Troubleshooting

Getting 401 Unauthorized

Is the Authorization header present?
Does the value start with exactly Bearer ?
Was the full key copied without truncation or trailing newline?
Is the key active and not revoked?

Getting UNKNOWN_UNIT

bash

curl "https://api.unifyunits.com/v1/units"
curl "https://api.unifyunits.com/v1/units/kg"

Ambiguous aliases like gallon are rejected; use gal or imp-gal.

Getting INCOMPATIBLE_UNITS (422)

Source and target must share a category. Mass cannot convert to length.

Getting INVALID_VALUE

Send a string, not a JSON number: "10"
Use . as the decimal separator
Do not include the unit in the value

Getting 429 Rate Limited

Check the error code. For RATE_LIMIT_EXCEEDED, use exponential backoff with the Retry-After header and prefer batch requests to reduce HTTP request count.

QUOTA_EXCEEDED means the monthly quota is used up. It sends no Retry-After and retrying will not help: wait for the UTC month to reset or upgrade your plan. See Rate limits and quotas.

Getting 403 PLAN_REQUIRED

The request uses a feature that needs the Developer plan or higher, such as format_locale (even on a parse without to), historical currency date, substance conversion, or unit price. See Pricing for what each plan includes.

Batch returns 200 but some items failed

Expected. Inspect each item's status field.