# AGENTS.md — Build guide for Mailcoach Cloud

## Project scope
Manage a small email audience and send through the owner's SES account. Keep marketing campaigns, transactional messages and a simple opt-in welcome sequence in separate queues with a shared suppression policy.

Catalogue verdict: kinda. The visible email marketing loop is buildable, but a credible replacement needs more than the first screen. Mailcoach Cloud earns its keep through deliverability, reputation, network, so expect a weekend or multi-day build and a narrower personal scope.
Use the implementation prompt below to define the deliverable. Complete each phase's acceptance checks before extending the scope.

## Working agreement
- Inspect the repository and its existing instructions before choosing paths, dependencies or commands. Keep one coherent stack and explain changes to the proposed architecture.
- Plan a vertical slice that accepts a real input and produces the useful output described below. Persist only the state the prompt calls for; respect memory-only and upstream-managed workflows. Use fixtures only when they are clearly labelled.
- After scaffolding, document the actual install, development, check and build commands in README and keep them synchronized with the package or project manifest. Do not report commands as successful unless they ran.
- Work in small steps. At handoff, list implemented flows, checks actually performed, remaining blockers, and any credentials or provider setup the owner must supply.
- Do not publish, spend money, contact customers, delete source data or run irreversible migrations without the project owner's authorization.

## Prerequisites
- A verified sending domain, SES account with suitable sending access, DNS ownership and permission-based subscriber records. Provider charges and deliverability work remain.
- Implementation components: Next.js App Router and TypeScript for server-rendered pages and validated mutations. PostgreSQL with Drizzle migrations; Better Auth sessions for a small private workspace. React Email templates, an Amazon SES adapter and a bounded outbox worker with provider event ingestion.
- Scope boundary: payments, recommendations, and audience network; sender reputation, deliverability, and suppression handling

## Stack and architecture
- Next.js App Router and TypeScript for server-rendered pages and validated mutations.
- PostgreSQL with Drizzle migrations; Better Auth sessions for a small private workspace.
- React Email templates, an Amazon SES adapter and a bounded outbox worker with provider event ingestion.
- Domain model: audiences, reusable templates, campaign snapshots, transactional requests, automation steps and suppression events

## Security and data integrity
- Keep consent evidence and suppression records, validate signed delivery callbacks, and recheck unsubscribes and complaints immediately before every send.
- Correctness boundary: A transactional endpoint cannot bypass authentication or become an open relay; unknown delivery is reconciled before a retry.
- Snapshot the campaign revision and recipient segment. Persist one delivery record per recipient, use provider-supported reconciliation after unknown outcomes, and pause on high failure rates.
- Export versioned JSON plus attachments and a readable CSV summary. Restore into a separate database and compare record IDs and attachment checksums before switching.

## Agent implementation rules
- Project rule — data model: audiences, reusable templates, campaign snapshots, transactional requests, automation steps and suppression events
- Project rule — preserve this invariant: A transactional endpoint cannot bypass authentication or become an open relay; unknown delivery is reconciled before a retry.
- Project rule — acceptance evidence: An unauthenticated API request sends nothing; unsubscribing during a welcome sequence prevents all remaining marketing steps.

## Optional agent skills and references
- Optional external skill: [supabase-postgres-best-practices](https://github.com/supabase/agent-skills/blob/main/skills/supabase-postgres-best-practices/SKILL.md) — Review PostgreSQL schemas, queries, indexes, pooling, concurrency and row-level security. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
- Optional external skill: [web-design-guidelines](https://github.com/vercel-labs/agent-skills/blob/main/skills/web-design-guidelines/SKILL.md) — Review web interfaces for accessibility, keyboard focus, forms, navigation and interaction quality. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
- Optional external skill: [copywriting](https://github.com/coreyhaines31/marketingskills/blob/main/skills/copywriting/SKILL.md) — Write landing pages and product copy grounded in the intended audience, product value and a clear next action. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.

