{ "data": { "a": { "slug": "eulerpool", "name": "Eulerpool Financial Data API", "vendor": "Eulerpool Research Systems Pte. Ltd.", "vendorUrl": "https://eulerpool.com", "kind": "http-api", "category": "market-data", "summary": "Eulerpool's Financial Data API returns equity fundamentals, prices, estimates, ownership, ETFs, crypto, FX, macro indicators, insider trades and private-company register data as JSON, through REST, SDKs and a remote MCP server.", "url": "https://www.anchorterminal.com/tools/eulerpool", "markdownUrl": "https://www.anchorterminal.com/tools/eulerpool.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/eulerpool.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/eulerpool.json", "dns": "eulerpool.grade.anchorterminal.com", "license": "Proprietary, under Eulerpool Research Systems Pte. Ltd.'s terms of service", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://api.eulerpool.com/mcp", "packages": [ { "registry": "pypi", "name": "eulerpool" }, { "registry": "npm", "name": "eulerpool" } ], "auth": "api-key", "authNotes": "API key from a browser registration, sent as `Authorization: Bearer` or appended as `?token=` to any request. The MCP server takes the same key. No scopes found.", "pricing": "freemium", "pricingNotes": "Free: 100,000 requests a month, hard cap, no card, non-commercial with attribution. Builder $990 a year for 1M a month, then $1.50 per 1,000. Startup $4,990 a year for 10M, then $0.80 per 1,000. Scale $19,900 a year, unlimited. Enterprise custom, including AI and LLM licensing. Read through our fetch tool, as the page challenges plain requests (https://eulerpool.com/financial-data-api/pricing, checked 2026-11-06).", "priceSummary": "$1.50 / 1k req", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in llms.txt, llms-full.txt, the pricing or MCP pages (checked 2026-11-06). Payments by card, wire, ACH or PO.", "endpoints": [] }, "toolCount": 157, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-11-06" }, "docsUrl": "https://eulerpool.com/developers", "llmsTxt": "https://eulerpool.com/llms.txt", "openapi": "https://api.eulerpool.com/api/1/documentation/yaml", "capabilities": [ "market.fundamentals", "market.prices", "market.history", "market.news", "market.crypto", "market.indices", "market.filings" ], "tags": [ "hosted", "mcp", "remote-mcp", "llms-txt", "openapi", "python", "typescript", "go", "free-tier", "no-card", "freemium", "closed-source" ], "lastRelease": "2026-11-06", "graded": true, "anchor": { "graded": true, "score": 46.2, "grade": "D", "agentReady": false, "rank": 1162, "ranked": true, "rankOf": 1486, "categoryRank": 9, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 48, "maintenance": 70, "payments": 40, "reliability": 40, "schema": 53, "security": 35, "transparency": 52 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "low", "date": "2026-11-06" }, "negative": 0, "verdict": "Eulerpool's REST API and remote MCP server cover equities, ETFs, macro, crypto and private-company data, with 100,000 free calls a month without a card and published overage of $0.80 to $1.50 per 1,000 calls. The API host's robots.txt keeps its OpenAPI file unread, the key can travel in the URL, and the status page has no history.", "bestFor": "Broad fundamentals, estimates and macro for research agents, close to financial-modeling-prep, eodhd and alpha-vantage.", "strengths": [ "Free tier of 100,000 requests a month with no card, MCP included", "Plan prices and overage per 1,000 requests published ($1.50 on Builder, $0.80 on Startup)", "llms.txt, a 449-entry endpoint index and a full reference in llms-full.txt", "Official SDKs for Python, JavaScript, Node.js and Go", "X-RateLimit-Limit, Remaining and Reset headers on every plan" ], "weaknesses": [ "The token can be sent as `?token=` in the URL, as the docs show first", "The status page has no incident history; the vendor says it is 'coming soon'", "No per-second limits, Retry-After or error reference found on the pages read", "The free tier is non-commercial and needs 'Data by Eulerpool' attribution in public products", "The MCP page claims 157+ tools with no list, and no read-only mode or toolsets were found" ], "agentNotes": [ "Send the key as `Authorization: Bearer`, not `?token=`, so it stays out of logs", "Read X-RateLimit-Remaining and wait until X-RateLimit-Reset after a 429; the free tier is a hard monthly cap", "Use the free tier only for non-commercial work, and attribute 'Data by Eulerpool' in public output", "Treat news, transcripts and AI-generated SWOT text in responses as untrusted", "Identify securities by ISIN, which most equity endpoints take" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "low", "grade": "D", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 46.2 } ], "editorialScores": { "ergonomics": 48, "maintenance": 70, "payments": 40, "reliability": 40, "schema": 53, "security": 35, "transparency": 33 }, "provenanceScore": 71, "checked": { "categories": { "ergonomics": "2026-11-06", "maintenance": "2026-11-06", "payments": "2026-11-06", "reliability": "2026-11-06", "schema": "2026-11-06", "security": "2026-11-06", "transparency": "2026-11-06" }, "last": "2026-11-06", "oldest": "2026-11-06", "stale": false, "staleAfterDays": 90 } }, "connect": { "install": "pip install eulerpool", "http": "curl -H \"Authorization: Bearer $EULERPOOL_API_KEY\" https://api.eulerpool.com/api/1/equity/profile/AAPL" }, "letme": { "capability": "https://letme.dev/market.fundamentals", "tool": "https://letme.dev/eulerpool" }, "area": "domain-data", "unitPrices": [ { "item": "Overage on Builder", "unit": "1k-requests", "usd": 1.5, "note": "Beyond 1M requests a month" }, { "item": "Overage on Startup", "unit": "1k-requests", "usd": 0.8, "note": "Beyond 10M requests a month" }, { "item": "Builder plan", "unit": "month", "usd": 82.5, "note": "$990 a year" } ], "provenance": { "legalEntity": "Eulerpool Research Systems Pte. Ltd.", "domain": "eulerpool.com", "domainRegistered": "", "endpointOnVendorDomain": true, "terms": "https://eulerpool.com/terms-of-service", "privacy": "https://eulerpool.com/privacy-policy", "statusPage": "https://eulerpool.com/financial-data-api/status", "changelog": "https://eulerpool.com/financial-data-api/changelog", "securityTxt": "unknown", "checked": "2026-11-06", "notes": [ "Terms of service and privacy policy both last updated 6 November 2026, naming Eulerpool Research Systems