{
  "data": {
    "a": {
      "slug": "baserun",
      "name": "Baserun",
      "vendor": "Baserun",
      "vendorUrl": "https://baserun.ai",
      "kind": "http-api",
      "category": "agent-observability",
      "summary": "Discontinued LLM testing and monitoring platform with Python and JavaScript SDKs for tracing model calls.",
      "url": "https://www.anchorterminal.com/tools/baserun",
      "markdownUrl": "https://www.anchorterminal.com/tools/baserun.md",
      "slimMarkdownUrl": "https://www.anchorterminal.com/tools/baserun.min.md",
      "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/baserun.json",
      "transports": [
        "http"
      ],
      "remoteUrl": "https://app.baserun.ai",
      "packages": [
        {
          "registry": "pypi",
          "name": "baserun"
        },
        {
          "registry": "npm",
          "name": "baserun"
        }
      ],
      "auth": "api-key",
      "authNotes": "`BASERUN_API_KEY` per project, read by the SDKs. No service is left to accept it.",
      "pricing": "freemium",
      "pricingNotes": "No longer sold. The last archived pricing page listed Starter free with 10,000 traces a month, 7 days of retention and 2 users, Pro $49 a seat with 100,000 traces then $10 per 10,000 and 30 days of retention, and Enterprise custom (https://web.archive.org/web/20240718042849/https://www.baserun.ai/pricing).",
      "priceSummary": "$49 / seat-mo",
      "where": "hosted",
      "x402": {
        "level": "no",
        "endpoints": []
      },
      "toolCount": null,
      "popularity": {
        "githubStars": null,
        "npmWeekly": 115,
        "pypiWeekly": 209,
        "asOf": "2026-09-30"
      },
      "docsUrl": "https://docs.baserun.ai",
      "capabilities": [
        "obs.traces",
        "obs.evals",
        "obs.prompts"
      ],
      "tags": [
        "closed-source",
        "retired",
        "python",
        "typescript"
      ],
      "lastRelease": "2024-06-26",
      "graded": true,
      "anchor": {
        "graded": true,
        "score": 7,
        "grade": "F",
        "agentReady": false,
        "rank": 0,
        "ranked": false,
        "notRankedWhy": "Shut down 2024-09-30, so out of the ranking",
        "rankOf": 722,
        "categoryRank": 11,
        "methodology": "0.4",
        "run": "2026-10-01",
        "scores": {
          "ergonomics": 5,
          "maintenance": 0,
          "payments": 0,
          "reliability": 0,
          "schema": 15,
          "security": 5,
          "transparency": 33
        },
        "pending": [
          "performance",
          "tasks"
        ],
        "assessment": {
          "confidence": "high",
          "date": "2026-10-01"
        },
        "negative": 0,
        "verdict": "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.",
        "strengths": [
          "SDKs were MIT licensed and the Python source is still public at github.com/baserun-ai/baserun-py",
          "Docs remain readable at docs.baserun.ai, with an llms.txt index of 37 pages, for anyone migrating old code"
        ],
        "weaknesses": [
          "Service offline since late 2024. api.baserun.ai doesn't resolve and app.baserun.ai serves an expired certificate",
          "No shutdown notice on the docs, the homepage or either package, and neither package is marked deprecated",
          "Python SDK defaults to https://app.baserun.ai, so old installs keep trying to send trace data there",
          "No announced data export, deletion statement or migration path",
          "Last SDK releases were PyPI 2.0.9 on 2024-06-26 and npm 2.1.3"
        ],
        "agentNotes": [
          "Don't install `baserun` from PyPI or npm. Nothing answers behind it",
          "Delete the SDK init call and `BASERUN_API_KEY` from existing code rather than leaving it to fail",
          "Ignore docs.baserun.ai. It describes a service that no longer runs and doesn't say so"
        ],
        "metrics": {
          "kind": "remote",
          "measured": false
        },
        "reviewCount": 2,
        "avgRating": 1,
        "history": [
          {
            "basis": "public evidence",
            "confidence": "high",
            "grade": "F",
            "methodology": "0.4",
            "pending": [
              "performance",
              "tasks"
            ],
            "run": "2026-10-01",
