Fetch FHFA House Price Index data with one API

Search official FHFA state markets and retrieve quarterly Purchase-Only house-price indexes for 50 states and DC. Source: FHFA House Price Index®. Aggregate modeled indices, not individual-property prices.

Read the docs How it works Try a request

What FHFA House Price Index endpoints does RealtyCrawl ship?

Discover state markets and retrieve seasonally adjusted or unadjusted quarterly index series. Each endpoint has a documented request, response schema, and credit cost.

Search markets

50 credits

POST /v1/markets/search

Search official FHFA Purchase-Only state HPI markets. platforms=["fhfa"], query matches state name or two-letter code, or US text/source_region location (region_id=state code); choose exactly query or location. 50 states and DC only. Limit 1–51 (default20), alphabetical state-name order, no cursor. Each successful live dataset request costs 50 credits. Returned market IDs are account-owned selectors retained 24 hours. No portal, national or metropolitan geography is inferred. Requires separate FHFA runtime enablement. Source: FHFA House Price Index®.

platforms · query

Read a named source market series

50 credits

GET /v1/markets/{market_id}/series

Fetch fresh official FHFA quarterly Purchase-Only state HPI for this account’s retained market ID. series=purchase_only_sa or purchase_only_nsa; unit index_1991_q1_100. Optional inclusive from/to must be quarter-start dates (YYYY-01/04/07/10-01), 1991 onward. Periods are quarter-start dates. Costs 50 credits per successful dataset request; no results in range returns404 with zero credits. Published history is revised and release-lagged. Includes source methodology, attribution and low-sample warning where provided. Not median price, property valuation, rents, comparables or property transaction history. Selectors expire after24h; existing7-day idempotency replay remains a prior response snapshot.

market_id · series

Check live capabilities for operation and market availability. Unavailable requests are not charged.

FHFA House Price Index API

2 endpoints documented

View docs

POST/v1/markets/searchGet API key

platformsquery

curl -X POST 'https://realtycrawl.dev/v1/markets/search' \
  -H "x-api-key: $REALTYCRAWL_API_KEY" \
  -H "content-type: application/json" \
  -d '{"platforms":["fhfa"],"query":"California"}'

API key required

// Live requests require a RealtyCrawl API key.
// Copy the request to your backend and set REALTYCRAWL_API_KEY.
// Check source and operation availability before running a request.

How the FHFA House Price Index API works

Integrate a source-linked real estate API with standard HTTP requests, one API key, and structured JSON responses.

Authenticate every call

Send your RealtyCrawl API key in the x-api-key header. Keep it in your server environment.

GET and POST requests

Use path and query parameters for GET requests. Send a JSON body for POST operations.

One credit system

These operations list 50 credits per successful call. Failed calls are refunded; usage and balance appear in the response headers.

Common JSON responses

Read results from data and keep meta for source outcomes, completeness, and request diagnostics.

The usual integration chain

From a supported source operation to data in your application.

1CheckGET /v1/meta/capabilitiesConfirm coverage and accepted selectors.
2RequestPOST /v1/markets/searchSend the inputs for the selected operation.
3Readdata + metaInspect results, source outcomes, and warnings.
4ConnectYour applicationPreserve identifiers and observation times.

Request

curl --request POST 'https://realtycrawl.dev/v1/markets/search' \
  --header "x-api-key: $REALTYCRAWL_API_KEY" \
  --header 'X-Max-Credits: 50' \
  --header 'Content-Type: application/json' \
  --header 'Idempotency-Key: YOUR_IDEMPOTENCY_KEY' \
  --data '{"platforms":["fhfa"],"query":"California"}'

Illustrative response

{
  "data": [{"id":"mkt_fhfa_state_CA","name":"California","country":"US","geography_type":"state","source":{"platform":"fhfa","native_id":"CA","provider":"example","observed_at":"2026-01-01T12:00:00Z","access_class":"modeled"}}],
  "meta": {
    "request_id": "example_request",
    "schema_version": "1.0.0",
    "generated_at": "2026-01-01T12:00:00Z",
    "completeness": "unknown",
    "sources": []
  }
}

What lands in data

Source context stays with each state market and modeled index series.

Market: id · name · country · geography_type
Index series: series · unit · frequency · methodology
Quarterly points: period · value
Source: platform · provider · observed_at · access_class

Inside the gateway

One request keeps the source, operation, and result connected.

Operation selection

Your path selects the platform and operation. Capabilities describe accepted selectors and markets.

Source collection

The gateway routes supported requests to the configured source and records its outcome.

Contract normalization

Quarterly index levels, state identity and methodology are mapped into a shared JSON schema.

Response metadata

Completeness, warnings, and source timestamps help your application interpret the result.

Billing rules that make evaluation clear

50 credits per successful call
100 signup trial credits
Failed calls are refunded
Usage in response headers
Set an X-Max-Credits budget
One key across the catalog

How we get the data

A source request becomes a structured observation, with its origin and collection time attached.

What your request targets

FHFA House Price Index quarterly house-price index records through a supported market operation. Catalog markets: United States.

How records are returned

Discovery returns state markets. A retained market ID selects a fresh official quarterly index series.