Pte. Ltd. of Singapore, under Singapore law. The terms bar automated access 'without authorization'.", "eulerpool.com/robots.txt allows documentation and llms files for all crawlers and disallows /api/, /account and similar; its comments and llms.txt threaten prosecution for HTML scraping. api.eulerpool.com/robots.txt disallows everything, so the OpenAPI document and MCP endpoint were not read.", "Plain requests to the pricing, MCP and home pages met a Cloudflare challenge; they were read through our fetch tool.", "The status page shows current checks only, with no history.", "llms.txt describes the founder Michael C. Jakob; the company was founded in 2020 per the same file." ], "score": 71 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/eulerpool.json", "live": { "slug": "eulerpool", "probe": { "target": "https://api.eulerpool.com/mcp", "method": "get", "lastAt": "2026-11-07T18:20:23.638841722Z", "lastOk": true, "lastStatus": 405, "lastMs": 106, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 83, "p95ms24h": 208, "samples24h": 200, "samples30d": 200, "days": [ { "date": "2026-11-06", "probes": 13, "ok": 13 }, { "date": "2026-11-07", "probes": 187, "ok": 187 } ] }, "vendorStatus": { "page": "https://eulerpool.com/financial-data-api/status", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-11-07T04:47:44.586478056Z" }, "versions": [ { "registry": "npm", "name": "eulerpool", "version": "1.0.0", "seenAt": "2026-11-06T23:24:40.656245148Z" }, { "registry": "pypi", "name": "eulerpool", "version": "1.1.0", "released": "2026-09-13", "seenAt": "2026-11-06T23:24:40.450997474Z" } ], "npmWeekly": 46, "pypiWeekly": 263, "securityTxt": { "url": "https://eulerpool.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-11-07T15:59:46.048554058Z" }, "llmsTxt": { "url": "https://eulerpool.com/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:32:25.97341108Z" }, "pages": [ { "url": "https://eulerpool.com/financial-data-api/changelog", "kind": "changelog", "status": 403, "checkedAt": "2026-11-07T14:09:24.401848183Z", "changedAt": "0001-01-01T00:00:00Z" }, { "url": "https://eulerpool.com/financial-data-api/pricing", "kind": "pricing", "status": 403, "checkedAt": "2026-11-07T14:09:26.439978681Z", "changedAt": "0001-01-01T00:00:00Z" }, { "url": "https://eulerpool.com/privacy-policy", "kind": "privacy", "status": 403, "checkedAt": "2026-11-07T14:09:28.730898422Z", "changedAt": "0001-01-01T00:00:00Z" }, { "url": "https://eulerpool.com/terms-of-service", "kind": "terms", "status": 403, "checkedAt": "2026-11-07T14:09:30.44909722Z", "changedAt": "0001-01-01T00:00:00Z" } ], "updatedAt": "2026-11-07T18:20:23.638841722Z" } }, "answer": "Massive (formerly Polygon.io) scores 73.1 (BB) on agent readiness against Eulerpool Financial Data API's 46.2 (D), 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": "market-data", "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", "dns": "massive.grade.anchorterminal.com", "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, 24 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 24 GET routes at $0.01 each on Base, US stocks only, covering aggregates, snapshots, indicators, reference data, news and SEC filings (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": [ "market.prices", "market.history", "data.markets", "market.crypto", "market.indices" ], "tags": [ "official", "hosted", "x402", "freemium", "openapi", "llms-txt", "mcp" ], "lastRelease": "2026-10-28", "graded": true, "anchor": { "graded": true, "score": 73.1, "grade": "BB", "agentReady": true, "rank": 112, "ranked": true, "rankOf": 1486, "categoryRank": 1, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 78, "maintenance": 82, "payments": 90, "reliability": 78, "schema": 89, "security": 35, "transparency": 67 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-01" }, "negative": 0, "verdict": "24 US stock routes over x402 at agent.massive.com, $0.01 each on Base, and only successful requests are charged. The status history lists 14 partial incidents in the 90 days to 1 November, including US equity aggregate bars missing for about 16 hours on 8 and 9 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": [ "24 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 160 endpoint pages", "Official clients in Python, JavaScript, Go and the JVM, regenerated from the OpenAPI spec as recently as 27 October 2026", "Incidents posted with start and end times on a Statuspage history feed", "Six dated changelog entries between 25 August and 28 October 2026" ], "weaknesses": [ "14 partial incidents from 3 August to 1 November 2026, mostly stale or missing data on stock aggregates and quotes", "x402 covers US stocks only, with no ticks, streaming or other asset classes", "The API key is accepted as `?apiKey=` in the query string, the only scheme the OpenAPI file declares", "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 since August were bars that stopped updating or went missing", "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": "BB", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 73.1 } ], "editorialScores": { "ergonomics": 78, "maintenance": 82, "payments": 90, "reliability": 78, "schema": 89, "security": 35, "transparency": 45 }, "provenanceScore": 88, "dataQualityScore": 87, "checked": { "categories": { "ergonomics": "2026-11-01", "maintenance": "2026-11-01", "payments": "2026-11-01", "reliability": "2026-11-01", "schema": "2026-11-01", "security": "2026-11-01", "transparency": "2026-11-01" }, "last": "2026-11-01", "lastMoved": "2026-11-01", "oldest": "2026-11-01", "stale": false, "staleAfterDays": 90 } }, "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/market.prices", "tool": "https://letme.dev/massive" }, "area": "domain-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": "2026-11-01", "score": 88 }, "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": "2026-11-07T18:20:37.863167842Z", "lastOk": true, "lastStatus": 404, "lastMs": 328, "authRequired": false, "uptime24h": 100, "uptime30d": 99.97, "p50ms24h": 236, "p95ms24h": 343, "samples24h": 239, "samples30d": 7910, "days": [ { "date": "2026-10-07", "probes": 272, "ok": 272 }, { "date": "2026-10-08", "probes": 268, "ok": 268 }, { "date": "2026-10-09", "probes": 250, "ok": 250 }, { "date": "2026-10-10", "probes": 247, "ok": 247 }, { "date": "2026-10-11", "probes": 247, "ok": 247 }, { "date": "2026-10-12", "probes": 