View Markdown

Agentfile

The Agentfile is a Dockerfile-like declaration for one agent.

Required idea

The Agentfile does not describe a cluster, fleet, workflow, or runtime implementation. It describes one agent and the contract a runner must satisfy before executing it.

Core directives

Directive	Purpose
AGENT	Stable agent identity
FROM	Optional base agent package or base image reference
CMD	Entrypoint command
TOOL	Declared tool capability
FUNCTION	Typed function capability
SKILL	Portable skill/procedure bundle
SERVER	MCP server or compatible tool server
MOUNT	Filesystem boundary
URL	Network egress boundary
CRED	Host-scoped credential reference (placeholder-substitution model)
LIMIT	Resource, time, or output cap
RATELIMIT	Invocation or egress rate cap
AUDIT	Audit capture level
SOP ... END	Embedded Standard Operating Procedure (instructions)
POLICY ... END	Inline policy block

Minimal pattern

AGENT <name>
CMD <command>
TOOL <tool-ref>
AUDIT basic
POLICY
  <policy statements>
END

Why single-agent only?

Keeping Agentfile single-agent prevents it from becoming a workflow language. Multi-agent applications should use a companion workflow specification that references packaged agents by digest.