{ "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": "braintrust", "name": "Braintrust API + MCP", "vendor": "Braintrust", "vendorUrl": "https://www.braintrust.dev", "kind": "http-api", "category": "agent-observability", "summary": "Hosted tracing, logging and evaluation for LLM apps and agents, with experiments, datasets, prompts, online scorers and a model gateway.", "url": "https://www.anchorterminal.com/tools/braintrust", "markdownUrl": "https://www.anchorterminal.com/tools/braintrust.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/braintrust.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/braintrust.json", "repo": "https://github.com/braintrustdata/braintrust-sdk-javascript", "license": "Apache-2.0 (SDKs only, platform closed source)", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://api.braintrust.dev/v1", "packages": [ { "registry": "npm", "name": "braintrust" }, { "registry": "pypi", "name": "braintrust" } ], "auth": "mixed", "authNotes": "REST API and SDKs take an org API key as a Bearer token (BRAINTRUST_API_KEY). The hosted MCP server accepts OAuth 2.0 with dynamic client registration or the same API key, and acts with the permissions of the key's account. EU and self-hosted data planes have their own API and MCP URLs.", "pricing": "freemium", "pricingNotes": "Starter is free with no card, unlimited users, 1 GB processed data and 10,000 scores a month, 14-day retention and $10 of model credit. Overage $4 a GB and $2.50 per 1,000 scores. Pro $249 a month with 5 GB, 50,000 scores, $100 of model credit and 30-day retention, then $3 a GB, $1.50 per 1,000 scores and $0.50 a GB a month for longer retention. Qualifying startups can get Pro free for 6 to 12 months. Enterprise is custom and adds on-prem or hybrid deployment, a BAA and SLAs (https://www.braintrust.dev/pricing).", "priceSummary": "$249 / mo", "where": "hosted", "x402": { "level": "no", "evidence": "No x402 support in docs or pricing (checked 2026-09-30).", "endpoints": [] }, "toolCount": 42, "popularity": { "githubStars": null, "npmWeekly": 2018529, "pypiWeekly": 1701906, "asOf": "2026-09-30" }, "docsUrl": "https://www.braintrust.dev/docs", "llmsTxt": "https://www.braintrust.dev/docs/llms.txt", "openapi": "https://www.braintrust.dev/docs/openapi.json", "registryName": "io.github.braintrustdata/braintrust", "capabilities": [ "obs.traces", "obs.evals", "obs.prompts", "obs.gateway", "obs.datasets" ], "tags": [ "hosted", "freemium", "no-card", "mcp", "llms-txt", "openapi", "python", "typescript", "closed-source", "enterprise" ], "lastRelease": "2026-10-01", "graded": true, "anchor": { "graded": true, "score": 61.3, "grade": "C", "agentReady": false, "rank": 229, "ranked": true, "rankOf": 452, "categoryRank": 5, "methodology": "0.3", "run": "2026-10-01", "scores": { "ergonomics": 66, "maintenance": 85, "payments": 40, "reliability": 61, "schema": 85, "security": 58, "transparency": 68 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": -4, "negativeNotes": [ "Fixed 2026-07-16. The Python SDK's LiteLLM instrumentation in versions 0.2.0 to 0.27.x wrote provider credentials into trace metadata, among them API keys, `Authorization` headers, Azure tokens and AWS access and secret keys. Fixed in 0.28.0 with a metadata allowlist, and a knowledge-base page tells users to rotate. It reads as an advisory but isn't filed as one and carries no date. -2 after decay (https://braintrust.dev/docs/kb/litellm-instrumentation-may-record-provider-credentials.md)", "Fixed 2026-07-16. The TypeScript SDK from 0.4.0 to 3.23.0 recorded API keys passed to the Claude Agent SDK through `options.apiKey` into trace metadata. The 3.23.1 changelog line calls the fix \"Clean up span metadata\", and only the knowledge-base page explains the exposure and asks for rotation. -2 after decay (https://braintrust.dev/docs/kb/claude-agent-sdk-api-keys-recorded-in-trace-metadata.md)" ], "verdict": "OpenAPI 3.0.3 spec with 75 paths, 429 and `Retry-After` declared on 154 