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Building a REST client for Surinamese Dollar (SRD) - N/A Price API

Building a REST client for Surinamese Dollar (SRD) - N/A Price API

Building a REST client for Surinamese Dollar (SRD) - N/A Price API

You need to quote, settle, or reconcile Surinamese Dollar (SRD) values alongside metals pricing, and you want a dependable JSON REST client that returns USD↔SRD in one hop. By the end of this guide, you’ll have a working SRD REST client using Metals-API’s latest endpoint, plus patterns for historical lookups and time-series analytics you can drop into pricing engines, P&L tools, or e-commerce rate converters.

What we’re building and why SRD matters in metals workflows

Many metals and manufacturing flows are priced in USD per troy ounce but need to be displayed, invoiced, or hedged in local currencies like SRD. You might:

  • Quote gold- or aluminum-linked products in SRD while sourcing spot inputs in USD.
  • Backfill SRD rates to align historical metals series to local currency for reporting.
  • Run alerts when USD/SRD moves beyond a threshold that impacts landed costs.

Metals-API provides both metals and currency rates in one schema. The same REST pattern you use for XAU also returns SRD consistently, so you can join FX and commodity logic in one pipeline. If you’re new to the service, get an API key at the Metals Customer Portal and registration page: Register and MCP.

Core endpoint: latest USD↔SRD in one call

We’ll start with the Latest Rates endpoint, requesting both SRD (SRD per 1 USD) and its inverse USDSRD (USD per 1 SRD). This keeps your client simple and numerically stable (no manual division required). For symbol definitions, use: Symbols.

Copy-pasteable curl request

curl "https://metals-api.com/api/latest?access_key=YOUR_API_KEY&symbols=SRD,USDSRD"

Real JSON response example (SRD)

This is an actual Metals-API response for SRD, provided for this article. Use it for parsing tests and field mapping:

{"success":true,"timestamp":1790640480,"date":"2026-09-29","base":"USD","rates":{"SRD":37.69075,"USD":1,"USDSRD":0.02653170870837009}}

What these fields mean for your client

  • success: Boolean success flag; check before using data.
  • timestamp: Unix epoch seconds. Convert to your app’s timezone; Metals-API timestamps are coordinated, so use them as the authoritative “as of” value.
  • date: Calendar date for the payload; aligns with timestamp.
  • base: USD here. That means rates are expressed relative to 1 USD by default.
  • rates.SRD: SRD per 1 USD. Multiply USD amounts by this to get SRD.
  • rates.USDSRD: USD per 1 SRD. Multiply SRD amounts by this to get USD.
  • rates.USD: USD per 1 USD (always 1 when base is USD).

In general for Metals-API:
- base=USD → rates.SYMBOL is “units of SYMBOL per 1 USD”.
- The pattern rates.USDSYMBOL represents the explicit inverse, “USD per 1 SYMBOL”. For FX like SRD, this is identical in concept to the metals inversion pattern (e.g., USD per ounce vs ounces per USD).

Minimal JavaScript client: convert between USD and SRD

The snippet below calls the Latest Rates endpoint, extracts SRD and USDSRD, and exposes two utility functions for conversions.

async function fetchSrdRates(apiKey) {
const url = `https://metals-api.com/api/latest?access_key=${encodeURIComponent(apiKey)}&symbols=SRD,USDSRD`;
const res = await fetch(url, { method: 'GET' });
if (!res.ok) throw new Error(`HTTP ${res.status}`);
const data = await res.json();
if (!data.success) throw new Error('API returned success=false');

const { base, date, timestamp, rates } = data;
if (base !== 'USD') {
// Optional: handle non-USD bases if your plan/account uses/returns them
// For this guide we expect USD base.
throw new Error(`Unexpected base: ${base}`);
}
const srdPerUsd = rates.SRD; // SRD per 1 USD
const usdPerSrd = rates.USDSRD; // USD per 1 SRD

return { date, timestamp, srdPerUsd, usdPerSrd };
}

function usdToSrd(usdAmount, srdPerUsd) {
return usdAmount * srdPerUsd;
}

function srdToUsd(srdAmount, usdPerSrd) {
return srdAmount * usdPerSrd;
}

// Example usage:
(async () => {
const apiKey = 'YOUR_API_KEY';
const { date, timestamp, srdPerUsd, usdPerSrd } = await fetchSrdRates(apiKey);

const invoiceUsd = 1250; // a USD-denominated metals invoice
const invoiceSrd = usdToSrd(invoiceUsd, srdPerUsd);

const paymentSrd = 100000; // SRD payment received
const paymentUsd = srdToUsd(paymentSrd, usdPerSrd);

console.log({ date, timestamp, srdPerUsd, usdPerSrd, invoiceUsd, invoiceSrd, paymentSrd, paymentUsd });
})().catch(console.error);

Notes on numerical handling

  • Avoid recomputing inverses yourself; prefer rates.USDSRD to reduce floating-point drift across services.
  • If you must invert, use high-precision math libraries when SRD exposures are large.
  • Cache results keyed by date and a rounded timestamp window to reduce network usage in UI refresh loops.

