# Comet Build

Plan, implement, and accept Classic tasks.

- Repository: https://github.com/rpamis/comet (3263 stars)
- Category: Engineering
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add rpamis/comet --skill comet-build -g -a claude-code -y`
Codex: `npx skills add rpamis/comet --skill comet-build -g -a codex -y`
Cursor: `npx skills add rpamis/comet --skill comet-build -g -a cursor -y`
Gemini CLI: `npx skills add rpamis/comet --skill comet-build -g -a gemini-cli -y`

## Description

Plan, implement, and accept Classic tasks. Use when the user invokes /comet-build or Classic Runtime enters Build or returns to Build for repairs.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Comet Phase 3: Plan and Build

On first entering a phase, handing off to a new Agent, or restoring context, read and follow [Task Context and Artifact Language](../comet-classic/reference/scripts.md#task-context-and-artifact-language). Prefer the current continuation or claimed Action's `contextRequest`; do not retrieve repeatedly during uninterrupted work in the same phase.

After entry returns layout, follow `comet-classic/reference/classic-layout.md` to bind each logical root to its directory. Do not reload the protocol if it is already in context. Use the adapter for all OpenSpec CLI calls and the bound `<classic-*>` roots for paths; do not run an extra root show first.

## SDK Run path

On first entering the current SDK phase, handing off to a new Agent, or restoring context, read [phase entry and recovery](../comet-classic/reference/sdk-methods.md#phase-entry-and-recovery) and the current phase's section in that reference. Reuse them when already available and still valid in this session. Continue with the phase below; recovery routes based on `nextAction.kind` apply only to older responses without a continuation mode.

Reuse the current valid result's `agent.continuation` / `data.nextAction` and bound state. Run `comet state next <change-name> --json` only on a cold resume, after external state changes, or when necessary information is missing. For `data.runtimeFormat: sdk`, advance only this Run; the implementation methods, plan content, and reviews are in SDK execution methods; submit state and evidence through this section. `data.phase` must be `build`. Reuse valid layout and configuration already in context; use `comet state check <change-name> build --json` only when they are missing. For `nextAction.kind: reconcile`, run `comet state check <change-name> build --recover --json` and establish the original outcome before repeating external work.

The rest: https://github.com/rpamis/comet/blob/HEAD/assets/skills/comet-build/SKILL.md