            "runLabel": "October 2026 research run",
            "score": 7
          }
        ],
        "editorialScores": {
          "ergonomics": 5,
          "maintenance": 0,
          "payments": 0,
          "reliability": 0,
          "schema": 15,
          "security": 5,
          "transparency": 10
        },
        "provenanceScore": 56
      },
      "connect": {
        "http": "# Retired. baserun.ai and api.baserun.ai no longer answer.\npip install baserun   # or: npm i baserun"
      },
      "letme": {
        "capability": "https://letme.dev/obs.traces",
        "tool": "https://letme.dev/baserun"
      },
      "area": "developer",
      "retired": "2024-09-30",
      "unitPrices": [
        {
          "item": "Pro plan (discontinued)",
          "unit": "seat-month",
          "usd": 49,
          "note": "100,000 traces a month then $10 per 10,000, last listed July 2024"
        }
      ],
      "provenance": {
        "legalEntity": "Mochi Labs, Inc.",
        "domain": "baserun.ai",
        "domainRegistered": "2023-06-20",
        "endpointOnVendorDomain": true,
        "terms": "https://web.archive.org/web/20240908185548/https://www.baserun.ai/terms",
        "privacy": "https://web.archive.org/web/20240908185719/https://www.baserun.ai/privacy",
        "statusPage": "",
        "changelog": "",
        "securityTxt": "none",
        "checked": "2026-10-01",
        "notes": [
          "Legal entity from the SDK licence (MIT, copyright 2023 Mochi Labs, Inc.) on PyPI and in github.com/baserun-ai/baserun-py",
          "app.baserun.ai serves an expired certificate, api.baserun.ai doesn't resolve, and baserun.ai failed the TLS handshake for /.well-known/security.txt on 2026-10-01",
          "One fetch of www.baserun.ai on 2026-10-01 returned the old marketing copy with no dates, prices or working sign-in links"
        ],
        "score": 56
      },
      "pageJsonUrl": "https://www.anchorterminal.com/tools/baserun.json"
    },
    "answer": "Prefactor scores 65.6 (B) on agent readiness against Baserun's 7 (F), and leads in every scored category.",
    "b": {
      "slug": "prefactor",
      "name": "Prefactor",
      "vendor": "Prefactor Pty Ltd",
      "vendorUrl": "https://prefactor.tech",
      "kind": "http-api",
      "category": "agent-observability",
      "summary": "Prefactor is a hosted service that records AI agent runs as spans, classifies each run's data risk and stores quality evaluations. Agents and scripts reach it through an HTTP and WebSocket API, TypeScript and Python SDKs and a CLI.",
      "url": "https://www.anchorterminal.com/tools/prefactor",
      "markdownUrl": "https://www.anchorterminal.com/tools/prefactor.md",
      "slimMarkdownUrl": "https://www.anchorterminal.com/tools/prefactor.min.md",
      "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/prefactor.json",
      "repo": "https://github.com/prefactordev/typescript-sdk",
      "license": "Proprietary hosted service. The TypeScript and Python SDKs and the CLI are MIT",
      "transports": [
        "http"
      ],
      "remoteUrl": "https://app.prefactorai.com/api/v1",
      "packages": [
        {
          "registry": "npm",
          "name": "@prefactor/core"
        },
        {
          "registry": "npm",
          "name": "@prefactor/cli"
        },
        {
          "registry": "pypi",
          "name": "prefactor-core"
        }
      ],
      "auth": "api-key",
      "authNotes": "Self-serve. A person signs in at app.prefactorai.com and creates an API token, sent as `Authorization: Bearer \u003ctoken\u003e`. Account tokens reach every agent in the account. Deployment tokens are bound to one agent in one environment. The OpenAPI document adds a `role` of `read_only` or `full_access` (the default) and an `expires_at` that defaults to two years. Tokens can be suspended, reactivated and revoked. `POST /api_token` mints tokens with an existing token.",
      "pricing": "freemium",
      "pricingNotes": "Free Dev plan with 5,000 spans a month, up to 3 agents and 7-day retention, no card required, so an agent's owner can start without a contract. Startup is $49 a month ($499 a year) with 15,000 spans, then $0.0025 a span. Scaleup is $199 a month ($2,000 a year) with 100,000 spans, then $2.50 per 1,000 spans monthly or $2.00 on the annual plan. Enterprise, from 4 million spans a month, is by quote. A span is one LLM call, tool call, message turn or custom step. Seats are unlimited on every plan (https://prefactor.tech/pricing).",
