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Protocol19 spec types · 6 templates

AGENT-TO-UI
PROTOCOL

A treasury agent identifies a $12M sweep opportunity. It does not write an email. It emits a spec. The UI renders a decision card with confidence score, reasoning, and consequence disclosure. The CFO approves in two taps. That is A2UI.

A2UI is a typed JSON contract between AI agents and the Nodus UI layer. Agents emit nodus:* specs. The surface renders them. Neither knows the other exists.

How It Works

Agent Logic
Reasoning, planning, decisions
→
JSON Spec
nodus:* typed payload
→
A2UISurface
Discriminated union renderer
→
Nodus UI
Design system components
// Agent emits this:
const spec = {
type: "nodus:approval-card",
title: "Transfer $4.2M to Orbit Commerce",
confidence: { score: 67, level: "medium" },
reasoning: ["Velocity 8× above 30-day baseline", "New counterparty"],
};
// Surface renders it:
<A2UISurface spec={spec} onAction={handleAction} />

Design Principles

01
Declarative
Agents describe what to show, not how to show it. The spec is data — pure, serializable JSON. No React in the agent layer.
02
Typed Contract
Every spec has a discriminated type. TypeScript narrows at each case. No casting, no runtime surprises, no ambiguity.
03
Multi-Renderer
The same spec can render in Nodus Desktop, web chat, Lit web components, or mobile. The protocol is surface-agnostic.

Spec Library — 19 Types

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Templates

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Morning BriefFlagship

Full Nodus-style daily operating surface. MIT, meetings, briefing — interactive and spec-driven.

nodus:morning-briefingnodus:mit-cardnodus:quick-wins
Agent ChatInteractive

Conversational AI that renders structured A2UI specs inline inside message responses.

nodus:approval-cardnodus:agent-timelinenodus:mit-card
Approval FlowWorkflow

Multi-step approval workflow with agent reasoning, consequence disclosure, and escalation.

nodus:approval-cardnodus:agent-timelinenodus:escalation-banner
ObservabilityMonitoring

Live agent monitoring dashboard: task trace, token budget, and cost breakdown.

nodus:agent-timelinenodus:context-windownodus:cost-dashboard
Clinical TrialDomain

Patient eligibility review with reasoning chain, source provenance, and enrollment decision.

nodus:reasoning-treenodus:provenance-chainnodus:approval-card
Carbon GovernanceGovernance

Verification workflow with SLA escalation, agent learning log, and audit trail.

nodus:escalation-bannernodus:learning-ledgernodus:agent-timeline