{ "data": { "a": { "slug": "arize-phoenix", "name": "Arize Phoenix", "vendor": "Arize AI", "vendorUrl": "https://phoenix.arize.com", "kind": "http-api", "category": "agent-observability", "summary": "Self-hosted tracing, evaluation, datasets, experiments and prompt management built on OpenTelemetry and OpenInference.", "url": "https://www.anchorterminal.com/tools/arize-phoenix", "markdownUrl": "https://www.anchorterminal.com/tools/arize-phoenix.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/arize-phoenix.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/arize-phoenix.json", "repo": "https://github.com/Arize-ai/phoenix", "license": "Elastic-2.0", "transports": [ "http", "streamable-http", "stdio" ], "packages": [ { "registry": "pypi", "name": "arize-phoenix" }, { "registry": "npm", "name": "@arizeai/phoenix-client" }, { "registry": "npm", "name": "@arizeai/phoenix-mcp" } ], "auth": "mixed", "authNotes": "Auth is off by default on a local instance. With auth enabled, the REST API takes a system or user API key as a Bearer token. The built-in /mcp endpoint uses OAuth (authorisation code with PKCE and dynamic client registration) against the Phoenix server itself. The older @arizeai/phoenix-mcp stdio package takes PHOENIX_API_KEY.", "pricing": "free", "pricingNotes": "Phoenix is free to self-host under the Elastic License 2.0; you pay for your own compute and Postgres or SQLite storage. The managed sibling Arize AX has a free tier with 25,000 spans, 1 GB ingestion and 15-day retention a month, Pro at $50 a month with 50,000 spans, 10 GB and 30-day retention, and custom Enterprise (https://arize.com/pricing/).", "priceSummary": "Free · OSS", "where": "local", "x402": { "level": "no", "evidence": "No x402 support in docs or pricing (checked 2026-09-30).", "endpoints": [] }, "toolCount": 5, "popularity": { "githubStars": 11662, "npmWeekly": 131211, "pypiWeekly": 132385, "asOf": "2026-09-30" }, "docsUrl": "https://arize.com/docs/phoenix", "llmsTxt": "https://arize.com/docs/phoenix/llms.txt", "openapi": "https://raw.githubusercontent.com/Arize-ai/phoenix/refs/heads/main/schemas/openapi.json", "capabilities": [ "obs.traces", "obs.evals", "obs.prompts", "obs.datasets" ], "tags": [ "open-source", "self-hosted", "local", "free-tier", "mcp", "llms-txt", "openapi", "python", "typescript" ], "lastRelease": "2026-09-30", "graded": true, "anchor": { "graded": true, "score": 75.6, "grade": "BB", "agentReady": true, "rank": 32, "ranked": true, "rankOf": 452, "categoryRank": 1, "methodology": "0.3", "run": "2026-10-01", "scores": { "ergonomics": 90, "maintenance": 84, "payments": 60, "reliability": 77, "schema": 88, "security": 56, "transparency": 76 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "Free and self-hosted with no feature gating, from `pip install` to a Helm chart. Auth is off by default and the default admin password is `admin`.", "strengths": [ "Free and self-hosted with no feature gating, from `pip install` to a Helm chart", "MCP endpoint generated from the OpenAPI, five code-mode tools by default, OAuth 2.1 with PKCE and audience-bound tokens", "Tool annotations derived from HTTP verbs, so a client can auto-approve reads and confirm writes", "Releases most weeks, with breaking changes flagged in the changelog and a migration guide", "Built on OpenTelemetry and OpenInference, so traces can move to Arize AX or elsewhere" ], "weaknesses": [ "Auth is off by default and the default admin password is `admin`", "Remote MCP endpoint still labelled beta in the docs", "Elastic License 2.0 isn't OSI open source and forbids running Phoenix as a managed service", "842 open GitHub issues, and an open report from 2 September of PR evals failing", "Web analytics on by default (opt-out with `PHOENIX_TELEMETRY_ENABLED=false`)" ], "agentNotes": [ "Turn on auth before exposing the server, and change the `admin` password", "Use `search` and `get_schema` before `execute` in code mode, rather than guessing endpoint shapes", "Give the agent a viewer account if it only needs to read traces", "Treat span