M26 Resend email automation

Assume the upstream layout scripts/emails/ exists (or will be materialized). All procedures below use cd into scripts/emails, a venv, and python <script>.py unless the user is in a full monorepo from the repository root, where python -m scripts.emails.<name> is also valid.

First: materialize scripts/emails

If the folder is missing, obtain a sparse checkout of only that path (not the whole monorepo working tree). Full step-by-step commands, Windows junctions, and Linux symlinks live in scripts/emails/MINIMAL_CLONE.md in the upstream repo.

Minimum idea:

1. Clone with --filter=blob:none --sparse, then git sparse-checkout init --no-cone and git sparse-checkout set --no-cone '/scripts/emails/'.
2. cd scripts/emails, create .venv, pip install -r requirements.txt, copy .env from .env.example (or from another machine — see below).
3. Updates: git pull from the sparse clone root.

New machine / copied workspace: Copy .env and every file paths inside it (service account JSON, Gmail OAuth client JSON, gmail_token.json, etc.), then edit paths so they match the new filesystem. Copying .env alone often breaks because paths still point at the old PC. Agents should ask for missing keys or files before sending. Full checklist: references/required-credentials.md.

Do not run python scripts/emails/foo.py from the monorepo root (path through scripts/emails/). Either cd scripts/emails and run python foo.py, or from full repo use python -m scripts.emails.foo.

Secrets stay in .env or the environment — never commit API keys, webhook secrets, or Gmail token files.

Core scripts (from scripts/emails)

Script	Role
send_campaign.py	Batch sends via Resend + Google Sheet rows
sync_replies_gmail.py	Pull inbox replies (Resend webhooks do not replace this)
webhook_server.py	Receives Resend events → Sheet columns (opened_N, clicked_N, …)
reply_followups.py	Threaded Gmail/Resend replies
build_utm_link.py	Build tracked links with consistent UTM params

Details, flags, and examples: scripts/emails/README.md. Operational guardrails: scripts/emails/AGENTS.md.

Resend behavior (short)

• Opens/clicks: Emitted when domain-level open/click tracking is enabled in Resend; webhooks can fire email.opened / click events. Open rates are imperfect (clients blocking images, etc.).
• Inbox replies: Not a substitute for sync_replies_gmail.py before follow-up sends.

UTM and readable links

Put long query strings in the HTML href (or Markdown [visible text](url)). Visible copy stays short; parameters stay on the URL. Parameter pattern and generators: see references/utm-and-links.md.

Idempotency and safety

• send_campaign: idempotency keys tie to campaign + chunk; reuse within 24h with a different body → 409. Use a test campaign id or --idempotency-suffix for experiments.
• Before production sends: --dry-run, --show-selected, validate templates.

When to load bundled references

• Clone/symlink mechanics, sparse-checkout pitfalls → references/clone-and-layout.md
• .env, paths, copied key files, webhook vs send-only, PostHog → references/required-credentials.md
• UTM + link presentation → references/utm-and-links.md
• Checklists (reply sync timing, batch columns, GIF env vars) → references/operational-rules.md

Upstream canonical copies evolve in scripts/emails/MINIMAL_CLONE.md and scripts/emails/AGENTS.md; refresh this skill when those change materially.