API reference

The complete REST contract: authentication, limits, response fields, endpoints, and errors. If you are making your first request, the quickstart is the faster place to begin.

Introduction

exchangerate.dev is a REST API for indicative foreign exchange rates — live intraday on trading days for actively traded currencies, with source, market_session, and honest freshness on every response. Try the free exchange rate API anonymously, or start with a free key — no credit card required.

Indicative rates — not for settlement

Rates are indicative only — not for settlement, regulated trading, or as a “source of record.” The market_session and source fields tell you exactly what you are looking at on every call.

Quickstart

Make your first data call without signup. The standalone 60-second quickstart has the request, exact response shape, and optional API-key step.

Authentication

You can evaluate data routes without a key. Pass your key in the Authorization: Bearer header for account-tier quotas and attribution. Anonymous access is limited to 12 requests/minute and 100 requests/hour per IP. Never embed an account key in public browser JavaScript; use anonymous access or a server-side proxy. Account quota resets at 00:00 UTC on the 1st.

NameTypeDescription

AuthorizationheaderBearer <your-key>. Optional for anonymous evaluation; required for account-tier quotas.

X-RateLimit-RemainingresponseCalls remaining in the current window.

X-RateLimit-ResetresponseUnix timestamp when the window resets.

Rate limits

Anonymous limits are per IP; account limits are per key and calendar month. On 429 the response includes Retry-After.

Free10,000/month12 req/minFree

Basic100,000/month120 req/min$10/mo

Pro1,000,000/month500 req/min$30/mo

Response metadata

Keep this metadata with the rate. It is the API's freshness and derivation context.

Field	Meaning and applicability
`source` and `sources`	`source` is the least-fresh contributing rate; `sources` maps returned currencies. Enum values: `live` (intraday indicative), `ecb_daily` and `fred_daily` (daily reference), `banxico_daily` only on `/v1/rate/usd-mxn-banxico`, and `dof_daily` only on `/v1/rate/usd-mxn-dof`. The two Mexican-peso reference values never apply to latest, historical, convert, or range routes.
`market_session`	`open`, `weekend`, or `interbank_closed`; it describes the market state for the response.
`data_updated_at`, `effective_at`, and `timestamp`	`data_updated_at` is the oldest contributing observation. `effective_at` maps each currency to its own observation time on latest and batch-convert responses. `timestamp` is when this response was served. Times are UTC ISO-8601 strings.
`derived_symbols`, `derived`, and `derivation_bps_max`	`derived_symbols` lists triangulated rates in multi-currency responses. Single-pair responses use `derived`; `derivation_bps_max` can be `null`, including for a derived pair without a fixed ceiling, so use `derived` to detect triangulation.
`notice`	A short reminder that rates are indicative, not for settlement. Daily-reference responses include the reference-data notice.

Operation registry

Every public integration operation is listed once by method and OpenAPI path. See the OpenAPI 3.1 schema or ReDoc for complete schemas.

Path and query base values must match when both are sent; conflicts return 400.

json · GET /v1/latest/USD?symbols=EUR,GBP

{
  "result": "success",
  "base": "USD",
  "source": "live",
  "sources": {
    "EUR": "live",
    "GBP": "live"
  },
  "market_session": "open",
  "timestamp": "2026-06-15T12:00:00Z",
  "data_updated_at": "2026-06-15T12:00:00Z",
  "effective_at": {
    "EUR": "2026-06-15T12:00:00Z",
    "GBP": "2026-06-15T12:00:00Z"
  },
  "rates": {
    "EUR": 0.86207,
    "GBP": 0.74627
  },
  "derived_symbols": [],
  "notice": "Indicative rates, not for settlement."
}

Operation	Purpose	Parameters	Request	Response	Endpoint errors
`GET /v1/latest`	Latest rates with USD as the default base.	base, path_base, symbols (query; optional)	`/v1/latest?base=USD&symbols=EUR,GBP`	LatestResponse	data and limit errors
`GET /v1/latest/{path_base}`	Latest rates with a path base.	path_base (path); base, symbols (query); path/query base must match	`/v1/latest/USD?symbols=EUR,GBP`	LatestResponse	conflicting base, data, and limit errors
`GET /v1/{date}`	Historical snapshot for a date.	date (path); base, path_base, symbols (query)	`/v1/2024-01-15?base=EUR&symbols=USD,GBP`	HistoricalResponse	bad date or unavailable data
`GET /v1/{date}/{path_base}`	Historical snapshot with a path base.	date, path_base (path); base, symbols (query); path/query base must match	`/v1/2024-01-15/EUR?symbols=USD,GBP`	HistoricalResponse	conflicting base, bad date, or unavailable data
`GET /v1/convert/{from_ccy}/{to_ccy}`	Convert one unit or a query-supplied amount.	from_ccy, to_ccy (path); amount (query, default 1)	`/v1/convert/USD/EUR?amount=100`	ConvertResponse	invalid pair, amount, or unavailable data
`GET /v1/convert/{from_ccy}/{to_ccy}/{amount}`	Convert a path-supplied amount.	from_ccy, to_ccy, amount (path)	`/v1/convert/USD/EUR/100`	ConvertResponse	invalid pair, amount, or unavailable data
`POST /v1/convert`	Convert several amounts in one request.	JSON body: from and pairs (required)	`POST /v1/convert`	ConvertBatchResponse	invalid request, amount, or unavailable data
`GET /v1/range`	Daily time series with JSON, CSV, or Parquet output.	symbols, start_date, end_date required by API validation; base, cursor, format optional	`/v1/range?base=USD&symbols=EUR,GBP&start_date=2024-01-01&end_date=2024-06-30`	RangeResponse	missing parameter, bad date, or unavailable data
`GET /v1/currencies`	List supported currencies and their display facts.	none	`/v1/currencies`	CurrenciesResponse	standard endpoint errors
`GET /v1/rate/{slug}`	Return one flat pair quote by slug.	slug (path)	`/v1/rate/eur-usd`	RateResponse	invalid pair or unavailable data
`POST /v1/account/provision`	Create an account organization and first key when absent.	session auth; optional JSON body: signup_attribution, marketing_consent	`POST /v1/account/provision`	ApiKeyCreatedResponse	authentication or account errors
`GET /v1/account`	Read account, active key, and monthly usage.	session authentication	`/v1/account`	AccountResponse	authentication or account errors
`GET /v1/account/usage/daily`	Read daily usage for up to 90 days.	session auth; days (query, optional)	`/v1/account/usage/daily?days=30`	DailyUsageResponse	authentication or account errors
`DELETE /v1/account`	Cancel billing and delete account data.	session authentication	`DELETE /v1/account`	DeleteAccountResponse	authentication, account, or billing errors
`POST /v1/keys/rotate`	Rotate the active API key with a grace period.	session authentication	`POST /v1/keys/rotate`	ApiKeyCreatedResponse	authentication or account errors
`DELETE /v1/keys`	Revoke the active API key.	session authentication	`DELETE /v1/keys`	success envelope	authentication or account errors
`POST /v1/consent`	Record acceptance of a policy version.	session auth; JSON body: policy_version (required)	`POST /v1/consent`	ConsentResponse	authentication or validation errors

