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.

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.

  1. 01

    Evaluate the runtime

    Open a persisted conversation with a working prompt loop, model setup, credentials, and text output in minutes.

    runQuickstartConversationCli
  2. 02

    Own the experience

    Use the conversation engine when your product owns tools, output, approvals, session browsing, and result presentation.

    createConversationEngine
  3. 03

    Run beyond one request

    Add addressable runs, ordered activity, bounded replay, cancellation, approval resolution, and remote reconnection.

    @heddleagent/runtime/runs

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.

U
Research this topic and prepare a cited brief.
H
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

What real integrations taught Heddle.

These case studies document where Heddle has been tested inside real products—what worked, what changed, and where the product/runtime boundary belongs. Some describe current integrations; others preserve lessons from historical deployments.

Integration retrospective

SlideX

Historical deployment · first third-party integration

A browser presentation workspace that integrated a conversational agent for creating and revising real decks.

What SlideX taught Heddle about becoming a product SDK.

In July 2026, SlideX deployed a Heddle-powered conversational presentation agent. The hosted product has since been retired as SlideX moved back toward local operation, but the integration became the pressure test that reshaped Heddle into a reusable SDK.

  • Integrated real presentation tools
  • Proved durable multi-turn conversations
  • Shaped Heddle's public SDK boundaries
SlideX editor showing a presentation beside a multi-turn conversation with the SlideX Agent
Captured during the July 2026 deployment: a real SlideX conversation asks the agent to restyle a slide, add SDK content, and insert a section header.

Reference host

See the same runtime in a complete product

Heddle's local coding agent, terminal UI, and browser control plane are built on the same conversation and run foundations exposed through the SDK.

Build the agentic experience
your product needs.

Start with a working conversation, keep control of your product, and adopt only the Heddle layers your experience needs.