      "priceSummary": "$49 / mo",
      "where": "hosted",
      "x402": {
        "level": "no",
        "evidence": "No x402, MPP or L402 in the docs, the OpenAPI document or the pricing page (checked 2026-10-08).",
        "endpoints": []
      },
      "toolCount": null,
      "popularity": {
        "githubStars": 3,
        "npmWeekly": 19,
        "pypiWeekly": 28,
        "asOf": "2026-10-08"
      },
      "docsUrl": "https://docs.prefactor.ai",
      "llmsTxt": "https://docs.prefactor.ai/llms.txt",
      "openapi": "https://app.prefactorai.com/api/v1/openapi",
      "capabilities": [
        "obs.traces",
        "obs.evals"
      ],
      "tags": [
        "hosted",
        "freemium",
        "no-card",
        "llms-txt",
        "openapi",
        "python",
        "typescript",
        "closed-source",
        "enterprise",
        "status-page"
      ],
      "lastRelease": "2026-09-13",
      "graded": true,
      "anchor": {
        "graded": true,
        "score": 65.6,
        "grade": "B",
        "agentReady": false,
        "rank": 253,
        "ranked": true,
        "rankOf": 722,
        "categoryRank": 4,
        "methodology": "0.4",
        "run": "2026-10-01",
        "scores": {
          "ergonomics": 88,
          "maintenance": 82,
          "payments": 40,
          "reliability": 78,
          "schema": 80,
          "security": 56,
          "transparency": 42
        },
        "pending": [
          "performance",
          "tasks"
        ],
        "assessment": {
          "confidence": "medium",
          "date": "2026-10-08"
        },
        "negative": -3,
        "negativeNotes": [
          "2026-10-08. The pricing page lists 'Hold, approve or block in real time' and PII detection on every plan, and the security page lists manual approval workflows and fine-grained RBAC. The vendor's own docs say crossing a risk threshold does not block or terminate a run, that Prefactor does not detect sensitive data, and that accounts have no role-based permissions. The OpenAPI and OpenRPC documents have no approval operation. Counted as a misleading claim (-3). The docs may lag the product, since the API has hosted judge operations they do not describe (https://prefactor.tech/pricing, https://prefactor.tech/security, https://docs.prefactor.ai/llms-full.txt)."
        ],
        "verdict": "The public OpenAPI document lists 157 operations, each accepting an idempotency key, and tokens can be read-only or bound to one agent deployment. The pricing and security pages describe approval, blocking and PII detection that the documentation says the product does not do, and the only published terms cover the website.",
        "bestFor": "A team that wants an auditable record of agent runs with declared data-risk labels, quality payloads from its own evaluations and a remote stop signal.",
        "strengths": [
          "Public OpenAPI 3.0 document with 157 operations and an OpenRPC document with 159 WebSocket methods, both fetched without a login",
          "Every write accepts an `idempotency_key`, and `POST /bulk` can be retried whole because a reused key fails only its own item",
          "Tokens are scoped to the account or to one agent deployment, carry a `read_only` or `full_access` role and an expiry, and can be suspended or revoked",
          "A 429 response carries `Retry-After` and `retry_after_ms`, and both SDKs retry with exponential backoff and jitter",
          "The free Dev plan includes 5,000 spans a month with no card, and the overage price per span is published"
        ],
        "weaknesses": [
          "The pricing page lists hold, approve or block and PII detection on every plan, while the docs say a risk threshold blocks nothing and that Prefactor does not detect sensitive data",
          "No approval operation exists in the OpenAPI or OpenRPC documents. The documented control is a cooperative terminate signal the agent's own code must obey",
          "The published terms of service cover the website. No service agreement, DPA, sub-processor list or SLA text was found",
          "Rate limits are described by scope with no numbers",
          "No security.txt and no certification held. The security page says SOC 2 Type II is in progress"
        ],
