{ "data": { "a": { "slug": "fred", "name": "FRED API", "vendor": "Federal Reserve Bank of St. Louis", "vendorUrl": "https://www.stlouisfed.org", "kind": "http-api", "category": "data-providers", "summary": "REST API from the Federal Reserve Bank of St. Louis for FRED, its database of more than 800,000 economic time series. Version 1 returns series, releases, categories and observations, and version 2 returns every series on a release in bulk.", "url": "https://www.anchorterminal.com/tools/fred", "markdownUrl": "https://www.anchorterminal.com/tools/fred.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/fred.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/fred.json", "license": "Proprietary service under the FRED Services Terms of Use. Some data series are third-party copyright", "transports": [ "http" ], "remoteUrl": "https://api.stlouisfed.org", "packages": [], "auth": "api-key", "authNotes": "Self-serve key. A person signs in to a free FRED account at fredaccount.stlouisfed.org and requests a 32-character key, one for each application. Version 1 takes it as the `api_key` query parameter, the only method its docs give. Version 2 takes it as `Authorization: Bearer`. Keys have no scopes, and the API is read-only. The separate FRED MCP Connector needs no API key and signs users in with OAuth on its own account.", "pricing": "free", "pricingNotes": "Free. No paid tier and no card. The cost is the rate limit, 120 requests a minute on version 1 and two a second on version 2, with higher limits by contacting the Bank (https://fred.stlouisfed.org/docs/api/fred/errors.html, checked 2026-10-09).", "priceSummary": "Free", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the API documentation or the terms (checked 2026-10-09).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-10-09" }, "docsUrl": "https://fred.stlouisfed.org/docs/api/fred/", "capabilities": [ "data.markets", "market.indices" ], "tags": [ "hosted", "free", "no-card", "api-key", "official", "closed-source", "mcp", "read-only-mode" ], "lastRelease": "2025-11-04", "graded": true, "anchor": { "graded": true, "score": 42.7, "grade": "E", "agentReady": false, "rank": 789, "ranked": true, "rankOf": 842, "categoryRank": 7, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 68, "maintenance": 15, "payments": 40, "reliability": 38, "schema": 43, "security": 35, "transparency": 53 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-09" }, "negative": 0, "verdict": "A free, read-only API to more than 800,000 economic series with revision history, documented endpoint by endpoint with typed parameters and examples. The terms forbid storing or caching FRED content and using the API to develop or train AI systems, version 1 carries the key in the URL, and no status page or OpenAPI file was found.", "bestFor": "Looking up US and international macroeconomic series, their metadata and their revision history in a live session.", "strengths": [ "Free, with no paid tier. One key per application from a free FRED account", "31 version 1 requests cover series, observations, search, releases, categories, sources and tags, each documented with typed parameters, defaults and XML and JSON examples", "Real-time periods and vintage dates return a series as it stood on a past date, from the ALFRED archive", "Observations can be transformed (nine `units` values) and aggregated to a lower frequency in the request", "Rate limits are published. 120 requests a minute on version 1 and two a second on version 2" ], "weaknesses": [ "The FRED Services Terms of Use forbid using the API to develop or train any AI or machine-learning system, and forbid storing, caching or archiving FRED content", "Version 1 takes the key only as the `api_key` query parameter, so it travels in the URL", "No OpenAPI file, llms.txt, official SDK or API changelog was found", "No status page, SLA or security.txt was found. The terms disclaim availability and allow changes without notice", "Version 1 answers in XML unless `file_type=json` is set, and default limits are 100,000 observations (version 1) and 500,000 (version 2)" ], "agentNotes": [ "Add `file_type=json` to every version 1 request. The default is XML", "Find a series with `fred/series/search?search_text=`, then read it with `fred/series/observations?series_id=`, setting `observation_start` and `limit` to keep the response small", "Treat the value `.