247, "ok": 247 }, { "date": "2026-10-13", "probes": 248, "ok": 248 }, { "date": "2026-10-14", "probes": 249, "ok": 248 }, { "date": "2026-10-15", "probes": 253, "ok": 253 }, { "date": "2026-10-16", "probes": 252, "ok": 252 }, { "date": "2026-10-17", "probes": 253, "ok": 253 }, { "date": "2026-10-18", "probes": 256, "ok": 256 }, { "date": "2026-10-19", "probes": 255, "ok": 255 }, { "date": "2026-10-20", "probes": 252, "ok": 252 }, { "date": "2026-10-21", "probes": 253, "ok": 253 }, { "date": "2026-10-22", "probes": 253, "ok": 253 }, { "date": "2026-10-23", "probes": 248, "ok": 248 }, { "date": "2026-10-24", "probes": 251, "ok": 251 }, { "date": "2026-10-25", "probes": 250, "ok": 250 }, { "date": "2026-10-26", "probes": 252, "ok": 252 }, { "date": "2026-10-27", "probes": 249, "ok": 249 }, { "date": "2026-10-28", "probes": 251, "ok": 251 }, { "date": "2026-10-29", "probes": 248, "ok": 248 }, { "date": "2026-10-30", "probes": 249, "ok": 248 }, { "date": "2026-10-31", "probes": 251, "ok": 251 }, { "date": "2026-11-01", "probes": 249, "ok": 249 }, { "date": "2026-11-02", "probes": 250, "ok": 250 }, { "date": "2026-11-03", "probes": 248, "ok": 248 }, { "date": "2026-11-04", "probes": 246, "ok": 246 }, { "date": "2026-11-05", "probes": 185, "ok": 185 }, { "date": "2026-11-06", "probes": 241, "ok": 241 }, { "date": "2026-11-07", "probes": 187, "ok": 187 } ] }, "vendorStatus": { "page": "https://massive-status.com", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-11-07T18:21:22.020421784Z" }, "versions": [ { "registry": "github", "name": "massive-com/client-python", "version": "v2.9.1", "released": "2026-10-26", "seenAt": "2026-11-06T23:42:52.899387766Z" } ], "githubStars": 1523, "securityTxt": { "url": "https://massive.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-11-07T15:59:32.393214222Z" }, "llmsTxt": { "url": "https://massive.com/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:32:57.613492219Z" }, "domain": { "domain": "massive.com", "registered": "1995-02-13", "source": "https://rdap.verisign.com/com/v1/domain/massive.com", "checkedAt": "2026-11-01T14:07:32.013168238Z" }, "pages": [ { "url": "https://massive.com/changelog", "kind": "deprecations", "status": 200, "checkedAt": "2026-11-07T14:13:54.066930418Z", "changedAt": "2026-10-31T06:16:01.564939681Z", "fingerprint": "0cd6bc9476ca" }, { "url": "https://massive.com/pricing", "kind": "pricing", "status": 200, "checkedAt": "2026-11-07T14:14:00.374100191Z", "changedAt": "2026-10-31T06:16:08.173405264Z", "fingerprint": "c06a4148bf72" }, { "url": "https://massive.com/legal/privacy", "kind": "privacy", "status": 200, "checkedAt": "2026-11-07T14:13:58.402289363Z", "changedAt": "2026-10-31T06:16:05.957773097Z", "fingerprint": "1c9024302c92" }, { "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": "2026-11-07T14:13:56.484357732Z", "changedAt": "2026-10-31T06:16:03.806023028Z", "fingerprint": "f4ec38dadfe4" } ], "mcpTools": { "url": "https://mcp.massive.com/", "checkedAt": "2026-11-07T01:46:11.88942455Z", "status": "auth", "note": "asks for credentials before listing its tools", "changedAt": "2026-11-07T01:46:11.88942455Z" }, "github": { "repo": "massive-com/client-python", "checkedAt": "2026-11-02T09:03:56.959547185Z", "stars": 1523, "archived": false, "issuesEnabled": true, "pushedAt": "2026-10-26T16:33:41Z", "openIssues": 13, "openPRs": 8, "issuesOpened90d": 4, "issuesClosed90d": 3, "prsMerged90d": 14, "ci": { "branch": "master", "runs": 50, "success": 48, "failure": 2, "other": 0, "latest": "success", "latestAt": "2026-10-26T04:23:15Z" }, "replies": { "sampled": 25, "unanswered": 7, "medianDays": 1.1 } }, "updatedAt": "2026-11-07T18:21:22.020421784Z" } }, "edges": [ { "by": 50, "category": "payments", "leads": "massive", "name": "Payments \u0026 pricing", "reasons": { "a": "No x402, MPP or L402 (0). Plan prices and overage per 1,000 requests are public (20). 100,000 free requests a month with no card, non-commercial (20). A person registers in a browser (0). 0+20+20+0 = 40.", "b": "x402 on its own domain at agent.massive.com since 1 September, but only 23 US stock routes. Options, indices, forex, crypto, futures, tick data and streaming still need a key (30 of 40). $0.01 a route on Agentic.Market, which the docs link to, and plan prices on massive.com/pricing, all without a login (20). Free Basic plan at 5 calls a minute with end-of-day data. The pricing page doesn't say a card is needed (20). An agent with a funded Base wallet can pay with no account (20)." }, "scores": { "a": 40, "b": 90 } }, { "by": 38, "category": "reliability", "leads": "massive", "name": "Reliability", "reasons": { "a": "Hosted lines. The status page lists three components with checks that were still loading, no history and a note that incident reporting is 'coming soon' (5 of 20). No incident history (5). Monthly quotas per plan are published, with no per-second figures (10 of 15). 429 at the free cap with X-RateLimit headers and a reset timestamp, no Retry-After or backoff guidance (10 of 15). No SLA found (0). Generally available (10). 5+5+10+10+0+10 = 40.", "b": "Atlassian Statuspage at massive-status.com with REST, WebSocket and flat-file components for each asset class (20). The history feed lists 14 unplanned incidents from 3 August to 1 November 2026, each limited to one product, one endpoint, one asset class or some accounts. They include US equity aggregate bars missing for roughly two-thirds of US equities from 18:46 ET on 8 September until 10:29 the next day, stale stocks quotes on 20 August, and slow responses with intermittent 502s on stocks v2 aggregates from 10:37 to 13:08 ET on 2 September. The newest, on 27 October, was delayed WebSocket data and REST errors for some accounts from 13:49 to 14:17 EDT. Read the way partial incidents are read on other listings, that is minor incidents only (20). Free plan limited to 5 calls a minute, paid plans unlimited, nothing stated for x402 (10 of 15). No 429 or Retry-After guidance found in the docs or the OpenAPI file, though the official Python client retries 429 with backoff (8 of 15). The business terms dated 6 October 2026 point to a separate Support Policy and SLA document for customers who buy service levels (10). The REST API is generally available (10)." }, "scores": { "a": 40, "b": 78 } }, { "by": 36, "category": "schema", "leads": "massive", "name": "Schema \u0026 documentation", "reasons": { "a": "An OpenAPI 3.0 document is linked at api.eulerpool.com/api/1/documentation/yaml, but that host's robots.txt disallows every path, so it was not read; partial credit for a linked contract we couldn't check (10 of 25). llms.txt, a 449-entry endpoint index and a 13,904-line llms-full.txt (10). Endpoint descriptions say what each returns, with the same marketing sentence repeated in every section and little on when not to use one (10 of 20). Parameter typing not visible in the llms files read (7 of 15). Response examples throughout; the errors page was not read (8 of 15). /api/1 paths and a dated changelog that mixes API changes with tutorial posts (8 of 15). 