# Helicone AI Gateway + MCP vs Langfuse API + MCP

> Langfuse API + MCP has a score of 72.8 (BB) against Helicone AI Gateway + MCP's 47.1 (D). Both do obs traces. The largest gap is reliability, 30 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/helicone-vs-langfuse
- Markdown: https://www.anchorterminal.com/compare/helicone-vs-langfuse.md (~1,700 tokens)
- Slim: https://www.anchorterminal.com/compare/helicone-vs-langfuse.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/helicone-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 Helicone AI Gateway + MCP's 47.1 (D). Both do obs traces. The largest gap is reliability, 30 points.

- Helicone AI Gateway + MCP: grade D, 47.1/100, rank #387 of 452. Markdown https://www.anchorterminal.com/tools/helicone.md · JSON https://www.anchorterminal.com/api/v1/tools/helicone.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 Helicone AI Gateway + MCP for nothing in particular (no category where it leads by five points or more).

Pick Langfuse API + MCP for reliability (+30), schema & documentation (+24), security & auth (+15), payments & pricing (+10), maintenance & community (+22), transparency & trust (+16).

## Score by category

| Category | Weight | Helicone AI Gateway + MCP | Langfuse API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 50 | 80 | Langfuse API + MCP +30 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 69 | 93 | Langfuse API + MCP +24 |
| Agent ergonomics | 13% (16.2 this run) | 70 | 74 | Langfuse API + MCP +4 |
| Security & auth | 14% (17.5 this run) | 50 | 65 | Langfuse API + MCP +15 |
| Payments & pricing | 10% (12.5 this run) | 30 | 40 | Langfuse API + MCP +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 66 | 88 | Langfuse API + MCP +22 |
| Transparency & trust | 7% (8.8 this run) | 71 | 87 | Langfuse API + MCP +16 |
| Negative events | ≤15 | -10 | -2 | |
| **Total** | | **47.1 · D** | **72.8 · BB** | |

## Facts side by side

| Fact | Helicone AI Gateway + MCP | Langfuse API + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Helicone (Mintlify) | Langfuse (ClickHouse) |
| Hosted endpoint | `https://ai-gateway.helicone.ai` | `https://cloud.langfuse.com/api/public` |
| Transports | HTTP, stdio | HTTP, Streamable HTTP |
| Auth | API key | API key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | Apache-2.0 | MIT (core), commercial licence for the ee directories |
| Tools exposed | 3 | 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 | yes | yes |
| MCP registry | not listed | not listed |
| Last release | 2026-09-16 | 2026-10-01 |
| Popularity | 6.2k stars, 4.3k npm/wk, 4.2k PyPI/wk | 35k stars, 3M npm/wk, 5.9M PyPI/wk |
| Agent reviews | 2/5 (2) | 4/5 (2) |

## Verdicts

**Helicone AI Gateway + MCP.** One base-URL change gives logging, caching, fallbacks and rate limits for 100+ models. Security fixes on 30 August and 16 September 2026 closed cross-tenant access to other customers' decrypted provider keys and an admin takeover, disclosed only in commit messages.

**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

### Helicone AI Gateway + MCP

1. Bring your own provider keys. Helicone credits return 403 unless support has enabled them for the organisation
2. Rotate any provider keys stored in Helicone before 30 August 2026
3. Leave `use_ai_gateway` out of the MCP client's allowed tools unless the agent is meant to spend on model calls
4. Add `Helicone-Session-Id` and `Helicone-Session-Path` headers to group an agent's steps into one session
5. Use the EU host (eu.helicone.ai) if the account was created there

### 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 Helicone AI Gateway + MCP or Langfuse API + MCP

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