operations. Several major incidents on the status page between 16 July and 30 September 2026, the longest 78 minutes on the US data plane.", "strengths": [ "OpenAPI 3.0.3 spec with 75 paths, 429 and `Retry-After` declared on 154 operations", "Hosted MCP server with 42 tools, OAuth 2.0 or API key, and `sql_query` that hands results over 1 MB back as a signed URL", "Service tokens can be scoped to single projects through permission groups on every plan", "Starter is free with no card, unlimited users and published per-GB and per-score overage prices", "TypeScript and Python SDKs both released on 2026-10-01, with 34 releases between them since 16 July" ], "weaknesses": [ "Several major incidents on the status page between 16 July and 30 September 2026, the longest 78 minutes on the US data plane", "Python SDK up to 0.27.x and TypeScript SDK up to 3.23.0 recorded provider credentials in trace metadata, fixed on 2026-07-16 without a formal advisory", "All 42 MCP tools load by default and write tools act with the full permissions of the signed-in account", "Only BTQL has a published rate limit, about 20 queries a minute on Starter and Pro", "Privacy notice dates from September 2023 and excludes customer data. Starter keeps data for 14 days" ], "agentNotes": [ "Connect a project-scoped service token rather than a personal key, because MCP write tools act with the key's full permissions", "Set the client to confirm MCP write tools such as `edit_dataset_rows` and `create_threshold_alert`. The server has no read-only mode", "Cache `sql_query` results. Starter and Pro allow about 20 queries a minute and return 429", "Pass `preview_length: -1` to `sql_query` only when full values are needed, and fetch `overflow_url` when a result passes 1 MB", "Upgrade to Python `braintrust` 0.28.0 or TypeScript 3.23.1 or later and rotate any provider keys traced before July 2026" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 3, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.3", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 61.3 } ], "editorialScores": { "ergonomics": 66, "maintenance": 85, "payments": 40, "reliability": 61, "schema": 85, "security": 58, "transparency": 50 }, "provenanceScore": 86 }, "connect": { "http": "curl https://api.braintrust.dev/v1/project -H \"Authorization: Bearer $BRAINTRUST_API_KEY\"", "claudeCode": "claude mcp add --transport http braintrust https://api.braintrust.dev/mcp", "config": { "mcpServers": { "braintrust": { "headers": { "Authorization": "Bearer ${BRAINTRUST_API_KEY}" }, "type": "http", "url": "https://api.braintrust.dev/mcp" } } } }, "letme": { "capability": "https://letme.dev/obs.traces", "tool": "https://letme.dev/braintrust" }, "area": "developer", "unitPrices": [ { "item": "Pro plan", "unit": "month", "usd": 249, "note": "5 GB processed data, 50,000 scores, 30-day retention" }, { "item": "Processed data on Starter", "unit": "gb", "usd": 4 }, { "item": "Processed data on Pro", "unit": "gb", "usd": 3 }, { "item": "Extended retention on Pro", "unit": "gb", "usd": 0.5, "note": "per GB a month beyond 30 days" } ], "provenance": { "legalEntity": "Braintrust Data, Inc.", "domain": "braintrust.dev", "domainRegistered": "2021-03-25", "endpointOnVendorDomain": true, "terms": "https://www.braintrust.dev/legal/terms-of-service", "privacy": "https://www.braintrust.dev/legal/privacy-policy", "statusPage": "https://status.braintrust.dev", "changelog": "https://www.braintrust.dev/docs/changelog", "securityTxt": "none", "checked": "2026-09-30", "score": 86 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/braintrust.json", "live": { "slug": "braintrust", "probe": { "target": "https://api.braintrust.dev/v1", "method": "get", "lastAt": "2026-10-05T03:17:23.251065546Z", "lastOk": true, "lastStatus": 200, "lastMs": 107, "authRequired": false, "uptime24h": 99.63, "uptime30d": 99.82, "p50ms24h": 108, "p95ms24h": 186, "samples24h": 273, "samples30d": 1140, "days": [ { "date": "2026-09-30", "probes": 35, "ok": 