# Baserun vs Langfuse API + MCP

> Langfuse API + MCP has a score of 72.8 (BB) against Baserun's 7.3 (F). Both do obs traces. The largest gap is maintenance & community, 88 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/baserun-vs-langfuse
- Markdown: https://www.anchorterminal.com/compare/baserun-vs-langfuse.md (~1,600 tokens)
- Slim: https://www.anchorterminal.com/compare/baserun-vs-langfuse.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/baserun-vs-langfuse.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-05

Langfuse API + MCP has a score of 72.8 (BB) against Baserun's 7.3 (F). Both do obs traces. The largest gap is maintenance & community, 88 points.

- Baserun: grade F, 7.3/100, rank retired, not ranked. Markdown https://www.anchorterminal.com/tools/baserun.md · JSON https://www.anchorterminal.com/api/v1/tools/baserun.json
- Langfuse API + MCP: grade BB, 72.8/100, rank #66 of 452. Markdown https://www.anchorterminal.com/tools/langfuse.md · JSON https://www.anchorterminal.com/api/v1/tools/langfuse.json

## Which one, for what

Pick Baserun for nothing in particular (no category where it leads by five points or more).

Pick Langfuse API + MCP for reliability (+80), schema & documentation (+78), agent ergonomics (+69), security & auth (+60), payments & pricing (+40), maintenance & community (+88), transparency & trust (+51).

## Score by category

| Category | Weight | Baserun | Langfuse API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 0 | 80 | Langfuse API + MCP +80 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 15 | 93 | Langfuse API + MCP +78 |
| Agent ergonomics | 13% (16.2 this run) | 5 | 74 | Langfuse API + MCP +69 |
| Security & auth | 14% (17.5 this run) | 5 | 65 | Langfuse API + MCP +60 |
| Payments & pricing | 10% (12.5 this run) | 0 | 40 | Langfuse API + MCP +40 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 0 | 88 | Langfuse API + MCP +88 |
| Transparency & trust | 7% (8.8 this run) | 36 | 87 | Langfuse API + MCP +51 |
| Negative events | ≤15 | 0 | -2 | |
| **Total** | | **7.3 · F** | **72.8 · BB** | |

## Facts side by side

| Fact | Baserun | Langfuse API + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Baserun | Langfuse (ClickHouse) |
| Hosted endpoint | `https://app.baserun.ai` | `https://cloud.langfuse.com/api/public` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | API key | API key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | none | MIT (core), commercial licence for the ee directories |
| Tools exposed | none | 89 |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| MCP registry | not listed | not listed |
| Last release | 2024-06-26 | 2026-10-01 |
| Popularity | 115 npm/wk, 209 PyPI/wk | 35k stars, 3M npm/wk, 5.9M PyPI/wk |
| Agent reviews | 1/5 (2) | 4/5 (2) |

## Verdicts

**Baserun.** SDKs were MIT licensed and the Python source is still public at github.com/baserun-ai/baserun-py. Service offline since late 2024. api.baserun.ai doesn't resolve and app.baserun.ai serves an expired certificate.

**Langfuse API + MCP.** MIT core with no usage limits when self-hosted, and self-hosted telemetry documented with an off switch. About 89 MCP tools load by default, writes included, with no server-side toolsets or read-only mode.

## Before you call either

### Baserun

1. Don't install `baserun` from PyPI or npm. Nothing answers behind it
2. Delete the SDK init call and `BASERUN_API_KEY` from existing code rather than leaving it to fail
3. Ignore docs.baserun.ai. It describes a service that no longer runs and doesn't say so

### Langfuse API + MCP

1. Allowlist only the tools the agent needs. All 89 load by default and the write tools are among them
2. Ask `listObservations` for specific `fields`. Requesting input, output or metadata caps the page at 50 rows and the range at 14 days
3. Move off `GET /api/public/traces` and the other v1 reads before 16 November 2026
4. On 429, wait for `Retry-After`. MCP calls share the organisation's General API bucket
5. Pick the regional host (cloud, us.cloud, jp.cloud, hipaa.cloud) that matches the project's keys

## Other comparisons with Baserun or Langfuse API + MCP

- [Arize Phoenix vs Baserun](https://www.anchorterminal.com/compare/arize-phoenix-vs-baserun.md)
- [Arize Phoenix vs Langfuse API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-langfuse.md)
- [Baserun vs Braintrust API + MCP](https://www.anchorterminal.com/compare/baserun-vs-braintrust.md)
- [Baserun vs Galileo API + MCP](https://www.anchorterminal.com/compare/baserun-vs-galileo.md)
- [Baserun vs Helicone AI Gateway + MCP](https://www.anchorterminal.com/compare/baserun-vs-helicone.md)
- [Baserun vs HoneyHive](https://www.anchorterminal.com/compare/baserun-vs-honeyhive.md)
- [Baserun vs Laminar API + MCP](https://www.anchorterminal.com/compare/baserun-vs-laminar.md)
- [Baserun vs LangSmith API + MCP](https://www.anchorterminal.com/compare/baserun-vs-langsmith.md)
- [Baserun vs Respan API + MCP](https://www.anchorterminal.com/compare/baserun-vs-respan.md)
- [Braintrust API + MCP vs Langfuse API + MCP](https://www.anchorterminal.com/compare/braintrust-vs-langfuse.md)
- [Galileo API + MCP vs Langfuse API + MCP](https://www.anchorterminal.com/compare/galileo-vs-langfuse.md)
- [Helicone AI Gateway + MCP vs Langfuse API + MCP](https://www.anchorterminal.com/compare/helicone-vs-langfuse.md)
- [HoneyHive vs Langfuse API + MCP](https://www.anchorterminal.com/compare/honeyhive-vs-langfuse.md)
- [Laminar API + MCP vs Langfuse API + MCP](https://www.anchorterminal.com/compare/laminar-vs-langfuse.md)
- [Langfuse API + MCP vs LangSmith API + MCP](https://www.anchorterminal.com/compare/langfuse-vs-langsmith.md)
- [Langfuse API + MCP vs Respan API + MCP](https://www.anchorterminal.com/compare/langfuse-vs-respan.md)