Data API — ByTheMath
Licensed access to the ByTheMath data feed — CD rates, HYSA rates, HSA provider scores, credit card data, and full rate history. Human-verified. Updated daily. Free tier available.
What the API provides
The ByTheMath data API gives licensed publishers and developers programmatic access to the same verified data that powers YourBestSavings.com and YourBestCards.com. Every record includes verified rates, composite scores, source URLs, and last-verified dates — updated daily from institution disclosure pages.
The API is backed by Supabase and returns JSON. All records reflect human-confirmed data only — no scanner output is published without a human review step. Every rate includes an apy_as_of field showing when it was last verified against the institution’s own site.
Access tiers
| Tier | What’s included | Rate limit | Price |
|---|---|---|---|
| Free | Transfer bonuses & transfer partners. Point valuations. Active bonus offers with start/end dates. | 1,000 req/day | $0 — available immediately |
| Developer | Free tier + all deposit products (462+ CDs & HYSAs) with APY, term, scores, and penalty data. | 5,000 req/day | Contact us |
| Publisher | Developer tier + HSA provider scores, full rate history time-series, and card scoring data. | 25,000 req/day | Contact us |
| Enterprise | Full access + webhook push events, bulk export, SLA, and custom data pipelines. | Unlimited | Contact us |
Endpoints
apy_as_of. Filterable by product type, term, and status.rate_changed, product_added, and product_removed events. Delivered within minutes of a verified change being committed.Example response
A single deposit product record from /deposit_products:
{
"product_id": "cd_popular_direct_6mo",
"institution": "Popular Direct",
"name": "Popular Direct CD 6-Month",
"product_type": "cd",
"apy": 4.10,
"term_months": 6,
"min_deposit": 10000,
"ewp_days": 180,
"no_penalty": false,
"fdic_insured": true,
"apy_as_of": "2026-05-25",
"status": "L",
"source_url": "https://www.populardirect.com/savings/cds/"
}Data quality and freshness
Every record reflects data verified by a human editor from the institution’s own disclosure page. Records include an apy_as_of date. Products not re-verified within seven days are flagged as stale and excluded from default query results (filtered via status=eq.L). No institution pays to appear in or be excluded from API results.
Rate changes are detected by an automated daily scan and confirmed by human review before being committed. This means changes typically appear in the API one to two days after the institution posts them. The product_rate_history endpoint provides the full audit trail of every change with before/after values and verification dates.
Licensing terms
API data is licensed for display and analysis only. Redistribution, resale, or white-labeling of raw data is not permitted without an Enterprise license agreement. Any public-facing display of ByTheMath data requires attribution — “Data: ByTheMath” with a link to bythemath.com. The attribution requirement applies to all tiers including Free.
Frequently asked questions
What data does the ByTheMath API provide?
Human-verified CD and HYSA rates (462+ deposit products), scored credit-card data (214+ cards), HSA provider scores, transfer-bonus offers with point valuations, and full product rate history — the same data that powers YourBestSavings.com and YourBestCards.com. Every record includes a composite score, source URL, and an apy_as_of verification date.
What format does the ByTheMath API return?
JSON. The API is backed by Supabase and returns JSON for every endpoint.
How often is the data updated?
Daily. An automated scan detects rate changes each day, and every change is confirmed by a human editor against the institution’s own disclosure page before it is committed — so changes typically appear one to two days after the institution posts them.
Is there a free tier?
Yes. The Free tier includes transfer bonuses, transfer partners, point valuations, and active bonus offers at 1,000 requests/day for $0, available immediately with no approval delay.
What are the API rate limits?
Free: 1,000 requests/day. Developer: 5,000/day. Publisher: 25,000/day. Enterprise: unlimited.
Can I redistribute or resell the data?
No. API data is licensed for display and analysis only; redistribution, resale, or white-labeling of raw data requires an Enterprise license agreement.
Is attribution required?
Yes. Any public-facing display of ByTheMath data must include attribution — “Data: ByTheMath” linked to bythemath.com — on every tier, including Free.
Get access
To request API access or discuss licensing, email contact@yourbestsavings.com with your use case, expected request volume, and intended display context. Free tier access is available immediately on request — no approval delay. Developer and Publisher tier access is typically approved within one business day.