Read the linked SKILL.md and its dependencies before adding a skill. Select only the skills matching this project's runtime and task; their documentation does not supply API access, credentials or approval to perform external actions. Pin the reviewed revision where the tool supports it. Follow the chosen agent's documented project-level installation mechanism.

## Distribution ideas
These are optional planning notes. Obtain the owner's approval before publishing or contacting anyone.
- Demonstrate the actual Mailcoach Cloud-inspired workflow with owned or clearly labeled sample data: Manage a small email audience and send through the owner's SES account. Keep marketing campaigns, transactional messages and a simple opt-in welcome sequence in separate queues with a shared suppression policy.
- Publish a reproducible walkthrough with this observable result: An unauthenticated API request sends nothing; unsubscribing during a welcome sequence prevents all remaining marketing steps.
- Explain who can operate this scoped tool, its setup and ongoing costs, and these remaining product gaps: payments, recommendations, and audience network; sender reputation, deliverability, and suppression handling Avoid guaranteed savings, performance scores or implied endorsement.

## Engineering roadmap
1. Phase 1 — Scope and fixtures. Implement this bounded workflow: Manage a small email audience and send through the owner's SES account. Keep marketing campaigns, transactional messages and a simple opt-in welcome sequence in separate queues with a shared suppression policy. Record prerequisites, select representative user-owned fixtures and document the unsupported features: payments, recommendations, and audience network; sender reputation, deliverability, and suppression handling
2. Phase 2 — Durable model. Model audiences, reusable templates, campaign snapshots, transactional requests, automation steps and suppression events Add migrations or a versioned document format, explicit validation, stable IDs and a visible import-error report. Preserve this rule: A transactional endpoint cannot bypass authentication or become an open relay; unknown delivery is reconciled before a retry.
3. Phase 3 — Complete the first useful path. Implement the workflow's input, review and output interface, with clear controls and explicit empty/error states. Snapshot the campaign revision and recipient segment. Persist one delivery record per recipient, use provider-supported reconciliation after unknown outcomes, and pause on high failure rates.
4. Phase 4 — Permissions and integration failure. Keep consent evidence and suppression records, validate signed delivery callbacks, and recheck unsubscribes and complaints immediately before every send. Request integration credentials and permissions only for the enabled feature; show a disconnected state instead of mock results.
5. Phase 5 — Portable handoff. Export versioned JSON plus attachments and a readable CSV summary. Restore into a separate database and compare record IDs and attachment checksums before switching. Include setup, operating limits, fixture walkthrough and shutdown/restart instructions in the README.
6. Phase 6 — Acceptance scenarios. An unauthenticated API request sends nothing; unsubscribing during a welcome sequence prevents all remaining marketing steps. Repeat the workflow after restart and with a denied permission or unavailable dependency; show recoverable failure rather than a success placeholder.

## Paid-product capabilities outside this build
- payments, recommendations, and audience network
- sender reputation, deliverability, and suppression handling
- sender reputation and deliverability operations
- bounce, complaint, and suppression handling
- large-scale segmentation and automation

## Implementation prompt
WORKING SLICE
Manage a small email audience and send through the owner's SES account. Keep marketing campaigns, transactional messages and a simple opt-in welcome sequence in separate queues with a shared suppression policy.

Build this scoped Mailcoach Cloud-inspired workflow with a documented data model and visible failure states.

Architecture
- Next.js App Router and TypeScript for server-rendered pages and validated mutations.
- PostgreSQL with Drizzle migrations; Better Auth sessions for a small private workspace.
- React Email templates, an Amazon SES adapter and a bounded outbox worker with provider event ingestion.

Prerequisites and limits
A verified sending domain, SES account with suitable sending access, DNS ownership and permission-based subscriber records. Provider charges and deliverability work remain.
Outside this release: payments, recommendations, and audience network; sender reputation, deliverability, and suppression handling

Data model and correctness
audiences, reusable templates, campaign snapshots, transactional requests, automation steps and suppression events
Invariant: A transactional endpoint cannot bypass authentication or become an open relay; unknown delivery is reconciled before a retry.
Snapshot the campaign revision and recipient segment. Persist one delivery record per recipient, use provider-supported reconciliation after unknown outcomes, and pause on high failure rates.