10+10+10+7+8+8 = 53.", "b": "OpenAPI document at api.massive.com/openapi (OpenAPI 3.0.3, 148 paths) with enums such as `timespan` and `sort`, and 400, 401 and 404 responses defined (25). llms.txt at massive.com/docs/rest/llms.txt indexing about 160 endpoint pages (10). One-line descriptions per endpoint in the index, longer ones in the reference, with little on when not to use a call (14 of 20). Typed path and query parameters with enums and required fields (13 of 15). Examples in the docs and error responses in the spec, though the llms.txt says nothing about error shapes (12 of 15). Versioned paths from /v1 to /v3 and a dated public changelog (15)." }, "scores": { "a": 53, "b": 89 } }, { "by": 30, "category": "ergonomics", "leads": "massive", "name": "Agent ergonomics", "reasons": { "a": "The MCP page claims 157+ tools with no toolsets or list, and response sizing on the API wasn't documented in the pages read (8 of 25). Filtering and pagination not documented in the pages read (8 of 20). Error codes not documented in the pages read (5 of 20). The data endpoints are reads (12 of 20). Official SDKs in Python, JavaScript, Node.js and Go (15). 8+8+5+12+15 = 48.", "b": "`limit`, `sort` and `adjusted` on most list and aggregate calls, no field selection found (15 of 25). `next_url` pagination that the official clients follow for you, plus date and ticker filters (18 of 20). Errors in the spec carry a status and message, with 400 responses on 64 of the 148 operations (14 of 20). All market data calls are GETs, and the x402 docs say only successful requests are charged and each page is charged separately. The hosted MCP's three tools carry readOnlyHint, per the 1 October check (16 of 20). Official clients in Python, JavaScript, Go and the JVM, with few required parameters (15)." }, "scores": { "a": 48, "b": 78 } }, { "by": 15, "category": "transparency", "leads": "massive", "name": "Transparency \u0026 trust", "reasons": { "a": "Closed service under terms dated 6 November 2026 naming Eulerpool Research Systems Pte. Ltd. of Singapore (15 of 30). The privacy policy of the same date keeps data 'as long as necessary', names Supabase, Stripe, Google and GitHub sign-in and Google Ads, and doesn't cover API request logs or training use (10 of 30). No deprecation policy or notices found (0 of 20). Some processors named; hosting location not stated (8 of 20). 15+10+0+8 = 33.", "b": "Closed service under business terms last updated 6 October 2026, Massive.com, Inc. under Georgia law, which now also cover pay-per-request purchases without an account. The MCP server and clients are MIT (15). Privacy policy last updated 22 March 2024, with retention 'as long as we are providing the Services' and no periods. The business terms require deleting data on termination. No DPA found (12 of 30). Dated sunsets in the changelog. The terms let Massive change the Services at its discretion, with a 30-day route to report a change that materially degrades a subscribed service (10 of 20). Stripe, Google and Hotjar are named, and data may sit 'in the United States and locations around the world'. No subprocessor list (8 of 20)." }, "scores": { "a": 52, "b": 67 } }, { "by": 12, "category": "maintenance", "leads": "massive", "name": "Maintenance \u0026 community", "reasons": { "a": "Closed service. The changelog's newest entry is dated 6 November 2026 (30), with daily entries through October, though many are tutorials rather than API changes (20). Contact by email; no public tracker or community found (5 of 15). Official SDKs in four languages, published 13 September 2026 (12 of 15). Package health not checked (3 of 10). 30+20+5+12+3 = 70.", "b": "Newest changelog entry 2026-10-28, new Insider Trading Activity and Insider Holdings endpoints (30). Changelog entries on 25 August, 1 September, 22 September, 2 October, 16 October and 28 October, six in 90 days, besides client releases (20). Public changelog and a support channel. We couldn't read GitHub issue activity in this run (10 of 15). Official clients are current, with Python v2.9.0 on 2026-10-16 and v2.9.1 on 2026-10-25, Go v3.5.0, v3.6.0 and v3.7.0 between 20 and 27 October and JavaScript v10.8.0 on 2026-09-17, each regenerated from the OpenAPI spec (15). The MCP and client repos run CI. The MCP server repository is still at v0.10.0 of 2026-05-05 and its README still calls the project experimental (7 of 10)." }, "scores": { "a": 70, "b": 82 } } ], "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "Eulerpool Research Systems Pte. Ltd.", "b": "Massive", "name": "Vendor" }, { "a": "https://api.eulerpool.com/mcp", "b": "https://api.massive.com", "name": "Hosted endpoint" }, { "a": "HTTP, Streamable HTTP", "b": "HTTP, Streamable HTTP", "name": "Transports" }, { "a": "API key", "b": "API key", "name": "Auth" }, { "a": "Freemium", "b": "Freemium", "name": "Pricing" }, { "a": "no", "b": "yes, from $0.01/call", "name": "x402" }, { "a": "Proprietary, under Eulerpool Research Systems Pte. Ltd.'s terms of service", "b": "MIT (clients)", "name": "Licence" }, { "a": "157", "b": "none", "name": "Tools exposed" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "yes", "name": "llms.txt" }, { "a": "2026-11-06", "b": "2026-10-28", "name": "Last release" }, { "a": "2026-11-06", "b": "2026-10-06", "name": "Terms last updated" }, { "a": "2026-11-06", "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": "not found in the text", "b": "yes", "name": "Terms restrict benchmarking" }, { "a": "not found in the text", "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 73.1 (BB) on agent readiness against Eulerpool Financial Data API's 46.2 (D), and leads in 6 of 7 scored categories.", "question": "Which is better for AI