` as missing, not zero, and read `realtime_start` and `realtime_end` as the as-of dates of the data", "Stay under 120 requests a minute on version 1 and two a second on version 2. Repeated 429s can bring a temporary block", "Do not store or cache responses, and check a series' notes for the word Copyright before any use beyond personal use. The terms forbid the first and require the second" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "E", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 42.7 } ], "editorialScores": { "ergonomics": 68, "maintenance": 15, "payments": 40, "reliability": 38, "schema": 43, "security": 35, "transparency": 37 }, "provenanceScore": 69, "dataQualityScore": 79 }, "connect": { "http": "curl \"https://api.stlouisfed.org/fred/series/observations?series_id=GNPCA\u0026api_key=$FRED_API_KEY\u0026file_type=json\"" }, "letme": { "capability": "https://letme.dev/data.markets", "tool": "https://letme.dev/fred" }, "area": "web-data", "provenance": { "legalEntity": "Federal Reserve Bank of St. Louis", "domain": "stlouisfed.org", "domainRegistered": "2001-03-05", "endpointOnVendorDomain": true, "terms": "https://fred.stlouisfed.org/legal/", "privacy": "https://www.stlouisfed.org/about-us/privacy-policy/online-notice", "statusPage": "", "changelog": "https://fred.stlouisfed.org/news", "securityTxt": "none", "checked": "2026-10-09", "notes": [ "The FRED Services Terms of Use name the Federal Reserve Bank of St. Louis, One Federal Reserve Bank Plaza, St. Louis, MO 63166-0442, and are governed by Missouri law.", "Two documents carry API terms. The page the API docs link (https://fred.stlouisfed.org/docs/api/terms_of_use.html) is the shorter one. The FRED Services Terms of Use at /legal/ repeat it in a section for the API and add clauses on AI training, caching and wholesale downloading, so the link here is to the fuller document. Neither carries a date.", "The privacy link is the Bank's Online Privacy Notice, which the FRED footer links and which covers user accounts. A separate addendum covers the MCP connector (https://www.stlouisfed.org/about-us/privacy-policy/mcp-connector-privacy-addendum).", "The API answers at api.stlouisfed.org and the MCP connector at mcp.stlouisfed.org, both on the Bank's domain.", "fred.stlouisfed.org/.well-known/security.txt and api.stlouisfed.org/.well-known/security.txt return 404, and www.stlouisfed.org redirects the same path to its 404 page.", "No status page was found in the API docs, the FRED footer or the help pages.", "The changelog link is the FRED News feed, which carries product updates and data additions. No changelog for the API itself was found.", "RDAP for stlouisfed.org gives a registration date of 2001-03-05 and GoDaddy.com, LLC as registrar." ], "score": 69 }, "dataQuality": { "coverage": "More than 800,000 economic time series from over 100 sources, per the Bank. US national and regional data in most depth, with international series", "coverageRating": 5, "freshness": "Updated after each source publishes a release and the FRED team validates it. The highest frequency is daily. No update time is promised in the pages read", "freshnessClass": "daily", "history": "Varies by series. The docs' example series GNPCA starts in 1929, and ALFRED keeps earlier vintages of revised series", "historyYears": 97, "methodology": "https://fred.stlouisfed.org/help/data/understanding-the-data/how-does-fred-update-its-database", "sourcesDisclosed": true, "licence": "Proprietary, under the FRED Services Terms of Use. Each series is labelled public domain, copyrighted with citation required, or copyrighted with pre-approval required", "licenceClass": "clear", "standing": "Published by a Federal Reserve Bank, which republishes series from statistical agencies and other sources. It is not the originating source for most series", "standingClass": "none", "reuse": "Non-commercial, educational and personal use by default. Storing, caching, archiving and building a database from FRED content are forbidden, as is use in developing or training AI