> ## Documentation Index
> Fetch the complete documentation index at: /docs/llms.txt
> Use this file to discover all available pages before exploring further.

# base

# `prefect.workers.base`

## Classes

### `BaseJobConfiguration` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L146](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L146)</sup>

**Methods:**

#### `from_template_and_values` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L209](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L209)</sup>

```python theme={null}
from_template_and_values(cls, base_job_template: dict[str, Any], values: dict[str, Any], client: 'PrefectClient | None' = None)
```

Creates a valid worker configuration object from the provided base
configuration and overrides.

Important: this method expects that the base\_job\_template was already
validated server-side.

#### `is_using_a_runner` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L179](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L179)</sup>

```python theme={null}
is_using_a_runner(self) -> bool
```

#### `json_template` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L337](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L337)</sup>

```python theme={null}
json_template(cls) -> dict[str, Any]
```

Returns a dict with job configuration as keys and the corresponding templates as values

Defaults to using the job configuration parameter name as the template variable name.

e.g.

```python theme={null}
{
    key1: '{{ key1 }}',     # default variable template
    key2: '{{ template2 }}', # `template2` specifically provide as template
}
```

#### `prepare_for_flow_run` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L361](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L361)</sup>

```python theme={null}
prepare_for_flow_run(self, flow_run: 'FlowRun', deployment: 'DeploymentResponse | None' = None, flow: 'APIFlow | None' = None, work_pool: 'WorkPool | None' = None, worker_name: str | None = None, worker_id: 'UUID | None' = None) -> None
```

Prepare the job configuration for a flow run.

This method is called by the worker before starting a flow run. It
should be used to set any configuration values that are dependent on
the flow run.

**Args:**

* `flow_run`: The flow run to be executed.
* `deployment`: The deployment that the flow run is associated with.
* `flow`: The flow that the flow run is associated with.
* `work_pool`: The work pool that the flow run is running in.
* `worker_name`: The name of the worker that is submitting the flow run.
* `worker_id`: The backend ID of the worker that is submitting the flow run.

#### `resolve_for_flow_run` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L278](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L278)</sup>

```python theme={null}
resolve_for_flow_run(cls, flow_run: 'FlowRun') -> Self
```

Build a fully-prepared job configuration for an existing flow run.

Reads the flow run's deployment (when present) and flow, merges
deployment- and flow-run-level job variables over the work pool's
base template, instantiates the configuration, and stamps
attribution metadata via `prepare_for_flow_run`.

### `BaseVariables` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L562](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L562)</sup>

**Methods:**

#### `model_json_schema` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L586](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L586)</sup>

```python theme={null}
model_json_schema(cls, by_alias: bool = True, ref_template: str = '#/definitions/{model}', schema_generator: Type[GenerateJsonSchema] = GenerateJsonSchema, mode: Literal['validation', 'serialization'] = 'validation') -> dict[str, Any]
```

TODO: stop overriding this method - use GenerateSchema in ConfigDict instead?

### `BaseWorkerResult` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L615](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L615)</sup>

### `BaseWorker` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L630](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L630)</sup>

**Methods:**

#### `cleanup_handler_registry` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L753](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L753)</sup>

```python theme={null}
cleanup_handler_registry(self) -> WorkerCleanupHandlerRegistry
```

#### `client` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L717](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L717)</sup>

```python theme={null}
client(self) -> PrefectClient
```

#### `get_all_available_worker_types` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L811](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L811)</sup>

```python theme={null}
get_all_available_worker_types() -> list[str]
```

Returns all worker types available in the local registry.

#### `get_and_submit_flow_runs` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1332](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1332)</sup>

```python theme={null}
get_and_submit_flow_runs(self) -> list['FlowRun']
```

#### `get_default_base_job_template` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L780](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L780)</sup>

```python theme={null}
get_default_base_job_template(cls) -> dict[str, Any]
```

#### `get_description` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L749](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L749)</sup>

```python theme={null}
get_description(cls) -> str
```

#### `get_documentation_url` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L741](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L741)</sup>

```python theme={null}
get_documentation_url(cls) -> str
```

#### `get_flow_run_logger` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L824](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L824)</sup>

```python theme={null}
get_flow_run_logger(self, flow_run: 'FlowRun') -> PrefectLogAdapter
```

#### `get_logo_url` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L745](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L745)</sup>

```python theme={null}
get_logo_url(cls) -> str
```

#### `get_name_slug` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L821](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L821)</sup>

```python theme={null}
get_name_slug(self) -> str
```

#### `get_status` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1748](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1748)</sup>

```python theme={null}
get_status(self) -> dict[str, Any]
```

Retrieves the status of the current worker including its name, current worker
pool, the work pool queues it is polling, and its local settings.

