{"uid":"cap_CIGHNn1P7RgXlgd2fS4iB","slug":"fathom-macroeconomic-data-api-compare-series-b139aee2","name":"Fathom Macroeconomic Data API — Compare Series","description":"Free macroeconomic data API powered by FRED. 816,000+ economic time series. GDP, inflation, unemployment, interest rates, and more.","url":"https://fredthom.vercel.app/api/compare","method":"POST","headers":{},"bodySchema":{"type":"object","required":["seriesIds"],"properties":{"limit":{"type":"string","description":"Observations per series (default: 10)"},"seriesIds":{"type":"array","description":"Array of 2-5 FRED series IDs to compare"}}},"responseSchema":{"type":"object","required":["source"],"properties":{"source":{"type":"string"},"comparison":{"type":"object"}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.35","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.35/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.35","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.35","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_M4SZ8Q6wQ5FK3eT05aaKg","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.35","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Compares 2–5 FRED economic time series side-by-side, returning aligned observations for cross-series analysis","exampleAgentPrompt":"Can you compare US GDP (GDPC1), CPI inflation (CPIAUCSL), and the federal funds rate (FEDFUNDS) side by side using the last 20 observations each, so I can see how they've moved together?","exampleUseCases":null,"resultDescription":"A JSON object with a 'source' field (FRED attribution) and a 'comparison' object containing aligned time series observations for each requested FRED series ID, enabling cross-series temporal analysis.","failureModes":["Invalid or non-existent FRED series ID returns error or empty data","Fewer than 2 or more than 5 series IDs causes validation failure","Non-numeric or malformed limit parameter may be ignored or cause error","Payment failure (x402) prevents API access","Network timeout on FRED upstream data fetch","Series with mismatched frequencies may return sparse or misaligned observations"],"whenToPreferThis":"Use this endpoint when you need to compare two or more macroeconomic time series from FRED simultaneously — such as correlating GDP with inflation, or benchmarking unemployment against interest rates. Prefer this over single-series lookup endpoints when cross-indicator analysis or alignment is the goal. Best for economic research, dashboards, and agent reasoning tasks requiring multi-variable economic context.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T18:41:44.859Z","isFirstParty":false}