Nexus EDGE tools
Nexus EDGE tools run on the end-user's desktop via the NexusEdge desktop client, not in the cloud. When the agent calls an edge tool the runtime sends a request down the chat stream to the desktop, which executes the tool locally (file access, printers, browsers, system APIs) and posts the result back.
Who it's for
Builders deploying Nexus agents on the NexusEdge desktop client — IT helpdesk, device support, and any use-case where the agent needs to interact with hardware or the local machine.
Tool types: read-only vs. mutating
Every edge tool is classified as either read-only or mutating in its definition.
| Type | Examples | Widget behaviour |
|---|---|---|
| Read-only | Get printers, Print queue, System info | Runs immediately, no prompt |
| Mutating | Cancel print job, Restart spooler, Set default printer | Shows an Allow / Deny gate before running |
You can see the classification in Tools → Add Tool → Nexus EDGE → Device: mutating tools are labelled "Mutating — requires user Allow" in the picker.
Approval gate for mutating tools
When the agent calls a mutating edge tool, the widget pauses and shows the user an Allow / Deny prompt. This gives the user explicit control over actions that change state on their machine.
How the timing works:
- Server starts a 10-minute decision window. The LLM turn is paused — the user can take their time.
- User clicks Allow. The widget sends
edge.tool.approvedimmediately. The server resets the timer to the tool's normal execution timeout (typically a few seconds), so deliberation time does not count against the tool run. - User clicks Deny. The tool resolves with a denial error and the agent continues the conversation.
- No response within 10 min. The tool times out and the agent continues with a
tool_timeouterror.
If a user needs more than 10 minutes to decide (e.g. they stepped away), they can ask the agent to retry — the agent will issue a new tool call and restart the gate.
Parallel dispatch
When one turn calls several edge tools, they're dispatched to the desktop together and their results awaited in parallel.
Practical effect: a turn that calls three read-only tools - printers, print queue, spooler health - takes as long as the slowest one rather than the sum of all three. So there's no cost to attaching several small, focused edge tools instead of one that does everything.
Printer test page
The printer.testPrint edge tool generates a diagnostic test page. It sends plain text rather than PostScript, which keeps it working on AirPrint-only printers - several Brother and HP models don't declare PostScript support and reject a .ps file silently.