Security and privacy
Keep consent evidence and suppression records, validate signed delivery callbacks, and recheck unsubscribes and complaints immediately before every send.

Recovery and export
Export versioned JSON plus attachments and a readable CSV summary. Restore into a separate database and compare record IDs and attachment checksums before switching.

Implementation order
1. Phase 1 — Scope and fixtures. Implement this bounded workflow: Manage a small email audience and send through the owner's SES account. Keep marketing campaigns, transactional messages and a simple opt-in welcome sequence in separate queues with a shared suppression policy. Record prerequisites, select representative user-owned fixtures and document the unsupported features: payments, recommendations, and audience network; sender reputation, deliverability, and suppression handling
2. Phase 2 — Durable model. Model audiences, reusable templates, campaign snapshots, transactional requests, automation steps and suppression events Add migrations or a versioned document format, explicit validation, stable IDs and a visible import-error report. Preserve this rule: A transactional endpoint cannot bypass authentication or become an open relay; unknown delivery is reconciled before a retry.
3. Phase 3 — Complete the first useful path. Implement the workflow's input, review and output interface, with clear controls and explicit empty/error states. Snapshot the campaign revision and recipient segment. Persist one delivery record per recipient, use provider-supported reconciliation after unknown outcomes, and pause on high failure rates.
4. Phase 4 — Permissions and integration failure. Keep consent evidence and suppression records, validate signed delivery callbacks, and recheck unsubscribes and complaints immediately before every send. Request integration credentials and permissions only for the enabled feature; show a disconnected state instead of mock results.
5. Phase 5 — Portable handoff. Export versioned JSON plus attachments and a readable CSV summary. Restore into a separate database and compare record IDs and attachment checksums before switching. Include setup, operating limits, fixture walkthrough and shutdown/restart instructions in the README.
6. Phase 6 — Acceptance scenarios. An unauthenticated API request sends nothing; unsubscribing during a welcome sequence prevents all remaining marketing steps. Repeat the workflow after restart and with a denied permission or unavailable dependency; show recoverable failure rather than a success placeholder.

Acceptance
An unauthenticated API request sends nothing; unsubscribing during a welcome sequence prevents all remaining marketing steps.
Use real source data or clearly labeled fixtures. Explain unsupported input and provider failures; do not fabricate analytics, delivery receipts, accuracy claims or security guarantees.

Optional agent guidance
Optional external skill: [supabase-postgres-best-practices](https://github.com/supabase/agent-skills/blob/main/skills/supabase-postgres-best-practices/SKILL.md) — Review PostgreSQL schemas, queries, indexes, pooling, concurrency and row-level security. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
Optional external skill: [web-design-guidelines](https://github.com/vercel-labs/agent-skills/blob/main/skills/web-design-guidelines/SKILL.md) — Review web interfaces for accessibility, keyboard focus, forms, navigation and interaction quality. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
Optional external skill: [copywriting](https://github.com/coreyhaines31/marketingskills/blob/main/skills/copywriting/SKILL.md) — Write landing pages and product copy grounded in the intended audience, product value and a clear next action. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
Project rule — data model: audiences, reusable templates, campaign snapshots, transactional requests, automation steps and suppression events
Project rule — preserve this invariant: A transactional endpoint cannot bypass authentication or become an open relay; unknown delivery is reconciled before a retry.
Project rule — acceptance evidence: An unauthenticated API request sends nothing; unsubscribing during a welcome sequence prevents all remaining marketing steps.

## Completion evidence
Demonstrate the prompt's acceptance scenarios against the scoped workflow. Include setup from a clean checkout and failure recovery. Check persistence across restart and export/restore only for the state the prompt says to store; for memory-only tools, confirm that temporary content is discarded as specified. Record actual results and remaining limitations. A detailed plan alone does not establish a working replacement.