What comes with each result

State identity, index units, quarter-start dates, methodology and source attribution accompany the series.

What an observation means

Retrieval time differs from source release time. FHFA revisions and reporting lag remain explicit; update time is unknown.

SOURCE → SHARED SCHEMA

State code

→ source.native_id

Quarterly index

→ points[].period + value

Collection timestamp

→ source.observed_at

What this API
is used for

Source-linked data for property products and research.

documented operations

credits per successful call

State market research

Discover US state markets, then compare seasonally adjusted or unadjusted Purchase-Only index series. Preserve FHFA attribution, units, quarter precision and revision warnings.

Coverage and field availability vary by source. Check capabilities before you start a workload.

What people build with the FHFA House Price Index API

Turn quarterly house-price index observations into tools your team can use.

Use case examples

Connect one source to the tools and workflows you already use.

Search applications

REST · application backend

Discover state markets and link index observations to the original official dataset.

Research pipelines

JSON · notebooks · BI

Compare state index levels with their base period, seasonal adjustment and methodology.

Assistant workflows

MCP · tools · agents

Give an assistant supported data operations with explicit request budgets.

Make your first request

Choose an operation, supply its inputs, and send your API key from your backend.

Search markets

curl --request POST 'https://realtycrawl.dev/v1/markets/search' \
  --header "x-api-key: $REALTYCRAWL_API_KEY" \
  --header 'X-Max-Credits: 50' \
  --header 'Content-Type: application/json' \
  --header 'Idempotency-Key: YOUR_IDEMPOTENCY_KEY' \
  --data '{"platforms":["fhfa"],"query":"California"}'

Read a named source market series

curl --request GET 'https://realtycrawl.dev/v1/markets/mkt_fhfa_state_CA/series?series=purchase_only_sa' \
  --header "x-api-key: $REALTYCRAWL_API_KEY" \
  --header 'X-Max-Credits: 50'

FHFA House Price Index API

Same key as the rest of the catalog

Get an API key Read the docs ↗

Endpoints

What data does the FHFA House Price Index API return?

Every endpoint returns structured JSON with source context. Open an endpoint to explore its inputs and example response.

Search markets

Read a named source market series

Comparison

How does RealtyCrawl structure FHFA House Price Index data?

Keep the source context while using the same request and response conventions across your integration.

Source context and RealtyCrawl conventions
Your application needs	Source context	RealtyCrawl contract
Market identity	Official state code	Source reference and RealtyCrawl ID
Index series	Base period and seasonal adjustment	Quarterly points and methodology
Freshness	Collection and update times	Explicit observation timestamps
Missing information	Source-dependent attributes	Nullable fields and field_status
Coverage	Operation and market availability	Live capabilities and source outcomes
Diagnostics	Source warnings and errors	Request IDs and completeness metadata
Authentication	A request to RealtyCrawl	One API key across supported platforms

FAQ

Have a question?
We got answers

Find answers to common questions about the FHFA House Price Index API, credits, and coverage.

How do I start using the FHFA House Price Index API?

Get a RealtyCrawl API key, check FHFA House Price Index in /v1/meta/capabilities, and send a supported request from your backend with the x-api-key header.

Are all FHFA House Price Index operations available?

The catalog describes request contracts. Live enablement, accepted location selectors, and supported markets are declared per operation in /v1/meta/capabilities. Check the exact operation before running a workload.

How much does a FHFA House Price Index request cost?

These operations list 50 credits per successful call. Signup includes 100 trial credits. Failed calls are refunded. Read the credit headers for the charge and remaining balance.

What does the index measure?

FHFA Purchase-Only HPI measures aggregate repeat-sale price changes for qualifying single-family properties. It is not a property valuation, median sale price or transaction record.

Are series requests fresh?

Each successful market discovery or series request retrieves the official public dataset for 50 credits. Account-owned market selectors expire after 24 hours; idempotent replay returns the prior snapshot. Published history can be revised. Source: FHFA House Price Index®.

Is this an official FHFA House Price Index API?

RealtyCrawl is an independent data API and is not affiliated with FHFA House Price Index. Source availability and supported operations are declared in the capabilities endpoint.

Can I use the same key for another platform?

Yes. One RealtyCrawl API key authenticates supported operations across the catalog. Check capabilities when adding a platform because availability and accepted inputs vary.

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Fetch FHFA House Price Index data with one API

What FHFA House Price Index endpoints does RealtyCrawl ship?

Search markets

Read a named source market series

How the FHFA House Price Index API works

Authenticate every call

GET and POST requests

One credit system

Common JSON responses

The usual integration chain

What lands in data

Inside the gateway

Operation selection

Source collection

Contract normalization

Response metadata

Billing rules that make evaluation clear

How we get the data

What your request targets

How records are returned

What comes with each result

What an observation means

What this APIis used for

State market research

What people build with the FHFA House Price Index API

State market research

Developer applications

Use case examples

Search applications

Research pipelines

Assistant workflows

Make your first request

Same key as the rest of the catalog

What data does the FHFA House Price Index API return?

Search markets

Read a named source market series

How does RealtyCrawl structure FHFA House Price Index data?

Have a question?We got answers

Related APIs and tools

What this API
is used for

Have a question?
We got answers