cloudkv 0.2.0

Hosted key/value store based on Cloudflare workers and KV store.

cloudkv

key/value store based on Cloudflare workers, with a Python client.

By default the cloudkv Python package connects to cloudkv.samuelcolvin.workers.dev but you can deploy an instance to your own cloudflare worker if you prefer. Code for the server is in ./cf-worker.

Some reasons you might use cloudkv:

• Zero DB setup or account required, just create a namespace with the CLI and get started
• Sync and async clients with almost identical APIs
• Completely open source, deploy your own cloudflare worker if you like or used the hosted one
• Pydantic integration to retrieve values as virtually and Python type
• View any value via it's URL

Installation

uv add cloudkv

(or pip install cloudkv if you're old school)

Usage

cloudkv stores key-value pairs in a Cloudflare worker using KV storage and D1.

To create a namespace, run

uvx cloudkv

Which should create a namespace and print the keys to use:

creating namespace...
Namespace created successfully.

cloudkv_read_token = '***'
cloudkv_write_token = '******'

(You can also create a namespace programmatically, see create_namespace below)

Sync API

With a namespace created, you can connect thus:

from cloudkv import SyncCloudKV

cloudkv_read_token = '***'
cloudkv_write_token = '******'
kv = SyncCloudKV(cloudkv_read_token, cloudkv_write_token)
url = kv.set('foo', 'bar')
print(url)
#> https://cloudkv.samuelcolvin.workers.dev/***/foo
print(kv.get('foo'))
#> b'bar'
print(kv.get_as('foo', str))
#> 'bar'

Storing structured and retrieving data:

from dataclasses import dataclass
from cloudkv import SyncCloudKV

cloudkv_read_token = '***'
cloudkv_write_token = '******'

@dataclass
class Foo:
    bar: float
    spam: list[dict[str, tuple[int, bytes]]]

kv = SyncCloudKV(cloudkv_read_token, cloudkv_write_token)
foo = Foo(1.23, [{'spam': (1, b'eggs')}])
url = kv.set('foo', foo)
print(url)
#> https://cloudkv.samuelcolvin.workers.dev/***/foo
print(kv.get('foo'))
#> b'{"bar":1.23,"spam":[{"spam":[1,"eggs"]}]}'
print(kv.get_as('foo', Foo))
#> Foo(bar=1.23, spam=[{'spam': (1, b'eggs')}])

Async API

You can also connect with the async client.

The sync and async client's have an identical API except AsyncCloudKV must be used as an async context manager, while SyncCloudKV can optionally be used as a context manager or directly after being initialised.

import asyncio
from cloudkv import AsyncCloudKV

cloudkv_read_token = '***'
cloudkv_write_token = '******'

async def main():
    async with AsyncCloudKV.create(cloudkv_read_token, cloudkv_write_token) as kv:
        await kv.set('foo', 'bar')
        print(await kv.get('foo'))
        #> bar

asyncio.run(main())

API

SyncCloudKV has the follow methods.

(AsyncCloudKV has identical methods except they're async and it must be used as an async context manager)

class SyncCloudKV:
    """Sync client for cloudkv.

    This client can be used either directly after initialization or as a context manager.
    """
    namespace_read_token: str
    """Key used to get values and list keys."""
    namespace_write_token: str | None
    """Key required to set and delete keys."""
    base_url: str
    """Base URL to connect to."""

    def __init__(self, read_token: str, write_token: str | None, *, base_url: str = ...):
        """Initialize a new sync client.

        Args:
            read_token: Read API key for the namespace.
            write_token: Write API key for the namespace, maybe unset if you only have permission to read values
                and list keys.
            base_url: Base URL to connect to.
        """

    @classmethod
    def create_namespace(cls, *, base_url: str = ...) -> CreateNamespaceDetails:
        """Create a new namespace, and return details of it.

        Args:
            base_url: Base URL to connect to.

