# AGENTS.md — Build guide for Trello

## Project scope
Run a small kanban board with drag-and-drop cards, checklists and due dates. Add one explicit automation such as marking a checklist complete when a card moves to a chosen list, with an audit note.

Catalogue verdict: kinda. The core loop is buildable, but a dependable replacement becomes a real weekend or multi-day project. For Trello, run kanban boards with cards, checklists, labels, dates, and simple automation. The hard boundary is atlassian ecosystem, power-ups, mobile apps, automation, and reliable collaboration, plus collaboration, integrations, and organizational trust.
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- Do not publish, spend money, contact customers, delete source data or run irreversible migrations without the project owner's authorization.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 supported Node release, PostgreSQL, HTTPS for a shared deployment, and a backup destination. Begin with one workspace and explicit owner/member permissions.
- 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.
- Scope boundary: Atlassian ecosystem, Power-Ups, mobile apps, automation, and reliable collaboration; deep integrations

## 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.
- Domain model: boards, lists, cards, checklist items, labels, memberships, ordered positions and activity records

## Security and data integrity
- Authorize every record read and mutation on the server using its workspace membership; validate payloads, protect mutations against CSRF, and escape user-authored HTML.
- Correctness boundary: Concurrent reorder operations use version checks; archiving a card preserves its comments and never removes another board's data.
- Commit related database changes in one transaction. Use version checks for competing edits and an outbox for external notifications; retry delivery independently of saving the record.
- 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: boards, lists, cards, checklist items, labels, memberships, ordered positions and activity records
- Project rule — preserve this invariant: Concurrent reorder operations use version checks; archiving a card preserves its comments and never removes another board's data.
- Project rule — acceptance evidence: Two users move the same card and receive a conflict or consistent final order; restoring an archived card brings back its checklist and history.

## Optional agent skills and references
- Optional external skill: [vercel-react-best-practices](https://github.com/vercel-labs/agent-skills/blob/main/skills/react-best-practices/SKILL.md) — Improve React and Next.js data fetching, rendering, bundle size and server performance. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
- 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.

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 Trello-inspired workflow with owned or clearly labeled sample data: Run a small kanban board with drag-and-drop cards, checklists and due dates. Add one explicit automation such as marking a checklist complete when a card moves to a chosen list, with an audit note.
- Publish a reproducible walkthrough with this observable result: Two users move the same card and receive a conflict or consistent final order; restoring an archived card brings back its checklist and history.
- Explain who can operate this scoped tool, its setup and ongoing costs, and these remaining product gaps: Atlassian ecosystem, Power-Ups, mobile apps, automation, and reliable collaboration; deep integrations Avoid guaranteed savings, performance scores or implied endorsement.

## Engineering roadmap
1. Phase 1 — Scope and fixtures. Implement this bounded workflow: Run a small kanban board with drag-and-drop cards, checklists and due dates. Add one explicit automation such as marking a checklist complete when a card moves to a chosen list, with an audit note. Record prerequisites, select representative user-owned fixtures and document the unsupported features: Atlassian ecosystem, Power-Ups, mobile apps, automation, and reliable collaboration; deep integrations
2. Phase 2 — Durable model. Model boards, lists, cards, checklist items, labels, memberships, ordered positions and activity records Add migrations or a versioned document format, explicit validation, stable IDs and a visible import-error report. Preserve this rule: Concurrent reorder operations use version checks; archiving a card preserves its comments and never removes another board's data.
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. Commit related database changes in one transaction. Use version checks for competing edits and an outbox for external notifications; retry delivery independently of saving the record.
4. Phase 4 — Permissions and integration failure. Authorize every record read and mutation on the server using its workspace membership; validate payloads, protect mutations against CSRF, and escape user-authored HTML. 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. Two users move the same card and receive a conflict or consistent final order; restoring an archived card brings back its checklist and history. 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
- Atlassian ecosystem, Power-Ups, mobile apps, automation, and reliable collaboration
- deep integrations
- enterprise permissions
- large-scale reporting
- battle-tested notifications and mobile apps

## Implementation prompt
WORKING SLICE
Run a small kanban board with drag-and-drop cards, checklists and due dates. Add one explicit automation such as marking a checklist complete when a card moves to a chosen list, with an audit note.

Build this scoped Trello-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.

Prerequisites and limits
A supported Node release, PostgreSQL, HTTPS for a shared deployment, and a backup destination. Begin with one workspace and explicit owner/member permissions.
Outside this release: Atlassian ecosystem, Power-Ups, mobile apps, automation, and reliable collaboration; deep integrations

Data model and correctness
boards, lists, cards, checklist items, labels, memberships, ordered positions and activity records
Invariant: Concurrent reorder operations use version checks; archiving a card preserves its comments and never removes another board's data.
Commit related database changes in one transaction. Use version checks for competing edits and an outbox for external notifications; retry delivery independently of saving the record.

Security and privacy
Authorize every record read and mutation on the server using its workspace membership; validate payloads, protect mutations against CSRF, and escape user-authored HTML.

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: Run a small kanban board with drag-and-drop cards, checklists and due dates. Add one explicit automation such as marking a checklist complete when a card moves to a chosen list, with an audit note. Record prerequisites, select representative user-owned fixtures and document the unsupported features: Atlassian ecosystem, Power-Ups, mobile apps, automation, and reliable collaboration; deep integrations
2. Phase 2 — Durable model. Model boards, lists, cards, checklist items, labels, memberships, ordered positions and activity records Add migrations or a versioned document format, explicit validation, stable IDs and a visible import-error report. Preserve this rule: Concurrent reorder operations use version checks; archiving a card preserves its comments and never removes another board's data.
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. Commit related database changes in one transaction. Use version checks for competing edits and an outbox for external notifications; retry delivery independently of saving the record.
4. Phase 4 — Permissions and integration failure. Authorize every record read and mutation on the server using its workspace membership; validate payloads, protect mutations against CSRF, and escape user-authored HTML. 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. Two users move the same card and receive a conflict or consistent final order; restoring an archived card brings back its checklist and history. Repeat the workflow after restart and with a denied permission or unavailable dependency; show recoverable failure rather than a success placeholder.

Acceptance
Two users move the same card and receive a conflict or consistent final order; restoring an archived card brings back its checklist and history.
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: [vercel-react-best-practices](https://github.com/vercel-labs/agent-skills/blob/main/skills/react-best-practices/SKILL.md) — Improve React and Next.js data fetching, rendering, bundle size and server performance. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
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.
Project rule — data model: boards, lists, cards, checklist items, labels, memberships, ordered positions and activity records
Project rule — preserve this invariant: Concurrent reorder operations use version checks; archiving a card preserves its comments and never removes another board's data.
Project rule — acceptance evidence: Two users move the same card and receive a conflict or consistent final order; restoring an archived card brings back its checklist and history.

## 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.