Agent Forge Kit (AFK) Python SDK

AFK is a Python 3.13+ SDK for building reliable AI agents with typed tools, runtime controls, memory, streaming, evals, and observability.

Documentation: afk.arpan.sh

Install

The distribution package is afk-py; the import package is afk.

python -m pip install afk-py

For repository development:

python -m pip install --upgrade pip
python -m pip install -e . pytest

Quick Start

from afk.agents import Agent
from afk.core import Runner

agent = Agent(
    name="ops-bot",
    model="gpt-4.1-mini",
    instructions="You are a helpful SRE assistant.",
)

result = Runner().run_sync(
    agent,
    user_message="What is an error budget?",
)

print(result.state)
print(result.final_text)

Core Model

AFK separates agent behavior from runtime execution:

• Agent describes identity, model, instructions, tools, subagents, skills, MCP servers, and fail-safe limits.
• Runner executes agents synchronously, asynchronously, or as a stream.
• Runtime subsystems provide LLM adapters, tool execution, memory, queues, policy, and telemetry.
• AgentResult records final text, state, run/thread ids, tool/subagent executions, usage, and cost.

Add a Tool

from pydantic import BaseModel

from afk.agents import Agent, FailSafeConfig
from afk.core import Runner
from afk.tools import tool


class LookupArgs(BaseModel):
    order_id: str


@tool(args_model=LookupArgs, name="lookup_order", description="Look up an order.")
def lookup_order(args: LookupArgs) -> dict:
    return {"order_id": args.order_id, "status": "shipped"}


agent = Agent(
    name="support-agent",
    model="gpt-4.1-mini",
    instructions="Use lookup_order when users ask about orders.",
    tools=[lookup_order],
    fail_safe=FailSafeConfig(max_steps=8, max_tool_calls=4, max_total_cost_usd=0.10),
)

result = Runner().run_sync(agent, user_message="Where is order A123?")
print(result.final_text)

Common Commands

PYTHONPATH=src pytest -q
PYTHONPATH=src pytest -q tests/agents/test_agent_runtime.py
ruff check src tests
ruff format src tests
./scripts/docs_dev.sh
./scripts/build_agentic_ai_assets.sh

Install AFK Codex Skills

Install AFK skills with Vercel's Skills CLI:

npx skills add https://github.com/arpan404/afk --skill afk-coder
npx skills add https://github.com/arpan404/afk --skill afk-maintainer

The skills CLI installs the selected skill into the configured agent environment, including Codex.

Docs Paths

• Start building: Quickstart
• Guided tutorial: Learn AFK in 15 Minutes
• Public imports: API Reference
• Contributor workflow: Developer Guide
• Environment variables: Environment Variables

When to Use AFK

Use AFK when your agent needs tools, multi-step execution, streaming, memory, approvals, cost limits, telemetry, evals, queues, or provider portability.

A direct provider SDK may be simpler for one-off single-turn text generation.