systems. Series labelled public domain or citation required may be used internally by a business with attribution.", "score": 79, "checks": null }, "pageJsonUrl": "https://www.anchorterminal.com/tools/fred.json", "live": { "slug": "fred", "probe": { "target": "https://api.stlouisfed.org", "method": "get", "lastAt": "2026-10-09T10:14:15.158660541Z", "lastOk": true, "lastStatus": 200, "lastMs": 433, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 506, "p95ms24h": 1026, "samples24h": 28, "samples30d": 28, "days": [ { "date": "2026-10-09", "probes": 28, "ok": 28 } ] }, "updatedAt": "2026-10-09T10:14:15.158660541Z" } }, "answer": "Massive (formerly Polygon.io) scores 69.8 (B) on agent readiness against FRED API's 42.7 (E), and leads in 6 of 7 scored categories.", "b": { "slug": "massive", "name": "Massive (formerly Polygon.io)", "vendor": "Massive", "vendorUrl": "https://massive.com", "kind": "http-api", "category": "data-providers", "summary": "US market data API for stocks, options, indices, forex, crypto and futures, from the consolidated tapes.", "url": "https://www.anchorterminal.com/tools/massive", "markdownUrl": "https://www.anchorterminal.com/tools/massive.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/massive.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/massive.json", "repo": "https://github.com/massive-com/client-python", "license": "MIT (clients)", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://api.massive.com", "packages": [], "auth": "api-key", "authNotes": "`?apiKey=` or Bearer. x402 payments at agent.massive.com need no key.", "pricing": "freemium", "pricingNotes": "Free Basic plan at 5 calls a minute with 2 years of end-of-day data. Stocks Starter $29, Developer $79 and Advanced $199 a month for individuals (non-commercial), business plans priced separately (https://massive.com/pricing). Over x402 at agent.massive.com, 23 US stock routes at $0.01 a request in USDC on Base, with the live price in each 402 response (https://agentic.market/services/agent-massive-com).", "priceSummary": "$0.01 / call", "where": "hosted", "x402": { "level": "yes", "evidence": "x402 on agent.massive.com since 2026-09-01 per the changelog. The docs say each route quotes its live price in the 402 response and only successful requests are charged. Agentic.Market lists 23 GET routes at $0.01 each on Base, US stocks only (https://massive.com/docs/ai-tools/x402).", "endpoints": [ { "url": "https://agent.massive.com/v2/aggs/ticker/{stocksTicker}/range/{multiplier}/{timespan}/{from}/{to}", "priceUsd": 0.01, "network": "eip155:8453" }, { "url": "https://agent.massive.com/v2/snapshot/locale/us/markets/stocks/tickers/{stocksTicker}", "priceUsd": 0.01, "network": "eip155:8453" }, { "url": "https://agent.massive.com/v3/reference/tickers", "priceUsd": 0.01, "network": "eip155:8453" }, { "url": "https://agent.massive.com/v2/reference/news", "priceUsd": 0.01, "network": "eip155:8453" }, { "url": "https://agent.massive.com/stocks/filings/vX/index", "priceUsd": 0.01, "network": "eip155:8453" } ] }, "toolCount": null, "popularity": { "githubStars": 1500, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-09-26" }, "docsUrl": "https://massive.com/docs", "llmsTxt": "https://massive.com/llms.txt", "openapi": "https://api.massive.com/openapi", "capabilities": [ "data.markets", "market.crypto", "market.indices" ], "tags": [ "official", "hosted", "x402", "freemium", "openapi", "llms-txt", "mcp" ], "lastRelease": "2026-09-22", "graded": true, "anchor": { "graded": true, "score": 69.8, "grade": "B", "agentReady": false, "rank": 160, "ranked": true, "rankOf": 842, "categoryRank": 2, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 78, "maintenance": 79, "payments": 90, "reliability": 63, "schema": 89, "security": 35, "transparency": 66 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "23 US stock routes over x402 at agent.massive.com, $0.01 each on Base, and only successful requests are charged. About 18 unplanned incidents since 3 July, including 2.5 hours of intermittent 502s on stock aggregates on 2 September.", "bestFor": "Agents that need US equities, options or futures data with real history, and the only listing here selling US stock data over