---
title: "build - implement spec - Air Market"
description: "You have a spec written down and now you want the code. This plans and then works through it, one task at a time, in a single straight loop. When a build or test fails, it stops to consider whether a…"
canonical: "https://airmarket.ai/app/build"
---

[Air Market](/) / [Developer Tools](/category/devtools) / build - implement spec

Skill by [Julius Brussee](/@juliusbrussee)

# build - implement spec

Work through the spec task by task, and learn from every failure

## What this does

You have a spec written down and now you want the code. This plans and then works through it, one task at a time, in a single straight loop. When a build or test fails, it stops to consider whether a new rule would prevent that failure from happening again before it tries once more.

### Top 3 things it does for you

- Build the next task from the spec
- Implement one specific task you name
- Handle a build or test failure before retrying

## Information

**build - implement spec at a glance**

|  |  |
| --- | --- |
| Kind | Skill |
| Publisher | [Julius Brussee](/@juliusbrussee) |
| Category | [Developer Tools](/category/devtools) |
| Works with | Agent Skills - an open standard supported by 40+ agents |
| Size | 3 KB |
| Licence | MIT |
| Repository | [JuliusBrussee/cavekit](https://github.com/JuliusBrussee/cavekit/tree/c322f0bb6db82163041930467f3ce32754d42827/skills/build) |
| GitHub stars | 1,142 (as of Nov 2026) |

## Security report

**Verified.** AIR scanned this exact version of build - implement spec and flagged nothing. AIR's verdict: **safe**.

**What build - implement spec's check was run against**

|  |  |
| --- | --- |
| Commit | c322f0bb6db82163041930467f3ce32754d42827 |
| Content hash | 00156742532d38d84a996380c01d91fb8a4af2de0591b82113fc0924522aa191 |
| Files read | [Browse the files at this exact commit](https://github.com/JuliusBrussee/cavekit/blob/c322f0bb6db82163041930467f3ce32754d42827/skills/build/SKILL.md) |

A scan is named by the exact content it read, not by a version number. A different version is a different artifact, and nothing here applies to a version AIR has not scanned.

[Read the full security report for build - implement spec](/security/build)

## About build - implement spec

This implements against your SPEC.md by planning first and then executing, running as a plain single-threaded loop with no sub-agents involved.

Failures are not simply retried. On a test or build failure it calls on the backprop skill first, so every failed verification is a chance to ask whether a new invariant would stop the problem recurring.

Ask it to build, to implement, to execute the spec, or to take on one particular task by name. If there is no SPEC.md to work from, it hands over to the spec skill instead.

## What's inside

- SKILL.md - instructions

## Questions

### Is build - implement spec safe to install?

AIR scanned this exact version of build - implement spec and flagged nothing. AIR's verdict: safe. The verdict is named by the content that was read, at commit c322f0bb6db8, so it cannot drift onto a version nobody scanned. The full report is at https://airmarket.ai/security/build.

### How do I install build - implement spec?

Open https://airmarket.ai/app/build on Air Market and use the install action: Air Market hands Claude a prompt naming this exact skill, and Claude sets it up. Source, pinned to the exact commit this listing describes: https://github.com/JuliusBrussee/cavekit/tree/c322f0bb6db82163041930467f3ce32754d42827/skills/build. Install from that link, not the branch.

## Related on Air Market

- [More Developer Tools listings](/category/devtools)
- [Everything by Julius Brussee](/@juliusbrussee)

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Canonical URL: <https://airmarket.ai/app/build>