE by LangChainNeutralCrane, Hacker News commenter (self-described: Hacker News thread: Open SWE by LangChain), Hacker News comment, published Aug 11, 2025
- bug(python-sdk): Using @observe with FastAPI StreamingResponse breaks everything up into separate traces.willriley, developer (issue author) (self-described: Self-hosted, FastAPI app), GitHub issue, published Jul 30, 2025
- Langfuse Data retention: self Hostednomo-fomo, Reddit user, r/LangChain (self-described: Self-hosted Langfuse community edition), Reddit post, published Jul 28, 2025
- Setting up a local Langfuse server with Kubernetes to trace Agentic systemsJetze Schuurmans, Machine Learning Engineer, Xebia (self-described: Xebia team's local GPU cluster for sensitive LLM applications), Engineering blog post, Xebia blog, published Jul 9, 2025
- Comment on: Show HN: HomeBrew HN, Generate personal context for content rankingazath92, Hacker News commenter (self-described: Small team, side project), Hacker News comment, published Jul 3, 2025
- Review of LangSmith by Kyle RushKyle Rush, Maker of Astrid: Personal Shopping Agent (self-described: Astrid shopping agent team), Product Hunt review, published Jun 22, 2025
- Comment on: Building Effective AI Agentssuninsight, Hacker News commenter (self-described: NonBioS, AI engineering agent), Hacker News comment, published Jun 19, 2025
- Add support for conditional rendering in prompt managementharrygao56, developer (issue author) (self-described: Prompts with conditional instructions), GitHub issue, published May 19, 2025
- Comment on: Gemini 2.5 Pro Previewsimple10, Hacker News commenter (self-described: Local LLM proxy for coding tools), Hacker News comment, published May 6, 2025
- Languse V3 Clickhouse Cpu Consumptionbenm5678, developer (issue author) (self-described: Team running Langfuse locally for developers), GitHub issue, published Apr 23, 2025
- Voice AI: Your Bot Isn't SpecialNik Caryotakis, Staff Software Engineer, SuperDial (SuperDial voice agents that place long healthcare phone calls, with a TensorZero gateway in front of the models), Conference talk with transcript, AI Engineer Summit 2025, published Apr 18, 2025
- The NonBioS LLM Observability PickAmit, NonBioS author (self-described: NonBioS AI engineer product), Company blog post, NonBioS blog, published Mar 5, 2025
- bug: Clickhouse Migration Failure After Version v3.28.2tubone24, developer (issue author) (self-described: Self-hosted upgrade), GitHub issue, published Feb 16, 2025
- Scaling AI in Education: A Khanmigo case studyShawn Jansepar, Director of AI and Learning, Khan Academy (self-described) (Khanmigo AI tutor, where an AI platform team owns the developer experience for product teams), Conference talk with transcript, AI Engineer World's Fair 2024, published Feb 5, 2025
Feb 2025 to Oct 2026.
88 sources from practitioners, by month and sentiment.
Where It Fits
Where does Langfuse belong in the stack?
Langfuse is Core across Evaluate and Operate and touches Model, Build, and Data.
- Business area
- Product & Engineering
- Function
- Software Development
- Operating stack
- AI Application Platform
- Primary role
- Open-Source LLM Tracing, Evaluation & Prompt Management
Model
Model APIs: Touches
Model APIs, touches. Langfuse records application calls to OpenAI, Anthropic, Google, Bedrock, and other providers, including token usage and cost. It supplies no models.
Model gateway: Touches
Model gateway, touches. Gateways such as LiteLLM, OpenRouter, and Portkey send traces to Langfuse. They route model traffic. Langfuse's Playground and LLM judges call providers through your configured LLM connections.
Build
Orchestration: Touches
Orchestration, touches. Langfuse traces agents through native integrations or OpenTelemetry and builds agent graphs from their traces. Supported frameworks include LangGraph, the OpenAI Agents SDK, Pydantic AI, the Vercel AI SDK, and CrewAI. Those frameworks run the agents.
Tool use: Touches
Tool use, touches. Langfuse records tool and MCP calls. Its MCP server and CLI let coding agents read traces and prompts, plus datasets. The agent runtime executes tools.
Data
Retrieval: Touches
Retrieval, touches. Langfuse records retrieval steps and latency. Evaluators score whether answers follow retrieved context. Your application embeds and indexes its documents and stores them elsewhere.
Evaluate
Evaluation: Core
Evaluation, core. Langfuse measures changes to prompts, models, or code before and after release through dataset experiments in the UI, SDK, or CI. It supports LLM judges and code or decision-model evaluators, plus annotation queues and score analytics.
Operate
Observability: Core
Observability, core. Langfuse traces apps and agents through Python and JS/TS SDKs, native integrations, or OpenTelemetry. Cloud and self-hosted versions track sessions and users, plus tokens and costs, with dashboards, monitors, and alerts.
Cloud deployment: Touches
Cloud deployment, touches. Langfuse Cloud runs on AWS and ClickHouse Cloud. Self-host through Docker Compose, a Helm chart, or Terraform modules for AWS, Azure, and GCP. Your models and agents run elsewhere.
Guardrails: Touches
Guardrails, touches. Langfuse traces and evaluates security checks from libraries such as LLM Guard, NeMo Guardrails, and Lakera. Those external libraries perform runtime screening and blocking.
Market mapThe layers Langfuse covers, and who else owns each one.
Evaluation & testing
Observability & tracing
Model APIs
Model gateways & routing
- LiteLLM
- OpenRouter
- Portkey
- Vercel AI Gateway
Orchestration & agent frameworks
4 more layers on the full map. Core, Supports and Touches describe coverage. They say nothing about quality.