ECC (Everything Claude Code) is a free, open-source agent harness that turns ad-hoc prompts into a full software-engineering-like infrastructure, enabling automated planning, testing, code review, and deployment across AI coding tools.

Over time, ECC has evolved from Claude Code-centric tooling into a cross-harness framework that standardizes engineering practices across tools, allowing automatic upgrades and consistent pipelines regardless of the AI coding platform.

AgentShield provides security scanning for AI agent configurations, protecting against credential leakage, prompt injection and other agent-specific risks, with an optional heavy mode that includes Red Team/Blue Team/Auditor components and a large test suite.

ECC addresses Claude Code’s cold-start problem by maintaining context, enforcing best practices, and loading rules and skills on demand to optimize token usage within Claude Code’s large 200,000-token limit.

ECC emphasizes safe installation practices, warns against unofficial mirrors, and directs users to official channels for installation and updates, while highlighting broad community participation in development.

ECC’s architecture rests on four pillars: specialized agents for planning and reviews, reusable skills and checklists, a persistent memory layer to preserve state and learnings, and slash commands like /ecc:plan to trigger orchestration pipelines.

The core claim is that infrastructure and configuration drive most of the performance in AI-assisted development, with ECC enabling compounding gains across model generations by preserving and evolving workflows, patterns, and security postures.

The project traces back to Affaan Mustafa’s Claude Code configuration system from an Anthropic hackathon in September 2025, which won a grand prize and grew to garner over 228,000 GitHub stars and 35,000 forks by now.

ECC supports multiple AI coding tools beyond Claude Code—OpenAI Codex, Cursor, Gemini, Zed, and GitHub Copilot—through a unified AGENTS.md abstraction, with ECC Pro offering hosted private repos at $19 per seat per month and the core MIT license remaining free.