# AGENTS.md — Build guide for Later

## Project scope
Plan image-led posts in a content calendar, preview a selected profile grid and publish through one approved network API. Add a simple link page whose public revision is independent of unpublished drafts.

Catalogue verdict: kinda. A post calendar and queue are buildable, but Later's value is social API access, visual planning, link-in-bio, analytics, media library, and platform compliance.
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- Do not publish, spend money, contact customers, delete source data or run irreversible migrations without the project owner's authorization.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
- Credentials and the required API access for one chosen network. Verify permissions and quotas; provide an export/manual-post workflow for unsupported networks.
- Implementation components: Node.js, TypeScript and Express with server-rendered HTML and small browser modules. SQLite through better-sqlite3 with migrations, prepared statements and a single background worker. One official platform API adapter with declared text/media capabilities and a persisted scheduled-post worker.
- Scope boundary: visual planner; social API maintenance

## Stack and architecture
- Node.js, TypeScript and Express with server-rendered HTML and small browser modules.
- SQLite through better-sqlite3 with migrations, prepared statements and a single background worker.
- One official platform API adapter with declared text/media capabilities and a persisted scheduled-post worker.
- Domain model: media library items, platform-specific drafts, calendar slots, profile-grid previews and link-page revisions

## Security and data integrity
- Keep OAuth tokens server-side and encrypt persistent tokens with a separately managed key. Publication requires an explicit approved revision and target account.
- Correctness boundary: The preview reflects planned ordering, not a guarantee of platform rendering; unpublished assets are not exposed through public link pages.
- Track each target independently with pending, publishing, delivered, failed and unknown states. Reconcile a timeout using provider receipts before retrying; respect rate-limit backoff.
- Use a consistent SQLite backup and an attachment manifest. Export portable JSON/CSV, then restore to a new directory without overwriting the original data.

## Agent implementation rules
- Project rule — data model: media library items, platform-specific drafts, calendar slots, profile-grid previews and link-page revisions
- Project rule — preserve this invariant: The preview reflects planned ordering, not a guarantee of platform rendering; unpublished assets are not exposed through public link pages.
- Project rule — acceptance evidence: Reorder two scheduled images and update the preview while preserving their approval status; a failed upload leaves the target undelivered and retryable.

## Optional agent skills and references
- Optional external skill: [sharp-edges](https://github.com/trailofbits/skills/blob/main/plugins/sharp-edges/skills/sharp-edges/SKILL.md) — Review security-sensitive APIs and configuration for dangerous defaults and easy-to-misuse interfaces. 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 Later-inspired workflow with owned or clearly labeled sample data: Plan image-led posts in a content calendar, preview a selected profile grid and publish through one approved network API. Add a simple link page whose public revision is independent of unpublished drafts.
- Publish a reproducible walkthrough with this observable result: Reorder two scheduled images and update the preview while preserving their approval status; a failed upload leaves the target undelivered and retryable.
- Explain who can operate this scoped tool, its setup and ongoing costs, and these remaining product gaps: visual planner; social API maintenance Avoid guaranteed savings, performance scores or implied endorsement.

## Engineering roadmap
1. Phase 1 — Scope and fixtures. Implement this bounded workflow: Plan image-led posts in a content calendar, preview a selected profile grid and publish through one approved network API. Add a simple link page whose public revision is independent of unpublished drafts. Record prerequisites, select representative user-owned fixtures and document the unsupported features: visual planner; social API maintenance
2. Phase 2 — Durable model. Model media library items, platform-specific drafts, calendar slots, profile-grid previews and link-page revisions Add migrations or a versioned document format, explicit validation, stable IDs and a visible import-error report. Preserve this rule: The preview reflects planned ordering, not a guarantee of platform rendering; unpublished assets are not exposed through public link pages.
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. Track each target independently with pending, publishing, delivered, failed and unknown states. Reconcile a timeout using provider receipts before retrying; respect rate-limit backoff.
4. Phase 4 — Permissions and integration failure. Keep OAuth tokens server-side and encrypt persistent tokens with a separately managed key. Publication requires an explicit approved revision and target account. Request integration credentials and permissions only for the enabled feature; show a disconnected state instead of mock results.
5. Phase 5 — Portable handoff. Use a consistent SQLite backup and an attachment manifest. Export portable JSON/CSV, then restore to a new directory without overwriting the original data. Include setup, operating limits, fixture walkthrough and shutdown/restart instructions in the README.
6. Phase 6 — Acceptance scenarios. Reorder two scheduled images and update the preview while preserving their approval status; a failed upload leaves the target undelivered and retryable. 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
- visual planner
- social API maintenance
- link-in-bio
- analytics
- media library
- approvals
- mobile app

