Extension Packaging

This chapter documents the design decisions for building and distributing the VSCode extension.

Architecture Overview

The extension consists of two parts that must be bundled together:

1. TypeScript code - The extension logic and webview, bundled via webpack
2. Native binary - The symposium-acp-agent Rust binary for the target platform

Platform-Specific Extensions

We publish separate extensions for each platform rather than a universal extension containing all binaries.

Rationale:

• A universal extension would be ~70MB+ (all platform binaries)
• Platform-specific extensions are ~7MB each
• VSCode Marketplace natively supports this - users automatically get the right variant
• Aligns with how other extensions with native dependencies work (rust-analyzer, etc.)

Supported platforms:

Binary Resolution

The extension uses a fallback chain for finding the conductor binary:

1. Bundled binary in bin/<platform>/ (production)
2. PATH lookup (development)
3. User override via the symposium.acpAgentPath setting — if set, this path is used verbatim and takes precedence

This enables local development without packaging - developers can cargo install the binary and the extension finds it in PATH.

Release Flow

Releases are orchestrated through release-plz and GitHub Actions:

release-plz creates tag
        ↓
GitHub Release created
        ↓
Binary build workflow triggered
        ↓
┌───────────────────────────────────────┐
│  Build binaries (parallel)            │
│  - macOS arm64/x64                    │
│  - Linux x64/arm64/musl               │
│  - Windows x64                        │
└───────────────────────────────────────┘
        ↓
Upload archives to GitHub Release
        ↓
┌───────────────────────────────────────┐
│  Build VSCode extensions (parallel)   │
│  - One per platform                   │
│  - Each bundles its platform binary   │
└───────────────────────────────────────┘
        ↓
Upload .vsix files to GitHub Release
        ↓
Publish to marketplaces (TODO)

Why GitHub Releases as the source:

• Single source of truth for all binaries
• Enables Zed extension (points to release archives)
• Enables direct downloads for users not on VSCode
• Versioned and immutable

Vendored mynah-ui

The extension depends on a fork of mynah-ui (AWS’s chat UI component) located in vendor/mynah-ui. This is managed as a git subtree.

Why vendor:

• Enables custom features not yet upstream
• Webpack bundles it into webview.js - only the built output ships in the extension

Local Development

For development without building platform packages:

1. Install the conductor: cargo install --path src/symposium-acp-agent
2. Build the extension: cd vscode-extension && npm run compile
3. Launch via F5 in VSCode

The extension finds the binary in PATH when no bundled binary exists.