Historical and time-series queries for SRD

For backfills, P&L explains, or charting, you’ll typically need prior daily rates. Metals-API provides historical and time-series endpoints. We’ll keep examples focused on SRD and use minimal illustrative payloads. Refer to the complete parameter set in the Documentation.

Historical SRD on a specific date (illustrative)

Request pattern (replace YYYY-MM-DD with your date):

curl "https://metals-api.com/api/YYYY-MM-DD?access_key=YOUR_API_KEY&symbols=SRD,USDSRD"

Illustrative minimal JSON (field names and structure only):

{
"success": true,
"timestamp": 1685577600,
"base": "USD",
"date": "2023-06-01",
"rates": {
"SRD": 00.00000,
"USDSRD": 0.0000000000000000
}
}

Use the same field mapping you implemented for the latest endpoint. Store daily snapshots by date so you can reconstruct valuations historically without re-querying.

Time-series SRD between two dates (illustrative)

Request pattern:

curl "https://metals-api.com/api/timeseries?access_key=YOUR_API_KEY&start_date=YYYY-MM-DD&end_date=YYYY-MM-DD&symbols=SRD,USDSRD"

Illustrative minimal JSON (structure only):

{
"success": true,
"timeseries": true,
"start_date": "2023-06-01",
"end_date": "2023-06-05",
"base": "USD",
"rates": {
"2023-06-01": { "SRD": 00.00000, "USDSRD": 0.0000000000000000 },
"2023-06-02": { "SRD": 00.00000, "USDSRD": 0.0000000000000000 },
"2023-06-05": { "SRD": 00.00000, "USDSRD": 0.0000000000000000 }
}
}

Practical tips:

  • Weekends and local holidays: FX markets may be inactive; expect repeating values or missing dates depending on your plan behavior. When computing returns, skip non-trading days or forward-fill cautiously.
  • Windowing: Request contiguous weeks or months rather than many single-day calls. Cache by date range to avoid redundant queries during chart pan/zoom.
  • Consistency: Align your SRD series date boundaries with metals series you use for hedging models to prevent look-ahead bias.

How SRD blends into metals pricing logic

Even if you quote only SRD, metals are quoted per troy ounce. Metals-API returns metals units per troy ounce and FX in currency units per USD. Common join patterns:

  • Compute USD price per troy ounce via metals endpoints, then translate to SRD using rates.SRD from your SRD latest/historical calls.
  • For UX display, round SRD prices to local conventions, but keep internal calculations in full precision.
  • If you must show both “USD per SRD” and “SRD per USD,” use both rates.SRD and rates.USDSRD instead of inverting in the client.

If you need exact symbol codes for any metals you combine with SRD, consult: Metals-API Supported Symbols.

Production checklists: correctness, caching, and edge cases

These are the gotchas that often consume hours in production—address them up front.

  • Base currency and inversion:
    • Assume base="USD" unless you confirm otherwise for your account. If you detect a different base, normalize your math or request USD explicitly if supported by your plan.
    • Use USDSRD for USD per SRD and SRD for SRD per USD to avoid manual inversion mistakes.
  • Timestamps and timezone:
    • Use timestamp as the canonical “as of.” Convert to your user’s local time only for display.
    • If you mix metals and SRD in one quote, ensure both come from the same or closest timestamp to minimize drift.
  • Units:
    • FX units are “currency units per 1 USD” (base=USD). SRD is not per ounce; it’s per USD.
    • If you add metals later, those are “per troy ounce.” Keep unit metadata in your model to avoid cross-unit math.
  • Market closures and weekends:
    • Expect fewer or no updates when FX markets are closed. Don’t treat lack of change as an error.
    • For day-over-day P&L, align to business days or implement a “previous valid day” lookup.
  • Caching and request economy:
    • Cache latest for a short TTL aligned to your plan’s update cadence. Avoid hammering the API on every keystroke in UI components.
    • For charts, prefetch time windows and maintain a local store to decouple scrolling from network calls.
  • Validation and fallbacks:
    • Check success and required fields before use. If a single symbol is missing in rates, fail gracefully and surface the condition.
    • Log the timestamp and symbols with any pricing decision for auditability.