        Returns:
            `CreateNamespaceDetails` instance with details of the namespace.
        """

    def __enter__(self): ...

    def __exit__(self, *args): ...

    def get(self, key: str) -> bytes | None:
        """Get a value from its key.

        Args:
            key: key to lookup

        Returns:
            Value as bytes, or `None` if the key does not exist.
        """

    def get_content_type(self, key: str) -> tuple[bytes | None, str | None]:
        """Get a value and content-type from a key.

        Args:
            key: key to lookup

        Returns:
            Value as tuple of `(value, content_type)`, value will be `None` if the key does not exist,
            `content_type` will be `None` if the key doesn't exist, or no content-type is set on the key.
        """

    def get_as(self, key: str, return_type: type[T], *, default: D = None, force_validate: bool = False) -> T | D:
        '''Get a value as the given type, or fallback to the `default` value if the value does not exist.

        Internally this method uses pydantic to parse the value as JSON if it has the correct content-type,
        "application/json; pydantic".

        Args:
            key: key to lookup
            return_type: type to of data to return, this type is used to perform validation in the raw value.
            default: default value to return if the key does not exist, defaults to None
            force_validate: whether to force validation of the value even if the content-type of the value is not
                "application/json; pydantic".

        Returns:
            The value as the given type, or the default value if the key does not exist.
        '''

    def set(
        self,
        key: str,
        value: T,
        *,
        content_type: str | None = None,
        expires: int | None = None,
        value_type: type[T] | None = None,
    ) -> str:
        """Set a value in the namespace.

        Args:
            key: key to set
            value: value to set
            content_type: content type of the value, defaults depends on the value type
            expires: Time in seconds before the value expires, must be >60 seconds, defaults to `None` meaning the
                key will expire after 10 seconds.
            value_type: type of the value, if set this is used by pydantic to serialize the value

        Returns:
            URL of the set operation.
        """

    def set_details(self, key: str, value: T, *, content_type: str | None = None, expires: int | None = None, value_type: type[T] | None = None) -> KeyInfo:
        """Set a value in the namespace and return details.

        Args:
            key: key to set
            value: value to set
            content_type: content type of the value, defaults depends on the value type
            expires: Time in seconds before the value expires, must be >60 seconds, defaults to `None` meaning the
                key will expire after 10 seconds.
            value_type: type of the value, if set this is used by pydantic to serialize the value

        Returns:
            Details of the key value pair as `KeyInfo`.
        """

    def delete(self, key: str) -> bool:
        """Delete a key.

        Args:
            key: The key to delete.

        Returns:
            True if the key was deleted, False otherwise.
        """

    def keys(
        self,
        *,
        starts_with: str | None = None,
        ends_with: str | None = None,
        contains: str | None = None,
        like: str | None = None,
        offset: int | None = None,
    ) -> list[KeyInfo]:
        """List keys in the namespace.

        Parameters `starts_with`, `ends_with`, `contains` and `like` are mutually exclusive - you can only used one
        them at a tie.

        Args:
            starts_with: Filter to keys that start with this string.
            ends_with: Filter to keys that end with this string.
            contains: Filter to keys that contain this string.
            like: Filter to keys that match this SQL-like pattern.
            offset: Offset the results by this number of keys.

        Returns:
            A list of keys.
        """

Types shown above have the following structure:

class CreateNamespaceDetails(pydantic.BaseModel):
    base_url: str
    """Base URL of the namespace"""
    read_token: str
    """Read API key for the namespace"""
    write_token: str
    """Write API key for the namespace"""
    created_at: datetime
    """Creation timestamp of the namespace"""


class KeyInfo(pydantic.BaseModel):
    url: str
    """URL of the key/value"""
    key: str
    """The key"""
    content_type: str | None
    """Content type set in the datastore"""
    size: int
    """Size of the value in bytes"""
    created_at: datetime
    """Creation timestamp of the key/value"""
    expiration: datetime
    """Expiration timestamp of the key/value"""