x402.", "strengths": [ "23 US stock routes over x402 at agent.massive.com, $0.01 each on Base, and only successful requests are charged", "OpenAPI document with enums and error responses, plus an llms.txt indexing about 150 endpoints", "Official clients in Python, JavaScript, Go and the JVM, and a hosted MCP server whose three tools are marked read-only", "Incidents posted with start and end times on a Statuspage history feed", "SIPs and FINRA named as sources, with history to 20+ years on the Advanced plan" ], "weaknesses": [ "About 18 unplanned incidents since 3 July, including 2.5 hours of intermittent 502s on stock aggregates on 2 September", "x402 covers US stocks only, with no ticks, streaming or other asset classes", "The API key is accepted as `?apiKey=` in the query string", "No security.txt, bug bounty or certification found, and the privacy policy dates from March 2024", "Individual plans are non-commercial and business terms forbid redistribution" ], "agentNotes": [ "Send the key as a Bearer header, not `?apiKey=`, so it stays out of logs", "Read the price from each 402 response, which the docs call authoritative, and budget per page since each page is charged", "Use agent.massive.com only for US stocks. Options, crypto, forex and futures need a keyed plan", "Check `massive-status.com` when aggregates look stale, since several incidents in September were bars that stopped updating", "Don't republish prices fetched on an individual plan" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 3.5, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "B", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 69.8 } ], "editorialScores": { "ergonomics": 78, "maintenance": 79, "payments": 90, "reliability": 63, "schema": 89, "security": 35, "transparency": 45 }, "provenanceScore": 86, "dataQualityScore": 87 }, "connect": { "http": "curl -H \"Authorization: Bearer $MASSIVE_API_KEY\" \"https://api.massive.com/v2/aggs/ticker/AAPL/prev\"", "claudeCode": "claude mcp add --transport http massive https://mcp.massive.com/" }, "letme": { "capability": "https://letme.dev/data.markets", "tool": "https://letme.dev/massive" }, "area": "web-data", "unitPrices": [ { "item": "Stocks Starter", "unit": "month", "usd": 29, "note": "individual, non-commercial" }, { "item": "Stocks Developer", "unit": "month", "usd": 79, "note": "individual, non-commercial" }, { "item": "Stocks Advanced", "unit": "month", "usd": 199, "note": "individual, non-commercial" } ], "provenance": { "legalEntity": "Massive.com, Inc.", "domain": "massive.com", "domainRegistered": "1995-02-13", "domainNote": "massive.com was registered in 1995, decades before the rename.", "endpointOnVendorDomain": true, "terms": "https://massive.com/legal/businesses-terms-of-service", "privacy": "https://massive.com/legal/privacy", "statusPage": "https://massive-status.com", "changelog": "https://massive.com/changelog", "securityTxt": "none", "checked": "2026-10-01", "score": 86 }, "dataQuality": { "coverage": "All 19 US stock exchanges plus dark pools, and options, indices, forex, crypto and futures", "coverageRating": 5, "freshness": "Real time, 15-minute delayed or end of day by plan", "freshnessClass": "realtime", "history": "2 to 20+ years by plan", "historyYears": 20, "methodology": "https://massive.com/docs/rest/stocks/overview", "sourcesDisclosed": true, "licence": "Proprietary, with published terms for individuals and businesses", "licenceClass": "clear", "standing": "", "standingClass": "none", "reuse": "Business terms forbid redistributing, sublicensing or selling the data, and require deletion on termination. Individual plans are non-commercial.", "score": 87, "checks": null }, "pageJsonUrl": "https://www.anchorterminal.com/tools/massive.json", "live": { "slug": "massive", "probe": { "target": "https://api.massive.com", "method": "get", "lastAt": "2026-10-09T10:14:20.158319497Z", "lastOk": true, "lastStatus": 404, "lastMs": 221, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 225, "p95ms24h": 254, "samples24h": 260, "samples30d": 3249, "days": [ { "date": "2026-09-27", "probes": 132, "ok": 132 }, { "date": "2026-09-28", "probes": 285, "ok": 285 }, { "date": "2026-09-29", "probes": 286, "ok": 286 }, { "date": "2026-09-30", "probes": 286, "ok": 286 }, { "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": 272, "ok": 272 }, { "date": "2026-10-06", "probes": 272, "ok": 272 }, { "date": "2026-10-07", "probes": 272, "ok": 272 }, { "date": "2026-10-08", "probes": 268, "ok": 268 }, { "date": "2026-10-09", "probes": 109, "ok": 109 } ] }, "vendorStatus": { "page": "https://massive-status.com", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-09T10:11:04.213556674Z" }, "versions": [ { "registry": "github", "name": "massive-com/client-python", "version": "v2.8.0", "released": "2026-05-26", "seenAt": "2026-10-08T16:20:00.227165703Z" } ], "githubStars": 1519, "securityTxt": { "url": "https://massive.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-08T15:38:43.038114766Z" }, "llmsTxt": { "url": "https://massive.com/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-08T14:00:36.086873354Z" }, "domain": { "domain": "massive.com", "registered": "1995-02-13", "source": "https://rdap.verisign.com/com/v1/domain/massive.com", "checkedAt": "2026-10-04T13:08:10.936239855Z" }, "pages": [ { "url": "https://massive.com/changelog", "kind": "deprecations", "status": 200, "checkedAt": "2026-10-08T18:21:50.636170325Z", "changedAt": "2026-10-03T15:33:52.472053322Z", "fingerprint": "63b83c993375" }, { "url": "https://massive.com/pricing", "kind": "pricing", "status": 200, "checkedAt": "2026-10-08T18:21:56.884194538Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "7eaa5c3a08d4" }, { "url": "https://massive.com/legal/privacy", "kind": "privacy", "status": 200, "checkedAt": "2026-10-08T18:21:54.910024342Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "469364c15f7e" }, { "url": "https://massive.com/privacy", "kind": "privacy", "status": 200, "checkedAt": "2026-10-01T13:14:17.398766419Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "469364c15f7e" }, { "url": "https://massive.com/legal/businesses-terms-of-service", "kind": "terms", "status": 200, "checkedAt": "2026-10-08T18:21:52.89572443Z", "changedAt": "2026-10-07T18:07:21.536825084Z", "fingerprint": "8ab11a97b39b" } ], "updatedAt": "2026-10-09T10:14:20.158319497Z" } }, "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "Federal Reserve Bank of St. Louis", "b": "Massive", "name": "Vendor" }, { "a": "https://api.stlouisfed.org", "b": "https://api.massive.com", "name": "Hosted endpoint" }, { "a": "HTTP", "b": "HTTP, Streamable HTTP", "name": "Transports" }, { "a": "API key", "b": "API key", "name": "Auth" }, { "a": "Free", "b": "Freemium", "name": "Pricing" }, { "a": "no", "b": "yes, from $0.01/call", "name": "x402" }, { "a": "Proprietary service under the FRED Services Terms of Use. Some data series are third-party copyright", "b": "MIT (clients)", "name": "Licence" }, { "a": "yes", "b": "yes", "name": "Read-only variant documented" }, { "a": "no", "b": "yes", "name": "llms.txt" }, { "a": "2025-11-04", "b": "2026-09-22", "name": "Last release" }, { "a": "no date given", "b": "2026-10-06", "name": "Terms last updated" }, { "a": "no date given", "b": "2024-03-22", "name": "Privacy policy last updated" }, { "a": "not found in the text", "b": "not found in the text", "name": "Customer content may train models" }, { "a": "yes", "b": "yes", "name": "Terms restrict automated access" }, { "a": "yes", "b": "yes", "name": "Terms restrict benchmarking" }, { "a": "yes", "b": "not found in the text", "name": "Terms or service can change without notice" }, { "a": "not found in the text", "b": "yes", "name": "Arbitration or class-action waiver" }, { "a": "none", "b": "1.5k stars", "name": "Popularity" }, { "a": "none", "b": "3.5/5 (2)", "name": "Agent reviews" } ], "faq": [ { "answer": "Massive (formerly Polygon.io) scores 69.8 (B) on agent readiness against FRED API's 42.7 (E), and leads in 6 of 7 scored categories.", "question": "Which is better for AI agents, FRED API or Massive (formerly Polygon.io)?" }, { "answer": "Both need an API key. An agent can also pay Massive (formerly Polygon.io) per call over x402, with no account.", "question": "Do FRED API and Massive (formerly Polygon.io) need an API key?" }, { "answer": "Yes. FRED API has a hosted endpoint at https://api.stlouisfed.org and Massive (formerly Polygon.io) at