ERCOT South Day-Ahead (ERCOT_SOUTH_DA) Price API

You need reliable, copy-pasteable Finance API calls to retrieve ERCOT South Day-Ahead power prices and wire them into your models, dashboards, or risk checks. By the end of this post, you will query the live ERCOT South Day-Ahead (ERCOT_SOUTH_DA) price, parse the response fields you actually need, and ship a small production-ready integration.

What the ERCOT South Day-Ahead symbol represents and how to use it in Finance

ERCOT South Day-Ahead is a power price benchmark for the ERCOT South hub in the Day-Ahead market, expressed in USD per MWh. In a Finance context, developers typically use it for P&L on load-serving positions, back-testing hedges against nodal or hub exposures, and portfolio valuation where power costs feed into margin models.

Illustration: ERCOT South Day-Ahead (ERCOT_SOUTH_DA) Price API

The symbol you will query is:

Symbol name: ERCOT South Day-Ahead
Symbol code: ERCOT_SOUTH_DA
Unit: USD/MWh

You will read the price from the rates.ERCOT_SOUTH_DA field, the price date from dates.ERCOT_SOUTH_DA, and confirm currency via currencies.ERCOT_SOUTH_DA.

Confirm the symbol is listed via GET /api/v1/symbols

Before wiring data into trading or risk logic, confirm the symbol is listed. Call the Finance symbols endpoint GET /api/v1/symbols, passing your api_key as a query parameter. In the response payload, search for the entry whose code equals ERCOT_SOUTH_DA and whose name equals “ERCOT South Day-Ahead.” This step prevents avoidable integration bugs (such as typos in the symbol code) and helps you validate that your account entitlements return this Energy market symbol.

What to check in the response:

The presence of code ERCOT_SOUTH_DA in the symbol list.
The symbol’s name matches “ERCOT South Day-Ahead.”
Category/segment aligns with Energy Finance instruments (if the response includes such metadata).

If ERCOT_SOUTH_DA is found, proceed to the latest price call.

Authentication and plan notes you must know

Authentication is via an api_key query parameter. Use the placeholder value YOUR_API_KEY in your code while testing examples from this post. Do not place your key in headers; pass it as a query parameter exactly as shown below.

Starter pricing is $19.99/mo with a 7-day trial that includes 50 calls. Design your integration to avoid unnecessary retries and poll with a cadence that aligns to your downstream needs.

Get the latest ERCOT South Day-Ahead price (copy-paste cURL)

The latest endpoint returns current values for one or more symbols. Use the official call below with the ERCOT_SOUTH_DA symbol and your api_key as a query parameter:

curl -G "https://energy-api.com/api/v1/latest" --data-urlencode "symbols=ERCOT_SOUTH_DA" --data-urlencode "api_key=YOUR_API_KEY"

Official JSON response (copy-pasteable):

{
"success": true,
"date": "2026-10-19",
"base": "USD",
"rates": {
"ERCOT_SOUTH_DA": 30.0025
},
"dates": {
"ERCOT_SOUTH_DA": "2026-10-19"
},
"currencies": {
"ERCOT_SOUTH_DA": "USD"
},
"base_filter_note": null
}

Field-by-field: what you actually need for Finance use

Use the same real response below as a reference for your parser. Your downstream code should read:

rates.ERCOT_SOUTH_DA as the numeric price (USD/MWh)
dates.ERCOT_SOUTH_DA as the price date
currencies.ERCOT_SOUTH_DA as the currency for that symbol
base, which may be MIXED depending on the symbol set requested

Real API response (verbatim):

{"success":true,"date":"2026-10-19","base":"USD","rates":{"ERCOT_SOUTH_DA":30.0025},"dates":{"ERCOT_SOUTH_DA":"2026-10-19"},"currencies":{"ERCOT_SOUTH_DA":"USD"},"base_filter_note":null}

Why these fields matter:

The top-level date reflects the response batch date. Always prefer the per-symbol date at dates.ERCOT_SOUTH_DA to anchor P&L or risk snapshots.
rates.ERCOT_SOUTH_DA is the price you will store, chart, or push to your pricers. Treat it as a floating-point USD/MWh.
currencies.ERCOT_SOUTH_DA confirms the denomination (USD). If you request multiple symbols in one call, currencies can differ across symbols, and base may be MIXED.
base_filter_note can appear when filters affect how base is represented. Handle null safely.

