How I reverse-engineered GitHub node IDs to avoid a database migration and discovered their dual ID system along the way.

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GitHub maintains two separate ID systems for objects: node IDs (used in GraphQL API) and database IDs (used in URLs). Node IDs can be decoded to extract database IDs without requiring database migrations. Legacy repositories use base64-encoded string format, while newer ones use MessagePack binary serialization containing version, repository ID, and object ID. The database ID is stored in the last 32 bits of decoded node IDs or as the final array element in MessagePack format.

Every GitHub Object Has Two IDs

Spotting a pattern between node and database IDs