build

A guided workflow for building a software feature from investigation through design, implementation, review, and testing. It uses approval points and keeps a task file showing progress.

In plain words
What is it for?
Use it to develop new features systematically, compare design options, track phases in tasks/todo.md, implement approved work, and verify the result.
Why use it?
It reduces the chance of coding against unclear requirements or skipping design, security, testing, and user verification.

Command

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/joncik91/ucai/build
Clone the repo
git clone --depth 1 https://github.com/Joncik91/ucai
Per session 10 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 7,558 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00010 $0.07558
Opus 5 $0.00005 $0.03779
Sonnet 5 $0.00002 $0.01512
Haiku 4.5 $0.00001 $0.00756

Measured 2d ago against content hash df90a998559c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

build scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

commands/build.md · 446 lines

How it starts

The opening of the file, as written. The whole thing — 446 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Feature Development

You are helping a developer implement a new feature. Follow a systematic approach: understand deeply, design with options, get approval, build, verify with agents, then have the user manually test before marking done.

Core Principles

  • Ask, don't assume: Identify all ambiguities and ask. Wait for answers.
  • Understand before acting: Read and comprehend existing code patterns first.
  • Read files identified by agents: After agents complete, read the key files they found.
  • Simple and elegant: Prioritize readable, maintainable code.
  • SOLID and DRY by default: When designing or reviewing, flag violations — classes doing too much, leaky abstractions, duplicated logic. These are architecture concerns, not style preferences.
  • Security by default: Validate inputs at system boundaries, never trust user-supplied data, avoid exposing sensitive data in logs or errors. Flag security implications during design and review — not as an afterthought.
  • Track progress: Write and update tasks/todo.md to track phase completion.
  • Sequential todo updates: Mark each phase complete in tasks/todo.md immediately when it finishes. Never batch-mark multiple phases at once.
  • Engine enforcement: A ContingencyEngine tracks dependencies and gates. Before each phase, check gates. After each phase, update engine state. If a gate blocks, do NOT proceed — complete the prerequisite first.

Skill Loading — MANDATORY

Before starting Phase 2, you MUST identify and load relevant skills. This is not optional.

  1. Determine the type of work: backend/API, frontend/UI, architecture, testing, DevOps, code review
  2. Load the matching skill using the Skill tool: Skill(ucai:backend), Skill(ucai:frontend), Skill(ucai:architect), Skill(ucai:qa), Skill(ucai:devops), Skill(ucai:code-reviewer)
  3. Apply the skill's guidance throughout all subsequent phases
  4. If the work spans multiple domains (e.g., full-stack), load multiple skills

Read the full file on GitHub · 446 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 446 lines · 10 tokens per session scan A df90a998559c

Subscribe to this mod's changes

build is a command published in the GitHub repository Joncik91/ucai (29 stars, last pushed 7d ago), licensed MIT. It adds 10 tokens to every session and 7,558 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.