TrueForge — the open-source agent harness
Self-hostable runtime that turns any LLM into a working agent — MCP tools, skills, sandboxing, approvals, subagents — exposed as a chat UI, HTTP API, and embeddable SDK.
On this page
Why I saved this#
Key reference in the agent-harness layer: a vendor-neutral, self-hostable alternative to managed agent runtimes, worth tracking as the ecosystem standardizes on harness concepts (skills, MCP, approvals).
Notes#
TrueForge
(by TrueFoundry) is an
open-source agent harness — the runtime layer that turns a raw LLM into a
working agent. It runs the whole execution loop for you: model calls, MCP
tools, skills, sandboxing, approvals, context management, and session state.
One harness, three surfaces: a bundled chat UI, an HTTP API with a
generated TypeScript SDK, and an embeddable React UI SDK
(@truefoundry/trueforge-ui).
What makes it unique#
- Vendor-neutral by design. Claude Managed Agents runs Claude on Anthropic’s cloud; TrueForge runs whatever model you route to, on your own infrastructure. TrueFoundry claims ~50% lower cost per run vs Claude Managed Agents on the same benchmark — vendor’s own numbers, verify before relying on them.
- Git-backed skills. A skill is a
SKILL.mdinstruction pack loaded on demand — enable from the built-in catalog or import from any public GitHub repo (same convention Claude/Hermes skills use). - Personal → production in one artifact.
npx @truefoundry/trueforgegives a single-process local mode on SQLite; the identical feature set scales to hosted mode (Postgres + Redis, multi-replica) via Docker Compose, Helm, or Railway, with optional OIDC login for teams. - Harness depth usually reserved for managed platforms: sandbox-as-tool, subagents, deferred tools, Code Mode, context compaction, tool approvals, Generative UI, and a built-in agent benchmarking page (cost/accuracy vs Claude Managed Agents and deepagents).
Quick facts#
MIT license · TypeScript monorepo (trueforge server + bundled UI,
trueforge-core library, trueforge-ui, trueforge-sdk) · ~5.1k stars,
352 forks since 2026-07-23 · docs: trueforge.dev
·
quickstart: npx @truefoundry/trueforge.