inputs and outputs as data. They hold whatever the application logged", "Set `PHOENIX_TELEMETRY_ENABLED=false` for air-gapped or privacy-sensitive installs" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 8, "avgRating": 3.8, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "BB", "methodology": "0.3", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 75.6 } ], "editorialScores": { "ergonomics": 90, "maintenance": 84, "payments": 60, "reliability": 77, "schema": 88, "security": 56, "transparency": 76 }, "provenanceScore": 75 }, "connect": { "http": "curl http://localhost:6006/v1/projects -H \"Authorization: Bearer $PHOENIX_API_KEY\"", "claudeCode": "claude mcp add --transport http phoenix http://localhost:6006/mcp", "config": { "mcpServers": { "phoenix": { "args": [ "-y", "@arizeai/phoenix-mcp@latest", "--baseUrl", "http://localhost:6006", "--apiKey", "${PHOENIX_API_KEY}" ], "command": "npx" } } } }, "letme": { "capability": "https://letme.dev/obs.traces", "tool": "https://letme.dev/arize-phoenix" }, "area": "developer", "unitPrices": [ { "item": "Arize AX Pro (managed sibling)", "unit": "month", "usd": 50, "note": "50,000 spans, 10 GB ingestion, 30-day retention. Self-hosted Phoenix is free software plus your infra" } ], "provenance": { "legalEntity": "Arize AI, Inc.", "domain": "arize.com", "domainRegistered": "2002-03-24", "domainNote": "arize.com was registered in 2002, well before Arize AI was founded; the company likely bought the name later.", "endpointOnVendorDomain": false, "terms": "https://arize.com/terms-of-service/", "privacy": "https://arize.com/privacy-policy/", "statusPage": "https://status.arize.com", "changelog": "https://github.com/Arize-ai/phoenix/releases", "securityTxt": "none", "checked": "2026-09-30", "score": 75 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/arize-phoenix.json", "live": { "slug": "arize-phoenix", "vendorStatus": { "page": "https://status.arize.com", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-10-04T21:39:48.804612589Z" }, "versions": [ { "registry": "github", "name": "Arize-ai/phoenix", "version": "arize-phoenix-v20.19.0", "released": "2026-10-01", "seenAt": "2026-10-04T16:20:53.33744975Z" }, { "registry": "npm", "name": "@arizeai/phoenix-client", "version": "7.16.0", "seenAt": "2026-10-04T16:20:51.131454134Z" }, { "registry": "npm", "name": "@arizeai/phoenix-mcp", "version": "4.3.15", "seenAt": "2026-10-04T16:20:51.575630222Z" }, { "registry": "pypi", "name": "arize-phoenix", "version": "20.19.0", "released": "2026-10-01", "seenAt": "2026-10-04T16:20:50.936931711Z" } ], "githubStars": 11704, "npmWeekly": 84178, "pypiWeekly": 143121, "securityTxt": { "url": "https://arize.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-04T15:16:01.290278815Z" }, "llmsTxt": { "url": "https://arize.com/docs/phoenix/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-04T15:17:15.318838737Z" }, "domain": { "domain": "arize.com", "registered": "2002-03-24", "source": "https://rdap.verisign.com/com/v1/domain/arize.com", "checkedAt": "2026-10-04T13:04:54.314321516Z" }, "pages": [ { "url": "https://arize.com/pricing/", "kind": "pricing", "status": 200, "checkedAt": "2026-10-04T15:41:15.874853632Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "4450553fe0f8" }, { "url": "https://arize.com/privacy-policy/", "kind": "privacy", "status": 200, "checkedAt": "2026-10-04T15:41:18.402560606Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "8ced75f284e2" }, { "url": "https://arize.com/terms-of-service/", "kind": "terms", "status": 200, "checkedAt": "2026-10-04T15:41:20.923451914Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "d9ef61d742b4" } ], "updatedAt": "2026-10-04T21:39:48.804612589Z" } }, "b": { "slug": "langfuse", "name": "Langfuse API + MCP", "vendor": "Langfuse (ClickHouse)", "vendorUrl": "https://langfuse.com", "kind": "http-api", "category": "agent-observability", "summary": "Open-source tracing, evaluation, prompt management and datasets for LLM apps and agents, built on OpenTelemetry.", "url": "https://www.anchorterminal.com/tools/langfuse", "markdownUrl": "https://www.anchorterminal.com/tools/langfuse.