This repo is fork, but we didn't go anywhere :)
To the official repo, go here: https://github.com/permitio/fastapi_websocket_rpc
RPC over Websockets made easy, robust, and production ready
A fast and durable bidirectional JSON RPC channel over Websockets. The easiest way to create a live async channel between two nodes via Python (or other clients).
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Both server and clients can easily expose Python methods that can be called by the other side. Method return values are sent back as RPC responses, which the other side can wait on.
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Remote methods are easily called via the
.other.method()
wrapper -
Connections are kept alive with a configurable retry mechanism (using Tenacity)
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As seen at PyCon IL 2021 and EuroPython 2021
Supports and tested on Python >= 3.7
pip install fastapi_websocket_rpc
Say the server exposes an "add" method, e.g. :
class RpcCalculator(RpcMethodsBase):
async def add(self, a, b):
return a + b
Calling it is as easy as calling the method under the client's "other" property:
response = await client.other.add(a=1,b=2)
print(response.result) # 3
getting the response with the return value.
import uvicorn
from fastapi import FastAPI
from fastapi_websocket_rpc import RpcMethodsBase, WebsocketRPCEndpoint
# Methods to expose to the clients
class ConcatServer(RpcMethodsBase):
async def concat(self, a="", b=""):
return a + b
# Init the FAST-API app
app = FastAPI()
# Create an endpoint and load it with the methods to expose
endpoint = WebsocketRPCEndpoint(ConcatServer())
# add the endpoint to the app
endpoint.register_route(app, "/ws")
# Start the server itself
uvicorn.run(app, host="0.0.0.0", port=9000)
import asyncio
from fastapi_websocket_rpc import RpcMethodsBase, WebSocketRpcClient
async def run_client(uri):
async with WebSocketRpcClient(uri, RpcMethodsBase()) as client:
# call concat on the other side
response = await client.other.concat(a="hello", b=" world")
# print result
print(response.result) # will print "hello world"
# run the client until it completes interaction with server
asyncio.get_event_loop().run_until_complete(
run_client("ws://localhost:9000/ws")
)
See the examples and tests folders for more server and client examples
- Clients can call
client.other.method()
- which is a shortcut for
channel.other.method()
- which is a shortcut for
- Servers also get the channel object and can call remote methods via
channel.other.method()
- See the bidirectional call example for calling client from server and server events (e.g.
on_connect
).
Websockets are ideal to create bi-directional realtime connections over the web.
- Push updates
- Remote control mechanism
- Pub / Sub (see fastapi_websocket_pubsub)
- Trigger events (see "tests/trigger_flow_test.py")
- Node negotiations (see "tests/advanced_rpc_test.py :: test_recursive_rpc_calls")
-
RpcChannel - implements the RPC-protocol over the websocket
- Sending RpcRequests per method call
- Creating promises to track them (via unique call ids), and allow waiting for responses
- Executing methods on the remote side and serializing return values as
- Receiving RpcResponses and delivering them to waiting callers
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RpcMethods - classes passed to both client and server-endpoint inits to expose callable methods to the other side.
- Simply derive from RpcMethodsBase and add your own async methods
- Note currently only key-word arguments are supported
- Checkout RpcUtilityMethods for example methods, which are also useful debugging utilities
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Foundations:
-
Based on asyncio for the power of Python coroutines
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Server Endpoint:
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Based on FAST-API: enjoy all the benefits of a full ASGI platform, including Async-io and dependency injections (for example to authenticate connections)
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Based on Pydnatic: easily serialize structured data as part of RPC requests and responses (see 'tests/basic_rpc_test.py :: test_structured_response' for an example)
-
-
Client :
- Based on Tenacity: allowing configurable retries to keep to connection alive
- see WebSocketRpcClient.init's retry_config
- Based on python websockets - a more comprehensive client than the one offered by Fast-api
- Based on Tenacity: allowing configurable retries to keep to connection alive
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fastapi-websocket-rpc provides a helper logging module to control how it produces logs for you.
See fastapi_websocket_rpc/logger.py.
Use logging_config.set_mode
or the 'WS_RPC_LOGGING' environment variable to choose the logging method you prefer or override completely via default logging config.
example:
# set RPC to log like UVICORN
from fastapi_websocket_rpc.logger import logging_config, LoggingModes
logging_config.set_mode(LoggingModes.UVICORN)
- Please include tests for new features