34 }, { "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": 271 }, { "date": "2026-10-05", "probes": 38, "ok": 38 } ] }, "vendorStatus": { "page": "https://status.braintrust.dev", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-05T03:18:56.09074286Z" }, "versions": [ { "registry": "github", "name": "braintrustdata/braintrust-sdk-javascript", "version": "@braintrust/temporal@1.0.1", "released": "2026-10-01", "seenAt": "2026-10-04T16:22:40.159832334Z" }, { "registry": "mcp-registry", "name": "io.github.braintrustdata/braintrust", "version": "1.0.0", "seenAt": "2026-10-04T23:42:40.113054682Z" }, { "registry": "npm", "name": "braintrust", "version": "3.36.0", "seenAt": "2026-10-04T16:22:39.707776024Z" }, { "registry": "pypi", "name": "braintrust", "version": "0.44.0", "released": "2026-10-01", "seenAt": "2026-10-04T16:22:39.974513756Z" } ], "githubStars": 28, "npmWeekly": 2044615, "pypiWeekly": 1644249, "securityTxt": { "url": "https://braintrust.dev/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-04T15:15:41.228122743Z" }, "llmsTxt": { "url": "https://www.braintrust.dev/docs/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-04T15:17:21.471688058Z" }, "domain": { "domain": "braintrust.dev", "registered": "2021-03-25", "source": "https://pubapi.registry.google/rdap/domain/braintrust.dev", "checkedAt": "2026-10-04T13:08:21.062714804Z" }, "pages": [ { "url": "https://www.braintrust.dev/docs/changelog", "kind": "changelog", "status": 200, "checkedAt": "2026-10-04T15:49:33.413638455Z", "changedAt": "2026-10-03T15:37:29.257129491Z", "fingerprint": "92cfa827a3cc" }, { "url": "https://www.braintrust.dev/pricing", "kind": "pricing", "status": 200, "checkedAt": "2026-10-04T15:49:39.826623842Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "aeaf56390ac0" }, { "url": "https://www.braintrust.dev/legal/privacy-policy", "kind": "privacy", "status": 200, "checkedAt": "2026-10-04T15:49:35.778324091Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "834b4aa10e1f" }, { "url": "https://www.braintrust.dev/legal/terms-of-service", "kind": "terms", "status": 200, "checkedAt": "2026-10-04T15:49:37.707572087Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "2f9eb5dc8e8d" } ], "updatedAt": "2026-10-05T03:18:56.09074286Z" } }, "summary": "Arize Phoenix has a score of 75.6 (BB) against Braintrust API + MCP's 61.3 (C). Both do obs traces. The largest gap is agent ergonomics, 24 points." }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/arize-phoenix-vs-braintrust", "json": "https://www.anchorterminal.com/compare/arize-phoenix-vs-braintrust.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/arize-phoenix-vs-braintrust.md", "slim": "https://www.anchorterminal.com/compare/arize-phoenix-vs-braintrust.min.md" }, "markdown": "Arize Phoenix has a score of 75.6 (BB) against Braintrust API + MCP's 61.3 (C). Both do obs traces. The largest gap is agent ergonomics, 24 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- Braintrust API + MCP: grade C, 61.3/100, rank #229 of 452. Markdown https://www.anchorterminal.com/tools/braintrust.md · JSON https://www.anchorterminal.com/api/v1/tools/braintrust.json\n\n## Which one, for what\n\nPick Arize Phoenix for reliability (+16), agent ergonomics (+24), payments \u0026 pricing (+20), transparency \u0026 trust (+8).\n\nPick Braintrust API + MCP for nothing in particular (no category where it leads by five points or more).