## Implementation prompt
WORKING SLICE
Plan image-led posts in a content calendar, preview a selected profile grid and publish through one approved network API. Add a simple link page whose public revision is independent of unpublished drafts.

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

Architecture
- Node.js, TypeScript and Express with server-rendered HTML and small browser modules.
- SQLite through better-sqlite3 with migrations, prepared statements and a single background worker.
- One official platform API adapter with declared text/media capabilities and a persisted scheduled-post worker.

Prerequisites and limits
Credentials and the required API access for one chosen network. Verify permissions and quotas; provide an export/manual-post workflow for unsupported networks.
Outside this release: visual planner; social API maintenance

Data model and correctness
media library items, platform-specific drafts, calendar slots, profile-grid previews and link-page revisions
Invariant: The preview reflects planned ordering, not a guarantee of platform rendering; unpublished assets are not exposed through public link pages.
Track each target independently with pending, publishing, delivered, failed and unknown states. Reconcile a timeout using provider receipts before retrying; respect rate-limit backoff.

Security and privacy
Keep OAuth tokens server-side and encrypt persistent tokens with a separately managed key. Publication requires an explicit approved revision and target account.

Recovery and export
Use a consistent SQLite backup and an attachment manifest. Export portable JSON/CSV, then restore to a new directory without overwriting the original data.

Implementation order
1. Phase 1 — Scope and fixtures. Implement this bounded workflow: Plan image-led posts in a content calendar, preview a selected profile grid and publish through one approved network API. Add a simple link page whose public revision is independent of unpublished drafts. Record prerequisites, select representative user-owned fixtures and document the unsupported features: visual planner; social API maintenance
2. Phase 2 — Durable model. Model media library items, platform-specific drafts, calendar slots, profile-grid previews and link-page revisions Add migrations or a versioned document format, explicit validation, stable IDs and a visible import-error report. Preserve this rule: The preview reflects planned ordering, not a guarantee of platform rendering; unpublished assets are not exposed through public link pages.
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. Track each target independently with pending, publishing, delivered, failed and unknown states. Reconcile a timeout using provider receipts before retrying; respect rate-limit backoff.
4. Phase 4 — Permissions and integration failure. Keep OAuth tokens server-side and encrypt persistent tokens with a separately managed key. Publication requires an explicit approved revision and target account. Request integration credentials and permissions only for the enabled feature; show a disconnected state instead of mock results.
5. Phase 5 — Portable handoff. Use a consistent SQLite backup and an attachment manifest. Export portable JSON/CSV, then restore to a new directory without overwriting the original data. Include setup, operating limits, fixture walkthrough and shutdown/restart instructions in the README.
6. Phase 6 — Acceptance scenarios. Reorder two scheduled images and update the preview while preserving their approval status; a failed upload leaves the target undelivered and retryable. Repeat the workflow after restart and with a denied permission or unavailable dependency; show recoverable failure rather than a success placeholder.

Acceptance
Reorder two scheduled images and update the preview while preserving their approval status; a failed upload leaves the target undelivered and retryable.
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: [sharp-edges](https://github.com/trailofbits/skills/blob/main/plugins/sharp-edges/skills/sharp-edges/SKILL.md) — Review security-sensitive APIs and configuration for dangerous defaults and easy-to-misuse interfaces. 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: media library items, platform-specific drafts, calendar slots, profile-grid previews and link-page revisions
Project rule — preserve this invariant: The preview reflects planned ordering, not a guarantee of platform rendering; unpublished assets are not exposed through public link pages.
Project rule — acceptance evidence: Reorder two scheduled images and update the preview while preserving their approval status; a failed upload leaves the target undelivered and retryable.

## 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.