# Compatibility

## Supported host

| Component | Supported |
| --- | --- |
| DeepSeek Harness | `0.1.0-rc.7` exactly |
| Node.js | `^22.19.0` or `>=24` |
| Client carrier | DSH Web rc.7; Electron uses the same public client module/slots but is not a separate browser target |
| Browser runtime | installed Chrome, Edge or Chromium discoverable by path/channel |
| Package manager evidence | npm, pnpm, Yarn, Bun |
| Real runtime fixtures | npm-launched Vite React, Vite Vue, Next.js and generic script |

The package uses exact DSH peer versions because release-candidate APIs and client contribution assembly can change. Installation on another DSH version should fail peer resolution rather than silently claim support. Repository installs use `npm ci --legacy-peer-deps`: several rc.7 packages expose caret peer suggestions that modern npm otherwise attempts to satisfy with rc.8, while the committed lockfile contains no rc.8 package.

## Verified public extension points

- Host: tools, subprocess, attachments, settings, System Prompt sections, lifecycle effects and loopback Connection RPC.
- Client: rc.7 lazy `dsh.client` CommonJS artifact, Client Module loader, Connection, Runtime, `conversation.view`, `tool.call.toolview`, `settings.section` and settings scope binding.
- Bundle: `dsh.bundle.patch` via `cordis.patch.yml`.

## UI placement

The rc.7 public additive session surface is `conversation.view`. A general append-only `details` plugin surface is not available to this out-of-tree bundle; replacing an existing details owner would be incompatible. Live Preview therefore appears as its own conversation view, and verification calls use the keyed Tool View.

## Browser discovery

An explicit `browserExecutablePath` or browser channel is authoritative and fails clearly if unusable. Automatic discovery checks Playwright's candidate, common platform paths, and Chrome/Edge/Chromium channels. The package ships `playwright-core`, not a downloaded browser.

## Known external constraints

- The published top-level DSH rc.7 CLI currently declares many internal DSH packages with caret ranges. A fresh registry resolution can therefore combine a top-level rc.7 CLI with rc.8 internals. This mixed graph failed the real clean-profile test. Use an official rc.7 lock/distribution or exact overrides for the complete internal package graph; the plugin itself keeps exact rc.7 peers and intentionally rejects a mixed ABI.
- CSP `frame-ancestors` and `X-Frame-Options` can forbid the direct UI iframe; browser verification and screenshot fallback still work.
- When DSH runs remotely, a local UI browser's `localhost` is a different machine. The Host-side browser remains authoritative; direct framing may be unavailable.
- Only Chromium is verified. Multi-browser compatibility is outside this plugin's target.
- The System Prompt workflow is guidance, not a hard Agent Loop completion gate, because rc.7 exposes no public out-of-tree enforcement hook for that policy.
- Cross-origin WebSockets are intentionally blocked. Same-origin dev-server HMR is supported.