Yield curve API reference

Bank of England nominal zero-coupon yields, from one source date to the full available curve. Retrieve one date or a paginated history.

Request

GET /v1/economics/{country}/yield-curve

curl --request GET \
  --url "https://api.narwhalapi.com/v1/economics/GBR/yield-curve?date=2026-09-10&maturity=2y%2C10y" \
  --header "Authorization: Bearer $NARWHAL_API_KEY"

REST and MCP use the same Bearer key, response schema and quota. MCP tool: economics_get_yield_curve.

Parameters

Name	Type	Required	Meaning
`country`	path · ISO alpha-3	Yes	USA is the only country in the verified yield archive.
`date`	YYYY-MM-DD string	No	Omit for the latest admitted observation. A supplied value selects that exact period; unavailable periods return 404.
`version_id`	UUID string	No	Optional immutable publication version. Omit to read the current admitted curve.
`maturity`	comma-separated string	No	Optional on both routes. Omit for the whole available curve. Allowed: 0.5y, 1y, 1.5y, 2y, 2.5y, 3y, 3.5y, 4y, 4.5y, 5y, 5.5y, 6y, 6.5y, 7y, 7.5y, 8y, 8.5y, 9y, 9.5y, 10y, 10.5y, 11y, 11.5y, 12y, 12.5y, 13y, 13.5y, 14y, 14.5y, 15y, 15.5y, 16y, 16.5y, 17y, 17.5y, 18y, 18.5y, 19y, 19.5y, 20y, 20.5y, 21y, 21.5y, 22y, 22.5y, 23y, 23.5y, 24y, 24.5y, 25y, 25.5y, 26y, 26.5y, 27y, 27.5y, 28y, 28.5y, 29y, 29.5y, 30y, 30.5y, 31y, 31.5y, 32y, 32.5y, 33y, 33.5y, 34y, 34.5y, 35y, 35.5y, 36y, 36.5y, 37y, 37.5y, 38y, 38.5y, 39y, 39.5y, 40y. Duplicates are removed and terms sorted; unsupported labels return 400.

Response

Example response Saved source sample · not a live request

{
  "country": "GBR",
  "curve_type": "nominal_zero_coupon",
  "date": "2026-09-10",
  "yields": [
    {
      "maturity": "2y",
      "yield_percent": "4.6509003413966044"
    },
    {
      "maturity": "10y",
      "yield_percent": "5.3572243604351168"
    }
  ]
}

Field	Type	Meaning
`country`	ISO alpha-3 string	The requested country or territory.
`curve_type`	"nominal_zero_coupon"	Bank of England continuously compounded nominal zero-coupon curve.
`date`	YYYY-MM-DD string	The source date shared by all points in this curve.
`yields`	array	Available maturities, ordered shortest to longest. Even one maturity remains an array.
`yields[].maturity`	string	One of the supported maturity labels.
`yields[].yield_percent`	decimal string	Yield in percent, preserving source decimal precision.

Values retain decimal strings. No source timestamp or publication date is invented. Request and quota metadata are returned in headers.

Errors and quota

Status	Meaning
`400`	Invalid country syntax, date, year, range, maturity, limit or cursor.
`401`	Missing or rejected API key.
`404`	No available observation matches the exact date, year or selected maturities.
`429`	Rate limit or monthly quota reached.
`503`	The accepted data cannot be served safely.

A successful response consumes one request, including an empty history result. Errors consume no quota. Shared errors and headers →

Coverage and freshness

United Kingdom · GBR · 2 Jan 1979 onward. The Bank of England aims to publish by noon Europe/London on the next business day. Weekends and holidays may have no new curve. Source values can be revised; a source check is not a promise of a new observation.

Missing maturities are omitted. Narwhal never fills a missing source point, substitutes an older curve, or invents a value.

Source: Bank of England · Yield curves.

Dataset overview →