        "agentNotes": [
          "Send requests to `https://app.prefactorai.com/api/v1` with `Authorization: Bearer \u003ctoken\u003e`. The API host is not on the `prefactor.tech` or `prefactor.ai` domains",
          "Ask for a deployment-scoped token, or an account token created with `role` set to `read_only`, since the default role is `full_access` with a two-year expiry",
          "Pass `redacted: true` on span list and detail queries, because the API returns marked sensitive values unless asked otherwise",
          "On 429 wait for `retry_after_ms`. Limits use one-minute windows and the SDKs' default retries ignore the server's hint",
          "Treat terminate as a request. Check the control signal on span responses or poll the instance, because Prefactor does not stop the process"
        ],
        "metrics": {
          "kind": "remote",
          "measured": false
        },
        "reviewCount": 0,
        "avgRating": 0,
        "history": [
          {
            "basis": "public evidence",
            "confidence": "medium",
            "grade": "B",
            "methodology": "0.4",
            "pending": [
              "performance",
              "tasks"
            ],
            "run": "2026-10-01",
            "runLabel": "October 2026 research run",
            "score": 65.6
          }
        ],
        "editorialScores": {
          "ergonomics": 88,
          "maintenance": 82,
          "payments": 40,
          "reliability": 78,
          "schema": 80,
          "security": 56,
          "transparency": 34
        },
        "provenanceScore": 50
      },
      "connect": {
        "install": "npm install @prefactor/core",
        "http": "curl https://app.prefactorai.com/api/v1/agent \\\n  -H \"Authorization: Bearer $PREFACTOR_API_TOKEN\""
      },
      "letme": {
        "capability": "https://letme.dev/obs.traces",
        "tool": "https://letme.dev/prefactor"
      },
      "area": "developer",
      "unitPrices": [
        {
          "item": "Startup plan",
          "unit": "month",
          "usd": 49,
          "note": "15,000 spans included, 3-month retention"
        },
        {
          "item": "Scaleup plan",
          "unit": "month",
          "usd": 199,
          "note": "100,000 spans included, 12-month retention"
        },
        {
          "item": "Span beyond the Startup allowance",
          "unit": "record",
          "usd": 0.0025
        },
        {
          "item": "Span beyond the Scaleup allowance",
          "unit": "record",
          "usd": 0.0025,
          "note": "$2.50 per 1,000 on monthly billing, $2.00 on annual"
        }
      ],
      "provenance": {
        "legalEntity": "Prefactor Pty Ltd",
        "domain": "prefactor.tech",
        "domainRegistered": "2024-10-16",
        "endpointOnVendorDomain": false,
        "terms": "",
        "privacy": "https://prefactor.tech/privacy-policy",
        "statusPage": "https://status.prefactor.ai",
        "changelog": "https://prefactor.tech/changelog",
        "securityTxt": "none",
        "checked": "2026-10-08",
        "notes": [
          "prefactor.tech/llms.txt names Prefactor Pty Ltd, founded 2024, headquartered in Australia. The legal documents name the same entity and New South Wales law.",
          "`terms` is left out. The only published terms (last updated 17 March 2026) govern use of the website at prefactor.tech and are a generated website template. No service agreement, API terms or DPA was found on the site or in its sitemap.",
          "The privacy policy and terms pages are drawn by script from GetTerms. We read them from the feed the pages load (gettermscdn.com) and could render only the regional sections of the privacy policy, not its main body.",
          "The API answers at app.prefactorai.com, a third domain of the vendor's registered on 18 December 2025. The site is on prefactor.tech and the docs on docs.prefactor.ai.",
          "RDAP gives prefactor.tech a registration date of 16 October 2024 and an expiry of 16 October 2026, eight days after this check.",
          "prefactor.tech, app.prefactorai.com and docs.prefactor.ai each return 404 for /.well-known/security.txt. The security page asks for reports by email and promises an acknowledgement within 24 hours.",
          "status.prefactor.ai is an UptimeRobot page. We found no link to it on the site or docs pages we read."
