ADR-010: Remove Deno Support

Status: Implemented Date: 2026-01-03

Context

v2 attempted to support both Node.js and Deno runtimes. This added complexity without clear benefit.

Issues:

• Dual testing required
• Different module systems
• Import path differences
• Limited adoption of Deno version

Decision

v3 will support Node.js 20+ only. Deno support removed.

Rationale

Focus on Node.js:

• Primary user base on Node
• Better ecosystem (npm packages)
• Simpler build and test
• Deno can run Node code via compatibility

If Deno support needed:

• Wait for Deno 2.0 full Node compatibility
• Add as plugin in v3.1+

Migration

// Remove Deno-specific code
- src/cli/main.deno.ts ❌
- deno.json ❌
- Deno imports ❌

// Keep Node-only
+ src/cli/main.ts ✅
+ package.json ✅
+ Node imports ✅

Implementation

Package.json Updates:

{
  "engines": {
    "node": ">=20.0.0"
  },
  "type": "module"
}

ESM-Only:

// All imports use ESM syntax
import { Agent } from './agent.js';
export { Agent };

// No CommonJS
// const Agent = require('./agent'); ❌

Node.js 20+ Features Used:

• Native ESM support
• Native fetch API
• Native FormData
• Built-in test runner (optional)
• Performance hooks
• Better TypeScript integration

Success Metrics

• All Deno code removed
• Single test suite (Node only)
• Build simplified
• Documentation updated

Implementation Date: 2026-01-04 Status: ✅ Complete