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GET
Japan overnight call rate

Authorizations

X-API-Key
string
header
required

Your HayInsights API key (prefixed apk_). Create and manage keys in the HayInsights dashboard (Account → API keys).

Send it in the X-API-Key header on every request to /openapi/v1/*. Which data domains you may access and your request quota are both governed by the subscription plan attached to the key — see the Plans & features and Rate limits guides.

Query Parameters

period
enum<string>
default:1M

Look-back window, counted back from the latest date with data (not from today).

Available options:
1M,
3M,
6M,
1Y,
3Y
asOf
string<date>

Backtest: return exactly what the system knew at the end of that day (UTC), not later revisions by the source. Omit for the latest data.

Example:

"2026-09-01"

Response

Daily overnight call rate.

Standard success envelope shared by every endpoint. Each operation's response wrapper extends this (via allOf) and adds a typed data property.

success
boolean
required

Always true for a successful response.

Example:

true

statusCode
integer
required

Mirrors the HTTP status code.

Example:

200

data
object
required
meta
object

Response metadata. Always present; timestamp is the server time the response was generated.