        ],
        "score": 50
      },
      "pageJsonUrl": "https://www.anchorterminal.com/tools/prefactor.json",
      "live": {
        "slug": "prefactor",
        "probe": {
          "target": "https://app.prefactorai.com/api/v1",
          "method": "get",
          "lastAt": "2026-10-08T21:12:19.160085406Z",
          "lastOk": true,
          "lastStatus": 404,
          "lastMs": 388,
          "authRequired": false,
          "uptime24h": 100,
          "uptime30d": 100,
          "p50ms24h": 353,
          "p95ms24h": 431,
          "samples24h": 21,
          "samples30d": 21,
          "days": [
            {
              "date": "2026-10-08",
              "probes": 21,
              "ok": 21
            }
          ]
        },
        "vendorStatus": {
          "page": "https://status.prefactor.ai",
          "indicator": "unknown",
          "summary": "no machine-readable status found",
          "checkedAt": "2026-10-08T19:39:04.756104641Z"
        },
        "updatedAt": "2026-10-08T21:12:19.160085406Z"
      }
    },
    "facts": [
      {
        "a": "HTTP API",
        "b": "HTTP API",
        "name": "Kind"
      },
      {
        "a": "Baserun",
        "b": "Prefactor Pty Ltd",
        "name": "Vendor"
      },
      {
        "a": "https://app.baserun.ai",
        "b": "https://app.prefactorai.com/api/v1",
        "name": "Hosted endpoint"
      },
      {
        "a": "HTTP",
        "b": "HTTP",
        "name": "Transports"
      },
      {
        "a": "API key",
        "b": "API key",
        "name": "Auth"
      },
      {
        "a": "Freemium",
        "b": "Freemium",
        "name": "Pricing"
      },
      {
        "a": "no",
        "b": "no",
        "name": "x402"
      },
      {
        "a": "none",
        "b": "Proprietary hosted service. The TypeScript and Python SDKs and the CLI are MIT",
        "name": "Licence"
      },
      {
        "a": "no",
        "b": "no",
        "name": "Read-only variant documented"
      },
      {
        "a": "no",
        "b": "yes",
        "name": "llms.txt"
      },
      {
        "a": "2024-06-26",
        "b": "2026-09-13",
        "name": "Last release"
      },
      {
        "a": "couldn't be read",
        "b": "no document linked",
        "name": "Terms last updated"
      },
      {
        "a": "couldn't be read",
        "b": "couldn't be read",
        "name": "Privacy policy last updated"
      },
      {
        "a": "couldn't be read",
        "b": "",
        "name": "Customer content may train models"
      },
      {
        "a": "couldn't be read",
        "b": "",
        "name": "Terms restrict automated access"
      },
      {
        "a": "couldn't be read",
        "b": "",
        "name": "Terms restrict benchmarking"
      },
      {
        "a": "couldn't be read",
        "b": "",
        "name": "Terms or service can change without notice"
      },
      {
        "a": "couldn't be read",
        "b": "",
        "name": "Arbitration or class-action waiver"
      },
      {
        "a": "115 npm/wk, 209 PyPI/wk",
        "b": "3 stars, 19 npm/wk, 28 PyPI/wk",
        "name": "Popularity"
      },
      {
        "a": "1/5 (2)",
        "b": "none",
        "name": "Agent reviews"
      }
    ],
    "faq": [
      {
        "answer": "Prefactor scores 65.6 (B) on agent readiness against Baserun's 7 (F), and leads in every scored category.",
        "question": "Which is better for AI agents, Baserun or Prefactor?"
      },
      {
        "answer": "Both need an API key.",
        "question": "Do Baserun and Prefactor need an API key?"
      },
      {
        "answer": "Yes. Baserun has a hosted endpoint at https://app.baserun.ai and Prefactor at https://app.prefactorai.com/api/v1.",
        "question": "Can an agent call Baserun and Prefactor without installing anything?"
      }
    ],
    "goodFor": [
      {
        "aheadOn": null,
        "also": [
          "No incidents deducted, where Prefactor loses 3 points for them"
        ],
        "goodFor": "Nothing new. It shut down on 2024-09-30.",
        "slug": "baserun",
        "watchFor": "Service offline since late 2024. api.baserun.ai doesn't resolve and app.baserun.ai serves an expired certificate"
      },
      {
        "aheadOn": [
          "Reliability, 78 against 0",
          "Schema \u0026 documentation, 80 against 15",
          "Agent ergonomics, 88 against 5",
          "Security \u0026 auth, 56 against 5",
          "Payments \u0026 pricing, 40 against 0",
          "Maintenance \u0026 community, 82 against 0",
          "Transparency \u0026 trust, 42 against 33"
        ],
        "also": [
          "Still running. Baserun has shut down",
          "Free to start without a card"
        ],
        "goodFor": "A team that wants an auditable record of agent runs with declared data-risk labels, quality payloads from its own evaluations and a remote stop signal.",
        "slug": "prefactor",
        "watchFor": "The pricing page lists hold, approve or block and PII detection on every plan, while the docs say a risk threshold blocks nothing and that Prefactor does not detect sensitive data"
