# OpenSpec Dependencies: Complete Runtime Requirements Guide

> Discover OpenSpec dependencies and runtime requirements. Learn about essential Node.js packages like Commander, Inquirer, and Zod needed to run OpenSpec, detailed in package.json.

- Repository: [Fission/OpenSpec](https://github.com/Fission-AI/OpenSpec)
- Tags: runtime-requirements-guide
- Published: 2026-06-28

---

**OpenSpec requires 10 core Node.js runtime dependencies—including Commander for CLI parsing, Inquirer for interactive prompts, Zod for schema validation, and YAML libraries—declared in the [`package.json`](https://github.com/Fission-AI/OpenSpec/blob/main/package.json) file of the Fission-AI/OpenSpec repository.**

OpenSpec is a Node-based CLI tool that generates code from YAML specifications. To run the compiled binary, you need only the production dependencies listed in [`package.json`](https://github.com/Fission-AI/OpenSpec/blob/main/package.json), not the development tools used for building the project.

## Core Runtime Dependencies

According to the [`package.json`](https://github.com/Fission-AI/OpenSpec/blob/main/package.json) in the Fission-AI/OpenSpec repository, the tool relies on the following production dependencies:

| Dependency | Purpose |
|------------|---------|
| `@inquirer/core` | Core primitives for building interactive command-line prompts |
| `@inquirer/prompts` | Ready-made prompts (checkboxes, confirm) built on `@inquirer/core` |
| `chalk` | Adds color and styling to terminal output |
| `commander` | Parses CLI arguments and defines commands for the `openspec` executable |
| `cross-spawn` | Cross-platform child process spawning for running user scripts |
| `fast-glob` | Fast file-system globbing for locating spec files and templates |
| `ora` | Displays spinner animations during long-running operations |
| `posthog-node` | Sends anonymous usage telemetry for product analytics |
| `yaml` | Parses and serializes YAML files—the primary OpenSpec format |
| `zod` | Runtime schema validation ensuring spec files match expected shapes |

These dependencies are installed automatically when you run `pnpm add -g @fission-ai/openspec` or `npm install` in a cloned repository.

## How Dependencies Power the OpenSpec Architecture

The runtime dependencies work together to create an interactive, cross-platform experience. When you invoke the `openspec` binary from [`bin/openspec.js`](https://github.com/Fission-AI/OpenSpec/blob/main/bin/openspec.js), the following flow occurs:

### Command Parsing and User Interaction

The `commander` library reads CLI arguments and routes to appropriate commands (e.g., `init`, `run`, `dev`). For interactive steps, `@inquirer/core` and `@inquirer/prompts` render terminal prompts, while `chalk` colorizes success messages and warnings.

### File Discovery and Validation

`fast-glob` scans the workspace for spec files (`*.yaml`, `*.yml`) and templates located in `schemas/`. The `yaml` library parses loaded content, and `zod` validates the structure against schemas defined in `src/utils/*.ts`.

### Process Orchestration and Telemetry

`cross-spawn` executes user-defined build scripts in a cross-platform manner, while `ora` provides visual spinner feedback. Throughout execution, `posthog-node` records anonymized events to improve the tool.

## Installation and Usage Examples

Install OpenSpec globally to access all runtime dependencies:

```bash

# Using pnpm (recommended)

pnpm add -g @fission-ai/openspec

# Or via npx without global install

npx @fission-ai/openspec@latest init

```

Run a spec-driven workflow:

```bash

# Initialize a new project (uses @inquirer prompts)

openspec init

# Validate and generate from a spec file

openspec run spec.yaml

```

Use the library programmatically in Node.js:

```typescript
import { runSpec } from '@fission-ai/openspec';

// Load a YAML spec (yaml and zod handle parsing/validation)
const specContent = await import('fs/promises')
  .then(fs => fs.readFile('spec.yaml', 'utf8'));

runSpec(specContent)
  .then(() => console.log('✅ Spec processed successfully!'))
  .catch(err => console.error('❌ Error:', err));

```

*Note: Programmatic imports require the package to be built with `pnpm run build`; the entry point lives in [`dist/index.js`](https://github.com/Fission-AI/OpenSpec/blob/main/dist/index.js).*

## Key Source Files

These files demonstrate how OpenSpec wires dependencies into the system:

- **[`bin/openspec.js`](https://github.com/Fission-AI/OpenSpec/blob/main/bin/openspec.js)** – Entry point that configures `commander`, loads commands, and initializes the runtime
- **`src/utils/*.ts`** – Utility modules containing Zod schema definitions and file handling logic
- **[`schemas/spec-driven/schema.yaml`](https://github.com/Fission-AI/OpenSpec/blob/main/schemas/spec-driven/schema.yaml)** – Canonical YAML schema used for validation via `zod`
- **[`package.json`](https://github.com/Fission-AI/OpenSpec/blob/main/package.json)** – Declares all runtime dependencies, entry points, and build scripts

## Summary

- OpenSpec requires **10 production dependencies** declared in [`package.json`](https://github.com/Fission-AI/OpenSpec/blob/main/package.json) to run the compiled CLI
- **Commander** handles CLI parsing, while **Inquirer** libraries manage interactive prompts
- **Zod** and **yaml** work together to validate spec files against schemas in `src/utils/*.ts`
- **Cross-spawn** provides reliable process execution across Windows, macOS, and Linux
- Development dependencies (TypeScript, ESLint, Vitest) are not required for end-users

## Frequently Asked Questions

### Do I need to install TypeScript to run OpenSpec?

No. TypeScript is listed as a `devDependency` and is only required for development and building the source code. End-users running the compiled CLI from npm need only the 10 production dependencies.

### Why does OpenSpec use both `@inquirer/core` and `@inquirer/prompts`?

`@inquirer/core` provides the foundational primitives for building custom prompts, while `@inquirer/prompts` offers ready-made implementations like checkboxes and confirm dialogs. This combination allows OpenSpec to maintain both flexibility and rapid development of the user interface.

### Can I run OpenSpec without internet access?

Yes, but with limited functionality. While the core依赖 (dependencies) work offline, the `posthog-node` library will fail silently or queue telemetry events if it cannot reach PostHog servers. All code generation and spec validation functions operate entirely offline using `yaml`, `zod`, and `fast-glob`.

### What Node.js version is required for these dependencies?

While the source code analysis does not specify exact Node.js version constraints, the use of modern ESM imports and modern dependencies like `commander` v11+ and `zod` suggests Node.js 18 or higher is recommended. Check the `engines` field in [`package.json`](https://github.com/Fission-AI/OpenSpec/blob/main/package.json) for definitive version requirements.