Add UDP socket support with platform-agnostic interface

[pcasaretto]

Hi there!

I've been learning more about Effect TS and coded this with Claude.
I thought it might be useful so I decided to open a PR.

Summary

Add comprehensive UDP socket support to the Effect platform with proper platform-agnostic design and implementations for Node.js and Bun.

Key Changes

• Platform-agnostic UDP interface (@effect/platform/UdpSocket)

  • Message-oriented UdpMessage with sender address information
  • Direct send(data, address) and run(handler) methods matching UDP semantics
  • Non-Effect address property for symmetry with other platform interfaces

• Node.js implementation (@effect/platform-node/NodeUdpSocket)

  • Full UDP socket support using Node.js dgram module
  • Proper resource management with acquireRelease pattern
  • Comprehensive error handling and graceful cleanup

• Bun implementation (@effect/platform-bun/BunUdpSocket)

  • Leverages Bun's Node.js API compatibility for dgram
  • Same interface as Node.js implementation

• Comprehensive test coverage

  • Socket creation, message sending/receiving
  • Error handling for invalid addresses
  • Resource cleanup and double-close scenarios

Design Journey & Architecture Decisions

Initial Approach: SocketServer Integration

Initially attempted to make UDP compatible with the existing SocketServer interface by:

• Adding UdpAddress to the Address union type
• Creating virtual Socket instances for each UDP message
• Treating each datagram as a "connection"

Why this felt wrong:

• Semantic mismatch: UDP is connectionless, but SocketServer assumes persistent connections
• Virtual connections: Creating Socket instances per message violated UDP's stateless nature
• RPC incompatibility: Would break RPC protocols expecting persistent, bidirectional streams
• Forced abstraction: Round peg, square hole - UDP semantics don't match TCP patterns

Final Approach: UDP-Specific Interface

Reverted to a dedicated UDP interface that properly represents UDP semantics:

• Message-oriented: UdpMessage with discrete datagrams
• Addressing explicit: Each send() specifies destination
• Stateless: No connection lifecycle management
• Platform-agnostic: Same interface works across Node.js, Bun, etc.

Platform Support Matrix

Platform	TCP Socket	UDP Socket	Notes
platform	✅ Interface	✅ Interface	Platform-agnostic definitions
platform-node	✅ NodeSocket	✅ NodeUdpSocket	Full raw socket support
platform-bun	✅ BunSocket	✅ BunUdpSocket	Node.js compatible dgram
platform-browser	✅ BrowserSocket (WebSockets)	❌ Not supported	Security limitations

Usage Example

// Platform-agnostic server
const createEchoServer = Effect.gen(function*() {
  const socket = yield* UdpSocket.UdpSocket
  
  yield* socket.run((message) => Effect.gen(function*() {
    const response = `Echo: ${new TextDecoder().decode(message.data)}`
    yield* socket.send(
      new TextEncoder().encode(response), 
      message.remoteAddress
    )
  }))
})

// Node.js
const nodeProgram = createEchoServer.pipe(
  Effect.provide(NodeUdpSocket.layer(address))
)

// Bun  
const bunProgram = createEchoServer.pipe(
  Effect.provide(BunUdpSocket.layer(address))
)

This implementation demonstrates Effect's platform-agnostic design principles while respecting the fundamental differences between TCP and UDP protocols.

🤖 Generated with Claude Code

Co-Authored-By: Claude [email protected]

[changeset-bot]

🦋 Changeset detected

Latest commit: 2224431

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 30 packages

Name	Type
@effect/platform-node	Major
@effect/platform	Minor
@effect/cli	Major
@effect/cluster	Major
@effect/experimental	Major
@effect/sql-clickhouse	Major
@effect/sql-drizzle	Major
@effect/sql-mssql	Major
@effect/sql-sqlite-node	Major
@effect/ai-amazon-bedrock	Major
@effect/ai-anthropic	Major
@effect/ai-google	Major
@effect/ai-openai	Major
@effect/opentelemetry	Major
@effect/platform-browser	Major
@effect/platform-bun	Major
@effect/platform-node-shared	Major
@effect/rpc	Major
@effect/sql-d1	Major
@effect/sql-libsql	Major
@effect/sql-mysql2	Major
@effect/sql-pg	Major
@effect/sql-sqlite-bun	Major
@effect/sql	Major
@effect/workflow	Major
@effect/ai	Major
@effect/sql-sqlite-do	Major
@effect/sql-sqlite-react-native	Major
@effect/sql-sqlite-wasm	Major
@effect/sql-kysely	Major

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