---
title: "RateAPI Developer Portal"
description: "Build with RateAPI Routes: connect confirmed customer facts to published credit-union products, membership paths, pricing, and source evidence over REST, direct MCP tools, the RateAPI CLI, and white-label widgets."
canonical: "https://rateapi.dev/developers"
last-updated: "2026-10-09"
source: "https://rateapi.dev/llms.txt"
---

# Build on RateAPI

Build product experiences that know which credit union products belong in front of each customer—and why. RateAPI Routes connects rates, membership paths, and source evidence through a CLI-first agent workflow, REST, white-label widgets, and a 89-tool MCP server for hosted or persistent native integrations.

## RateAPI Quickstart

Generate a key, run one safe default request, and see the result before choosing a more specialized endpoint.

### Choose your product surface

Terminal-capable agents start with the RateAPI CLI. Hosted/no-shell agents use MCP, while applications and server jobs use REST. A self-serve key starts on the Free core Rates plan. RateAPI Routes—including its REST operations, MCP tools, and managed widgets—requires an Enterprise organization. Creating a Free key requires an email address; no card is required. [Contact us to activate Routes.](https://rateapi.dev/contact)

```
npm install --global @rateapi/cli
rateapi agent --json
```

The CLI verifies a synthetic demo and checks for an existing key before it asks the human to create or store anything. For a direct REST integration, create the key server-side with the request below.

```
RATEAPI_ENROLLMENT_ID="${RATEAPI_ENROLLMENT_ID:-$(node -e 'console.log(crypto.randomUUID())')}"; curl -X POST https://api.rateapi.dev/keys \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $RATEAPI_ENROLLMENT_ID" \
  -d '{"email":"you@example.com","source":"developer-portal"}'
```

### Make your first request

Start with the read-only `GET /v1/benchmarks` endpoint. It needs no request body and is available on the Free plan. If you generate a key with the button below, you can run this request in the dialog and see its JSON response immediately.

```
curl https://api.rateapi.dev/v1/benchmarks \
  -H "X-API-Key: rk_your_key_here"
```

1. Generate a key and run the request

### Read the rate-limit headers

Every response carries your remaining budget, so you can self-throttle instead of discovering the ceiling with a 429. See the table below.

```
RateLimit-Limit: 20
RateLimit-Remaining: 19
RateLimit-Reset: 2591940
RateLimit-Policy: 20;w=2592000
```

## Sandbox & keyless demo

Two ways to exercise the API before you commit to an integration.

### Keyless demo endpoint

`GET /v1/demo/rates` needs no key. It returns fixed synthetic contract data in the same response shape as `/v1/rates` ; it is not live market data and must not be quoted as a current offer.

```
curl https://api.rateapi.dev/v1/demo/rates
```

### Sandbox keys

A key prefixed `rk_test_` returns deterministic stub data for endpoints included in that organization's plan. Calls remain metered against that plan, and the Enterprise gate still applies to Routes. Ask us for one at [support@rateapi.dev](mailto:support@rateapi.dev) .

## RateAPI documentation & reference

The REST surface, described both for people and for machines.

- [Free API Key Create a free developer key with an email address. No credit card, no trial clock, and 20 API requests each month. rateapi.dev/api-key](https://rateapi.dev/api-key)
- [RateAPI Routes POST /v1/reachable-offers matches confirmed customer facts to one exact product search across the active credit union fleet, preserving membership and product evidence. rateapi.dev/financial-product-eligibility-api](https://rateapi.dev/financial-product-eligibility-api)
- [RateAPI API Reference Every REST endpoint with request and response shapes, filters, and worked examples. api.rateapi.dev](https://api.rateapi.dev/)
- [RateAPI OpenAPI Specification The complete OpenAPI 3 document — typed parameters, response schemas, examples, and documented recovery and rate-limit headers. Feed it straight to a code generator or an agent. api.rateapi.dev/openapi.json](https://api.rateapi.dev/openapi.json)
- [Capabilities Catalog Machine-readable, no key required: every flow RateAPI supports, paired with its REST route and its MCP tool. api.rateapi.dev/v1/capabilities](https://api.rateapi.dev/v1/capabilities)
- [Decision API Reference POST /v1/decisions — personalized, ranked offers with savings math. The endpoint most integrations start and stay on. rateapi.dev/api/reference](https://rateapi.dev/api/reference)
- [Rate Query API GET /v1/rates — filter the live book by product, state, occupancy, term, and audience. rateapi.dev/rates-api](https://rateapi.dev/rates-api)
- [Auto Loan Rates API Current US credit-union auto-loan offers by state, term, and vehicle condition, with rate, APR, provenance, and observation time. rateapi.dev/auto-loan-api](https://rateapi.dev/auto-loan-api)
- [Mortgage Rates API Current mortgage offers by state and loan scenario, with rate, APR, points, product identity, and observation time. rateapi.dev/mortgage-rates-api](https://rateapi.dev/mortgage-rates-api)
- [Deposit Rate API POST /v1/deposit-rates — query or benchmark savings, CD, share-certificate, and money-market APYs with exact product enums and copy-paste JSON examples. rateapi.dev/what-is-deposit-rate-api](https://rateapi.dev/what-is-deposit-rate-api)
- [Eligibility API Explore published membership paths, unresolved conditions, and the verbatim evidence behind each result. Unknown is not rejection. rateapi.dev/api/eligibility](https://rateapi.dev/api/eligibility)

## RateAPI integrations

Everything past a plain HTTP call: agents, events, embeds, and the rules of the road.

