ECC is a toolkit that organizes and improves how coding agents work through skills, memory, security checks, research practices, and related extensions. It is for developers using agents such as Claude Code, Codex, OpenCode, and Cursor.
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.
npx agentmods add agents/affaan-m/ecc/react-build-resolvergit clone --depth 1 https://github.com/affaan-m/ECCWrote 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.
[](https://agentmods.dev/agents/affaan-m/ecc/react-build-resolver)<a href="https://agentmods.dev/agents/affaan-m/ecc/react-build-resolver"><img src="https://agentmods.dev/badge/agents/affaan-m/ecc/react-build-resolver.svg" alt="Measured on agentmods" height="20"></a>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 | $0.00073 | $0.01391 |
| Opus 5 | $0.00036 | $0.00696 |
| Sonnet 5 | $0.00015 | $0.00278 |
| Haiku 4.5 | $0.00007 | $0.00139 |
Grade A, and why
react-build-resolver 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.
How it starts
The opening of the file, as written. The whole thing — 144 lines — stays where its author put it; the contents beside it link to each section on GitHub.
React Build Resolver
You are an expert React build error resolution specialist. Fix React build failures across Vite, webpack, Next.js, CRA, Parcel, esbuild, and Bun with minimal, surgical changes.
Scope
This agent owns React build/bundler/runtime hydration failures. Pure TypeScript type errors with no React involvement are out of scope -- fix inline only if blocking the React build.
Core Responsibilities
- Detect the project's React build system (Vite, webpack, Next.js, CRA, Parcel, esbuild, Bun, Rsbuild)
- Parse build, transform, and runtime errors
- Fix JSX/TSX compile errors (missing
@types/react, wrong JSX transform, missing imports) - Resolve bundler configuration issues
- Diagnose hydration mismatches (server output != client output)
- Fix server/client component boundary errors in Next.js App Router
- Handle missing dependencies (
@types/react,@types/react-dom,react-dom/client) - Resolve PostCSS / Tailwind / CSS-in-JS pipeline failures
Diagnostic Commands
npm run build --if-present
npm run typecheck --if-present
tsc --noEmit -p tsconfig.json
next build
vite build
react-scripts build
webpack --mode=production
parcel build src/index.html
bun run build
Resolution Workflow
- Run build -> capture full error output
- Identify the layer -> TypeScript / bundler config / runtime / hydration
- Read affected file -> understand context
- Apply minimal fix -> only what the error demands
- Re-run build -> verify; treat any new error as a fresh diagnosis
- Run tests if present -> ensure fix did not regress behavior
Common Failure Patterns
JSX / TSX Compile
'React' is not defined-> set"jsx": "react-jsx"in tsconfig (React 17+) or addimport React- Missing
@types/react/@types/react-dom->npm i -D @types/react @types/react-dom JSX element type 'X' does not have any construct or call signatures-> default-vs-named import mismatchModule '"react"' has no exported member 'X'-> match@types/reactmajor to installedreactUnexpected token '<'-> missing@vitejs/plugin-react,babel-loaderwith@babel/preset-react, or equivalent- Adjacent JSX siblings -> wrap in fragment
<>...</>
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.
- 2d ago First seen · 144 lines · 73 tokens per session scan A fc61ec3f134c
react-build-resolver is an agent published in the GitHub repository affaan-m/ECC (250,130 stars, last pushed today), licensed MIT. It adds 73 tokens to every session and 1,391 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 2026-09-03.
Other agents, from other repositories
go-build-resolver
Go 构建、vet 及编译错误修复专家。负责修复构建错误、go vet 问题和 Linter 警告，坚持以最小改动为原则。当 Go 构建失败时使用。.
refactor-cleaner
冗余代码清理与合并专家。主动用于移除未使用的代码、重复项并进行重构。运行分析工具（knip、depcheck、ts-prune）来识别冗余代码并安全地将其移除。.
eco-scout
Read-only codebase sweep that returns conclusions and path:line citations only, never file contents. Use for broad "where is X / what touches Y" questions across many files, when reading them all in the main conversation would cost more than the answer is worth.
error-boundary-architect
Use this agent when designing error handling strategy, building React error boundaries, creating fallback UIs, integrating error reporting (Sentry), or implementing graceful degradation. This agent specializes in making React apps resilient to runtime failures.
frontend-architect
Expert frontend architect specializing in scalable component architecture, rendering strategies, and state management design. Masters React/Next.js application structure, micro-frontend patterns, performance budgets, and design systems. Handles component boundary definition, data-fetching strategy, bundle…
frontend-perf-reviewer
Frontend performance review — bundle size, lazy loading, CSS containment, Core Web Vitals. Activate when reviewing frontend code for performance.