agents, Eulerpool Financial Data 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 Eulerpool Financial Data API and Massive (formerly Polygon.io) need an API key?" }, { "answer": "Yes. Eulerpool Financial Data API has a hosted endpoint at https://api.eulerpool.com/mcp and Massive (formerly Polygon.io) at https://api.massive.com.", "question": "Can an agent call Eulerpool Financial Data API and Massive (formerly Polygon.io) without installing anything?" } ], "goodFor": [ { "aheadOn": null, "also": [ "Free to start without a card" ], "goodFor": "Broad fundamentals, estimates and macro for research agents, close to financial-modeling-prep, eodhd and alpha-vantage.", "slug": "eulerpool", "watchFor": "The token can be sent as `?token=` in the URL, as the docs show first" }, { "aheadOn": [ "Reliability, 78 against 40", "Schema \u0026 documentation, 89 against 53", "Agent ergonomics, 78 against 48", "Payments \u0026 pricing, 90 against 40", "Maintenance \u0026 community, 82 against 70", "Transparency \u0026 trust, 67 against 52" ], "also": [ "Agent-ready, a grade of BB or better", "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": "14 partial incidents from 3 August to 1 November 2026, mostly stale or missing data on stock aggregates and quotes" } ], "history": { "eulerpool": null, "massive": [ { "causes": [ "product", "correction" ], "date": "2026-11-01", "delta": 3.2, "from": 69.9, "fromGrade": "B", "to": 73.1, "toGrade": "BB" }, { "causes": [ "method" ], "date": "2026-10-27", "delta": 0.1, "from": 69.8, "fromGrade": "B", "to": 69.9, "toGrade": "B" }, { "causes": [ "method" ], "date": "2026-10-08", "delta": -0.2, "from": 70, "fromGrade": "BB", "to": 69.8, "toGrade": "B" } ] }, "job": { "capability": "market.prices", "name": "Market prices" }, "others": [ { "json": "https://www.anchorterminal.com/compare/alpha-vantage-vs-eulerpool.json", "title": "Alpha Vantage vs Eulerpool Financial Data API", "url": "https://www.anchorterminal.com/compare/alpha-vantage-vs-eulerpool" }, { "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/benzinga-vs-massive.json", "title": "Benzinga vs Massive (formerly Polygon.io)", "url": "https://www.anchorterminal.com/compare/benzinga-vs-massive" }, { "json": "https://www.anchorterminal.com/compare/databento-vs-eulerpool.json", "title": "Databento vs Eulerpool Financial Data API", "url": "https://www.anchorterminal.com/compare/databento-vs-eulerpool" }, { "json": "https://www.anchorterminal.com/compare/databento-vs-massive.json", "title": "Databento vs Massive (formerly Polygon.io)", "url": "https://www.anchorterminal.com/compare/databento-vs-massive" }, { "json": "https://www.anchorterminal.com/compare/financial-datasets-vs-massive.json", "title": "Financial Datasets vs Massive (formerly Polygon.io)", "url": "https://www.anchorterminal.com/compare/financial-datasets-vs-massive" }, { "json": "https://www.anchorterminal.com/compare/financial-modeling-prep-vs-massive.json", "title": "Financial Modeling Prep vs Massive (formerly Polygon.io)", "url": "https://www.anchorterminal.com/compare/financial-modeling-prep-vs-massive" }, { "json": "https://www.anchorterminal.com/compare/finnhub-vs-massive.json", "title": "Finnhub vs Massive (formerly Polygon.io)", "url": "https://www.anchorterminal.com/compare/finnhub-vs-massive" }, { "json": "https://www.anchorterminal.com/compare/intrinio-vs-massive.json", "title": "Intrinio vs Massive (formerly Polygon.io)", "url": "https://www.anchorterminal.com/compare/intrinio-vs-massive" }, { "json": "https://www.anchorterminal.com/compare/massive-vs-tiingo.json", "title": "Massive (formerly Polygon.io) vs Tiingo", "url": "https://www.anchorterminal.com/compare/massive-vs-tiingo" }, { "json": "https://www.anchorterminal.com/compare/massive-vs-twelve-data.json", "title": "Massive (formerly Polygon.io) vs Twelve Data", "url": "https://www.anchorterminal.com/compare/massive-vs-twelve-data" }, { "json": "https://www.anchorterminal.com/compare/eulerpool-vs-financial-datasets.json", "title": "Eulerpool Financial Data API vs Financial Datasets", "url": "https://www.anchorterminal.com/compare/eulerpool-vs-financial-datasets" }, { "json": "https://www.anchorterminal.com/compare/eulerpool-vs-financial-modeling-prep.json", "title": "Eulerpool Financial Data API vs Financial Modeling Prep", "url": "https://www.anchorterminal.com/compare/eulerpool-vs-financial-modeling-prep" }, { "json": "https://www.anchorterminal.com/compare/eulerpool-vs-finnhub.json", "title": "Eulerpool Financial Data API vs Finnhub", "url": "https://www.anchorterminal.com/compare/eulerpool-vs-finnhub" }, { "json": "https://www.anchorterminal.com/compare/eulerpool-vs-intrinio.json", "title": "Eulerpool Financial Data API vs Intrinio", "url": "https://www.anchorterminal.com/compare/eulerpool-vs-intrinio" }, { "json": "https://www.anchorterminal.com/compare/eulerpool-vs-tiingo.json", "title": "Eulerpool Financial Data API vs Tiingo", "url": "https://www.anchorterminal.com/compare/eulerpool-vs-tiingo" }, { "json": "https://www.anchorterminal.com/compare/eulerpool-vs-twelve-data.json", "title": "Eulerpool Financial Data API vs Twelve Data", "url": "https://www.anchorterminal.com/compare/eulerpool-vs-twelve-data" }, { "json": "https://www.anchorterminal.com/compare/eodhd-vs-eulerpool.json", "title": "EODHD vs Eulerpool Financial Data API", "url": "https://www.anchorterminal.com/compare/eodhd-vs-eulerpool" }, { "json": "https://www.anchorterminal.com/compare/eodhd-vs-massive.json", "title": "EODHD vs Massive (formerly Polygon.io)", "url": "https://www.anchorterminal.com/compare/eodhd-vs-massive" }, { "json": "https://www.anchorterminal.com/compare/benzinga-vs-eulerpool.json", "title": "Benzinga vs Eulerpool Financial Data API", "url": "https://www.anchorterminal.com/compare/benzinga-vs-eulerpool" } ], "panel": null, "scores": [ { "by": 38, "edge": "massive", "eulerpool": 40, "key": "reliability", "massive": 78, "name": "Reliability", "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 36, "edge": "massive", "eulerpool": 53, "key": "schema", "massive": 89, "name": "Schema \u0026 documentation", "weight": 13 }, { "by": 30, "edge": "massive", "eulerpool": 48, "key": "ergonomics", "massive": 78, "name": "Agent ergonomics", "weight": 13 }, { "by": 0, "edge": "", "eulerpool": 35, "key": "security", "massive": 35, "name": "Security \u0026 auth", "weight": 14 }, { "by": 50, "edge": "massive", "eulerpool": 