GET /v1/latest

Latest rates for all supported pairs, or a filtered subset via ?symbols=.

curl

GET /v1/latest[/{BASE}]

# Examples
curl /v1/latest/USD                         # base=USD (default)
curl /v1/latest/EUR?symbols=USD,GBP,JPY     # EUR base, 3 symbols

NameTypeDescription

basestringBase currency (default USD). Also accepts path: /v1/latest/EUR.

symbolsstringComma-separated list to filter rates (e.g. EUR,GBP). Omit for all.

GET /v1/{YYYY-MM-DD}

Historical snapshot — returns the reference rate as published on that date. Published coverage starts on 1999-01-04. The historical data guide covers weekends, ranges, pagination, and downloads.

curl

GET /v1/2024-01-15/EUR?symbols=USD,GBP

# On a weekend or holiday: returns the most recent published fix
# is_forward_filled: true will be set in the response

GET /v1/convert

Single or batch currency conversion. The POST form accepts multiple pairs in one call.

curl

# Single
GET /v1/convert/USD/EUR/100

# Batch POST (counts as N calls)
POST /v1/convert
{
  "from": "USD",
  "pairs": [["EUR", 100], ["GBP", 50], ["JPY", 1000]]
}

GET /v1/rate/{slug}

Single-pair quote by slug (e.g. eur-usd) — a flat, single-pair shape distinct from /v1/convert (which nests per-pair results under conversions[] and adds amount/converted). Slug is case-insensitive; malformed or unknown pairs return invalid_pair.

curl

GET /v1/rate/{slug}

curl https://api.exchangerate.dev/v1/rate/eur-usd \
  -H "Authorization: Bearer YOUR_KEY"

# Response
{
  "result": "success",
  "pair": "eur-usd",
  "base": "EUR",
  "quote": "USD",
  "rate": 1.0824,
  "source": "live",
  "sources": { "USD": "live" },
  "market_session": "open",
  "timestamp": "2026-06-16T14:02:11Z",
  "data_updated_at": "2026-06-16T14:01:41Z",
  "derived": false,
  "derivation_bps_max": null,
  "notice": "Indicative rates, not for settlement."
}

GET /v1/range

Daily time-series for a date window. JSON responses are capped at 366 rows/page with keyset pagination; pass format=csv or format=parquet to download the full window as a single file.

curl

GET /v1/range?base=USD&symbols=EUR,GBP&start_date=2024-01-01&end_date=2024-06-30

# Response includes next_cursor + has_more for pagination

GET /v1/currencies

Full list of supported currencies with name, type, decimal precision, minor units, and derived flag. This endpoint takes no parameters.

curl

GET /v1/currencies

GET /v1/account

Your org, active key, and current-month usage.

response

{
  "result": "success",
  "email": "you@example.com",
  "org": { "id": "...", "tier": "pro", "status": "active" },
  "key": { "prefix": "exr_live_ab12", "plaintext": null, "created_at": "2026-06-01T00:00:00Z", "last_used_at": "2026-07-01T18:02:00Z" },
  "usage": { "calls_this_month": 142820, "limit": 1000000, "resets_on": "2026-08-01" }
}

Errors

Every error uses the same envelope. A 429 response also includes a Retry-After header.

json · error envelope

{
  "result": "error",
  "code": "missing_parameter",
  "message": "missing required parameter: symbols"
}

Data errors: invalid_pair, unsupported_base, bad_date, invalid_amount, invalid_request, missing_parameter, data_unavailable, no_data_for_date, live_unavailable, source_unavailable, and service_unavailable.

Authentication and limit errors: invalid_api_key, auth_unavailable, forbidden, rate_limited, ip_rate_limited, quota_exceeded, and quota_unavailable.

Python

Use any HTTP client. The Python integration guide has a compact production example.

Node

Use built-in fetch or another HTTP client. The JavaScript conversion guide covers server-safe use.

MCP server

Use exchangerate.dev as a tool in any MCP-compatible AI agent. The dedicated MCP quickstart has setup, authentication, and the tool table.