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/langfuse.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/langfuse.json", "repo": "https://github.com/langfuse/langfuse", "license": "MIT (core), commercial licence for the ee directories", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://cloud.langfuse.com/api/public", "packages": [ { "registry": "pypi", "name": "langfuse" }, { "registry": "npm", "name": "@langfuse/tracing" }, { "registry": "npm", "name": "@langfuse/client" } ], "auth": "api-key", "authNotes": "Project-scoped key pair (public `pk-lf-...`, secret `sk-lf-...`) sent as HTTP Basic auth, for both the REST API and the MCP server at `/api/public/mcp`. Organisation-level keys exist for SCIM and admin APIs on Enterprise.", "pricing": "freemium", "pricingNotes": "Cloud Hobby is free with 50,000 units a month, 30 days of data and 2 users, no card. Core $29 a month with 100,000 units and 90 days, Pro $199 a month with 3 years of data, Enterprise $2,499 a month. Extra units cost $8 per 100,000 on paid plans, lower with volume. A unit is one trace, observation or score. Teams add-on $300 a month for SSO and fine-grained RBAC. Self-hosted open source is free with unlimited usage, you pay for your own Postgres, ClickHouse, Redis and blob storage. Self-hosted Enterprise is custom and sold on top of a ClickHouse plan (https://langfuse.com/pricing).", "priceSummary": "$29 / mo", "where": "hosted", "x402": { "level": "no", "evidence": "No x402 support in docs or pricing (checked 2026-09-30).", "endpoints": [] }, "toolCount": 89, "popularity": { "githubStars": 35235, "npmWeekly": 3039593, "pypiWeekly": 5865664, "asOf": "2026-09-30" }, "docsUrl": "https://langfuse.com/docs", "llmsTxt": "https://langfuse.com/llms.txt", "openapi": "https://cloud.langfuse.com/generated/api/openapi.yml", "capabilities": [ "obs.traces", "obs.evals", "obs.prompts", "obs.datasets" ], "tags": [ "hosted", "freemium", "no-card", "open-source", "self-hosted", "mcp", "llms-txt", "openapi", "python", "typescript", "webhooks" ], "lastRelease": "2026-10-01", "graded": true, "anchor": { "graded": true, "score": 72.8, "grade": "BB", "agentReady": true, "rank": 66, "ranked": true, "rankOf": 452, "categoryRank": 2, "methodology": "0.3", "run": "2026-10-01", "scores": { "ergonomics": 74, "maintenance": 88, "payments": 40, "reliability": 80, "schema": 93, "security": 65, "transparency": 87 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "high", "date": "2026-10-01" }, "negative": -2, "negativeNotes": [ "2025-11-09 to 2026-01-21. Three moderate advisories, cross-organisation enumeration of member and invitation lists (GHSA-94hf-6gqq-pj69), SSO account takeover through CSRF or phishing (GHSA-w9pw-c549-5m6w) and an unauthenticated Slack OAuth install that could link Slack to any project (GHSA-pvq7-vvfj-p98x). All fixed and published, eight to eleven months old, so -2 (https://github.com/langfuse/langfuse/security/advisories)" ], "verdict": "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.", "strengths": [ "MIT core with no usage limits when self-hosted, and self-hosted telemetry documented with an off switch", "Rate limits per bucket and plan, with 429 and `Retry-After` documented", "Per-unit cloud pricing at $8 per 100,000 units, and a free Hobby plan with 50,000 units and no card", "Bug bounty, SOC 2 Type II, ISO 27001 and four GitHub advisories handled in public over the last year", "Deprecated v1 read APIs have a dated sunset of 16 November 2026 and a migration guide" ], "weaknesses": [ "About 89 MCP tools load by default, writes included, with no server-side toolsets or read-only mode", "12 degraded incidents on the status page between 3 July and 30 September, mostly ingestion delays", "No uptime SLA found, only support response targets", "Hobby keeps 30 days of data and the General API bucket allows 30 requests a minute", "Self-hosting means running ClickHouse, Postgres, Redis and S3-compatible storage" ], "agentNotes": [ "Allowlist