One API for multiple harnesses
Integrate once and select the harness for each task. HarnessRouter presents a shared contract for Codex, Claude Code, and Hermes so teams can switch harnesses without rebuilding their backend integration.
HarnessRouter
Freemium
HarnessRouter is an agent backend layer that lets teams connect Codex, Claude Code, and Hermes to their product through a single API on their own infrastructure. A managed cloud option is also available for teams that prefer not to operate the agent runtime themselves.
What is HarnessRouter?
HarnessRouter is an agent infrastructure product for teams building AI features into software products. It provides one Agent API for running supported harnesses such as Codex, Claude Code, and Hermes, while keeping the product’s own UI, authentication, and data model in the customer’s application.
The open-source Community Edition runs on infrastructure you control and packages the Gateway, Runner, and Console in one Docker container. The same product line also includes HarnessRouter Cloud for teams that want the API without operating the backend themselves. The homepage and docs emphasize production agent workflows such as sessions, streaming, files, artifacts, cancellation, and structured failure handling.
The product is positioned as a backend layer for completed work rather than a simple model router. The docs and guides focus on product integration patterns, server-side authorization, multi-tenant behavior, and the workflow needed when users expect agents to return finished outputs instead of only model responses.
What can HarnessRouter do?
Self-hosted Community Edition
The open-source edition runs in a single Docker container on infrastructure you control. The page says no managed database, external vault, or cloud account is required, and that the API, console, SQLite state, and workspace files stay on your own infrastructure.
Session and streaming workflow
The docs list sessions, response streaming, continuing a session, and canceling a session as core API capabilities. This supports long-running agent work where users need progress updates and the ability to resume or stop tasks.
Files, artifacts, and workspace persistence
HarnessRouter supports uploading files, persisting workspace files, and returning finished artifacts. That makes it suitable for product flows that need input documents, generated outputs, and downloadable results.
Unified Harness Protocol
UHP is the public, versioned contract behind the platform. The homepage describes it as an open protocol with OpenAPI 3.1, JSON Schema 2020-12, versioned API definitions, and runnable checks that can be verified locally.
Starter Kit and reference demos
The Starter Kit provides complete examples that show how sessions, streaming, files, and finished work fit into real product experiences. The site also highlights a Cursor-style coding app, a family-care demo, and a Slides Kit production example.
Use Cases
“Building a product that runs agents server-side”
Use HarnessRouter when your product needs to launch harnessed agents behind the scenes while keeping the product UI and user experience in your own app. The docs and examples frame it as a server-side agent backend layer.
“Adding long-running, resumable task flows”
Use the session model for work that unfolds over time, such as coding tasks, document work, or other jobs that need streaming progress, follow-up actions, and later inspection.
“Supporting file-based workflows”
Use the files and artifacts flow when users need to upload source material and receive generated outputs back from the agent. The homepage explicitly calls out workspace files and finished outputs as part of the lifecycle.
“Starting from a working reference app”
Use the Starter Kit when you want a concrete starting point instead of an empty repository. The site shows reference demos and production kits for teams that want to adapt an existing agent product pattern.
“Choosing between self-hosted and managed deployment”
Use Community Edition if you want to control infrastructure yourself, or move to HarnessRouter Cloud if you want the same API without running the agent backend. The pricing page and homepage both present this split clearly.
Frequently Asked Questions
Is HarnessRouter only self-hosted?
No. The site presents Community Edition as the open-source, self-hosted option and also offers HarnessRouter Cloud for teams that want a fully managed service.
What does the Community Edition include?
The homepage says Community Edition includes the Gateway, Runner, and Console in one container, along with local SQLite state and workspace files on infrastructure you control.
Which agent frameworks or harnesses are mentioned?
The public pages mention Codex, Claude Code, and Hermes as supported examples. The docs and guides also discuss how to run Claude Code and Hermes through an API.
What kinds of tasks does the API support?
The product is built for session-based agent work with streaming, file handling, artifacts, cancellation, and error handling. The examples page shows a Cursor-style coding workflow, and the Starter Kit includes other product patterns.
Is there a free way to start?
The pricing page says you can build and integrate for free, and that 500 launch credits are available for a limited time after adding a card. It also lists a Developer plan starting at $20 per month.
Quick Facts
- Category
- Developer Tool
- Product type
- Agent backend / agent infrastructure
- Deployment options
- Self-hosted Community Edition and managed HarnessRouter Cloud
- Open-source license
- Apache 2.0 for the Community Edition
- Primary workflow
- Run configured agent harnesses through one API with sessions, streaming, files, and artifacts
- Source domain
- harnessrouter.ai
HarnessRouter Traffic Analysis
Traffic data is for reference only.
- Domain Rating
- 13
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