single-endpoint-router 1.0.1

A simple single-endpoint router for all provided APIs with caching

SingleEndpointRouter

SingleEndpointRouter is a lightweight, FastAPI-based reverse proxy and router that forwards each incoming request to the first backend server that responds with 200 OK. It supports advanced routing based on endpoint paths and request payloads, and remembers successful routes in a SQLite cache for fast subsequent lookups.

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Features

• Single endpoint: Expose one API endpoint and route requests to multiple backend servers.
• Payload-aware routing: Route requests based on both endpoint path and request payload.
• YAML configuration: Flexible, human-readable configuration for endpoints and payloads.
• Automatic caching: Remembers which backend handled which request for faster future routing.
• FastAPI & Uvicorn: High-performance async Python stack.
• SQLite cache: Persistent, lightweight caching of routing decisions.

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Installation

Install from PyPI:

pip install single-endpoint-router

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Quick Start

1. Create a config.yaml

Example:

"http://127.0.0.1:3000":
  cache_timeout: 6000
  endpoints:
    "/get_log_files":
      payload:
        - name: "log_file.log"
          path: "c:/logs"
        - name: "backup_log.log"
          path: "d:/backup/logs"
    "/load_log_file":
      payload:
        - name: "log_file.log"
          path: "c:/logs"

"http://127.0.0.1:3100":
  cache_timeout: 5000
  endpoints:
    "/archive_logs":
      payload:
        - source: "c:/logs"
          destination: "e:/archives"
          compress: true

2. Start the router

from SingleEndpointRouter import Server

# Option 1: Use only the config file
app = Server("config.yaml")

# Option 2: Provide fallback endpoints and config file
endpoints = [
    "http://127.0.0.1:3000",
    "http://127.0.0.1:3100",
    "http://127.0.0.1:3200",
]
app = Server(endpoints, "config.yaml")

app.run(debug=True, host="0.0.0.0", port=8000)

Console output:

* Running on http://0.0.0.0:8000 (Press CTRL+C to quit)

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How It Works

1. Routing by Path and Payload:
   When a request is received, the router checks the YAML config for a matching backend server based on the request path and payload (for POST/PUT/PATCH). If a match is found, the request is forwarded to that server.

2. Fallback and Caching:
   If no match is found, the router checks its cache for a previously successful backend for this method/path/payload combination. If still not found, it tries all configured endpoints in order until one responds with 200 OK, then caches that choice.

3. Payload Matching:
   For endpoints with a payload list, the request payload must match one of the payload dictionaries exactly (all keys and values must match).

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Configuration File (config.yaml)

The configuration file is a YAML file where each top-level key is a backend server URL. Each server can define:

• cache_timeout: (optional) Not currently used, for future cache expiry support.
• endpoints: A mapping of endpoint paths to payload matchers.

Example:

"http://127.0.0.1:3000":
  cache_timeout: 6000
  endpoints:
    "/get_log_files":
      payload:
        - name: "log_file.log"
          path: "c:/logs"
        - name: "backup_log.log"
          path: "d:/backup/logs"
    "/load_log_file":
      payload:
        - name: "log_file.log"
          path: "c:/logs"

Routing logic:

• If a request matches both the endpoint path and one of the payloads, it is routed to that server.
• If no payload matches, the router tries all servers in order as fallback.

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API

class Server(endpoints_or_conf, conf_path="config.yaml")

Parameter	Type	Description
endpoints_or_conf	Sequence[str] | str	List of fallback backend URLs or path to config file
conf_path	str (optional)	Path to config file when first argument is a list

Methods

• run(debug=True, host="127.0.0.1", port=8000)
  Starts the FastAPI/Uvicorn server.
• clean_cache()
  Removes all cached routing data from the SQLite cache.

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Example: Cleaning the Cache

You can clear all cached routing decisions before starting the server:

from SingleEndpointRouter import Server

endpoints = [
    "http://127.0.0.1:3000",
    "http://127.0.0.1:3100",
    "http://127.0.0.1:3200",
]
app = Server(endpoints, "config.yaml")

# Clean the cache
app.clean_cache()

app.run(debug=True, host="0.0.0.0", port=8000)

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Example Request

Suppose your config contains:

"http://127.0.0.1:3000":
  endpoints:
    "/get_log_files":
      payload:
        - name: "log_file.log"
          path: "c:/logs"
"http://127.0.0.1:3100":
  endpoints:
    "/get_log_files":
      payload:
        - name: "backup_log.log"
          path: "d:/backup/logs"

A POST to http://127.0.0.1:8000/get_log_files with payload:

{"name": "backup_log.log", "path": "d:/backup/logs"}

will be routed to http://127.0.0.1:3100/get_log_files.

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Advanced Usage

• Fallback: If no config match is found, the router tries all endpoints in order.
• Caching: Once a backend is found for a method/path/payload, it is cached for future requests.
• Stateless: The router does not modify request or response bodies.

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License

MIT

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Project Links

• GitHub Repository
• PyPI Project