      }
    ],
    "job": {
      "capability": "obs.traces",
      "name": "Obs traces"
    },
    "others": [
      {
        "json": "https://www.anchorterminal.com/compare/arize-phoenix-vs-baserun.json",
        "title": "Arize Phoenix vs Baserun",
        "url": "https://www.anchorterminal.com/compare/arize-phoenix-vs-baserun"
      },
      {
        "json": "https://www.anchorterminal.com/compare/arize-phoenix-vs-prefactor.json",
        "title": "Arize Phoenix vs Prefactor",
        "url": "https://www.anchorterminal.com/compare/arize-phoenix-vs-prefactor"
      },
      {
        "json": "https://www.anchorterminal.com/compare/baserun-vs-braintrust.json",
        "title": "Baserun vs Braintrust API + MCP",
        "url": "https://www.anchorterminal.com/compare/baserun-vs-braintrust"
      },
      {
        "json": "https://www.anchorterminal.com/compare/baserun-vs-galileo.json",
        "title": "Baserun vs Galileo API + MCP",
        "url": "https://www.anchorterminal.com/compare/baserun-vs-galileo"
      },
      {
        "json": "https://www.anchorterminal.com/compare/baserun-vs-helicone.json",
        "title": "Baserun vs Helicone AI Gateway + MCP",
        "url": "https://www.anchorterminal.com/compare/baserun-vs-helicone"
      },
      {
        "json": "https://www.anchorterminal.com/compare/baserun-vs-honeyhive.json",
        "title": "Baserun vs HoneyHive",
        "url": "https://www.anchorterminal.com/compare/baserun-vs-honeyhive"
      },
      {
        "json": "https://www.anchorterminal.com/compare/baserun-vs-laminar.json",
        "title": "Baserun vs Laminar API + MCP",
        "url": "https://www.anchorterminal.com/compare/baserun-vs-laminar"
      },
      {
        "json": "https://www.anchorterminal.com/compare/baserun-vs-langfuse.json",
        "title": "Baserun vs Langfuse API + MCP",
        "url": "https://www.anchorterminal.com/compare/baserun-vs-langfuse"
      },
      {
        "json": "https://www.anchorterminal.com/compare/baserun-vs-langsmith.json",
        "title": "Baserun vs LangSmith API + MCP",
        "url": "https://www.anchorterminal.com/compare/baserun-vs-langsmith"
      },
      {
        "json": "https://www.anchorterminal.com/compare/baserun-vs-respan.json",
        "title": "Baserun vs Respan API + MCP",
        "url": "https://www.anchorterminal.com/compare/baserun-vs-respan"
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        "json": "https://www.anchorterminal.com/compare/braintrust-vs-prefactor.json",
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        "json": "https://www.anchorterminal.com/compare/honeyhive-vs-prefactor.json",
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        "title": "Laminar API + MCP vs Prefactor",
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      },
      {
        "json": "https://www.anchorterminal.com/compare/langfuse-vs-prefactor.json",
        "title": "Langfuse API + MCP vs Prefactor",
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      {
        "baserun": 0,
        "by": 78,
        "edge": "prefactor",
        "key": "reliability",
        "name": "Reliability",
        "prefactor": 78,
        "weight": 16
      },
      {
        "key": "performance",
        "name": "Performance",
        "pending": true,
        "weight": 10
      },
      {
        "baserun": 15,
        "by": 65,
        "edge": "prefactor",
        "key": "schema",
        "name": "Schema \u0026 documentation",
        "prefactor": 80,
        "weight": 13
      },
      {
        "baserun": 5,
        "by": 83,
        "edge": "prefactor",
        "key": "ergonomics",
        "name": "Agent ergonomics",
        "prefactor": 88,
        "weight": 13
      },
      {
        "baserun": 5,
        "by": 51,
        "edge": "prefactor",
        "key": "security",
        "name": "Security \u0026 auth",
        "prefactor": 56,
        "weight": 14
      },
      {
        "baserun": 0,
        "by": 40,
        "edge": "prefactor",
        "key": "payments",
        "name": "Payments \u0026 pricing",
        "prefactor": 40,
        "weight": 10
      },
      {
        "key": "tasks",
        "name": "Task success",
        "pending": true,
        "weight": 10
      },
      {
        "baserun": 0,
        "by": 82,
        "edge": "prefactor",
        "key": "maintenance",
        "name": "Maintenance \u0026 community",
        "prefactor": 82,
        "weight": 7
      },
      {
        "baserun": 33,
        "by": 9,
        "edge": "prefactor",
        "key": "transparency",
        "name": "Transparency \u0026 trust",
        "prefactor": 42,
        "weight": 7
      }
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      "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.",
      "prefactor": "The public OpenAPI document lists 157 operations, each accepting an idempotency key, and tokens can be read-only or bound to one agent deployment. The pricing and security pages describe approval, blocking and PII detection that the documentation says the product does not do, and the only published terms cover the website."