Language examples: parse only the fields you need

Python 3 (requests)

import os
import requests

API_KEY = os.getenv("ENERGY_API_KEY", "YOUR_API_KEY")
BASE_URL = "https://energy-api.com/api/v1/latest"

params = {
"symbols": "ERCOT_SOUTH_DA",
"api_key": API_KEY
}

resp = requests.get(BASE_URL, params=params, timeout=10)
resp.raise_for_status()
data = resp.json()

# Required fields
price = data["rates"]["ERCOT_SOUTH_DA"]
price_date = data["dates"]["ERCOT_SOUTH_DA"]
currency = data["currencies"]["ERCOT_SOUTH_DA"]
base = data.get("base")

print("Symbol:", "ERCOT_SOUTH_DA")
print("Price (USD/MWh):", price)
print("Price Date:", price_date)
print("Currency:", currency)
print("Base field:", base)

# Persist the minimal set you need downstream
record = {
"symbol": "ERCOT_SOUTH_DA",
"price": price,
"unit": "USD/MWh",
"price_date": price_date,
"currency": currency,
"base": base
}
print("Upsert record:", record)

JavaScript (Node.js fetch)

import fetch from "node-fetch";

const API_KEY = process.env.ENERGY_API_KEY || "YOUR_API_KEY";
const url = new URL("https://energy-api.com/api/v1/latest");
url.searchParams.set("symbols", "ERCOT_SOUTH_DA");
url.searchParams.set("api_key", API_KEY);

const resp = await fetch(url.toString(), { method: "GET" });
if (!resp.ok) {
throw new Error(`HTTP ${resp.status}`);
}
const data = await resp.json();

// Extract the fields you actually need
const price = data.rates.ERCOT_SOUTH_DA;
const priceDate = data.dates.ERCOT_SOUTH_DA;
const currency = data.currencies.ERCOT_SOUTH_DA;
const base = data.base;

console.log({
symbol: "ERCOT_SOUTH_DA",
price,
unit: "USD/MWh",
priceDate,
currency,
base
});

One more complete JSON example for testing your parser

Use this identical payload to add a second test fixture to your unit tests. It’s the same official structure and values, which helps ensure idempotent parsing and safe upgrades.

{
"success": true,
"date": "2026-10-19",
"base": "USD",
"rates": {
"ERCOT_SOUTH_DA": 30.0025
},
"dates": {
"ERCOT_SOUTH_DA": "2026-10-19"
},
"currencies": {
"ERCOT_SOUTH_DA": "USD"
},
"base_filter_note": null
}

Units, base currency, and symbol sets: details that prevent bugs

Units: ERCOT_SOUTH_DA is in USD/MWh. Never assume kWh; always label stored values with unit metadata to avoid silent unit drift in downstream analytics.

Base currency: The top-level base can be USD or MIXED. When you request only ERCOT_SOUTH_DA, base may show as USD as in the samples. When combining symbols with different native currencies (for example if you add other Energy instruments), base can change to MIXED. Your parser must not assume a constant base.

Important constraint when mixing symbols: Do not pass base=USD when you also need TTF_GAS or EUA_CO2. If you require multiple symbols across different native currencies, request them together and handle a MIXED base and per-symbol currencies explicitly. That keeps you from unintentionally converting or filtering out instruments you actually need.

Timestamps and dates: Use dates.ERCOT_SOUTH_DA as the authoritative price date. It is safe to store and to display in UIs that summarize portfolio valuation by day.

Caching, update cadence, and non-trading days

Many Finance workflows do not need sub-minute polling for Day-Ahead prices. Cache results server-side and invalidate on a schedule aligned to Day-Ahead publication windows. This keeps you within the 7-day / 50-call trial while validating your pipeline and avoids rate spikes on plan upgrades.

Non-trading or holiday effects: Energy markets publish on specific schedules. If your integration runs during off-hours or holidays, design your job to carry forward the most recent dates. Always compare dates.ERCOT_SOUTH_DA to your expected valuation date and alert if it lags beyond your policy threshold.

Retries: Network hiccups happen. Use short, bounded retries with exponential backoff and a global timeout. Persist the last known-good price and surface an operational alert rather than failing critical valuation jobs.

Validation: guardrails for Finance and risk systems

Put guardrails around the numeric range of rates.ERCOT_SOUTH_DA. For example, verify the value is positive and within a known operational band from historical norms before calculating VaR or P&L. If outside, require a manual override or a secondary confirmation source.

Schema checks: Assert that rates, dates, and currencies objects all contain keys for ERCOT_SOUTH_DA. Fail fast if any field is missing to prevent partial writes in your valuation store.

