io.github.nexus-api-lab/codebook-mcp

Look up a country by ISO 3166-1 alpha-2 or alpha-3 code. Returns both codes, English name, and the primary ISO 4217 currency. Use instead of recalling codes from memory.

Look up an ISO 4217 currency: name and minor units (decimal places). Critical for payment APIs — e.g. JPY has 0 minor units (¥500 is amount=500, NOT 50000), KWD has 3.

Look up the official reason phrase for an HTTP status code, or list all codes in a class (e.g. 4xx). Use instead of recalling status semantics from memory.

Look up the MIME type for a file extension, or find extensions for a MIME type. Use instead of guessing Content-Type values.