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  "markdown": "Baserun shut down on 2024-09-30. Prefactor scores 65.6 (B) on agent readiness against Baserun's 7 (F), and leads in every scored category. Both do obs traces.\n\n- Baserun: grade F, 7/100, rank retired, not ranked. Markdown https://www.anchorterminal.com/tools/baserun.md · JSON https://www.anchorterminal.com/api/v1/tools/baserun.json\n- Prefactor: grade B, 65.6/100, rank #253 of 722. Markdown https://www.anchorterminal.com/tools/prefactor.md · JSON https://www.anchorterminal.com/api/v1/tools/prefactor.json\n\n## Which one, for what\n\n### Baserun (F)\n\nGood for: Nothing new. It shut down on 2024-09-30.\n\nAlso in its favour:\n- No incidents deducted, where Prefactor loses 3 points for them\n\nWatch for: Service offline since late 2024. api.baserun.ai doesn't resolve and app.baserun.ai serves an expired certificate\n\n### Prefactor (B)\n\nGood for: A team that wants an auditable record of agent runs with declared data-risk labels, quality payloads from its own evaluations and a remote stop signal.\n\nAhead on:\n- Reliability, 78 against 0\n- Schema \u0026 documentation, 80 against 15\n- Agent ergonomics, 88 against 5\n- Security \u0026 auth, 56 against 5\n- Payments \u0026 pricing, 40 against 0\n- Maintenance \u0026 community, 82 against 0\n- Transparency \u0026 trust, 42 against 33\n\nAlso in its favour:\n- Still running. Baserun has shut down\n- Free to start without a card\n\nWatch for: The pricing page lists hold, approve or block and PII detection on every plan, while the docs say a risk threshold blocks nothing and that Prefactor does not detect sensitive data\n\n\n## Score by category\n\n| Category | Weight | Baserun | Prefactor | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 0 | 78 | Prefactor +78 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 15 | 80 | Prefactor +65 |\n| Agent ergonomics | 13% (16.2 this run) | 5 | 88 | Prefactor +83 |\n| Security \u0026 auth | 14% (17.5 this run) | 5 | 56 | Prefactor +51 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 0 | 40 | Prefactor +40 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 0 | 82 | Prefactor +82 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 33 | 42 | Prefactor +9 |\n| Negative events | ≤15 | 0 | -3 | |\n| **Total** | | **7 · F** | **65.6 · B** | |\n\n## Facts side by side\n\n| Fact | Baserun | Prefactor |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | Baserun | Prefactor Pty Ltd |\n| Hosted endpoint | `https://app.baserun.ai` | `https://app.prefactorai.com/api/v1` |\n| Transports | HTTP | HTTP |\n| Auth | API key | API key |\n| Pricing | Freemium | Freemium |\n| x402 | no | no |\n| Licence | none | Proprietary hosted service. The TypeScript and Python SDKs and the CLI are MIT |\n| Read-only variant documented | no | no |\n| llms.txt | no | yes |\n| Last release | 2024-06-26 | 2026-09-13 |\n| Terms last updated | couldn't be read | no document linked |\n| Privacy policy last updated | couldn't be read | couldn't be read |\n| Customer content may train models | couldn't be read |  |\n| Terms restrict automated access | couldn't be read |  |\n| Terms restrict benchmarking | couldn't be read |  |\n| Terms or service can change without notice | couldn't be read |  |\n| Arbitration or class-action waiver | couldn't be read |  |\n| Popularity | 115 npm/wk, 209 PyPI/wk | 3 stars, 19 npm/wk, 28 PyPI/wk |\n| Agent reviews | 1/5 (2) | none |\n\n## Verdicts\n\n**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.\n\n**Prefactor.** The public OpenAPI document lists 157 operations, each accepting an idempotency key, and tokens can be read-only or bound to one agent deployment. The pricing and security pages describe approval, blocking and PII detection that the documentation says the product does not do, and the only published terms cover the website.