Idempotency: If you run batch jobs multiple times per day, write rows keyed by (symbol, price_date) to avoid duplicative records and compounding P&L.

Batching multiple symbols correctly

It is common to request multiple Energy symbols in one call to reduce HTTP overhead. When you do this:

Pass a comma-separated list in symbols if supported by your endpoint usage.
Always check currencies.{symbol} per instrument, not just the top-level base.
Accept that base may be MIXED for heterogeneous symbol sets.
Do not pass base=USD when you also need TTF_GAS or EUA_CO2, to avoid unintended conversions or symbol filtering.

When batching, keep a small post-fetch normalization step that emits records like: symbol, price, price_date, currency, base, unit. This keeps your downstream analytics consistent across diverse instruments.

Storage and downstream usage

For databases, store decimals with adequate precision (e.g., DECIMAL(18,6) or similar) and include unit and currency columns. Storing both price_date and an inserted_at timestamp helps with lineage. Add a source column like “energy-api/latest” for auditability.

In analytics code, pass prices downstream as typed numeric values and avoid string math. Keep the per-symbol date field tight throughout pipeline steps.

Operational checklist before go-live

GET /api/v1/symbols returns ERCOT_SOUTH_DA in your account context.
Your latest call returns rates.ERCOT_SOUTH_DA, dates.ERCOT_SOUTH_DA, and currencies.ERCOT_SOUTH_DA, and your code handles base possibly being MIXED.
Unit-labeled storage (USD/MWh) is implemented.
Retry, caching, and alerting policies are configured.
Trial usage aligns with the 7-day / 50-call envelope during UAT.

Official samples you can paste into unit tests

Use these blocks to seed fixtures in your test suite. They are identical on purpose so your validators can compare the same canonical payload across code paths.

curl -G "https://energy-api.com/api/v1/latest" --data-urlencode "symbols=ERCOT_SOUTH_DA" --data-urlencode "api_key=YOUR_API_KEY"

{
"success": true,
"date": "2026-10-19",
"base": "USD",
"rates": {
"ERCOT_SOUTH_DA": 30.0025
},
"dates": {
"ERCOT_SOUTH_DA": "2026-10-19"
},
"currencies": {
"ERCOT_SOUTH_DA": "USD"
},
"base_filter_note": null
}

{"success":true,"date":"2026-10-19","base":"USD","rates":{"ERCOT_SOUTH_DA":30.0025},"dates":{"ERCOT_SOUTH_DA":"2026-10-19"},"currencies":{"ERCOT_SOUTH_DA":"USD"},"base_filter_note":null}

Common pitfalls to avoid

Assuming base is always USD. It may be MIXED when you combine symbols with different currencies.
Forcing base=USD while requesting Energy instruments that require their native denomination, e.g., when you also need TTF_GAS or EUA_CO2. Do not pass base=USD in that scenario.
Dropping the dates.ERCOT_SOUTH_DA field and relying solely on the top-level date. Always anchor valuations to the per-symbol date.
Caching without invalidation. If you cache, set reasonable TTLs aligned to your reporting or trading cadence.

FAQ

Q: What unit is the ERCOT_SOUTH_DA price in?
A: USD/MWh. Read it from rates.ERCOT_SOUTH_DA and treat it as a floating-point USD-per-megawatt-hour value.

Q: Which fields should I store for portfolio valuation?
A: At minimum: symbol (ERCOT_SOUTH_DA), price (from rates.ERCOT_SOUTH_DA), price_date (from dates.ERCOT_SOUTH_DA), currency (from currencies.ERCOT_SOUTH_DA), base, and unit (USD/MWh).

Q: Can I force the base to USD when fetching multiple symbols?
A: Do not pass base=USD when you also need TTF_GAS or EUA_CO2. For mixed symbol sets, handle a MIXED base and use per-symbol currencies.

Q: How should I handle weekends or holidays?
A: Use the most recent dates.ERCOT_SOUTH_DA available and carry forward according to your risk policy. Alert if the price_date lags your valuation date beyond your tolerance.

Q: How many calls does the trial include?
A: The trial is 7 days with 50 calls. Cache aggressively during UAT and schedule queries to stay within that envelope.

Next step: register and integrate

Get your API key and run the cURL above in minutes. Read the endpoint and field notes, then plug ERCOT_SOUTH_DA into your valuation job. Start here: Register. For deeper parameter and object references, open the Documentation and keep this post’s code as your starter template.