What is tester-build?

A command that creates a signed Windows test build through GitHub Actions, Microsoft's service for running automated work in a repository, and finds the installer for a remote tester.

Use it to build Windows installers for x64 computers, ARM64 computers, or both, then download the build artifacts for testing.

It checks that the code is committed and guides the build target before starting a remote build that can take about 10–15 minutes.

How lebek/modmixer configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to lebek/modmixer. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/lebek/modmixer/main/.claude/commands/tester-build.md

Clone the repo

git clone --depth 1 https://github.com/lebek/modmixer

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/commands/lebek/modmixer/tester-build/github.svg)](https://agentmods.dev/commands/lebek/modmixer/tester-build)

Your own site

<a href="https://agentmods.dev/commands/lebek/modmixer/tester-build"><img src="https://agentmods.dev/badge/commands/lebek/modmixer/tester-build/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.

Your own site · 80×15

<a href="https://agentmods.dev/commands/lebek/modmixer/tester-build"><img src="https://agentmods.dev/badge/commands/lebek/modmixer/tester-build.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 20 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 656 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.

Model	Per session	Once invoked
Fable 5.1	$0.00020	$0.00656
Opus 5.5	$0.00008	$0.00262
Sonnet 5.5	$0.00004	$0.00131
Haiku 4.5	$0.00002	$0.00066

Measured 1mo ago against content hash 43339795394c, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

tester-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 1mo 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.

.claude/commands/tester-build.md · 56 lines

How it starts

The opening of the file, as written. The whole thing — 56 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/tester-build

You are running the /tester-build command. Walk through these steps in order. Be concise — one sentence per step at most. Do not narrate plans; just do the work.

1. Check working tree

Run git status --porcelain. If it has any output, tell the user the tree is dirty (show what's changed) and stop. The build runs from the committed branch state — uncommitted changes wouldn't be tested.

2. Confirm target

Default is win-x64 (covers most testers). Ask:

Build for which target? (win-x64 / win-arm64 / all) [default: win-x64]

Accept these answers:

empty / yes / default → win-x64
win-x64, win-arm64, all → use as-is
anything else → ask again

all builds every matrix entry but takes the same wall-clock time (parallel runners) and downloads both Windows installers.

3. Run the script

Run:

node scripts/tester-build.mjs --target <target>

Stream output so the user sees progress. The script will:

Verify gh is authed.
Push the current branch if it has unpushed commits.
gh workflow run release.yml --ref <branch> to dispatch.
Poll for the new run, then gh run watch it (~10–15 min).
Download the artifact to out/tester-build/<run-id>/<target>/.
Print the path to the Setup.exe and the run URL.

4. Report

When the script finishes:

Success: print the absolute path(s) to the Setup.exe and the run URL. Remind the user that Discord's 25 MB free / 50 MB Nitro upload cap means they'll need a file host (Drive, WeTransfer) for the ~150-200 MB installer, or share the GitHub artifact link if the tester has repo read access.
Failure: print the run URL the script logged. Don't try to fix it automatically — the user decides whether to retry, edit code and re-dispatch, or check signing config.

Notes on edge cases

If gh complains about auth: tell the user to run gh auth login (interactive — they need to do it themselves).
If the user is on main and wants to test an unmerged change, they should switch to a feature branch first. /tester-build always dispatches against the current branch.
The signed installer is a real Squirrel .exe — testers won't see SmartScreen warnings (Trusted Signing certs are recognized). It installs to %LOCALAPPDATA%\modmixer\ and self-updates from GitHub Releases, same as a tagged release.
If the user has Trusted Signing quota concerns, mention that each tester build burns a small amount of quota (sign operations per day are limited).

Read the full file on GitHub · 56 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.

1mo ago First seen · 56 lines · 20 tokens per session scan A 43339795394c

Subscribe to this mod's changes

tester-build is a command published in the GitHub repository lebek/modmixer (30 stars, last pushed 2mo ago), licensed MIT. It adds 20 tokens to every session and 656 once invoked, about $0.0001 per session on Opus 5.5. 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.

CI and CD Claude Code DevOps and cloud Testing agent agents ai-agent codex desktop-app

quality-check

Execute a comprehensive quality gate check (lint, test, build, format) before allowing code to merge.

yeaight7/agent-powerups · 21 tokens

test-feature

Test a React Native feature on the running simulator/emulator. Verifies UI, user flows, and internal state. Generates a persistent Maestro test file.

Lykhoyda/rn-dev-agent · 30 tokens

qa-pr

Device-test a GitHub pull request on iOS simulator, Android emulator, and/or physical device. Installs the PR head via rn-dev-agent and reports pass/fail with repro steps and screenshots.

Lykhoyda/rn-dev-agent · 40 tokens

run-workflow

Validate and establish the proven rn-dev-agent operating sequence before a real React Native journey — declared package manager and dependencies, read-only inventory, typed session recovery, one exclusive device, managed integration and Metro, only the requested proof, reverse-order cleanup.

Lykhoyda/rn-dev-agent · 49 tokens

lock-e2e

Promote a verified action into a frozen, locked e2e regression test. Runs the action once strict (no repair) via cdplocke2etest and freezes it to .rn-agent/e2e/ .yaml only if it passes. v1 supports param-free actions only.

Lykhoyda/rn-dev-agent · 60 tokens

ci-readout

Generate a comprehensive summary of recent CI runs and failing jobs.

yeaight7/agent-powerups · 11 tokens

modmixer: Command for Claude Code