pace-python 1.0.5

Rust-powered rate limiting SDK for Python

pace-python

Rust-powered rate limiting for Python. Native engine via PyO3 — no Redis, no network hop, sub-millisecond decisions.

Install

pip install pace-python

Quick Start

from pace_sdk import Pace, PaceConfig, ProtectionMode, Algorithm

pace = Pace(PaceConfig(
    mode=ProtectionMode.ACTIVE,
    algorithm=Algorithm.TOKEN_BUCKET,
    capacity=100,
    refill_rate=10.0,
))

result = pace.check(ip="127.0.0.1", route="/api/generate")

if result.allowed:
    print("✅ Request allowed")
else:
    print(f"🚫 Blocked — reason: {result.reason}")

Algorithms

Algorithm	Config Fields
TOKEN_BUCKET	capacity, refill_rate
LEAKY_BUCKET	capacity, refill_rate
FIXED_WINDOW	capacity, window
SLIDING_WINDOW	capacity, window

Modes

ProtectionMode.ACTIVE    # blocks requests over limit
ProtectionMode.SHADOW    # logs but never blocks
ProtectionMode.DISABLED  # zero overhead passthrough

FastAPI

from fastapi import FastAPI, Depends
from pace_sdk import Pace, PaceConfig, ProtectionMode, Algorithm

app = FastAPI()
pace = Pace(PaceConfig(
    mode=ProtectionMode.ACTIVE,
    algorithm=Algorithm.SLIDING_WINDOW,
    capacity=100,
    refill_rate=10.0,
))

@app.post("/api/generate", dependencies=[Depends(pace.middleware_fastapi())])
async def generate():
    return {"success": True}

Flask

from flask import Flask
from pace_sdk import Pace, PaceConfig, ProtectionMode, Algorithm

app = Flask(__name__)
pace = Pace(PaceConfig(
    mode=ProtectionMode.ACTIVE,
    algorithm=Algorithm.TOKEN_BUCKET,
    capacity=100,
    refill_rate=10.0,
))

app.before_request(pace.middleware_flask())

@app.route("/api/generate", methods=["POST"])
def generate():
    return {"success": True}

Debug Output

pace = Pace(PaceConfig(
    mode=ProtectionMode.ACTIVE,
    algorithm=Algorithm.TOKEN_BUCKET,
    capacity=3,
    refill_rate=1.0,
    debug="pretty"   # or "compact"
))

│ IP:        127.0.0.1
│ Algorithm: token_bucket
│ Reason:    token_exhausted
│ Mode:      active
│ Remaining: 0
│ Latency:   0ms
└────────────────────────────────────────

Connect to Pace Cloud

pace = Pace(PaceConfig(
    mode=ProtectionMode.ACTIVE,
    algorithm=Algorithm.TOKEN_BUCKET,
    capacity=100,
    refill_rate=10.0,
    api_key="your-api-key",
))

License

Apache 2.0 © Suvodeep Mishra