agent-runtime-kit

agent-runtime-kit is a small Python runtime layer for agent SDKs. It gives applications one typed async API for dispatching an agentic task through Claude Agent SDK, OpenAI Codex SDK, or Google Antigravity SDK while keeping provider capabilities visible.

The package is intentionally not a router, benchmark harness, queue, hosted service, or full agent framework. It is the reusable layer underneath those systems: task models, runtime capabilities, event sinks, availability diagnostics, and adapters.

Install

Core only:

pip install agent-runtime-kit

Provider extras:

pip install "agent-runtime-kit[claude]"
pip install "agent-runtime-kit[codex]"
pip install "agent-runtime-kit[antigravity]"
pip install "agent-runtime-kit[all]"

import asyncio

from agent_runtime_kit import AgentTask, FakeAgentRuntime


async def main() -> None:
    runtime = FakeAgentRuntime(output="done")
    result = await runtime.run(AgentTask(goal="Summarize this repository"))
    print(result.output)


asyncio.run(main())

The core package has no Claude, Codex, or Antigravity dependency. Vendor SDKs are added through optional extras.

Real Providers

import asyncio

from agent_runtime_kit import AgentTask
from agent_runtime_kit.adapters import ClaudeAgentRuntime


async def main() -> None:
    runtime = ClaudeAgentRuntime(default_model="claude-sonnet-4-6")
    diagnostic = runtime.availability()
    if not diagnostic.available:
        raise RuntimeError(diagnostic.message)
    result = await runtime.run(AgentTask(goal="Summarize this repository"))
    print(result.output)


asyncio.run(main())

Runtime Fields

AgentTask supports goal, system prompt, working directory, permission profile, MCP stdio servers, session/resume handles, output schema, budget, metadata, and an async event sink. Where a runtime cannot honor a field (for example only Claude maps budget_usd; Codex and Antigravity reject it with a typed UnsupportedTaskInputError) the adapter raises rather than silently dropping it.

AgentResult returns output, finish reason, parsed structured output, usage, cost, session id, artifacts, tool-call audits, and provider metadata.

Docs

• Quickstart
• Provider diagnostics
• Capability matrix
• Live smoke tests
• Mestre migration notes
• Publish checklist
• SDK evolution agent