API Reference

Every public RateAPI endpoint in one place. 27 REST endpoints over real, ranked credit union rates — decisions, rate analytics, borrower tools, monitors, and reference data. Authenticate with your API key in the X-API-Key header.

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The machine-readable contract lives at https://api.rateapi.dev/openapi.json. Use it to generate a typed client in any language.

Decisions

Rank real credit union offers for a borrower scenario and explain the result.

  • POST/v1/decisionsRank the best qualifying lender offers for a financing scenario.
  • POST/v1/decisions/batchRun many decision scenarios in a single request.
  • POST/v1/explain-rankingDecompose why each top lender ranked where it did, with cost breakdowns.
  • POST/v1/simulate-decisionSweep one input (credit score, down payment, rate shift) and see the winner per value.

Rate analytics

Position quotes and watch how the live market distribution moves.

  • GET/v1/statsHeadline coverage stats across the dataset.
  • GET/v1/benchmarksNational and per-state benchmark APR distributions by product.
  • POST/v1/rate-sanity-checkPosition an external quote in the live market distribution (percentile + classification).
  • POST/v1/rate-deltaCompare the market APR distribution now vs ~1/2/4 weeks ago.
  • POST/v1/competitive-positionSee where a given rate sits against the live competitive set.
  • POST/v1/buy-timingForward buy/refi-now vs wait lean from recent movement and break-even sensitivity.

Borrower tools

Affordability, monthly cost, refinance, and savings math grounded in real rates.

  • POST/v1/affordabilityMax monthly payment, loan amount, and home price from income and DTI caps.
  • POST/v1/monthly-costFull monthly cost (PITI) estimate for a loan.
  • POST/v1/refinance-break-evenBreak-even months and lifetime savings for a refinance.
  • POST/v1/scan-savingsFind the best refinance offer for each debt in a stack and quantify savings.
  • POST/v1/advice-guardrailsGuardrail checks (DTI strain, long terms, balloon, stale data) over a scenario.

Monitors

Standing decision monitors that re-evaluate scenarios and fire webhooks on change.

  • POST/v1/monitorsCreate a decision monitor (borrower or competitor).
  • GET/v1/monitorsList your monitors.
  • GET/v1/monitors/{id}Fetch a single monitor.
  • PATCH/v1/monitors/{id}Update a monitor.
  • DELETE/v1/monitors/{id}Delete a monitor.
  • POST/v1/monitors/{id}/simulateDry-run a monitor against current rates without persisting.

Reference data & keys

Credit union directory, metadata, and API key management.

  • GET/credit-unionsSearch the credit union directory.
  • GET/credit-unions/{state}/{slug}Fetch a single credit union profile.
  • GET/metaDataset metadata: products, states, freshness.
  • POST/keysProvision a new API key.
  • GET/keys/{keyId}/usageUsage stats for an API key.
  • DELETE/keys/{keyId}Revoke an API key.

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