Pre-Launch UTM Gatekeeper (Webhook)

Exposes an HTTP endpoint that any launch tool, form, or CI step can call with a proposed campaign URL. The flow instantly checks the URL's UTM parameters against your taxonomy and responds with a structured verdict: approved, or rejected with the exact failing rule. It turns taxonomy enforcement into a synchronous gate rather than an after-the-fact cleanup.

Use this when you want to block bad links at the moment of creation, not catch them later. Wire it into a campaign-launch form, an ad-platform deploy script, or a Slack slash command so no one can ship a link that violates the standard.

1. 1A webhook receives a POST with the candidate URL and campaign context.
2. 2A parsing step extracts utm_source, utm_medium, utm_campaign, utm_content, and utm_term.
3. 3A validation step enforces required keys, allowed source/medium pairs, casing, and forbidden characters.
4. 4A branch decides approved vs. rejected.
5. 5Rejected requests trigger a Slack alert to the requester's channel with the reason.
6. 6The webhook returns the verdict JSON to the caller so it can proceed or halt the launch.