lithic 0.3.1

Client library for the lithic API

Lithic Python API Library

The Lithic Python library provides convenient access to the Lithic REST API from any Python 3.7+ application. It includes type definitions for all request params and response fields, and offers both synchronous and asynchronous clients powered by httpx.

Documentation

The API documentation can be found here.

Installation

pip install lithic

Usage

from lithic import Lithic

lithic = Lithic(
    # defaults to os.environ.get("LITHIC_API_KEY")
    api_key="my api key",
    # defaults to "production".
    environment="sandbox",
)

card = lithic.cards.create({
    "type": "SINGLE_USE",
})

print(card.token)

While you can provide an api_key keyword argument, we recommend using python-dotenv and adding LITHIC_API_KEY="my api key" to your .env file so that your API keys are not stored in source control.

Async Usage

Simply import AsyncLithic instead of Lithic and use await with each API call:

from lithic import AsyncLithic

lithic = AsyncLithic(
    # defaults to os.environ.get("LITHIC_API_KEY")
    api_key="my api key",
    # defaults to "production".
    environment="sandbox",
)

async def main():
    card = await lithic.cards.create({
        "type": "SINGLE_USE"
    })
    print(card.token)

asyncio.run(main())

Functionality between the synchronous and asynchronous clients are otherwise identical.

Using Types

Request parameters are TypedDicts, while responses are Pydantic models. This helps provide autocomplete and documentation within your editor.

If you would like to see type errors in VS Code to help catch bugs earlier, set python.analysis.typeCheckingMode to "basic".

Pagination

List methods in the Lithic API are paginated.

This library provides auto-paginating iterators with each list response, so you do not have to request successive pages manually:

from typing import List
import lithic

lithic = Lithic()

all_cards = []
# Automatically fetches more pages as needed.
for card in lithic.cards.list():
    # Do something with card here
    all_cards.append(card)
return all_cards

Or, asynchronously:

import asyncio
from typing import List
import lithic

lithic = AsyncLithic()

async def main() -> None:
    all_cards = []
    # Iterate through items across all pages, issuing requests as needed.
    async for card in lithic.cards.list():
        all_cards.append(card)
    return all_cards

asyncio.run(main())

Alternatively, you can use the .has_next_page(), .next_page_params(), or .get_next_page() methods for more granular control working with pages:

first_page = await client.cards.list({"page_size": 2})
if first_page.has_next_page():
    print("will fetch next page, with params", first_page.next_page_params())
    next_page = await first_page.get_next_page()
    print(f"number of items we just fetched: {len(next_page.data)}")

# Remove `await` for non-async usage.

Or just work directly with the returned data:

first_page = await client.cards.list()

print(f"page number: {first_page.page}") # => "page number: 1"
for card in first_page.data:
    print(card.token)

# Remove `await` for non-async usage.

Handling errors

When the library is unable to connect to the API (e.g., due to network connection problems or a timeout), a subclass of lithic.APIConnectionError is raised.

When the API returns a non-success status code (i.e., 4xx or 5xx response), a subclass of lithic.APIStatusError will be raised, containing status_code and response properties.

All errors inherit from lithic.APIError.

from lithic import Lithic

lithic = Lithic()

try:
    lithic.cards.create({
        "type": "an_incorrect_type"
    })
except lithic.APIConnectionError as e:
    print("The server could not be reached")
    print(e.__cause__) # an underlying Exception, likely raised within httpx.
except lithic.RateLimitError as e:
    print("A 429 status code was received; we should back off a bit.")
except lithic.APIStatusError as e:
    print("Another non-200-range status code was received")
    print(e.status_code)
    print(e.response)

Error codes are as followed:

Status Code	Error Type
400	BadRequestError
401	AuthenticationError
403	PermissionDeniedError
404	NotFoundError
422	UnprocessableEntityError
429	RateLimitError
>=500	InternalServerError
N/A	APIConnectionError

Retries

Certain errors will be automatically retried 2 times by default, with a short exponential backoff. Connection errors (for example, due to a network connectivity problem), 409 Conflict, 429 Rate Limit, and >=500 Internal errors will all be retried by default.

You can use the max_retries option to configure or disable this:

from lithic import Lithic

# Configure the default for all requests:
lithic = Lithic(
    # default is 2
    max_retries=0,
)

# Or, configure per-request:
lithic.cards.list({
    "page_size": 10
}, max_retries=5);

Timeouts

Requests time out after 60 seconds by default. You can configure this with a timeout option, which accepts a float or an httpx.Timeout:

from lithic import Lithic

# Configure the default for all requests:
lithic = Lithic(
    # default is 60s
    timeout=20.0,
)

# More granular control:
lithic = Lithic(
    timeout=httpx.Timeout(60.0, read=5.0, write=10.0, connect=2.0),
)

# Override per-request:
lithic.cards.list({
    "page_size": 10
}, timeout=5 * 1000)

On timeout, an APITimeoutError is thrown.

Note that requests which time out will be retried twice by default.

Advanced: Configuring custom URLs, proxies, and transports

You can configure the following keyword arguments when instantiating the client:

import httpx
from lithic import Lithic

lithic = Lithic(
    # Use a custom base URL
    base_url="http://my.test.server.example.com:8083",
    proxies="http://my.test.proxy.example.com",
    transport=httpx.HTTPTransport(local_address="0.0.0.0"),
)

See the httpx documentation for information about the proxies and transport keyword arguments.

Status

This package is in beta. Its internals and interfaces are not stable and subject to change without a major semver bump; please reach out if you rely on any undocumented behavior.

We are keen for your feedback; please email us at [e-mail] or open an issue with questions, bugs, or suggestions.

Requirements

Python 3.7 or higher.