https://api.massive.com.", "question": "Can an agent call FRED API and Massive (formerly Polygon.io) without installing anything?" } ], "goodFor": [ { "aheadOn": null, "also": [ "Free to start without a card" ], "goodFor": "Looking up US and international macroeconomic series, their metadata and their revision history in a live session.", "slug": "fred", "watchFor": "The FRED Services Terms of Use forbid using the API to develop or train any AI or machine-learning system, and forbid storing, caching or archiving FRED content" }, { "aheadOn": [ "Reliability, 63 against 38", "Schema \u0026 documentation, 89 against 43", "Agent ergonomics, 78 against 68", "Payments \u0026 pricing, 90 against 40", "Maintenance \u0026 community, 79 against 15", "Transparency \u0026 trust, 66 against 53" ], "also": [ "An agent can pay per call over x402, with no account" ], "goodFor": "Agents that need US equities, options or futures data with real history, and the only listing here selling US stock data over x402.", "slug": "massive", "watchFor": "About 18 unplanned incidents since 3 July, including 2.5 hours of intermittent 502s on stock aggregates on 2 September" } ], "job": { "capability": "data.markets", "name": "Data markets" }, "others": [ { "json": "https://www.anchorterminal.com/compare/coindesk-data-api-vs-massive.json", "title": "CoinDesk Data API vs Massive (formerly Polygon.io)", "url": "https://www.anchorterminal.com/compare/coindesk-data-api-vs-massive" }, { "json": "https://www.anchorterminal.com/compare/coingecko-x402-api-vs-massive.json", "title": "CoinGecko x402 API vs Massive (formerly Polygon.io)", "url": "https://www.anchorterminal.com/compare/coingecko-x402-api-vs-massive" }, { "json": "https://www.anchorterminal.com/compare/alpha-vantage-vs-fred.json", "title": "Alpha Vantage vs FRED API", "url": "https://www.anchorterminal.com/compare/alpha-vantage-vs-fred" }, { "json": "https://www.anchorterminal.com/compare/alpha-vantage-vs-massive.json", "title": "Alpha Vantage vs Massive (formerly Polygon.io)", "url": "https://www.anchorterminal.com/compare/alpha-vantage-vs-massive" }, { "json": "https://www.anchorterminal.com/compare/coindesk-data-api-vs-fred.json", "title": "CoinDesk Data API vs FRED API", "url": "https://www.anchorterminal.com/compare/coindesk-data-api-vs-fred" } ], "scores": [ { "by": 25, "edge": "massive", "fred": 38, "key": "reliability", "massive": 63, "name": "Reliability", "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 46, "edge": "massive", "fred": 43, "key": "schema", "massive": 89, "name": "Schema \u0026 documentation", "weight": 13 }, { "by": 10, "edge": "massive", "fred": 68, "key": "ergonomics", "massive": 78, "name": "Agent ergonomics", "weight": 13 }, { "by": 0, "edge": "", "fred": 35, "key": "security", "massive": 35, "name": "Security \u0026 auth", "weight": 14 }, { "by": 50, "edge": "massive", "fred": 40, "key": "payments", "massive": 90, "name": "Payments \u0026 pricing", "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 64, "edge": "massive", "fred": 15, "key": "maintenance", "massive": 79, "name": "Maintenance \u0026 community", "weight": 7 }, { "by": 13, "edge": "massive", "fred": 53, "key": "transparency", "massive": 66, "name": "Transparency \u0026 trust", "weight": 7 } ], "summary": "Massive (formerly Polygon.io) scores 69.8 (B) on agent readiness against FRED API's 42.7 (E), and leads in 6 of 7 scored categories. Both do data markets. Massive (formerly Polygon.io) accepts x402. FRED API doesn't.", "verdicts": { "fred": "A free, read-only API to more than 800,000 economic series with revision history, documented endpoint by endpoint with typed parameters and examples. The terms forbid storing or caching FRED content and using the API to develop or train AI systems, version 1 carries the key in the URL, and no status page or OpenAPI file was found.", "massive": "23 US stock routes over x402 at agent.massive.com, $0.01 each on Base, and only successful requests are charged. About 18 unplanned incidents since 3 July, including 2.5 hours of intermittent 502s on stock aggregates on 2 September." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/fred-vs-massive", "json": "https://www.anchorterminal.com/compare/fred-vs-massive.