Python snippet: batch conversions and a small in-memory cache

This example fetches SRD, exposes two conversion helpers, and uses a minimal TTL cache to avoid repeated calls in short windows.

import time
import requests

CACHE = {"data": None, "fetched_at": 0}
TTL_SECONDS = 45 # align with your update cadence and UI needs

def get_srd_rates(api_key):
now = time.time()
if CACHE["data"] and (now - CACHE["fetched_at"] < TTL_SECONDS):
return CACHE["data"]

url = "https://metals-api.com/api/latest"
params = {"access_key": api_key, "symbols": "SRD,USDSRD"}
resp = requests.get(url, params=params, timeout=10)
resp.raise_for_status()
data = resp.json()
if not data.get("success"):
raise RuntimeError("API returned success=false")

rates = data.get("rates", {})
srd_per_usd = rates.get("SRD")
usd_per_srd = rates.get("USDSRD")
if srd_per_usd is None or usd_per_srd is None:
raise KeyError("Missing SRD or USDSRD in response")

result = {
"date": data.get("date"),
"timestamp": data.get("timestamp"),
"base": data.get("base"),
"srd_per_usd": srd_per_usd,
"usd_per_srd": usd_per_srd,
}
CACHE["data"] = result
CACHE["fetched_at"] = now
return result

def usd_to_srd(amount_usd, srd_per_usd):
return amount_usd * srd_per_usd

def srd_to_usd(amount_srd, usd_per_srd):
return amount_srd * usd_per_srd

# Example:
# api_key = "YOUR_API_KEY"
# rates = get_srd_rates(api_key)
# quote_srd = usd_to_srd(2500, rates["srd_per_usd"])
# settlement_usd = srd_to_usd(150000, rates["usd_per_srd"])

Designing for analytics: day-over-day changes and joins

SRD volatility can impact landed costs when matched to metals inputs. A simple pattern is to compute daily changes in both SRD and a metals series, then analyze covariance or hedge ratios. With the time-series endpoint, store aligned pairs:

  • For each date, keep USD per SRD (USDSRD) and a metal’s USD per troy ounce (if you later add metals). This keeps units consistent in USD space for correlation.
  • When displaying in SRD, transform at visualization time: price_in_SRD = price_in_USD * rates.SRD for the same date.
  • Handle missing days by forward-filling SRD only within a short tolerance and never across weekends unless your policy allows it.

For more about the available endpoints and constraints, see the Metals-API Documentation.

Integration details your future self will thank you for

  • Error handling: Differentiate HTTP errors, transport timeouts, and logical errors (success=false). Retry only idempotent reads with backoff.
  • Precision: Use decimal types for accounting. Round only at presentation or ledger boundaries.
  • Auditing: Persist the exact JSON blob (or at least timestamp + symbols + rates) used for each financial operation.
  • Security: Keep YOUR_API_KEY server-side in backend calls if possible. If you must call directly from a client, consider a proxy or scoped controls.
  • Testing: Seed your test suite with the real SRD JSON shown above so parsers and mappers are validated end-to-end.
  • Versioning: Track any changes in field availability by pinning integration tests to specific symbols (SRD, USDSRD) and verifying presence before deploy.

FAQs

1) How do I convert an SRD amount to USD without doing manual math?
Use rates.USDSRD from the latest or historical response. Multiply your SRD amount by rates.USDSRD to get USD. For USD→SRD, multiply by rates.SRD.

2) What should I use for the “as of” time—the date or timestamp?
Use timestamp for precision and store it with your transaction. The date is helpful for daily grouping, but timestamp resolves intraday updates and audit windows.

3) Do I need both SRD and USDSRD?
It’s convenient. Requesting both avoids inversion and rounding differences across services. If you only convert in one direction, one symbol may suffice.

4) How do weekends affect SRD data?
FX markets are typically inactive on weekends. Expect no changes or repeats in values. Forward-fill only within your risk and accounting policies.

5) Can I combine SRD with metals prices in the same app?
Yes. Metals-API returns both in a consistent JSON format. Keep track of units: FX in currency per USD; metals per troy ounce. Align timestamps when you combine them.

Get your API key and ship your SRD client

Register to obtain your API key and begin calling the Latest, Historical, and Time-Series endpoints for SRD today. Start here: Register, explore available symbols at Symbols, and review endpoint specifics in Documentation. Manage your account and keys in the MCP.

Additional references (general market context): Central Bank of Suriname, World Bank Country Data (Suriname).

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