- [RateAPI CLI The default for terminal-capable agents: stable JSON, stdin for sensitive inputs, secure credential reuse, and explicit approval gates. npm: @rateapi/cli](https://rateapi.dev/agents)
- [RateAPI MCP Server 89 tools over Streamable HTTP for hosted/no-shell agents, persistent native discovery, and rich MCP Apps widgets. mcp.rateapi.dev/mcp](https://rateapi.dev/mcp)
- [Webhooks Subscribe to rate movements and monitor triggers; inspect and replay past deliveries. api.rateapi.dev/webhooks](https://api.rateapi.dev/webhooks)
- [RateAPI Routes Widget Publish a governed, white-label customer product journey while keeping API keys, product scope, and design policy server-side. rateapi.dev/widget-docs/routes](https://rateapi.dev/widget-docs/routes)
- [Market Rates Widget Embed a public rate leaderboard, ticker, or stat with one script and no browser credential. rateapi.dev/widget-docs/rates](https://rateapi.dev/widget-docs/rates)
- [Agent Skills Gallery Ready-made recipes (SKILL.md + recipe.json) for rate shopping, affordability, refinance break-even, and monitoring. rateapi.dev/skills](https://rateapi.dev/skills)
- [Idempotency How to make writes safely retryable with the Idempotency-Key header. rateapi.dev/api/idempotency](https://rateapi.dev/api/idempotency)
- [Versioning & Deprecation Policy How RateAPI versions its API and how a breaking change is signalled before it lands. rateapi.dev/deprecation-policy](https://rateapi.dev/deprecation-policy)

## RateAPI for AI agents

Machine-readable orientation files. Fetch any of them directly; none require a key. Every RateAPI page also answers `Accept: text/markdown` with a markdown representation of itself.

- [llms.txt Compact orientation for an LLM: what RateAPI covers, what it uniquely answers, and how to call it. rateapi.dev/llms.txt](https://rateapi.dev/llms.txt)
- [llms-full.txt The long form — full API documentation, methodology, coverage, and FAQ in one plain-text document. rateapi.dev/llms-full.txt](https://rateapi.dev/llms-full.txt)
- [Agent Instructions When an agent should reach for RateAPI, which tool to pick per job, and the rules for quoting a rate. rateapi.dev/.well-known/agent-instructions.md](https://rateapi.dev/.well-known/agent-instructions.md)
- [MCP Manifest Discovery document for MCP clients: server URL, transport, auth, and tool count. rateapi.dev/.well-known/mcp](https://rateapi.dev/.well-known/mcp)

## Rate limits

RateAPI returns the RFC 9331 `RateLimit-*` headers on every response, authenticated or not, alongside the legacy `X-RateLimit-*` pair. On a 429 you also get `Retry-After` in seconds.

| Header |  Meaning |
| `RateLimit-Limit` |  Requests allowed in the current window. |
| `RateLimit-Remaining` |  Requests left in the current window. |
| `RateLimit-Reset` |  Seconds until the window resets. |
| `RateLimit-Policy` |  The quota and window, e.g. `20;w=2592000` for 20 requests per 30 days. |
| `Retry-After` |  On a 429 only: seconds to wait before retrying. |

## Start with core Rates

The Free key is for the core Rates API. For Routes over REST, MCP, or a managed white-label widget, [talk to us about Enterprise](https://rateapi.dev/contact) . If you get stuck, write to [support@rateapi.dev](mailto:support@rateapi.dev) or see the [contact page](https://rateapi.dev/contact) — a person answers.

Generate a free API key

Developer Portal

RateAPI

RateAPI Routes turns confirmed customer facts into source-backed shortlists of published products from 3,700+ tracked US credit unions. Every promoted route keeps its membership and price evidence.

