Protocol coverage

Implemented as real remote/runtime behavior:

• Transports — stdio, WebSocket, Unix-socket daemon, and app-server proxy raw stdio forwarding.
• Thread lifecycle — start, resume, fork, list, read, turns list, name, archive/unarchive, unsubscribe, interrupt.
• Claude runtime — query, session resume/fork, partial text streaming, interrupt, MCP config, allowed tools, add dirs, file checkpointing.
• Approval bridge — Bash → command approval; Edit / Write / MultiEdit → file-change approval with diffs.
• Streaming — turn started/completed, thread status changes, agent text deltas, reasoning deltas, command output deltas, file patches, generic tool item completion, and aggregated git diff updates.
• Remote utilities — file read/write/list/metadata/copy/remove/watch, command exec with stdin/terminate, process spawn/stdin/kill, fuzzy file search, direct MCP stdio/HTTP tool and resource calls.
• Per-thread git worktree isolation (optional).

Compatibility-only surfaces

Some app UI methods return stable empty or inert responses because they are OpenAI-account / plugin-marketplace / realtime-specific rather than Claude Code runtime capabilities — for example marketplace install/update, OpenAI account login/logout, realtime audio, and Windows sandbox setup. They ack so the App's capability probe does not error.

See the Capability matrix for the full per-area breakdown.