architect-brownfield

architect-brownfield is a command for Claude Code from Hainrixz/the-architect. It costs 71 tokens per session (2,094 once invoked), scanned A, original, MIT.

A command that plans a feature, refactor, integration, or migration in an existing code repository. It first maps the repository's technologies, structure, conventions, and tests, then creates a change blueprint.

In plain words
What is it for?
Preparing implementation plans for changes in an existing project, with acceptance criteria and a blueprint saved under the repository's blueprints directory.
Why use it?
Changes to an existing codebase must fit what is already there; this reduces the risk of proposing a from-scratch design that conflicts with the repository.

Command for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: reads .claude/ paths; mentions CLAUDE.md; mentions subagents.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the the-architect plugin — 1 skill, 6 commands, 3 agents shipped together

Good fit Preparing implementation plans for changes in an existing project, with acceptance criteria and a blueprint saved under the repository's blueprints directory.

Compare 6 commands from other repositories ↓
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add Hainrixz/the-architect
Claude Code
/plugin install the-architect

Made for: Claude Code.

Or install the-architect, the plugin that ships this one along with the rest of its 1 skill, 6 commands, 3 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for architect-brownfield

README.md
[![agentmods](https://agentmods.dev/badge/commands/hainrixz/the-architect/architect-brownfield/github.svg)](https://agentmods.dev/commands/hainrixz/the-architect/architect-brownfield)
Your own site
<a href="https://agentmods.dev/commands/hainrixz/the-architect/architect-brownfield"><img src="https://agentmods.dev/badge/commands/hainrixz/the-architect/architect-brownfield/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for architect-brownfield

Your own site · 80×15
<a href="https://agentmods.dev/commands/hainrixz/the-architect/architect-brownfield"><img src="https://agentmods.dev/badge/commands/hainrixz/the-architect/architect-brownfield.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 71 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,094 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00071 $0.02094
Opus 5 $0.00036 $0.01047
Sonnet 5 $0.00014 $0.00419
Haiku 4.5 $0.00007 $0.00209

Measured 10d ago against content hash d676fba87648, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

architect-brownfield 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 10d 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/architect-brownfield.md · 151 lines

How it starts

The opening of the file, as written. The whole thing — 151 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/architect-brownfield — design a change to code that already exists

You are being invoked as /architect-brownfield. Most coding-agent work is not greenfield — roughly a quarter of sessions write new code, and the rest modify what is already there. This is the entry point for the rest.

Read the skill first — the phases, the shapes, and the acceptance-criteria contract are unchanged:

  • Plugin install: ${CLAUDE_PLUGIN_ROOT}/skills/architect/SKILL.md
  • Clone install: ./CLAUDE.md at the repo root — the clone-mode mirror of the skill. Same rules, same state machine, repo-relative paths, and the subagent work done inline.

Mode

Setting Value
Entry Existing repo in the cwd
Deliverable A change blueprint — feature, refactor, integration, or migration
Shapes Same files. They are stack-agnostic, so they describe a system that already exists just as well as one that does not.
Output Bundle or single file — ask at phase-4 Step 2, recommend bundle. Both land under ./blueprints/ in the repo.
Gate blueprint-validator must return PASS

Phase 0 — map the repo (this is the phase that does not exist in the greenfield flow)

Before any question, read the codebase. Do not ask the user what you can read.

What Where to look
Runtime track Package manifest + lockfile, language version files, container base image
Framework and topology Entry points, routing directory, server vs client split, workspace layout
Conventions Naming, module boundaries, error handling, the linter/formatter config that is actually enforced
Data layer Migrations directory, schema files, ORM usage sites
Test setup Runner, where tests live, how they are named, what the coverage floor is if any
CI and deploy Workflow files, deploy config, environment variable surface
Existing agent instructions CLAUDE.md / AGENTS.md — these outrank the plugin's defaults

Then print a Repo Map: track, framework, data layer, test command, lint command, build command, deploy target, and the 3-5 conventions the change must respect. Ask the user to correct anything you read wrong. Their correction is cheaper than your assumption.

Read the full file on GitHub · 151 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. 10d ago First seen · 151 lines · 71 tokens per session scan A d676fba87648

Subscribe to this mod's changes

architect-brownfield is a command published in the GitHub repository Hainrixz/the-architect (490 stars, last pushed 1mo ago), licensed MIT. It adds 71 tokens to every session and 2,094 once invoked, about $0.0004 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.