mach12:issue-implement

A command that implements one or more specified stages of an issue’s implementation plan, where an issue is a tracked GitHub work item.

In plain words
What is it for?
Use it to implement a numbered stage or stage range for a GitHub issue, with optional limits such as working only on its frontend parts.
Why use it?
It keeps a large change organized by gathering the issue context and ensuring implementation happens on a suitable feature branch instead of the default branch.

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/leanandmean/scramjet/mach12-issue-implement
Clone the repo
git clone --depth 1 https://github.com/LeanAndMean/scramjet
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 2,906 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 $0.02906
Opus 5 $0.00005 $0.01453
Sonnet 5 $0.00002 $0.00581
Haiku 4.5 $0.00001 $0.00291

Measured 3d ago against content hash 15193c622306, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mach12:issue-implement 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 3d 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.

packages/scramjet/mach12/commands/mach12:issue-implement.md · 177 lines

How it starts

The opening of the file, as written. The whole thing — 177 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Implement Stage

You are implementing a specific stage of a staged implementation plan. This command gathers context from a GitHub issue, then walks through the implementation under the structured development workflow.

Step 1: Parse Input

The user's input typically contains:

  • An issue number (required)
  • A stage number or range (required)
  • Additional context or constraints (optional)

Example inputs:

  • 55 1
  • 55 2 but only the frontend parts
  • 55 stages 3-4

Extract the issue number and stage(s). If the input is ambiguous, ask the user to clarify.

Step 2: Ensure Feature Branch

Before gathering context or doing any work, ensure you are on an appropriate feature branch. Implementation must never happen directly on the default branch.

Determine the current branch and the default branch:

git branch --show-current
gh repo view --json defaultBranchRef --jq .defaultBranchRef.name

If on the default branch

  1. Check for uncommitted changes with git status --porcelain. If the working tree is dirty, stop and tell the user to commit or stash their changes before proceeding.

  2. Search for convention-named branches that match the issue number. Run git branch -a and normalize each result by trimming leading whitespace and stripping the remotes/origin/ prefix if present. Then filter for branches that start with feature/issue-<number>- or fix/issue-<number>-, or that equal feature/issue-<number> or fix/issue-<number> exactly. Use strict matching so that issue-4- does not match issue-42-.

  3. Exactly one match found: Check it out with git checkout <branch> and git pull --ff-only. If the pull fails because local and remote have diverged, stop and tell the user to resolve the divergence before continuing.

  4. Multiple matches found: Present the list to the user and ask them to choose. Use the branch names as option labels (if more than 4 branches match, list the 4 most recently updated; let the user supply another value if none fit).

Read the full file on GitHub · 177 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. 3d ago First seen · 177 lines · 10 tokens per session scan A 15193c622306

Subscribe to this mod's changes

mach12:issue-implement is a command published in the GitHub repository LeanAndMean/scramjet (5 stars, last pushed 5d ago), licensed Apache-2.0. It adds 10 tokens to every session and 2,906 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 2026-08-31.