[Get API key →](https://rateapi.dev/api-key) [Sign in](https://app.rateapi.dev)

### Build

- [RateAPI Routes →](https://rateapi.dev/routes)
- [Product Matching API](https://rateapi.dev/financial-product-eligibility-api)
- [Membership Eligibility API](https://rateapi.dev/api/eligibility)
- [Rate Query API](https://rateapi.dev/rates-api)
- [Decision API](https://rateapi.dev/api/reference)
- [Batch Decisions API](https://rateapi.dev/api/batch-decisions)

### Deliver

- [Developer Portal →](https://rateapi.dev/developers)
- [Create a free API key](https://rateapi.dev/api-key)
- [REST API docs](https://api.rateapi.dev/)
- [OpenAPI spec](https://api.rateapi.dev/openapi.json)
- [MCP Server](https://rateapi.dev/mcp)
- [Widget builder](https://rateapi.dev/widget-builder)
- [RateAPI Routes widget](https://rateapi.dev/widget-docs/routes)
- [Market Rates widget](https://rateapi.dev/widget-docs/rates)
- [Webhooks](https://api.rateapi.dev/webhooks)
- [Versioning & deprecation](https://rateapi.dev/deprecation-policy)
- [GitHub](https://github.com/rate-api)

### Solutions

- [Personal finance apps](https://rateapi.dev/use-cases/personal-finance-apps)
- [AI purchase advisors](https://rateapi.dev/use-cases/ai-purchasing-tools)
- [AI agents](https://rateapi.dev/use-cases/ai-agents)
- [Car buying platforms](https://rateapi.dev/use-cases/car-buying-platforms)
- [Credit unions](https://rateapi.dev/for-credit-unions)
- [Loan officers](https://rateapi.dev/use-cases/loan-officers)
- [Rate data for ALM](https://rateapi.dev/alm-rate-data)

### Trust

- [Data coverage](https://rateapi.dev/data-coverage)
- [Rate methodology](https://rateapi.dev/methodology)
- [Eligibility methodology](https://rateapi.dev/eligibility-methodology)
- [Transparency](https://rateapi.dev/transparency)
- [Independence](https://rateapi.dev/independence)
- [Corrections](https://rateapi.dev/corrections)
- [Pricing](https://rateapi.dev/pricing)
- [About](https://rateapi.dev/about)
- [Contact](https://rateapi.dev/contact)
- Talk to a human

### Inspect the data behind the API

Public data explorer

- [Current mortgage rates](https://rateapi.dev/current-mortgage-rates)
- [Current auto rates](https://rateapi.dev/current-auto-loan-rates)
- [Current CD rates](https://rateapi.dev/current-cd-rates)
- [Current HELOC rates](https://rateapi.dev/current-heloc-rates)
- [Current personal loan rates](https://rateapi.dev/current-personal-loan-rates)
- [Mortgage rates](https://rateapi.dev/mortgage-rates)
- [Refinance rates](https://rateapi.dev/refinance-rates)
- [Auto loan rates](https://rateapi.dev/auto-loan-rates)
- [RV loan rates](https://rateapi.dev/rv-loan-rates)
- [Boat rates](https://rateapi.dev/boat-loan-rates)
- [Motorcycle rates](https://rateapi.dev/motorcycle-loan-rates)
- [HELOC rates](https://rateapi.dev/heloc-rates)
- [Personal loan rates](https://rateapi.dev/personal-loan-rates)
- [Credit card rates](https://rateapi.dev/credit-card-rates)
- [Deposit rates](https://rateapi.dev/deposit-rates)
- [CD rates](https://rateapi.dev/cd-rates)
- [Savings rates](https://rateapi.dev/savings-rates)
- [Money market rates](https://rateapi.dev/money-market-rates)
- [Credit union directory](https://rateapi.dev/credit-unions)
- [Who can join](https://rateapi.dev/who-can-join)
- [Mortgage benchmark](https://rateapi.dev/mortgage-rate-benchmark)
- [Auto benchmark](https://rateapi.dev/auto-loan-rate-benchmark)
- [HELOC benchmark](https://rateapi.dev/heloc-rate-benchmark)
- [Personal loan benchmark](https://rateapi.dev/personal-loan-rate-benchmark)
- [CD benchmark](https://rateapi.dev/cd-rate-benchmark)
- [Credit union rate index](https://rateapi.dev/credit-union-rate-index)
- [Deposit beta](https://rateapi.dev/deposit-beta)
- [Credit unions vs banks: mortgage](https://rateapi.dev/compare/credit-union-vs-bank-rates)
- [Credit unions vs banks: auto](https://rateapi.dev/compare/credit-union-vs-bank-auto-loan-rates)
- [Credit unions vs banks: HELOC](https://rateapi.dev/compare/credit-union-vs-bank-heloc-rates)
- [Credit unions vs banks: CD](https://rateapi.dev/compare/credit-union-vs-bank-cd-rates)
- [Mortgage rate API comparison](https://rateapi.dev/compare/mortgage-rate-apis)
- [Rate datasets](https://rateapi.dev/credit-union-rate-dataset)

© 2026 RateAPI · US credit unions only · Published pricing is not approval.

[Privacy](https://rateapi.dev/privacy) [Terms](https://rateapi.dev/terms) [llms.txt](https://rateapi.dev/llms.txt)

---

Source: https://rateapi.dev/developers
Rate data API: https://api.rateapi.dev · OpenAPI: https://api.rateapi.dev/openapi.json · MCP: https://mcp.rateapi.dev/mcp