Agent UIRuntime-first UI contracts for agent products.

Project agent facts into controllable conversation, process, task, artifact, evidence, and session surfaces.

Read the specification

Implementation quickstart

Standards ecosystem

LLM full context

Runtime projection

Agent UI starts from typed runtime events, durable snapshots, artifact facts, and evidence facts.

Surface separation

Composer, messages, status, tools, tasks, artifacts, timeline, evidence, and sessions each own a clear user question.

Controlled writes

Approvals, interrupts, queue actions, steering, artifact edits, and evidence exports write through owning systems.

Clean final answers

Text, reasoning, tools, actions, artifacts, and evidence stay separate so generated answers do not become process dumps.

Progressive recovery

Old sessions can hydrate shells and recent messages before fetching full timelines, tool details, artifacts, and evidence.

Product-native

The standard does not require a UI bundle, design system, CSS framework, or manifest-based pack format.

What Agent UI Defines

Contract	What it answers
Projection model	How do runtime facts become user-visible UI state without becoming authority?
Message parts	Which text, reasoning, tool, action, artifact, and evidence parts should be rendered separately?
Standard surfaces	Which surface answers conversation, process, task, artifact, evidence, and session questions?
User actions	Which buttons, approvals, interrupts, edits, exports, and queue controls are controlled writes?
Hydration	What should appear immediately, and what can load progressively?
Acceptance	Which behavior-level scenarios prove the UI is compatible?

Start Here

For AI Clients

llms.txt: concise navigation index.
llms-full.txt: current English core documentation in one file.
llm.txt and llm-full.txt: compatibility aliases.

Agent Standards Ecosystem

UI owns the projection layer. Runtime owns execution facts, Artifact systems own deliverables, Evidence owns trust records, and Knowledge owns source-grounded context.