Get naira (NGN) exchange rates by API in Python and JavaScript

Sign up — no card. Your first key is minted automatically and shown under Account → API keys. A free key allows 50 requests per UTC day; Individual allows 250 and Team 1,000. Every request carries the key in the X-API-Key header.

One call returns every tracked provider's latest quote on the corridor, each with rate, fee, spread_bps (distance below the best rate of the same kind) and last_updated, plus mid_rate and per-provider vs_mid_bps when the independent mid is available. The response also states its freshness: data_freshness is hourly on Free and Individual keys (with an as_of timestamp) and realtime on Team keys.

curl "https://modan.io/api/v1/rates?from=GBP&to=NGN" \
  -H "X-API-Key: mdn_live_YOUR_KEY_HERE"

Print the providers ranked by spread, and the mid if there is one.

import os, requests

BASE = "https://modan.io/api/v1"
HEADERS = {"X-API-Key": os.environ["MODAN_API_KEY"]}

r = requests.get(f"{BASE}/rates", params={"from": "GBP", "to": "NGN"}, headers=HEADERS, timeout=15)
r.raise_for_status()
book = r.json()

print(book["corridor"], "as of", book.get("as_of") or book["timestamp"], f"({book['data_freshness']})")
if book.get("mid_rate"):
    print("independent mid:", book["mid_rate"], "from", book["mid_source"])

for p in sorted(book["providers"], key=lambda p: p["spread_bps"]):
    vs_mid = f'{p["vs_mid_bps"]:+.1f} bps vs mid' if "vs_mid_bps" in p else "no mid"
    print(f'{p["provider_name"]:<16} {p["rate"]:>12,.2f}  fee {p["fee"]:>6}  {p["spread_bps"]:>6.1f} bps  {vs_mid}')

print("remaining today:", r.headers.get("X-RateLimit-Remaining"))

The same call with fetch, in Node 18+ or the browser.

const BASE = "https://modan.io/api/v1";
const headers = { "X-API-Key": process.env.MODAN_API_KEY };

const res = await fetch(`${BASE}/rates?from=GBP&to=NGN`, { headers });
if (res.status === 429) throw new Error(`quota exhausted until ${res.headers.get("X-RateLimit-Reset")}`);
if (!res.ok) throw new Error(`HTTP ${res.status}`);
const book = await res.json();

const executable = book.providers.filter((p) => !["official", "parallel"].includes(p.rate_type ?? "retail"));
const best = executable.reduce((a, b) => (b.rate > a.rate ? b : a));
console.log(`${book.corridor}: best executable ${best.provider_name} ${best.rate} (${book.data_freshness})`);

/convert?from=GBP&to=NGN&amount=1000 returns, for every provider, the gross converted amount and the amount net of the provider's fee, and names the provider that delivers the most — among executable quotes only. A central bank's official reference is returned and labelled but never chosen as best.

/rates/history?from=GBP&to=NGN&period=30d returns timestamped observations (oldest first, paginated); /time-series buckets them daily or hourly; /historical?date=… returns the book as it stood on a past date. Every response carries X-RateLimit-Limit, X-RateLimit-Remaining and X-RateLimit-Reset; past the daily limit you receive 429 until midnight UTC. /status needs no key and does not count.

If your consumer is an AI agent rather than a script, the MCP server exposes the same data as tools, on the same key and quota.