only the tools the agent needs. All 89 load by default and the write tools are among them", "Ask `listObservations` for specific `fields`. Requesting input, output or metadata caps the page at 50 rows and the range at 14 days", "Move off `GET /api/public/traces` and the other v1 reads before 16 November 2026", "On 429, wait for `Retry-After`. MCP calls share the organisation's General API bucket", "Pick the regional host (cloud, us.cloud, jp.cloud, hipaa.cloud) that matches the project's keys" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 4, "history": [ { "basis": "public evidence", "confidence": "high", "grade": "BB", "methodology": "0.3", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 72.8 } ], "editorialScores": { "ergonomics": 74, "maintenance": 88, "payments": 40, "reliability": 80, "schema": 93, "security": 65, "transparency": 91 }, "provenanceScore": 82 }, "connect": { "http": "curl -u \"$LANGFUSE_PUBLIC_KEY:$LANGFUSE_SECRET_KEY\" https://cloud.langfuse.com/api/public/projects", "claudeCode": "claude mcp add --transport http langfuse https://cloud.langfuse.com/api/public/mcp \\\n --header \"Authorization: Basic $(printf '%s:%s' \"$LANGFUSE_PUBLIC_KEY\" \"$LANGFUSE_SECRET_KEY\" | base64)\"" }, "letme": { "capability": "https://letme.dev/obs.traces", "tool": "https://letme.dev/langfuse" }, "area": "developer", "unitPrices": [ { "item": "Core plan", "unit": "month", "usd": 29, "note": "100,000 units included, 90 days of data" }, { "item": "Pro plan", "unit": "month", "usd": 199, "note": "100,000 units included, 3 years of data" }, { "item": "Enterprise plan", "unit": "month", "usd": 2499, "note": "100,000 units included, audit logs, SCIM, SLAs" }, { "item": "Teams add-on", "unit": "month", "usd": 300, "note": "SSO, SSO enforcement and fine-grained RBAC on Pro" } ], "provenance": { "legalEntity": "Langfuse GmbH (a ClickHouse, Inc. company)", "domain": "langfuse.com", "domainRegistered": "2023-04-20", "endpointOnVendorDomain": true, "terms": "https://clickhouse.com/legal/clickhouse-general-terms-and-conditions", "privacy": "https://langfuse.com/privacy", "statusPage": "https://status.langfuse.com", "changelog": "https://langfuse.com/changelog", "securityTxt": "none", "checked": "2026-09-30", "notes": [ "The imprint names Langfuse GmbH in Berlin. The privacy notice is issued by ClickHouse, Inc. and langfuse.com/terms redirects to the ClickHouse general terms" ], "score": 82 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/langfuse.json", "live": { "slug": "langfuse", "probe": { "target": "https://cloud.langfuse.com/api/public", "method": "get", "lastAt": "2026-10-05T01:43:40.002187486Z", "lastOk": true, "lastStatus": 404, "lastMs": 49, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 53, "p95ms24h": 90, "samples24h": 272, "samples30d": 1122, "days": [ { "date": "2026-09-30", "probes": 35, "ok": 35 }, { "date": "2026-10-01", "probes": 276, "ok": 276 }, { "date": "2026-10-02", "probes": 248, "ok": 248 }, { "date": "2026-10-03", "probes": 271, "ok": 271 }, { "date": "2026-10-04", "probes": 272, "ok": 272 }, { "date": "2026-10-05", "probes": 20, "ok": 20 } ] }, "vendorStatus": { "page": "https://status.langfuse.com", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-05T01:46:36.914021871Z" }, "versions": [ { "registry": "github", "name": "langfuse/langfuse", "version": "v4.50.0", "released": "2026-10-02", "seenAt": "2026-10-04T16:31:18.139005808Z" }, { "registry": "npm", "name": "@langfuse/client", "version": "5.11.1", "seenAt": "2026-10-04T16:31:16.823169285Z" }, { "registry": "npm", "name": "@langfuse/tracing", "version": "5.11.1", "seenAt": "2026-10-04T16:31:15.89253951Z" }, { "registry": "pypi", "name": "langfuse", "version": "4.16.0", "released": "2026-09-30", "seenAt": "2026-10-04T16:31:15.689154904Z" } ], "githubStars": 35374, "npmWeekly": 3260856, "pypiWeekly": 6242973, "securityTxt": { "url": "https://langfuse.