Feature request: local automation API for Claude Desktop (message send / event stream / permission hooks)

We're building a hardware companion device for Claude users — a small desktop controller with a screen and a physical "approve" key (long-press 1.5s to approve dangerous operations, with haptic feedback), so you can supervise an agent without switching screens.

With Claude Code this works beautifully today:

• --input-format stream-json / --output-format stream-json to dispatch tasks and stream status/answers to the device screen
• PreToolUse hooks to gate dangerous tools behind a deliberate physical press

With Claude Desktop there is no equivalent surface, so the same experience is impossible. We'd love to see:

1. A local API to send a message into a conversation — the claude:// deep link can only prefill, cannot submit, and gives no response back
2. A local event stream — assistant streaming text, tool use, task done — so external hardware/software can mirror conversation state
3. A way for an external process or MCP server to answer permission prompts — so approvals can require a deliberate physical action

Essentially: expose on Desktop what Claude Code already exposes via stream-json + hooks (even a read-only event stream + approval delegation would go a long way).

Happy to share more about our use case.