README.md

Threadplane — Production-ready chat, threads, and generative UI for AI agents.

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Threadplane is a production-ready agent UI framework for Angular. @threadplane/chat provides chat surfaces (headless primitives, opinionated compositions, interrupts, generative UI). @threadplane/langgraph adapts a LangGraph Platform endpoint into Angular Signals via provideAgent() + injectAgent(). @threadplane/ag-ui bridges any AG-UI-compatible backend into the same chat surface. @threadplane/render renders JSON specs to Angular components inside your design system.

injectAgent() is the Angular equivalent of LangGraph's React useStream() hook, projected through a runtime-neutral Agent contract that @threadplane/chat consumes. Configure it once with provideAgent({...}), inject it into any Angular 20+ component, and get signal-driven access to messages, status, tool calls, interrupts, subagents, history, and thread management — no subscriptions, no async pipe, no zone.js required.

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Install

npm install @threadplane/langgraph @threadplane/chat

Peer dependencies: @angular/core ^20.0.0 || ^21.0.0, @langchain/core ^1.1.33, @langchain/langgraph-sdk ^1.7.4, rxjs ~7.8.0

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30-Second Example

// app.config.ts — wire the adapter once
import { provideAgent } from '@threadplane/langgraph';

export const appConfig: ApplicationConfig = {
  providers: [
    provideAgent({
      apiUrl: 'https://your-langgraph-platform.com',
      assistantId: 'my-agent',
    }),
  ],
};

// support-chat.component.ts
import { Component } from '@angular/core';
import { ChatComponent as ThreadplaneChatComponent } from '@threadplane/chat';
import { injectAgent } from '@threadplane/langgraph';

@Component({
  selector: 'app-support-chat',
  imports: [ThreadplaneChatComponent],
  template: `
    <chat [agent]="chat" />

    @if (chat.isLoading()) {
      <span>Streaming…</span>
    }

    <button (click)="send()">Send</button>
  `,
})
export class SupportChatComponent {
  protected readonly chat = injectAgent();

  send() {
    void this.chat.submit({ message: 'Hello' });
  }
}

chat.messages() and chat.status() are Angular Signals. Bind them directly in your template — no subscriptions, no async pipe, no zone.js required.

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Feature Comparison

Feature	injectAgent() (Angular)	useStream() (React)
Streaming state as reactive primitives	Angular Signals	React state
Messages signal	messages()	messages
Loading state	isLoading()	isLoading
Error state	error()	—
Runtime-neutral status	status() — 'idle' | 'running' | 'error'	partial
Interrupt / human-in-the-loop	interrupt() (runtime-neutral) / langGraphInterrupts() (raw plural)	interrupt / interrupts
Tool call progress	toolCalls()	toolCalls
Branch / history	branch() / history() / experimentalBranchTree()	branch / history / experimental_branchTree
Pending run queue	queue()	queue
Subagent map and lookup	subagents() — Signal<Map<string, Subagent>> / getSubagent(toolCallId)	subagents / helper methods
Reactive thread switching	switchThread(id)	prop
Submit	submit(values, opts?)	submit(values, opts?)
Stop	stop()	stop()
Regenerate response	regenerate(assistantMessageIndex)	—
Reload last submission	reload()	—
Custom transport (for testing)	MockAgentTransport	mock fetch
Angular ResourceRef<T> compatibility	Full duck-type parity	N/A
Angular 20+ Signals API	Native	N/A
SSR / Server Components	Client-side only	React Server Components (React)

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Packages

All packages are published at version 0.0.47 under a patch-only 0.0.x release policy.

Package	Purpose	License
@threadplane/chat	Drop-in agent chat UI for Angular: headless primitives and opinionated compositions (<chat>, popup, sidebar, interrupts, GenUI)	PolyForm Noncommercial + Commercial (dual)
@threadplane/langgraph	LangGraph adapter; provideAgent()/injectAgent() exposes a LangGraph run as Angular Signals	MIT
@threadplane/ag-ui	AG-UI adapter; bridges any @ag-ui/client-compatible backend into the chat surface	MIT
@threadplane/render	@json-render/core-backed Angular engine that renders JSON specs to components (powers GenUI)	MIT
@threadplane/a2ui	A2UI protocol types, streaming parser, and dynamic-value resolver; pure TypeScript, no Angular dependency	MIT
@threadplane/licensing	Browser-safe Ed25519 license-token verification and evaluation (backs the chat commercial check)	MIT
@threadplane/telemetry	Transparent, opt-out anonymous usage telemetry (node + browser)	MIT

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Architecture

provideAgent() creates the agent's internal BehaviorSubjects at injection-context time — once, when the provider factory runs. injectAgent() retrieves the configured LangGraphAgent in any component. The StreamManager bridge (the only file that touches @langchain/langgraph-sdk internals) pushes stream events into those subjects. toSignal() converts each subject to an Angular Signal, also at construction time. Dynamic actions (submit, stop, switchThread) push into the existing subjects — no new subjects are ever created after construction. This architecture is required because toSignal() must be called in an injection context and cannot be called again later.

The runtime-neutral Agent contract is the stability boundary between adapters and the chat surface. @threadplane/chat consumes Agent — not LangGraphAgent — so swapping @threadplane/langgraph for @threadplane/ag-ui requires no changes to your chat components or templates.

Reliability: Every pull request runs the "Library — lint / test / build" CI job across all packages. Testing uses MockAgentTransport to swap the transport layer, so you never need to mock injectAgent() itself — just substitute the transport. The patch-only 0.0.x release policy ensures no minor or major version bumps silently break your lockfile.

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Documentation

• LangGraph Quickstart
• injectAgent() API
• Choosing an adapter (LangGraph vs AG-UI)
• Chat Introduction
• Human-in-the-Loop / Interrupts
• Subgraph and Subagent Streaming

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License

Most published libraries in this repository (@threadplane/render, @threadplane/langgraph, @threadplane/ag-ui, @threadplane/a2ui, @threadplane/licensing, @threadplane/telemetry) are released under the MIT License — free for any use, including commercial, with attribution.

@threadplane/chat is the exception. It is dual-licensed under PolyForm Noncommercial 1.0.0 for free noncommercial use, or a Threadplane Commercial license for production use inside a for-profit context. See libs/chat/LICENSE.md, libs/chat/COMMERCIAL-USE.md, COMMERCIAL.md, and threadplane.ai/docs/licensing for details.