Kitaru (来る, "to arrive") is a self-hosted, framework-agnostic runtime for autonomous agents — underneath the harness your team already picked. You keep your agent SDK, your prompts, your tools, your model. Kitaru adds durable execution: checkpoints, replay, resume, wait(), versioned deployments, and isolated runtimes, running on your own infrastructure.

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Agent stacks break cleanly into four layers. Kitaru is exactly one of them.

Kitaru lives in the middle row. Harnesses define behavior, your stack defines policy, and Kitaru gives you the durable execution layer in between.

If you're buying an agent platform, Kitaru may feel low-level. If you're building one, that's the point.

Platform teams get the durable execution layer they'd otherwise build themselves — run lifecycle, checkpoint boundaries, replay, invocation routing, and self-hosted execution — without mandating which harness application teams use on top.

• Durable execution. A crash, pod eviction, or timeout doesn't send the run back to zero. Fix the bug, replay, and the completed checkpoints return cached output instead of re-burning tokens.
• Pause and resume. kitaru.wait() suspends a flow, releases compute, and resumes minutes, hours, or days later when input lands from a human, another agent, a webhook, or a CLI call.
• Versioned deployments. flow.deploy() freezes a flow as an immutable snapshot consumers invoke by name. Tag to roll out, re-tag to roll back. Nothing that calls the agent redeploys when a new version ships.
• Artifact lineage. Every checkpoint output is written to your object store as a typed, versioned artifact. Step through any run, diff artifacts across runs, and trace a bad output back to the step that produced it.
• Isolated execution. @checkpoint(runtime="isolated") runs a specific step in its own pod or job on Kubernetes, AWS, GCP, or Azure. Heavy or risky steps stay isolated; orchestration stays inline.
• Durable memory. Scoped, versioned state for long-running agents. Write from Python, read from the CLI or MCP. Agents remember conventions, context, and prior work across runs.

Write normal Python. Use if, for, try/except — whatever your agent needs. Kitaru gives you two decorators (@flow and @checkpoint) and a handful of utility functions. That's all you need.

from kitaru import checkpoint, flow

@checkpoint
def research(topic: str) -> str:
    return do_research(topic)

@checkpoint
def write_draft(research: str) -> str:
    return generate_draft(research)

@flow
def writing_agent(topic: str) -> str:
    data = research(topic)
    return write_draft(data)

result = writing_agent.run("quantum computing").wait()

A single self-hosted server, your own infra. Flows run on whichever stack you pick — local, Kubernetes, GCP, AWS, or Azure — with artifacts in your own S3/GCS/Azure Blob bucket. No mandatory SaaS control plane.

Every execution is observable from day one. See your agent runs, inspect checkpoint outputs, and approve human-in-the-loop wait steps, all from a UI that ships with the Kitaru server.

To start the server locally, run kitaru login after installing kitaru[local]. To connect to an existing remote server, run kitaru login <server>.

Wrap an existing PydanticAI agent with KitaruAgent — no rewrite. For agents built on the OpenAI Agents SDK, Anthropic Agent SDK, or raw Python, use @flow and @checkpoint around your calls. Your model, your tools, your framework — Kitaru wraps them, not the other way around.

from kitaru import flow
from kitaru.adapters.pydantic_ai import KitaruAgent
from pydantic_ai import Agent

researcher = KitaruAgent(
    Agent("openai:gpt-5.4", system_prompt="You summarize research topics.")
)

@flow
def research_flow(topic: str) -> str:
    return researcher.run_sync(topic).output

pip install kitaru

Or with uv (recommended):

uv pip install kitaru

To wrap a PydanticAI agent, install the adapter extra:

uv pip install "kitaru[pydantic-ai]"

Flows run locally by default with the base install. If you also want the local dashboard and REST API, install the local extra and then run bare kitaru login:

uv pip install "kitaru[local]"
kitaru login
kitaru status

If you already have a deployed Kitaru server, connect to it explicitly:

kitaru login https://my-server.example.com
# add --project <PROJECT> or other remote-login flags if your setup requires them
kitaru status

kitaru init

# agent.py
from kitaru import checkpoint, flow

@checkpoint
def fetch_data(url: str) -> str:
    return "some data"

@checkpoint
def process_data(data: str) -> str:
    return data.upper()

@flow
def my_agent(url: str) -> str:
    data = fetch_data(url)
    return process_data(data)

result = my_agent.run("https://example.com").wait()
print(result)  # SOME DATA

python agent.py

Every checkpoint's output is persisted automatically. You can inspect what happened, replay from any checkpoint, or resume a waiting flow:

kitaru executions list
kitaru executions get <EXECUTION_ID>
kitaru executions logs <EXECUTION_ID>
kitaru executions replay <EXECUTION_ID> --from process_data

When the flow is ready, deploy it as a versioned snapshot and invoke it by name — no redeploy of whatever calls the agent.

# Freeze the current code + dependencies as a versioned snapshot.
# Parameterized flows take representative deployment-time inputs;
# consumers can override them at invocation time.
my_agent.deploy(url="https://example.com")

# Consumers invoke by name — from Python, CLI, MCP, or HTTP.
from kitaru import KitaruClient
KitaruClient().deployments.invoke(
    flow="my_agent",
    inputs={"url": "https://example.com"},
)

# Tag a version into a stage; re-tag to roll back.
kitaru flow tag my_agent latest --stage=prod
kitaru flow tag my_agent v2     --stage=prod   # rollback

Kitaru is built by the team behind ZenML, drawing on five years of production orchestration experience (JetBrains, Adeo, Brevo). The orchestration primitives (stacks, artifacts, lineage) are purpose-rebuilt here for autonomous agents.

We welcome contributions! See CONTRIBUTING.md for development setup, code style, and how to submit changes. The default branch is develop — all PRs should target it.

• Discussions — ask questions, share ideas
• Issues — report bugs, request features
• Roadmap — see what's coming next
• Docs — guides and reference

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