40, "key": "payments", "massive": 90, "name": "Payments \u0026 pricing", "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 12, "edge": "massive", "eulerpool": 70, "key": "maintenance", "massive": 82, "name": "Maintenance \u0026 community", "weight": 7 }, { "by": 15, "edge": "massive", "eulerpool": 52, "key": "transparency", "massive": 67, "name": "Transparency \u0026 trust", "weight": 7 } ], "summary": "Massive (formerly Polygon.io) scores 73.1 (BB) on agent readiness against Eulerpool Financial Data API's 46.2 (D), and leads in 6 of 7 scored categories. Both do market prices. Massive (formerly Polygon.io) accepts x402. Eulerpool Financial Data API doesn't.", "tasks": null, "tutorials": [], "verdicts": { "eulerpool": "Eulerpool's REST API and remote MCP server cover equities, ETFs, macro, crypto and private-company data, with 100,000 free calls a month without a card and published overage of $0.80 to $1.50 per 1,000 calls. The API host's robots.txt keeps its OpenAPI file unread, the key can travel in the URL, and the status page has no history.", "massive": "24 US stock routes over x402 at agent.massive.com, $0.01 each on Base, and only successful requests are charged. The status history lists 14 partial incidents in the 90 days to 1 November, including US equity aggregate bars missing for about 16 hours on 8 and 9 September." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/eulerpool-vs-massive", "json": "https://www.anchorterminal.com/compare/eulerpool-vs-massive.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/eulerpool-vs-massive.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/eulerpool-vs-massive.min.md" }, "markdown": "Massive (formerly Polygon.io) scores 73.1 (BB) on agent readiness against Eulerpool Financial Data API's 46.2 (D), and leads in 6 of 7 scored categories. Both do market prices. Massive (formerly Polygon.io) accepts x402. Eulerpool Financial Data API doesn't.\n\n- Eulerpool Financial Data API: grade D, 46.2/100, rank #1162 of 1486. Markdown https://www.anchorterminal.com/tools/eulerpool.md · JSON https://www.anchorterminal.com/api/v1/tools/eulerpool.json\n- Massive (formerly Polygon.io): grade BB, 73.1/100, rank #112 of 1486. Markdown https://www.anchorterminal.com/tools/massive.md · JSON https://www.anchorterminal.com/api/v1/tools/massive.json\n- Best financial market data APIs for AI agents: https://www.anchorterminal.com/best/market-data/index.md\n- All 66 markets comparisons: https://www.anchorterminal.com/compare/market-data/index.md\n\n## Which one, for what\n\n### Eulerpool Financial Data API (D)\n\nGood for: Broad fundamentals, estimates and macro for research agents, close to financial-modeling-prep, eodhd and alpha-vantage.\n\nAlso in its favour:\n- Free to start without a card\n\nWatch for: The token can be sent as `?token=` in the URL, as the docs show first\n\n### Massive (formerly Polygon.io) (BB)\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, 78 against 40\n- Schema \u0026 documentation, 89 against 53\n- Agent ergonomics, 78 against 48\n- Payments \u0026 pricing, 90 against 40\n- Maintenance \u0026 community, 82 against 70\n- Transparency \u0026 trust, 67 against 52\n\nAlso in its favour:\n- Agent-ready, a grade of BB or better\n- An agent can pay per call over x402, with no account\n\nWatch for: 14 partial incidents from 3 August to 1 November 2026, mostly stale or missing data on stock aggregates and quotes\n\n\n## Why the edge\n\n### Payments \u0026 pricing: Massive (formerly Polygon.io) +50\n\n- Eulerpool Financial Data API (40): No x402, MPP or L402 (0). Plan prices and overage per 1,000 requests are public (20). 100,000 free requests a month with no card, non-commercial (20). A person registers in a browser (0). 0+20+20+0 = 40.\n- Massive (formerly Polygon.io) (90): x402 on its own domain at agent.massive.com since 1 September, but only 23 US stock routes. Options, indices, forex, crypto, futures, tick data and streaming still need a key (30 of 40). $0.01 a route on Agentic.Market, which the docs link to, and plan prices on massive.com/pricing, all without a login (20). Free Basic plan at 5 calls a minute with end-of-day data. The pricing page doesn't say a card is needed (20). An agent with a funded Base wallet can pay with no account (20).\n\n### Reliability: Massive (formerly Polygon.io) +38\n\n- Eulerpool Financial Data API (40): Hosted lines. The status page lists three components with checks that were still loading, no history and a note that incident reporting is 'coming soon' (5 of 20). No incident history (5). Monthly quotas per plan are published, with no per-second figures (10 of 15). 429 at the free cap with X-RateLimit headers and a reset timestamp, no Retry-After or backoff guidance (10 of 15). No SLA found (0). Generally available (10). 5+5+10+10+0+10 = 40.\n- Massive (formerly Polygon.io) (78): Atlassian Statuspage at massive-status.com with REST, WebSocket and flat-file components for each asset class (20). The history feed lists 14 unplanned incidents from 3 August to 1 November 2026, each limited to one product, one endpoint, one asset class or some accounts. They include US equity aggregate bars missing for roughly two-thirds of US equities from 18:46 ET on 8 September until 10:29 the next day, stale stocks quotes on 20 August, and slow responses with intermittent 502s on stocks v2 aggregates from 10:37 to 13:08 ET on 2 September. The newest, on 27 October, was delayed WebSocket data and REST errors for some accounts from 13:49 to 14:17 EDT. Read the way partial incidents are read on other listings, that is minor incidents only (20). Free plan limited to 5 calls a minute, paid plans unlimited, nothing stated for x402 (10 of 15). No 429 or Retry-After guidance found in the docs or the OpenAPI file, though the official Python client retries 429 with backoff (8 of 15). The business terms dated 6 October 2026 point to a separate Support Policy and SLA document for customers who buy service levels (10). The REST API is generally available (10).