Routers

pRPC uses a procedure registry to hold your RPC procedures. You register procedures with @rpc, then mount the registry onto your app using an adapter. There is no separate router object — the registry is the router.

The Registry

Procedures are stored in a global registry (default_registry). The @rpc decorator registers a function:

from prpc import rpc
from prpc_fastapi import mount_fastapi

@rpc
def add(a: int, b: int) -> int:
    return a + b

@rpc
def greet(name: str = "World") -> str:
    return f"Hello, {name}!"

mount_fastapi(app)  # Exposes add and greet at POST /rpc

When a request arrives, pRPC looks up the procedure by name in the registry and invokes it with the request params.

Custom Procedure Names

By default, the procedure name is the function name. Override it with the name parameter:

@rpc(name="getUserById")
def get_user(user_id: int) -> dict:
    return {"id": user_id, "name": "Jane"}

The client calls getUserById, not get_user.

Organizing Procedures

You can spread procedures across multiple modules. All procedures decorated with @rpc end up in the same registry:

myapp/
  procedures/
    users.py    # @rpc def get_user, create_user, ...
    products.py # @rpc def get_product, list_products, ...
  main.py       # imports procedures, mount_fastapi(app)

procedures/users.py:

from prpc import rpc

@rpc
def get_user(user_id: int) -> dict:
    ...

@rpc
def create_user(name: str, email: str) -> dict:
    ...

main.py:

from fastapi import FastAPI
from prpc_fastapi import mount_fastapi

# Import so @rpc runs and registers procedures
import procedures.users
import procedures.products

app = FastAPI()
mount_fastapi(app)

Mounting happens once. All registered procedures are available at the adapter's endpoint (e.g. POST /rpc).

Mounting with Adapters

How you mount depends on the adapter. See Adapters for details.

• FastAPI — mount_fastapi(app) adds a POST /rpc route
• Flask — mount_flask(app) adds a POST /rpc route
• ASGI — Use PRPCAsgiApp or asgi_app for a standalone app

Next Steps

• Procedures — Validation, types, and async
• Context — Accessing request context
• Adapters — FastAPI, Flask, ASGI