Heym

Build agentic systems. Run them with confidence.

Heym is a self-hosted runtime and platform for building, orchestrating, running, observing, evaluating, and controlling agentic systems on your infrastructure.

Visually compose agents and deterministic workflows, or generate them with AI. Connect models, tools, MCP, company knowledge, and internal systems, then operate them with approval checkpoints, retries, and visibility into execution and model costs.

heym.run

Try locally: git clone https://github.com/heymrun/heym.git && cd heym && ./run.sh Quick Start · Deploy & Call Workflows · Extending Heym · Security

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What Is Heym?

In Heym, a workflow defines how agents, deterministic steps, tools, and data work together. The runtime executes that graph, coordinates dependent and parallel work, records execution history, and supports human review checkpoints.

The canvas is one interface into Heym. It is not Heym itself. Use it to build, inspect, debug, and understand systems running on the runtime. Those same workflows also run through APIs, schedules, event triggers, MCP clients, and Portal conversations.

Explore the product site at heym.run.

One Runtime for the Agent Lifecycle

Build → Orchestrate → Run → Observe → Evaluate → Control → Expose

These are connected parts of operating an agentic system in Heym.

Stage	What you do in Heym
Build	Compose agents and deterministic workflows visually, generate them with AI, or start from reusable templates and skills.
Orchestrate	Coordinate agents, sub-agents, sub-workflows, and tools with explicit data flow, branching, and parallel execution where dependencies allow.
Run	Execute from APIs, schedules, event triggers, or interactive interfaces, with configurable retries, error paths, and browser automation.
Observe	Inspect execution history, live state, traces, tool calls, tokens, latency, errors, and model costs. Review analytics and alerts, and export OpenTelemetry traces.
Evaluate	Test prompts and model responses against expected outputs, compare results across models, and inspect saved evaluation runs.
Control	Pause Agent execution at review checkpoints and resume from saved state after a human decision. Configure guardrails, credentials, authentication, and team access.
Expose	Serve workflows through REST, SSE streaming, MCP tools, and Portal chat interfaces, or connect their results to in-app dashboard widgets.

Use observations and evaluation results to refine prompts, tools, and workflow logic, then run and inspect the next iteration.

🗺️ Platform Overview

The workflow definition connects the build experience to execution. The runtime uses that definition to coordinate nodes and tools, while execution state feeds the interfaces people use to inspect, review, and consume the results.