gridpilot.gg/docs/architecture/website/CLIENT_STATE.md

Client State (Strict)

This document defines the only allowed usage of client state in apps/website.

Authoritative contract: WEBSITE_CONTRACT.md.

1) Core rule

Client state is allowed only for UI concerns.

The API remains the single source of truth.

2) Allowed client state

Client state MAY represent:

• selection (table rows, active tab)
• open/closed dialogs and drawers
• input values before submission
• loading flags
• best-effort optimistic flags

3) Forbidden client state

Client state MUST NOT be used as:

• business truth
• security truth
• permission truth

Examples of forbidden behavior:

• client code deciding that a user is allowed based on local flags
• client code persisting an authoritative list state that overrides server truth

4) Conflict resolution rule (hard)

If client state and API truth disagree, API truth wins.

Correct handling is:

• show the API result
• revalidate and reload server-rendered truth

5) Relationship to Blockers

Blockers exist to prevent UX mistakes.

• Blockers are not security.
• Blockers may reduce unnecessary requests.
• The API still enforces rules.

See docs/architecture/shared/BLOCKERS_AND_GUARDS.md and docs/architecture/website/BLOCKERS.md.

6) Canonical placement in this repo

• apps/website/lib/blockers/**
• apps/website/lib/hooks/**
• apps/website/lib/command-models/**