build

build is a command for Claude Code from rahulkeerthi/expo-toolkit. It costs 20 tokens per session (3,355 once invoked), scanned C, original, MIT.

A preparation command for building mobile apps with Expo Application Services, a cloud service for creating app builds. It checks settings, signing credentials, secrets, and dependencies before giving you the build command to run.

In plain words
What is it for?
Use it to prepare iOS, Android, or both builds, check submission settings, and receive a validated EAS Build command.
Why use it?
It helps find missing credentials, invalid configuration, and environment problems before a build fails or includes the wrong data.

Command for Claude Code

Written for Claude Code: argument-hint in frontmatter. Also seen: model in frontmatter; names the AskUserQuestion tool.

Not installable on its own: it runs a file from its repository that does not travel with it. Clone the repository, or install whatever ships that file. The line is node tools/check-version.js /path/to/user/project.

Part of the expo-toolkit plugin — 6 skills, 7 commands, 5 agents shipped together

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 rahulkeerthi/expo-toolkit
Claude Code
/plugin install expo-toolkit

Made for: Claude Code.

Or install expo-toolkit, the plugin that ships this one along with the rest of its 6 skills, 7 commands, 5 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 build

README.md
[![agentmods](https://agentmods.dev/badge/commands/rahulkeerthi/expo-toolkit/build.svg)](https://agentmods.dev/commands/rahulkeerthi/expo-toolkit/build)
Your own site
<a href="https://agentmods.dev/commands/rahulkeerthi/expo-toolkit/build"><img src="https://agentmods.dev/badge/commands/rahulkeerthi/expo-toolkit/build.svg" alt="Measured on agentmods" 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 3,355 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 1 finding. 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 5.1 $0.00020 $0.03355
Opus 5 $0.00010 $0.01677
Sonnet 5 $0.00004 $0.00671
Haiku 4.5 $0.00002 $0.00335

Measured 5d ago against content hash b12772bf7747, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade C, and why

build scanned grade C with 1 finding 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 5d 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.

Harvests environment variableshighData exfiltration

Enumerating or grepping the environment for keys collects credentials unrelated to what the mod says it does.

// Read eas.json and extract env vars for selected profile
commands/build.md · 557 lines

How it starts

The opening of the file, as written. The whole thing — 557 lines — stays where its author put it; the contents beside it link to each section on GitHub.

EAS Build Preparation

Prepare for an EAS build by validating all configuration, credentials, and environment settings. This command does NOT run the build - it ensures everything is ready and provides the exact command to run.

Workflow Overview

  1. Gather build parameters - Platform, profile, submission preference
  2. Validate configuration - eas.json, app.config.js
  3. Check credentials - iOS certificates, Android keystore, push notifications
  4. Verify environment - Environment variables, secrets
  5. Run pre-flight checks - expo doctor, native dependencies
  6. Output ready-to-run command - With all validated parameters

Interactive Setup

Use AskUserQuestion to gather build parameters:

AskUserQuestion({
  questions: [
    {
      question: "Which platform are you building for?",
      header: "Platform",
      options: [
        {
          label: "iOS",
          description: "Build for iPhone/iPad",
        },
        {
          label: "Android",
          description: "Build for Android devices",
        },
        {
          label: "Both",
          description: "Build for iOS and Android",
        },
      ],
      multiSelect: false,
    },
    {
      question: "Which build profile?",
      header: "Profile",
      options: [
        {
          label: "development",
          description: "Dev client build for local development",
        },
        {
          label: "preview",
          description: "Internal testing build (TestFlight/Internal track)",
        },
        {
          label: "production",
          description: "Production build for app store release",
        },
      ],
      multiSelect: false,
    },
    {
      question: "Auto-submit after build completes?",
      header: "Submit",
      options: [
        {
          label: "Yes, auto-submit (Recommended for iOS)",
          description: "Automatically submit to TestFlight/Play Store",
        },
        {
          label: "No, just build",
          description: "Build only, submit manually later",
        },
      ],
      multiSelect: false,
    },
  ],
});

Read the full file on GitHub · 557 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. 5d ago First seen · 557 lines · 20 tokens per session scan C b12772bf7747

Subscribe to this mod's changes

build is a command published in the GitHub repository rahulkeerthi/expo-toolkit (5 stars, last pushed 3mo ago), licensed MIT. It adds 20 tokens to every session and 3,355 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it C with 1 finding (harvests environment variables). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.