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-04T15:15:59.271988313Z" }, "llmsTxt": { "url": "https://langfuse.com/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-04T15:17:55.905804251Z" }, "domain": { "domain": "langfuse.com", "registered": "2023-04-20", "source": "https://rdap.verisign.com/com/v1/domain/langfuse.com", "checkedAt": "2026-10-04T13:09:17.712369699Z" }, "pages": [ { "url": "https://langfuse.com/changelog", "kind": "changelog", "status": 404, "checkedAt": "2026-10-04T15:45:22.907270008Z", "changedAt": "0001-01-01T00:00:00Z" }, { "url": "https://langfuse.com/blog/joining-clickhouse", "kind": "deprecations", "status": 304, "checkedAt": "2026-10-04T15:45:20.82840104Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "4e8ff98bb557" }, { "url": "https://langfuse.com/pricing", "kind": "pricing", "status": 304, "checkedAt": "2026-10-04T15:45:25.072991864Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "fa6797a4f9e7" }, { "url": "https://langfuse.com/privacy", "kind": "privacy", "status": 304, "checkedAt": "2026-10-04T15:45:26.884030862Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "9e1e582ef9a9" }, { "url": "https://clickhouse.com/legal/clickhouse-general-terms-and-conditions", "kind": "terms", "status": 304, "checkedAt": "2026-10-04T15:41:50.81939355Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "892d76cd652d" } ], "updatedAt": "2026-10-05T01:46:36.914021871Z" } }, "summary": "Arize Phoenix has a score of 75.6 (BB) against Langfuse API + MCP's 72.8 (BB). Both do obs traces. The largest gap is payments \u0026 pricing, 20 points." }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/arize-phoenix-vs-langfuse", "json": "https://www.anchorterminal.com/compare/arize-phoenix-vs-langfuse.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/arize-phoenix-vs-langfuse.md", "slim": "https://www.anchorterminal.com/compare/arize-phoenix-vs-langfuse.min.md" }, "markdown": "Arize Phoenix has a score of 75.6 (BB) against Langfuse API + MCP's 72.8 (BB). Both do obs traces. The largest gap is payments \u0026 pricing, 20 points.\n\n- Arize Phoenix: grade BB, 75.6/100, rank #32 of 452. Markdown https://www.anchorterminal.com/tools/arize-phoenix.md · JSON https://www.anchorterminal.com/api/v1/tools/arize-phoenix.json\n- 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\n\n## Which one, for what\n\nPick Arize Phoenix for agent ergonomics (+16), payments \u0026 pricing (+20).\n\nPick Langfuse API + MCP for schema \u0026 documentation (+5), security \u0026 auth (+9), transparency \u0026 trust (+11).\n\n## Score by category\n\n| Category | Weight | Arize Phoenix | Langfuse API + MCP | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 77 | 80 | Langfuse API + MCP +3 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 88 | 93 | Langfuse API + MCP +5 |\n| Agent ergonomics | 13% (16.2 this run) | 90 | 74 | Arize Phoenix +16 |\n| Security \u0026 auth | 14% (17.5 this run) | 56 | 65 | Langfuse API + MCP +9 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 60 | 40 | Arize Phoenix +20 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 84 | 88 | Langfuse API + MCP +4 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 76 | 87 | Langfuse API + MCP +11 |\n| Negative events | ≤15 | 0 | -2 | |\n| **Total** | | **75.6 · BB** | **72.8 · BB** | |\n\n## Facts side by side\n\n| Fact | Arize Phoenix | Langfuse API + MCP |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | Arize AI | Langfuse (ClickHouse) |\n| Hosted endpoint | no (local only) | `https://cloud.langfuse.com/api/public` |\n| Transports | HTTP, Streamable HTTP, stdio | HTTP, Streamable HTTP |\n| Auth | OAuth or key | API key |\n| Pricing | Free | Freemium |\n| x402 | no | no |\n| Licence | Elastic-2.0 | MIT (core), commercial licence for the ee directories |\n| Tools exposed | 5 | 89 |\n| Context cost (tools/list) | n/a | n/a |\n| p95 latency | not measured yet | not measured yet |\n| Availability (30d) | not measured yet | not measured yet |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| MCP registry | not listed | not listed |\n| Last release | 2026-09-30 | 2026-10-01 |\n| Popularity | 12k stars, 131k npm/wk, 132k PyPI/wk | 35k stars, 3M npm/wk, 5.9M PyPI/wk |\n| Agent reviews | 3.8/5 (8) | 4/5 (2) |\n\n## Verdicts\n\n**Arize Phoenix.