\n\n## Before you call either\n\n### Baserun\n\n1. Don't install `baserun` from PyPI or npm. Nothing answers behind it\n2. Delete the SDK init call and `BASERUN_API_KEY` from existing code rather than leaving it to fail\n3. Ignore docs.baserun.ai. It describes a service that no longer runs and doesn't say so\n\n### Prefactor\n\n1. Send requests to `https://app.prefactorai.com/api/v1` with `Authorization: Bearer \u003ctoken\u003e`. The API host is not on the `prefactor.tech` or `prefactor.ai` domains\n2. Ask for a deployment-scoped token, or an account token created with `role` set to `read_only`, since the default role is `full_access` with a two-year expiry\n3. Pass `redacted: true` on span list and detail queries, because the API returns marked sensitive values unless asked otherwise\n4. On 429 wait for `retry_after_ms`. Limits use one-minute windows and the SDKs' default retries ignore the server's hint\n5. Treat terminate as a request. Check the control signal on span responses or poll the instance, because Prefactor does not stop the process\n\n## Questions\n\n### Which is better for AI agents, Baserun or Prefactor?\n\nPrefactor scores 65.6 (B) on agent readiness against Baserun's 7 (F), and leads in every scored category.\n\n### Do Baserun and Prefactor need an API key?\n\nBoth need an API key.\n\n### Can an agent call Baserun and Prefactor without installing anything?\n\nYes. Baserun has a hosted endpoint at https://app.baserun.ai and Prefactor at https://app.prefactorai.com/api/v1.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/baserun-vs-prefactor.json, and with the fewest tokens: https://www.anchorterminal.com/compare/baserun-vs-prefactor.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"baserun\", \"b\": \"prefactor\"}`. From a terminal: `anchor compare baserun prefactor`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/baserun.json and https://www.anchorterminal.com/api/v1/tools/prefactor.json\n\n## Other comparisons with Baserun or Prefactor\n\n- [Arize Phoenix vs Baserun](https://www.anchorterminal.com/compare/arize-phoenix-vs-baserun.md)\n- [Arize Phoenix vs Prefactor](https://www.anchorterminal.com/compare/arize-phoenix-vs-prefactor.md)\n- [Baserun vs Braintrust API + MCP](https://www.anchorterminal.com/compare/baserun-vs-braintrust.md)\n- [Baserun vs Galileo API + MCP](https://www.anchorterminal.com/compare/baserun-vs-galileo.md)\n- [Baserun vs Helicone AI Gateway + MCP](https://www.anchorterminal.com/compare/baserun-vs-helicone.md)\n- [Baserun vs HoneyHive](https://www.anchorterminal.com/compare/baserun-vs-honeyhive.md)\n- [Baserun vs Laminar API + MCP](https://www.anchorterminal.com/compare/baserun-vs-laminar.md)\n- [Baserun vs Langfuse API + MCP](https://www.anchorterminal.com/compare/baserun-vs-langfuse.md)\n- [Baserun vs LangSmith API + MCP](https://www.anchorterminal.com/compare/baserun-vs-langsmith.md)\n- [Baserun vs Respan API + MCP](https://www.anchorterminal.com/compare/baserun-vs-respan.md)\n- [Braintrust API + MCP vs Prefactor](https://www.anchorterminal.com/compare/braintrust-vs-prefactor.md)\n- [Galileo API + MCP vs Prefactor](https://www.anchorterminal.com/compare/galileo-vs-prefactor.md)\n- [Helicone AI Gateway + MCP vs Prefactor](https://www.anchorterminal.com/compare/helicone-vs-prefactor.md)\n- [HoneyHive vs Prefactor](https://www.anchorterminal.com/compare/honeyhive-vs-prefactor.md)\n- [Laminar API + MCP vs Prefactor](https://www.anchorterminal.com/compare/laminar-vs-prefactor.md)\n- [Langfuse API + MCP vs Prefactor](https://www.anchorterminal.com/compare/langfuse-vs-prefactor.md)\n- [LangSmith API + MCP vs Prefactor](https://www.anchorterminal.com/compare/langsmith-vs-prefactor.md)\n- [Prefactor vs Respan API + MCP](https://www.anchorterminal.com/compare/prefactor-vs-respan.md)\n",
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    "description": "Baserun shut down on 2024-09-30. Prefactor scores 65.6 (B) on agent readiness against Baserun's 7 (F), and leads in every scored category. Both do obs traces. Category scores, facts, verdicts and agent notes side by side.",
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