README.md

metadata

title: Chat UI Agent Runtime
emoji: 🧰
colorFrom: yellow
colorTo: indigo
sdk: docker
short_description: Pinned pi runtime image for chat-ui sandboxes

Chat UI Agent Runtime

Prebuilt Node, git, ripgrep, pi, and reconnect-safe RPC bridge image used by chat-ui Agent workspaces. The Space itself exposes a small health endpoint; Hugging Face Jobs overrides the command to start sbx-server, then chat-ui spawns bridge.mjs inside the dedicated sandbox.

No Hugging Face or provider credential is baked into this image.

The image applies fail-closed patches to the pinned Pi 0.84.2 RPC handler. replace_queue performs an atomic expected-snapshot compare-and-swap over Pi's steering and follow-up queues. Correlated extension_ui_response commands report semantic success only while the native Pi request is still pending. The image build fails if either upstream handler shape changes, so an upgrade cannot silently apply a patch to an incompatible release.

bridge.mjs explicitly loads /opt/chat-ui-agent/approval-gate.mjs. Before every tool call, the extension reads the bounded policy file at AGENT_POLICY_PATH (normally /run/chat-ui-agent/policy). A missing, invalid, or oversized file falls back to AGENT_POLICY:

• auto confirms remote publishes, uploads, deployments, other likely exit points, and reads of credential-bearing files or process-environment values.
• ask confirms all writes, edits, shell commands, and sensitive reads.
• read-only hard-blocks every write, edit, and shell command; sensitive direct reads still require confirmation.

Missing or invalid policy values use ask. This live policy file makes “always allow” effective for the active session without restarting Pi. If the RPC UI is unavailable, gated calls are blocked. Run the runtime-only tests with node --test agent-runtime/*.test.mjs from the repository root.