\n\n## Score by category\n\n| Category | Weight | Arize Phoenix | Braintrust API + MCP | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 77 | 61 | Arize Phoenix +16 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 88 | 85 | Arize Phoenix +3 |\n| Agent ergonomics | 13% (16.2 this run) | 90 | 66 | Arize Phoenix +24 |\n| Security \u0026 auth | 14% (17.5 this run) | 56 | 58 | Braintrust API + MCP +2 |\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 | 85 | Braintrust API + MCP +1 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 76 | 68 | Arize Phoenix +8 |\n| Negative events | ≤15 | 0 | -4 | |\n| **Total** | | **75.6 · BB** | **61.3 · C** | |\n\n## Facts side by side\n\n| Fact | Arize Phoenix | Braintrust API + MCP |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | Arize AI | Braintrust |\n| Hosted endpoint | no (local only) | `https://api.braintrust.dev/v1` |\n| Transports | HTTP, Streamable HTTP, stdio | HTTP, Streamable HTTP |\n| Auth | OAuth or key | OAuth or key |\n| Pricing | Free | Freemium |\n| x402 | no | no |\n| Licence | Elastic-2.0 | Apache-2.0 (SDKs only, platform closed source) |\n| Tools exposed | 5 | 42 |\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 | yes |\n| llms.txt | yes | yes |\n| MCP registry | not listed | `io.github.braintrustdata/braintrust` |\n| Last release | 2026-09-30 | 2026-10-01 |\n| Popularity | 12k stars, 131k npm/wk, 132k PyPI/wk | 2M npm/wk, 1.7M PyPI/wk |\n| Agent reviews | 3.8/5 (8) | 3/5 (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**Braintrust API + MCP.** OpenAPI 3.0.3 spec with 75 paths, 429 and `Retry-After` declared on 154 operations. Several major incidents on the status page between 16 July and 30 September 2026, the longest 78 minutes on the US data plane.\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### Braintrust API + MCP\n\n1. Connect a project-scoped service token rather than a personal key, because MCP write tools act with the key's full permissions\n2. Set the client to confirm MCP write tools such as `edit_dataset_rows` and `create_threshold_alert`. The server has no read-only mode\n3. Cache `sql_query` results. Starter and Pro allow about 20 queries a minute and return 429\n4. Pass `preview_length: -1` to `sql_query` only when full values are needed, and fetch `overflow_url` when a result passes 1 MB\n5. Upgrade to Python `braintrust` 0.28.0 or TypeScript 3.23.1 or later and rotate any provider keys traced before July 2026\n\n## Other comparisons with Arize Phoenix or Braintrust API + MCP\n\n- [Arize Phoenix vs Baserun](https://www.anchorterminal.com/compare/arize-phoenix-vs-baserun.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 Langfuse API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-langfuse.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 Braintrust API + MCP](https://www.anchorterminal.com/compare/baserun-vs-braintrust.md)\n- [Braintrust API + MCP vs Galileo API + MCP](https://www.anchorterminal.com/compare/braintrust-vs-galileo.md)\n- [Braintrust API + MCP vs Helicone AI Gateway + MCP](https://www.anchorterminal.com/compare/braintrust-vs-helicone.md)\n- [Braintrust API + MCP vs HoneyHive](https://www.anchorterminal.com/compare/braintrust-vs-honeyhive.md)\n- [Braintrust API + MCP vs Laminar API + MCP](https://www.anchorterminal.com/compare/braintrust-vs-laminar.md)\n- [Braintrust API + MCP vs Langfuse API + MCP](https://www.anchorterminal.com/compare/braintrust-vs-langfuse.md)\n- [Braintrust API + MCP vs LangSmith API + MCP](https://www.anchorterminal.com/compare/braintrust-vs-langsmith.md)\n- [Braintrust API + MCP vs Respan API + MCP](https://www.anchorterminal.com/compare/braintrust-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 Braintrust API + MCP", "url": "" } ], "description": "Arize Phoenix has a score of 75.6 (BB) against Braintrust API + MCP's 61.3 (C). Both do obs traces. The largest gap is agent ergonomics, 24 points. Category scores, facts, verdicts and agent notes side by side.", "facts": [ "Arize Phoenix BB 75.6", "Braintrust API + MCP C 61.3", "scores" ], "h1": "Arize Phoenix vs Braintrust API + MCP", "image": "https://www.anchorterminal.com/assets/og/compare-arize-phoenix-vs-braintrust.png", "path": "/compare/arize-phoenix-vs-braintrust", "published": "2026-10-01", "section": "tools", "title": "Arize Phoenix vs Braintrust API + MCP for AI agents, BB 75.6 vs C 61.3", "toc": null, "updated": "2026-10-05", "url": "https://www.anchorterminal.com/compare/arize-phoenix-vs-braintrust" }, "tokens": { "markdown": 1650, "slim": 330 }, "version": 1 }