#### `get_worker_class_from_type` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L798](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L798)</sup>

```python theme={null}
get_worker_class_from_type(type: str) -> Optional[Type['BaseWorker[Any, Any, Any]']]
```

Returns the worker class for a given worker type. If the worker type
is not recognized, returns None.

#### `handled_cleanup_kinds` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L757](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L757)</sup>

```python theme={null}
handled_cleanup_kinds(self) -> tuple[CleanupKind, ...]
```

#### `is_worker_still_polling` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1300](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1300)</sup>

```python theme={null}
is_worker_still_polling(self, query_interval_seconds: float) -> bool
```

This method is invoked by a webserver healthcheck handler
and returns a boolean indicating if the worker has recorded a
scheduled flow run poll within a variable amount of time.

The `query_interval_seconds` is the same value that is used by
the loop services - we will evaluate if the \_last\_polled\_time
was within that interval x 30 (so 10s -> 5m)

While the Prefect API is in maintenance, requests wait out the
`Retry-After` it sends, so the window counts from the later of
`self._last_polled_time` and the end of the latest maintenance back-off.

The instance property `self._last_polled_time`
is currently set/updated in `get_and_submit_flow_runs()`

#### `kill_infrastructure` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1961](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1961)</sup>

```python theme={null}
kill_infrastructure(self, infrastructure_pid: str, configuration: C, grace_seconds: int = 30) -> None
```

Kill infrastructure for a flow run.

Override this method in subclasses to implement infrastructure-specific
termination logic.

**Args:**

* `infrastructure_pid`: The infrastructure identifier from the flow run.
* `configuration`: The job configuration for connecting to infrastructure.
* `grace_seconds`: Time to allow for graceful shutdown before force killing.

**Raises:**

* `NotImplementedError`: If the worker doesn't support killing infrastructure.
* `InfrastructureNotFound`: If the infrastructure doesn't exist.
* `InfrastructureNotAvailable`: If the infrastructure can't be killed by this worker.

#### `limiter` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L733](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L733)</sup>

```python theme={null}
limiter(self) -> anyio.CapacityLimiter
```

#### `max_cleanup_concurrency` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L763](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L763)</sup>

```python theme={null}
max_cleanup_concurrency(self) -> int
```

#### `run` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L936](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L936)</sup>

```python theme={null}
run(self, flow_run: 'FlowRun', configuration: C, task_status: Optional[anyio.abc.TaskStatus[int]] = None) -> R
```

Runs a given flow run on the current worker.

#### `setup` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1235](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1235)</sup>

```python theme={null}
setup(self) -> None
```

Prepares the worker to run.

#### `start` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L840](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L840)</sup>

```python theme={null}
start(self, run_once: bool = False, with_healthcheck: bool = False, printer: Callable[..., None] = print) -> None
```

Starts the worker and runs the main worker loops.

By default, the worker will run loops to poll for scheduled/cancelled flow
runs and sync with the Prefect API server.

If `run_once` is set, the worker will only run each loop once and then return.

If `with_healthcheck` is set, the worker will start a healthcheck server which
can be used to determine if the worker is still polling for flow runs and restart
the worker if necessary.

**Args:**

* `run_once`: If set, the worker will only run each loop once then return.
* `with_healthcheck`: If set, the worker will start a healthcheck server.
* `printer`: A `print`-like function where logs will be reported.

#### `submit` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L968](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L968)</sup>

```python theme={null}
submit(self, flow: 'Flow[..., FR]', parameters: dict[str, Any] | None = None, job_variables: dict[str, Any] | None = None, flow_run: 'FlowRun | None' = None) -> 'PrefectFlowRunFuture[FR]'
```

EXPERIMENTAL: The interface for this method is subject to change.

Submits a flow to run via the worker.

**Args:**

* `flow`: The flow to submit
* `parameters`: The parameters to pass to the flow
* `job_variables`: Job variables for infrastructure configuration
* `flow_run`: Optional existing flow run to retry (reuses ID instead of creating new)

**Returns:**

* A flow run future

#### `sync_with_backend` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1394](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1394)</sup>

```python theme={null}
sync_with_backend(self) -> None
```

Updates the worker's local information about it's current work pool and
queues. Sends a worker heartbeat to the API.

#### `teardown` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1269](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L1269)</sup>

```python theme={null}
teardown(self, *exc_info: Any) -> None
```

Cleans up resources after the worker is stopped.

#### `work_pool` <sup>[https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L725](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/workers/base.py#L725)</sup>

```python theme={null}
work_pool(self) -> WorkPool
```