Finds creators similar to a seed profile, a natural-language content direction, or both, on YouTube or TikTok. `platform` is required; supply `seedProfileUrl`, `contentDirection` (max 800 characters) or both, with `limit` (1–100, default 25) and optional `filters` for regions, languages, follower and average-view ranges. The response echoes the resolved `mode` — `homepage` for a seed alone, `direction` for a direction alone, `homepage_direction` for both — and sets `sourceUserId` only when a seed resolved. Each match carries `username`, `platformHandle`, `description`, `email`, `profileUrl`, `avatar`, `similarityScore` (sorted descending), `followerCount`, `averagePlayCount`, `lastPublishedTime`, `region` and `language`. Field shape differs by platform: YouTube matches add `channelId` and `channelTitle`; TikTok matches add `userId`, `uniqueId`, `nickname` and `averageLikeCount`, none of which YouTube returns. Measured at 4.2 KB for 5 YouTube matches (about 8 seconds) and 2.5 KB for 3 TikTok matches. Most matches already include an `email`; use `post_waveinflu_email_lookup` for the ones that come back null and for Instagram creators, which this endpoint does not match.