\n\n### Schema \u0026 documentation: Massive (formerly Polygon.io) +36\n\n- Eulerpool Financial Data API (53): An OpenAPI 3.0 document is linked at api.eulerpool.com/api/1/documentation/yaml, but that host's robots.txt disallows every path, so it was not read; partial credit for a linked contract we couldn't check (10 of 25). llms.txt, a 449-entry endpoint index and a 13,904-line llms-full.txt (10). Endpoint descriptions say what each returns, with the same marketing sentence repeated in every section and little on when not to use one (10 of 20). Parameter typing not visible in the llms files read (7 of 15). Response examples throughout; the errors page was not read (8 of 15). /api/1 paths and a dated changelog that mixes API changes with tutorial posts (8 of 15). 10+10+10+7+8+8 = 53.\n- Massive (formerly Polygon.io) (89): OpenAPI document at api.massive.com/openapi (OpenAPI 3.0.3, 148 paths) with enums such as `timespan` and `sort`, and 400, 401 and 404 responses defined (25). llms.txt at massive.com/docs/rest/llms.txt indexing about 160 endpoint pages (10). One-line descriptions per endpoint in the index, longer ones in the reference, with little on when not to use a call (14 of 20). Typed path and query parameters with enums and required fields (13 of 15). Examples in the docs and error responses in the spec, though the llms.txt says nothing about error shapes (12 of 15). Versioned paths from /v1 to /v3 and a dated public changelog (15).\n\n### Agent ergonomics: Massive (formerly Polygon.io) +30\n\n- Eulerpool Financial Data API (48): The MCP page claims 157+ tools with no toolsets or list, and response sizing on the API wasn't documented in the pages read (8 of 25). Filtering and pagination not documented in the pages read (8 of 20). Error codes not documented in the pages read (5 of 20). The data endpoints are reads (12 of 20). Official SDKs in Python, JavaScript, Node.js and Go (15). 8+8+5+12+15 = 48.\n- Massive (formerly Polygon.io) (78): `limit`, `sort` and `adjusted` on most list and aggregate calls, no field selection found (15 of 25). `next_url` pagination that the official clients follow for you, plus date and ticker filters (18 of 20). Errors in the spec carry a status and message, with 400 responses on 64 of the 148 operations (14 of 20). All market data calls are GETs, and the x402 docs say only successful requests are charged and each page is charged separately. The hosted MCP's three tools carry readOnlyHint, per the 1 October check (16 of 20). Official clients in Python, JavaScript, Go and the JVM, with few required parameters (15).\n\n### Transparency \u0026 trust: Massive (formerly Polygon.io) +15\n\n- Eulerpool Financial Data API (52): Closed service under terms dated 6 November 2026 naming Eulerpool Research Systems Pte. Ltd. of Singapore (15 of 30). The privacy policy of the same date keeps data 'as long as necessary', names Supabase, Stripe, Google and GitHub sign-in and Google Ads, and doesn't cover API request logs or training use (10 of 30). No deprecation policy or notices found (0 of 20). Some processors named; hosting location not stated (8 of 20). 15+10+0+8 = 33.\n- Massive (formerly Polygon.io) (67): Closed service under business terms last updated 6 October 2026, Massive.com, Inc. under Georgia law, which now also cover pay-per-request purchases without an account. The MCP server and clients are MIT (15). Privacy policy last updated 22 March 2024, with retention 'as long as we are providing the Services' and no periods. The business terms require deleting data on termination. No DPA found (12 of 30). Dated sunsets in the changelog. The terms let Massive change the Services at its discretion, with a 30-day route to report a change that materially degrades a subscribed service (10 of 20). Stripe, Google and Hotjar are named, and data may sit 'in the United States and locations around the world'. No subprocessor list (8 of 20).\n\n### Maintenance \u0026 community: Massive (formerly Polygon.io) +12\n\n- Eulerpool Financial Data API (70): Closed service. The changelog's newest entry is dated 6 November 2026 (30), with daily entries through October, though many are tutorials rather than API changes (20). Contact by email; no public tracker or community found (5 of 15). Official SDKs in four languages, published 13 September 2026 (12 of 15). Package health not checked (3 of 10). 30+20+5+12+3 = 70.\n- Massive (formerly Polygon.io) (82): Newest changelog entry 2026-10-28, new Insider Trading Activity and Insider Holdings endpoints (30). Changelog entries on 25 August, 1 September, 22 September, 2 October, 16 October and 28 October, six in 90 days, besides client releases (20). Public changelog and a support channel. We couldn't read GitHub issue activity in this run (10 of 15). Official clients are current, with Python v2.9.0 on 2026-10-16 and v2.9.1 on 2026-10-25, Go v3.5.0, v3.6.0 and v3.7.0 between 20 and 27 October and JavaScript v10.8.0 on 2026-09-17, each regenerated from the OpenAPI spec (15). The MCP and client repos run CI. The MCP server repository is still at v0.10.0 of 2026-05-05 and its README still calls the project experimental (7 of 10).\n\n## Score by category\n\n| Category | Weight | Eulerpool Financial Data API | Massive (formerly Polygon.io) | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 40 | 78 | Massive (formerly Polygon.io) +38 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 53 | 89 | Massive (formerly Polygon.io) +36 |\n| Agent ergonomics | 13% (16.2 this run) | 48 | 78 | Massive (formerly Polygon.io) +30 |\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) | 70 | 82 | Massive (formerly Polygon.io) +12 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 52 | 67 | Massive (formerly Polygon.io) +15 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **46.2 · D** | **73.1 · BB** | |\n\n## Facts side by side\n\n| Fact | Eulerpool Financial Data API | Massive (formerly Polygon.io) |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | Eulerpool Research Systems Pte. Ltd. | Massive |\n| Hosted endpoint | `https://api.eulerpool.com/mcp` | `https://api.massive.com` |\n| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP |\n| Auth | API key | API key |\n| Pricing | Freemium | Freemium |\n| x402 | no | yes, from $0.01/call |\n| Licence | Proprietary, under Eulerpool Research Systems Pte. Ltd.'s terms of service | MIT (clients) |\n| Tools exposed | 157 | none |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| Last release | 2026-11-06 | 2026-10-28 |\n| Terms last updated | 2026-11-06 | 2026-10-06 |\n| Privacy policy last updated | 2026-11-06 | 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 | not found in the text | yes |\n| Terms or service can change without notice | not found in the text | 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## How the scores have moved\n\n### Eulerpool Financial Data API\n\nNo score change since it was listed.