• The template editor is reachable by API key. /v1/templates adds a cursor-paginated list, full detail, create, partial update, /:id/publish and /:id/duplicate — publish running the same sequence the dashboard uses. A limit bound on GET /v1/templates/pull is opt-in — it used to return every code-pushed template with full TSX source and no pagination, its only ceiling Lambda’s response limit — so the CLI’s push/pull protocol is byte-for-byte unchanged when the bound is omitted. The API does not compile TSX, so compiledHtml must come from the caller. There is no DELETE: templates are referenced by send history, and removing one would silently detach it
• /v1/segments adds list, read, create, update, delete and /preview for an unsaved condition. The whole group sits behind a Pro plan gate on every verb including reads; memberCount is always computed live rather than read from the cached column, and a delete refuses with 409 while a scheduled or processing broadcast still targets the segment
• /v1/batch adds a list, per-recipient outcomes and a click breakdown, so a caller can see who a broadcast reached instead of only creating, promoting, getting, cancelling and resuming it
• GET /v1/domains, GET /v1/email/metrics and GET /v1/account/health round out what a caller can read about its own connected account: domain verification and DKIM status (an unreachable connected account is marked rather than failing the whole request), aggregate email numbers by dimension and granularity with no plan gate, and the SES verdict — sandbox status, production access, enforcement pauses, 24-hour quota — a hosted provider has no equivalent for, since there is no per-customer SES account to describe. Health thresholds come from the classifier’s exported constants, so a caller computes its own headroom without hardcoding AWS’s numbers; unknown never collapses to healthy, and the read costs zero AWS calls

API v1.2