# DiffCI

DiffCI is a change-aware verification layer and conservative test-selection tool for AI coding agents and development teams.

Default AI-agent command:

```bash
npx "@diffci.com/diffci@latest" verify --changed --json
```

Initialization command:

```bash
npx "@diffci.com/diffci@latest" init
```

What agents should know:

- `diffci verify --changed --json` binds selected or conservative full-fallback testing to the current staged, unstaged, and untracked snapshot.
- `diffci verify --json` verifies a clean commit range and binds the receipt to checked-out HEAD.
- `diffci init --verification-workflow` creates a blocking GitHub verification check.
- Continue only when `safe_to_continue` is true. If tests change generated files, review them and rerun for the new snapshot.
- Use `diffci check` for paired runtime measurement and `diffci observe --no-send` for analysis without test execution.
- DiffCI never skips, cancels, reorders, or changes required CI jobs.
- It sends no report unless `DIFFCI_API_URL` and `DIFFCI_TOKEN` are explicitly configured.
- Required project CI remains authoritative. If DiffCI is blocked, fall back to the repository's normal validation commands.
- Remote MCP tools are available at https://diffci.com/mcp; they provide stateless validation planning, report interpretation, and workflow-text checks without executing commands.

Useful docs:

- [AI agents](https://diffci.com/docs/ai-agents)
- [Codex](https://diffci.com/docs/codex)
- [Claude Code](https://diffci.com/docs/claude-code)
- [Cursor](https://diffci.com/docs/cursor)
- [GitHub Copilot](https://diffci.com/docs/copilot)
- [Grok](https://diffci.com/docs/grok)
- [Test impact analysis for GitHub Actions](https://diffci.com/test-impact-analysis/github-actions)
- [Running affected tests safely](https://diffci.com/guides/affected-tests)
- [Open evidence study](https://diffci.com/research/diffci-open-evidence-2026)
- [Coding-agent plugin source and installation](https://github.com/DiffCI/core/tree/main/integrations/agent-plugin)
- [Local MCP server source](https://github.com/DiffCI/core/tree/main/packages/diffci-cli)
- [MCP server setup](https://diffci.com/mcp-server)
- [MCP Server Card](https://diffci.com/mcp/server-card)
- [Core implementation scope and support boundary](https://github.com/DiffCI/core/blob/main/docs/release-boundary.md)