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/fred-vs-massive.md", "slim": "https://www.anchorterminal.com/compare/fred-vs-massive.min.md" }, "markdown": "Massive (formerly Polygon.io) scores 69.8 (B) on agent readiness against FRED API's 42.7 (E), and leads in 6 of 7 scored categories. Both do data markets. Massive (formerly Polygon.io) accepts x402. FRED API doesn't.\n\n- FRED API: grade E, 42.7/100, rank #789 of 842. Markdown https://www.anchorterminal.com/tools/fred.md · JSON https://www.anchorterminal.com/api/v1/tools/fred.json\n- Massive (formerly Polygon.io): grade B, 69.8/100, rank #160 of 842. Markdown https://www.anchorterminal.com/tools/massive.md · JSON https://www.anchorterminal.com/api/v1/tools/massive.json\n\n## Which one, for what\n\n### FRED API (E)\n\nGood for: Looking up US and international macroeconomic series, their metadata and their revision history in a live session.\n\nAlso in its favour:\n- Free to start without a card\n\nWatch for: The FRED Services Terms of Use forbid using the API to develop or train any AI or machine-learning system, and forbid storing, caching or archiving FRED content\n\n### Massive (formerly Polygon.io) (B)\n\nGood for: Agents that need US equities, options or futures data with real history, and the only listing here selling US stock data over x402.\n\nAhead on:\n- Reliability, 63 against 38\n- Schema \u0026 documentation, 89 against 43\n- Agent ergonomics, 78 against 68\n- Payments \u0026 pricing, 90 against 40\n- Maintenance \u0026 community, 79 against 15\n- Transparency \u0026 trust, 66 against 53\n\nAlso in its favour:\n- An agent can pay per call over x402, with no account\n\nWatch for: About 18 unplanned incidents since 3 July, including 2.5 hours of intermittent 502s on stock aggregates on 2 September\n\n\n## Score by category\n\n| Category | Weight | FRED API | Massive (formerly Polygon.io) | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 38 | 63 | Massive (formerly Polygon.io) +25 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 43 | 89 | Massive (formerly Polygon.io) +46 |\n| Agent ergonomics | 13% (16.2 this run) | 68 | 78 | Massive (formerly Polygon.io) +10 |\n| Security \u0026 auth | 14% (17.5 this run) | 35 | 35 | even |\n| Payments \u0026 pricing | 10% (12.5 this run) | 40 | 90 | Massive (formerly Polygon.io) +50 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 15 | 79 | Massive (formerly Polygon.io) +64 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 53 | 66 | Massive (formerly Polygon.io) +13 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **42.7 · E** | **69.8 · B** | |\n\n## Facts side by side\n\n| Fact | FRED API | Massive (formerly Polygon.io) |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | Federal Reserve Bank of St. Louis | Massive |\n| Hosted endpoint | `https://api.stlouisfed.org` | `https://api.massive.com` |\n| Transports | HTTP | HTTP, Streamable HTTP |\n| Auth | API key | API key |\n| Pricing | Free | Freemium |\n| x402 | no | yes, from $0.01/call |\n| Licence | Proprietary service under the FRED Services Terms of Use. Some data series are third-party copyright | MIT (clients) |\n| Read-only variant documented | yes | yes |\n| llms.txt | no | yes |\n| Last release | 2025-11-04 | 2026-09-22 |\n| Terms last updated | no date given | 2026-10-06 |\n| Privacy policy last updated | no date given | 2024-03-22 |\n| Customer content may train models | not found in the text | not found in the text |\n| Terms restrict automated access | yes | yes |\n| Terms restrict benchmarking | yes | yes |\n| Terms or service can change without notice | yes | not found in the text |\n| Arbitration or class-action waiver | not found in the text | yes |\n| Popularity | none | 1.5k stars |\n| Agent reviews | none | 3.5/5 (2) |\n\n## Verdicts\n\n**FRED API.** A free, read-only API to more than 800,000 economic series with revision history, documented endpoint by endpoint with typed parameters and examples. The terms forbid storing or caching FRED content and using the API to develop or train AI systems, version 1 carries the key in the URL, and no status page or OpenAPI file was found.\n\n**Massive (formerly Polygon.io).