# Build Computed

> Build a feature's ecs computed-database — derived observable values.

- Skill: `adobe/build-computed-2` (Agent Skill)
- Install (CLI): `npx skillmds@latest add adobe/build-computed-2`
- Raw SKILL.md: https://api.skillmd.com/api/skills/adobe/build-computed-2/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: Adobe (https://skillmd.com/u/adobe)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/adobe/build-computed-2

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Create `ecs/computed-database/`: `computed-database.ts` (extends the previous layer, adds
`computed` from `./computed/index.js`) plus a `computed/` folder — one `cached` derived value
per file + barrel. Derivation logic lives in `data/`; a computed only wires a db observable to it.

Comes after `transaction-database`.

The how is in the auto-loading `features/ecs/computed.md` rule.