Open-source agent runtime + SDK

Build agentic experiencesinto your product.

Heddle gives TypeScript teams durable conversations, tools and MCP, approvals, artifacts, traceable activity, and reconnectable hosted runs. You keep control of identity, data, policy, deployment, transport, and UI.

npm install @roackb2/heddle

Explore SDK examples

Progressive integration

Start small. Own more when you need it.

Use the lowest layer that already owns the runtime mechanics your product needs, then replace assumptions one boundary at a time.

01
Evaluate the runtime
Open a persisted conversation with a working prompt loop, model setup, credentials, and text output in minutes.
runQuickstartConversationCli
02
Own the experience
Use the conversation engine when your product owns tools, output, approvals, session browsing, and result presentation.
createConversationEngine
03
Run beyond one request
Add addressable runs, ordered activity, bounded replay, cancellation, approval resolution, and remote reconnection.
@roackb2/heddle/hosted

Choose an integration layer

Clear responsibility boundaries

Reuse the runtime. Keep the product.

Heddle handles reusable agent mechanics without becoming your application framework or taking over your product decisions.

Heddle SDK owns

Persisted multi-turn conversations, continuation, compaction, and session behavior
Model and tool loops, native tools, Agent Skills, and curated MCP capabilities
Approval lifecycle, semantic activity, traces, artifacts, and typed turn results
Addressable runs, event ordering, replay, cancellation, and terminal settlement

Your product owns

Identity, tenancy, access rules, and who is allowed to approve
Product records, relationships, retention, encryption, backup, and compliance
Product tools, system context, models, credentials, and capability policy
API, deployment, transport, UI, and how results are applied

Runtime foundations for real products.

The reusable mechanics between a model call and an agentic experience people can trust.

Research this topic and prepare a cited brief.

Running tools and preserving context...

Durable Conversations

Persist sessions across turns, resume work later, compact long histories, and keep conversation behavior consistent as your product grows.

page.tsx

12<Button onClick={submit}>

13- <span>Submit</span>

13+ <Loader className="animate-spin" />

14</Button>

Approved

Approvals & Traceable Activity

Pause for product-owned decisions and expose understandable activity, traces, artifacts, tool outcomes, and safe typed failures.

native tools + MCP

Tools, Skills & MCP

Bring native product tools, reusable Agent Skills, and curated MCP-backed capabilities into one host-controlled execution model.

agent service

web client

mobile

replay

approval

worker

Hosted & Remote Runs

Give every active run an address, ordered events, bounded replay, cancellation, approval resolution, and browser-safe reconnection.

Case studies

Real products, built with Heddle.

Heddle is the reusable agent runtime beneath these experiences. See how product teams use it to ship agentic features to real users while keeping control of their application.

Product case study

SlideX

Working product integration

A browser workspace for creating, editing, and exporting professional presentations.

Turn an idea into slides through conversation.

SlideX makes it easier to create polished presentations. Heddle powers the conversational agent that lets users describe an idea, refine it together, and turn it into slides inside the editor.