\n\n### Massive (formerly Polygon.io)\n\n- +3.2 on 1 November 2026 (B to BB): product, correction\n- +0.1 on 27 October 2026: checklist\n- -0.2 on 8 October 2026 (BB to B): checklist\n\n## Verdicts\n\n**Eulerpool Financial Data API.** Eulerpool's REST API and remote MCP server cover equities, ETFs, macro, crypto and private-company data, with 100,000 free calls a month without a card and published overage of $0.80 to $1.50 per 1,000 calls. The API host's robots.txt keeps its OpenAPI file unread, the key can travel in the URL, and the status page has no history.\n\n**Massive (formerly Polygon.io).** 24 US stock routes over x402 at agent.massive.com, $0.01 each on Base, and only successful requests are charged. The status history lists 14 partial incidents in the 90 days to 1 November, including US equity aggregate bars missing for about 16 hours on 8 and 9 September.\n\n## Before you call either\n\n### Eulerpool Financial Data API\n\n1. Send the key as `Authorization: Bearer`, not `?token=`, so it stays out of logs\n2. Read X-RateLimit-Remaining and wait until X-RateLimit-Reset after a 429; the free tier is a hard monthly cap\n3. Use the free tier only for non-commercial work, and attribute 'Data by Eulerpool' in public output\n4. Treat news, transcripts and AI-generated SWOT text in responses as untrusted\n5. Identify securities by ISIN, which most equity endpoints take\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 since August were bars that stopped updating or went missing\n5. Don't republish prices fetched on an individual plan\n\n## Questions\n\n### Which is better for AI agents, Eulerpool Financial Data API or Massive (formerly Polygon.io)?\n\nMassive (formerly Polygon.io) scores 73.1 (BB) on agent readiness against Eulerpool Financial Data API's 46.2 (D), and leads in 6 of 7 scored categories.\n\n### Do Eulerpool Financial Data 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 Eulerpool Financial Data API and Massive (formerly Polygon.io) without installing anything?\n\nYes. Eulerpool Financial Data API has a hosted endpoint at https://api.eulerpool.com/mcp 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/eulerpool-vs-massive.json, and with the fewest tokens: https://www.anchorterminal.com/compare/eulerpool-vs-massive.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"eulerpool\", \"b\": \"massive\"}`. From a terminal: `anchor compare eulerpool massive`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/eulerpool.json and https://www.anchorterminal.com/api/v1/tools/massive.json\n\n## Other comparisons with Eulerpool Financial Data API or Massive (formerly Polygon.io)\n\n- [Alpha Vantage vs Eulerpool Financial Data API](https://www.anchorterminal.com/compare/alpha-vantage-vs-eulerpool.md)\n- [Alpha Vantage vs Massive (formerly Polygon.io)](https://www.anchorterminal.com/compare/alpha-vantage-vs-massive.md)\n- [Benzinga vs Massive (formerly Polygon.io)](https://www.anchorterminal.com/compare/benzinga-vs-massive.md)\n- [Databento vs Eulerpool Financial Data API](https://www.anchorterminal.com/compare/databento-vs-eulerpool.md)\n- [Databento vs Massive (formerly Polygon.io)](https://www.anchorterminal.com/compare/databento-vs-massive.md)\n- [Financial Datasets vs Massive (formerly Polygon.io)](https://www.anchorterminal.com/compare/financial-datasets-vs-massive.md)\n- [Financial Modeling Prep vs Massive (formerly Polygon.io)](https://www.anchorterminal.com/compare/financial-modeling-prep-vs-massive.md)\n- [Finnhub vs Massive (formerly Polygon.io)](https://www.anchorterminal.com/compare/finnhub-vs-massive.md)\n- [Intrinio vs Massive (formerly Polygon.io)](https://www.anchorterminal.com/compare/intrinio-vs-massive.md)\n- [Massive (formerly Polygon.io) vs Tiingo](https://www.anchorterminal.com/compare/massive-vs-tiingo.md)\n- [Massive (formerly Polygon.io) vs Twelve Data](https://www.anchorterminal.com/compare/massive-vs-twelve-data.md)\n- [Eulerpool Financial Data API vs Financial Datasets](https://www.anchorterminal.com/compare/eulerpool-vs-financial-datasets.md)\n- [Eulerpool Financial Data API vs Financial Modeling Prep](https://www.anchorterminal.com/compare/eulerpool-vs-financial-modeling-prep.md)\n- [Eulerpool Financial Data API vs Finnhub](https://www.anchorterminal.com/compare/eulerpool-vs-finnhub.md)\n- [Eulerpool Financial Data API vs Intrinio](https://www.anchorterminal.com/compare/eulerpool-vs-intrinio.md)\n- [Eulerpool Financial Data API vs Tiingo](https://www.anchorterminal.com/compare/eulerpool-vs-tiingo.md)\n- [Eulerpool Financial Data API vs Twelve Data](https://www.anchorterminal.com/compare/eulerpool-vs-twelve-data.md)\n- [EODHD vs Eulerpool Financial Data API](https://www.anchorterminal.com/compare/eodhd-vs-eulerpool.md)\n- [EODHD vs Massive (formerly Polygon.io)](https://www.anchorterminal.com/compare/eodhd-vs-massive.md)\n- [Benzinga vs Eulerpool Financial Data API](https://www.anchorterminal.com/compare/benzinga-vs-eulerpool.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "attributionRequired": true, "credit": "CC BY 4.0, credit Anchor Terminal and link the page or API address you took it from (https://www.anchorterminal.com/terms/#data)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-11-07", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.7", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run", "terms": "https://www.anchorterminal.com/terms/#data" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "Eulerpool Financial Data API vs Massive (formerly Polygon.io)", "url": "" } ], "description": "Massive scores 73.1 (BB) to Eulerpool Financial Data's 46.2 (D) for market prices. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "Eulerpool Financial Data API D 46.2", "Massive (formerly Polygon.io) BB 73.1", "scores" ], "h1": "Eulerpool Financial Data API vs Massive (formerly Polygon.io)", "image": "https://www.anchorterminal.com/assets/og/default.png", "path": "/compare/eulerpool-vs-massive", "published": "2026-10-01", "section": "tools", "title": "Eulerpool Financial Data vs Massive for AI agents (2026)", "toc": null, "updated": "2026-11-07", "url": "https://www.anchorterminal.com/compare/eulerpool-vs-massive" }, "tokens": { "markdown": 4550, "slim": 2630 }, "version": 1 }