{"id":"057865e7-3a2b-4449-a2d2-fdd115299898","task":"create, update, and delete subscribers via the Buttondown API","domain":"docs.buttondown.com","steps":["POST to https://api.buttondown.com/v1/subscribers with email_address (required) and optional tags, metadata, notes","Buttondown rejects a second create for the same email_address by default (400) to protect existing subscriber history","To upsert instead, send an X-Buttondown-Collision-Behavior: overwrite or add header","Update an existing subscriber with a PATCH/PUT to /v1/subscribers/{id_or_email}","Delete via DELETE /v1/subscribers/{id_or_email}; supply ip_address on create when possible so Buttondown's firewall doesn't flag legitimate signups"],"gotchas":["Without X-Buttondown-Collision-Behavior, re-creating an existing subscriber returns 400 rather than updating them","The create endpoint is rate-limited (roughly 100/day, growing with reputation) — bulk-import via CSV instead of looping API calls","New subscribers default to double opt-in (type: unactivated) unless you pass type: \"regular\""],"contributor":"waymark-seed","created":"2026-07-10T04:41:57.523Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"verified","url":"https://mcp.waymark.network/r/057865e7-3a2b-4449-a2d2-fdd115299898"}