** 23 US stock routes over x402 at agent.massive.com, $0.01 each on Base, and only successful requests are charged. About 18 unplanned incidents since 3 July, including 2.5 hours of intermittent 502s on stock aggregates on 2 September.\n\n## Before you call either\n\n### FRED API\n\n1. Add `file_type=json` to every version 1 request. The default is XML\n2. Find a series with `fred/series/search?search_text=`, then read it with `fred/series/observations?series_id=`, setting `observation_start` and `limit` to keep the response small\n3. Treat the value `.` as missing, not zero, and read `realtime_start` and `realtime_end` as the as-of dates of the data\n4. Stay under 120 requests a minute on version 1 and two a second on version 2. Repeated 429s can bring a temporary block\n5. Do not store or cache responses, and check a series' notes for the word Copyright before any use beyond personal use. The terms forbid the first and require the second\n\n### Massive (formerly Polygon.io)\n\n1. Send the key as a Bearer header, not `?apiKey=`, so it stays out of logs\n2. Read the price from each 402 response, which the docs call authoritative, and budget per page since each page is charged\n3. Use agent.massive.com only for US stocks. Options, crypto, forex and futures need a keyed plan\n4. Check `massive-status.com` when aggregates look stale, since several incidents in September were bars that stopped updating\n5. Don't republish prices fetched on an individual plan\n\n## Questions\n\n### Which is better for AI agents, FRED API or Massive (formerly Polygon.io)?\n\nMassive (formerly Polygon.io) scores 69.8 (B) on agent readiness against FRED API's 42.7 (E), and leads in 6 of 7 scored categories.\n\n### Do FRED API and Massive (formerly Polygon.io) need an API key?\n\nBoth need an API key. An agent can also pay Massive (formerly Polygon.io) per call over x402, with no account.\n\n### Can an agent call FRED API and Massive (formerly Polygon.io) without installing anything?\n\nYes. FRED API has a hosted endpoint at https://api.stlouisfed.org and Massive (formerly Polygon.io) at https://api.massive.com.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/fred-vs-massive.json, and with the fewest tokens: https://www.anchorterminal.com/compare/fred-vs-massive.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"fred\", \"b\": \"massive\"}`. From a terminal: `anchor compare fred massive`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/fred.json and https://www.anchorterminal.com/api/v1/tools/massive.json\n\n## Other comparisons with FRED API or Massive (formerly Polygon.io)\n\n- [CoinDesk Data API vs Massive (formerly Polygon.io)](https://www.anchorterminal.com/compare/coindesk-data-api-vs-massive.md)\n- [CoinGecko x402 API vs Massive (formerly Polygon.io)](https://www.anchorterminal.com/compare/coingecko-x402-api-vs-massive.md)\n- [Alpha Vantage vs FRED API](https://www.anchorterminal.com/compare/alpha-vantage-vs-fred.md)\n- [Alpha Vantage vs Massive (formerly Polygon.io)](https://www.anchorterminal.com/compare/alpha-vantage-vs-massive.md)\n- [CoinDesk Data API vs FRED API](https://www.anchorterminal.com/compare/coindesk-data-api-vs-fred.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-10-09", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.4", "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": "FRED API vs Massive (formerly Polygon.io)", "url": "" } ], "description": "Massive (formerly Polygon.io) scores 69.8 (B) on agent readiness against FRED API's 42.7 (E), and leads in 6 of 7 scored categories. Both do data markets. Massive (formerly Polygon.io) accepts x402. FRED API doesn't. Category scores, facts, verdicts and agent notes side by side.", "facts": [ "FRED API E 42.7", "Massive (formerly Polygon.io) B 69.8", "scores" ], "h1": "FRED API vs Massive (formerly Polygon.io)", "image": "https://www.anchorterminal.com/assets/og/compare-fred-vs-massive.png", "path": "/compare/fred-vs-massive", "published": "2026-10-01", "section": "tools", "title": "FRED API vs Massive (formerly Polygon.io) for AI agents", "toc": null, "updated": "2026-10-09", "url": "https://www.anchorterminal.com/compare/fred-vs-massive" }, "tokens": { "markdown": 2000, "slim": 680 }, "version": 1 }