Trigger a Hermes hot-reload of the React Native / Expo app currently under test. Thin wrapper over POST /dev/reload — computes a native-fingerprint delta against the dev-server baseline and broadcasts a hot_reload (or native_rebuild_required) command via the BlackBox SSE channel to all connected ...
AI agents invoke mobile_hermes_reload to trigger actions in Yaver. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
| Parameter | Type | Required | Description |
|---|---|---|---|
mode | string | — | Reload mode: "dev" (Metro fast-refresh, default) or "bundle" (push pre-built bundle). |
device_id | string | — | Optional owned Yaver agent device id/name/alias that should perform the reload. Use this for remote boxes; target_device_id is only the receiving mobile SDK ses |
target_device_id | string | — | Optional SDK device id to scope the broadcast to. Empty/omitted = broadcast to ALL subscribed devices. Used by the Path-C cross-device flow where Phone A drives |
Parameters from the server's own tool schema.
mobile_hermes_reload triggers real processes with real consequences. An agent gone sideways doesn't fire it once — it starts dozens of builds, sends mass notifications, or burns through compute before anyone looks up.
Attacks that exploit this kind of access
Trigger a Hermes hot-reload of the React Native / Expo app currently under test. Thin wrapper over POST /dev/reload — computes a native-fingerprint delta against the dev-server baseline and broadcasts a hot_reload (or native_rebuild_required) command via the BlackBox SSE channel to all connected SDK devices. Use this when an MCP client (Claude Code, glass-terminal vibe chip, ChatGPT) wants the app reloaded without an LLM round-trip. Returns { ok, changeClass: "js_only"|"native_rebuild_required"|"unknown", nativeChanges?, nativeChangesDetected }. It is categorised as a Execute tool in the Yaver MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
mobile_hermes_reload accepts 3 parameters: mode, device_id, target_device_id. The full parameter table on this page comes from the server's own tool schema.
Register the Yaver MCP server in PolicyLayer and add a rule for mobile_hermes_reload: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Yaver. Nothing to install.
mobile_hermes_reload is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the mobile_hermes_reload rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for mobile_hermes_reload. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
mobile_hermes_reload is provided by the Yaver MCP server (yaver-cli). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.