Deposit Rate API — CD, Savings & Money Market APY

A deposit rate API (Application Programming Interface) is a software interface that provides programmatic access to deposit yield data — CD, savings, and money market APY — from financial institutions. Instead of manually visiting websites or scraping data, developers make standardized HTTP requests to retrieve current deposit rates in a structured format.

Deposit products are where an institution pays you to hold your money, the mirror image of a loan. Because the yield is what matters to the saver, deposit data is quoted as APY (Annual Percentage Yield), which includes the effect of compounding. A deposit rate API bridges the raw APY data institutions publish and the applications that need to display or analyze it.

Key Characteristics of a Deposit Rate API

• Frequently refreshed data: APY moves with the rate environment, so data is updated daily
• Standardized format: Data is returned in consistent JSON regardless of source
• Category separation: CD, savings, and money market are distinct product categories; CDs are keyed by term
• Queryable: Supports filtering by category, term, and geography
• Authentication: Requires API keys to track usage and prevent abuse

Why Deposit Rate APIs Exist

Before deposit rate APIs, tracking the best CD or savings yield meant visiting hundreds of institution websites or maintaining fragile scrapers. A deposit rate API abstracts away the collection: the provider handles scraping, classifying, validating, and updating, while developers make API calls to access clean, structured APY information.

This is the single most important distinction when working with deposit data. APY is what a deposit account pays you; APR is what a loan costs you. They point in opposite directions:

Key insight: a deposit rate API must never present APY as if it were a loan APR. RateAPI keeps deposit yields in their own endpoint and never treats a deposit APY as a loan rate.

Here's how the typical deposit rate API pipeline works:

Typical API Request Flow

# Get a 12-month CD benchmark for Texas
POST /v1/deposit-rates
Host: api.rateapi.dev
X-API-Key: YOUR_API_KEY
Content-Type: application/json

{
  "product_category": "cd",
  "term_months": 12,
  "state": "TX",
  "mode": "benchmark"
}

{
  "product_category": "cd",
  "term_months": 12,
  "state": "TX",
  "as_of": "2026-08-18T14:00:00Z",
  "best": { "lender": "Example Federal Credit Union", "apy": 4.85 },
  "market": {
    "min_apy": 3.10,
    "median_apy": 4.15,
    "max_apy": 4.85,
    "institution_count": 42
  }
}

Deposit rate APIs power a variety of savings, fintech, and AI applications:

When evaluating deposit rate API providers, consider these features:

For deposits the saver wants the highest APY, so ranking is the mirror of loan ranking — but the pitfalls are similar.

Three Common Ranking Approaches

• Headline-APY sorting: Shows the highest advertised APY first even when it requires a large minimum balance or a promotional window that expires.
• Affiliate-driven ranking: Institutions pay placement fees to appear on top, so the "best" account is whoever paid more.
• Evidence-validated ranking: Ranks by verified APY within a matched category and term, requiring a real source and enough observations to be meaningful. No affiliate relationships = no bias.

RateAPI validates every deposit benchmark and has zero affiliate relationships — only accurate, matched APY reaches the response.

RateAPI covers three deposit product categories:

Aggregate Fields

• min_apy / median_apy / max_apy: The market spread of APY within the matched category and term
• best.lender / best.apy: The highest-yielding qualifying institution
• institution_count: How many institutions back the aggregate
• as_of: Upstream timestamp for freshness (ISO 8601)

Here's how the major options compare for deposit data:

Choosing the Right Provider

• Building an AI agent? Choose a provider with an MCP or function-calling deposit tool (like RateAPI)
• Need term-aware CD data? Look for APIs that key CDs by maturity
• Research and analysis? Public datasets may suffice for national averages

RateAPI provides daily-updated deposit rate data from credit unions across America. Here's how to get started:

curl -X POST https://api.rateapi.dev/keys -H "Content-Type: application/json" -d '{"email": "[email protected]","source":"curl-what-is-deposit-rate-api"}'

# Get a savings APY benchmark
curl -X POST "https://api.rateapi.dev/v1/deposit-rates" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"product_category":"savings","mode":"benchmark"}'

# Add to Claude Code
claude mcp add rateapi https://mcp.rateapi.dev/mcp \
  --transport http \
  --header "x-api-key: YOUR_API_KEY"

Code Examples

const response = await fetch(
  'https://api.rateapi.dev/v1/deposit-rates',
  {
    method: 'POST',
    headers: {
      'X-API-Key': 'YOUR_API_KEY',
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      product_category: 'cd',
      term_months: 12,
      mode: 'benchmark'
    })
  }
);
const data = await response.json();
console.log(data.market, data.best);

import requests

response = requests.post(
    'https://api.rateapi.dev/v1/deposit-rates',
    json={
        'product_category': 'cd',
        'term_months': 12,
        'mode': 'benchmark'
    },
    headers={'X-API-Key': 'YOUR_API_KEY'}
)
data = response.json()
print(data['market'], data['best'])

Related Resources

• Deposit Rates - Explore live CD, savings, and money market rates
• CD Rates - Certificate of deposit APY by term and state
• Savings Rates - Liquid savings APY benchmarks
• Money Market Rates - Money market APY benchmarks
• Data Methodology - How we collect, normalize, and verify rate data
• What Is RateAPI? - Overview of the full platform across every rate product

What is a deposit rate API?

A deposit rate API is a programmatic interface that lets software retrieve real-time deposit yields — CD, savings, and money market APY — from multiple institutions through standardized HTTP requests that return structured JSON.

What is the difference between APY and APR?

APY is what a deposit account pays you (including compounding); APR is what a loan costs you. A deposit rate API returns APY, so higher is better for the saver. RateAPI never treats a deposit APY as a loan APR.

Is there a free deposit rate API?

Yes. RateAPI has a free tier (20 requests/month, email required) and requires no signup — you generate a key in one request. See pricing for higher limits.

Can a deposit rate API be used with AI agents like Claude or ChatGPT?

Yes. RateAPI ships an MCP server with a get_deposit_benchmarks tool so AI agents can answer live CD and savings questions and compare institutions by APY.