Introduction

Spawnfile is a spec and compiler for autonomous agent runtimes — systems that host agents as long-lived services with markdown workspace identity.

The Problem

Every autonomous agent runtime has its own config format. OpenClaw, PicoClaw, and TinyClaw each expect different runtime config, workspace layout, skill wiring, and MCP wiring.

Your agent’s identity — its personality, instructions, skills, and tool connections — gets locked into one runtime’s conventions.

The Solution

Spawnfile gives you one canonical source format. You write a Spawnfile manifest and a set of markdown docs. The compiler generates the runtime-native config and workspace files each target expects.

spawnfile_version: "0.1"
kind: agent
name: research-assistant
runtime:
  name: openclaw

workspace:
  docs:
    identity: IDENTITY.md
    soul: SOUL.md
    system: AGENTS.md
  skills:
    - ref: ./skills/web_search

environment:
  packages:
    - id: playwright
      manager: npm
      name: playwright

execution:
  model:
    primary:
      provider: anthropic
      name: claude-sonnet-4-5
      auth:
        method: claude-code

Set runtime.name to an adapter-supported runtime and run spawnfile compile. The compiler emits that runtime’s native files and reports any capability that is degraded or unsupported.

What Spawnfile Targets

Spawnfile targets autonomous agent runtimes — systems that:

• Run as long-lived services or daemons
• Use a markdown workspace as a first-class agent surface
• Expose a declarative configuration surface the compiler can emit to

This is not for coding assistants, chat CLIs, or one-shot tools. Those may share conventions like AGENTS.md, but they are not the long-lived host runtimes that Spawnfile compiles for.

Supported Runtimes

Runtime	Language	Status
OpenClaw	Node.js	Active
PicoClaw	Go	Active
TinyClaw	Node.js	Active
NullClaw	Zig	Exploratory
ZeroClaw	Rust	Exploratory

Open Source

Spawnfile is fully open source under the MIT license. Contributions and discussion are welcome on GitHub.