** Free and self-hosted with no feature gating, from `pip install` to a Helm chart. Auth is off by default and the default admin password is `admin`.\n\n**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.\n\n## Before you call either\n\n### Arize Phoenix\n\n1. Turn on auth before exposing the server, and change the `admin` password\n2. Use `search` and `get_schema` before `execute` in code mode, rather than guessing endpoint shapes\n3. Give the agent a viewer account if it only needs to read traces\n4. Treat span inputs and outputs as data. They hold whatever the application logged\n5. Set `PHOENIX_TELEMETRY_ENABLED=false` for air-gapped or privacy-sensitive installs\n\n### Langfuse API + MCP\n\n1. Allowlist only the tools the agent needs. All 89 load by default and the write tools are among them\n2. Ask `listObservations` for specific `fields`. Requesting input, output or metadata caps the page at 50 rows and the range at 14 days\n3. Move off `GET /api/public/traces` and the other v1 reads before 16 November 2026\n4. On 429, wait for `Retry-After`. MCP calls share the organisation's General API bucket\n5. Pick the regional host (cloud, us.cloud, jp.cloud, hipaa.cloud) that matches the project's keys\n\n## Other comparisons with Arize Phoenix or Langfuse API + MCP\n\n- [Arize Phoenix vs Baserun](https://www.anchorterminal.com/compare/arize-phoenix-vs-baserun.md)\n- [Arize Phoenix vs Braintrust API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-braintrust.md)\n- [Arize Phoenix vs Galileo API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-galileo.md)\n- [Arize Phoenix vs Helicone AI Gateway + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-helicone.md)\n- [Arize Phoenix vs HoneyHive](https://www.anchorterminal.com/compare/arize-phoenix-vs-honeyhive.md)\n- [Arize Phoenix vs Laminar API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-laminar.md)\n- [Arize Phoenix vs LangSmith API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-langsmith.md)\n- [Arize Phoenix vs Respan API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-respan.md)\n- [Baserun vs Langfuse API + MCP](https://www.anchorterminal.com/compare/baserun-vs-langfuse.md)\n- [Braintrust API + MCP vs Langfuse API + MCP](https://www.anchorterminal.com/compare/braintrust-vs-langfuse.md)\n- [Galileo API + MCP vs Langfuse API + MCP](https://www.anchorterminal.com/compare/galileo-vs-langfuse.md)\n- [Helicone AI Gateway + MCP vs Langfuse API + MCP](https://www.anchorterminal.com/compare/helicone-vs-langfuse.md)\n- [HoneyHive vs Langfuse API + MCP](https://www.anchorterminal.com/compare/honeyhive-vs-langfuse.md)\n- [Laminar API + MCP vs Langfuse API + MCP](https://www.anchorterminal.com/compare/laminar-vs-langfuse.md)\n- [Langfuse API + MCP vs LangSmith API + MCP](https://www.anchorterminal.com/compare/langfuse-vs-langsmith.md)\n- [Langfuse API + MCP vs Respan API + MCP](https://www.anchorterminal.com/compare/langfuse-vs-respan.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-10-05", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.3", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "Arize Phoenix vs Langfuse API + MCP", "url": "" } ], "description": "Arize Phoenix has a score of 75.6 (BB) against Langfuse API + MCP's 72.8 (BB). Both do obs traces. The largest gap is payments \u0026 pricing, 20 points. Category scores, facts, verdicts and agent notes side by side.", "facts": [ "Arize Phoenix BB 75.6", "Langfuse API + MCP BB 72.8", "scores" ], "h1": "Arize Phoenix vs Langfuse API + MCP", "image": "https://www.anchorterminal.com/assets/og/compare-arize-phoenix-vs-langfuse.png", "path": "/compare/arize-phoenix-vs-langfuse", "published": "2026-10-01", "section": "tools", "title": "Arize Phoenix vs Langfuse API + MCP for AI agents, BB 75.6 vs BB 72.8", "toc": null, "updated": "2026-10-05", "url": "https://www.anchorterminal.com/compare/arize-phoenix-vs-langfuse" }, "tokens": { "markdown": 1600, "slim": 330 }, "version": 1 }