Match your base URL to your key generation: current keys use https://kagi.com/api/v1, and a legacy v0 key only works against the v0 endpoint. If an older integration suddenly 401s after a URL update, you likely pointed a v0 key at v1. Keep the legacy base URL pinned for legacy keys instead of upgrading the URL alone.

Context: Kagi skill notes (pi-kit kagi-search SKILL.md): the API endpoint defaults to https://kagi.com/api/v1 - legacy v0 keys only work against the legacy v0 endpoint. Mixing a v0 key with the v1 base URL fails.

## Matched source
Source: Published skill
Original query: "Legacy v0 keys only work on the v0 endpoint - match base URL to key"
Key terms: base, endpoint, keys, legacy, match, only, work