The portable AI agent format
An open protocol to package, share, and deploy AI agents across any platform. Build once, run everywhere.
Agents are portable. Intelligence is not.
A .fylle package contains everything needed to understand, transport, and run an AI agent — without vendor lock-in.
Agents are described in YAML and Markdown, not code. Anyone can read, edit, and understand what an agent does.
Tools are declared with protocol: "mcp" — the runtime maps them to available servers. Graceful degradation for optional tools.
Agents declare their inputs explicitly. The runtime knows what to inject — making agents composable in pipelines and multi-agent workflows.
Works on LangChain, CrewAI, OpenClaw, or any platform that implements a simple adapter. No lock-in, ever.
The memory schema travels with the agent, the data doesn't. The agent knows what to remember — the runtime decides how.
API keys and credentials are never stored in the package. Sensitive values are declared as requirements, configured at runtime.
MCP connects agents to tools. A2A connects agents to agents. But nothing packages and transports the agent itself. Until now.
| Standard | What it does | What it doesn't |
|---|---|---|
| MCP | Connects agents to external tools & data | Doesn't package or transport agents |
| A2A | Enables agent-to-agent communication | Doesn't define or export agents |
| Agent File (.af) | Exports/imports agents in Letta | Tied to one ecosystem |
| ADL | Declares agent definitions | No memory, skills, or runtime |
| .fylle | Full portable agent — tools, skills, memory, inputs | Open, universal, runtime-agnostic |
The .fylle format is designed to create value across the entire AI agent ecosystem — not just inside one platform.
Package your agent, publish it to the Hub, sell or share it. You're never locked into a single framework or marketplace.
Define how your team builds agents internally. Swap runtimes without rewriting. Audit and version every agent like code.
LangChain, CrewAI, or any runtime can offer .fylle import/export. Lower the barrier to entry. Attract more users.
Like npm for packages or Docker Hub for images. A universal format to list, discover, and distribute AI agents.
The .fylle format is Apache 2.0.
Use it to package, share, and deploy agents across any platform.
No fees, no lock-in, no strings attached.
Agent portability is a public good.
Fylle the product is the execution layer where agents accumulate permanent context and improve through feedback loops. Every interaction compounds. Your agent on day 100 is fundamentally smarter than on day 1. Agents are portable — the intelligence they build is not.
Build your agent anywhere.
Run it everywhere.
When you want agents that compound →
run them on Fylle.
The protocol is the foundation. These tools bring it to life.
Create .fylle agent packages visually. Define identity, model, prompt, tools, guardrails — and export.
Explore →Discover, inspect, and download portable AI agents built by the community. The marketplace for .fylle agents.
Explore →The Fylle acceleration program for startups. Our vision, pillars, and how we make agent portability a public good.
Explore →
The spec is open. The CLI works. The first agents are live.
Join the community shaping how AI agents move.