Glossary · APIs and AI agents

What are API credits?

The short answer

API credits are prepaid units that a service deducts each time a program calls its API. The provider decides how many credits a call or a result costs, so the price of a job depends on how many lookups it runs, how many results come back and, with some providers, whether a lookup that finds nothing is charged too.

Updated
Read
3 min
Written by
Antoine Blitz
On this page8 sections
  1. Real data
  2. How do API credits work?
  3. What does one call cost in API credits?
  4. API credits, usage-based pricing and flat plans: what is the difference?
  5. Why are API credits hard to forecast?
  6. How does BlitzAPI count usage instead of API credits?
  7. Related terms
  8. Questions people ask

Real data

What three real calls counted

Three calls to a data API that meters in records rather than credits, with the count each response returned. One record is one item returned; a lookup that finds nothing counts nothing.

Returned by the BlitzAPI API on

POST/v2/jobs/search

A job search that matched 252 postings and returned 3

Postings that match
252 job postings
Postings returned
3 job postings (max_results set to 3)
Counted
3 records

The search: US job postings from the last 30 days with Revenue Operations Manager in the title.

POST/v2/enrichment/domain-to-linkedin

A domain lookup that finds the company

Domain
stripe.com
Found
Yes, the Stripe company page
Counted
1 record
POST/v2/enrichment/domain-to-linkedin

A domain lookup that finds nothing

Domain
no-company-here-blitz-glossary.com (made up for the test)
Found
No
Counted
0 records

Each count is the fair_usage.records_used field of the response, the same value as its x-records-used header.

How do API credits work?

With API credits, you buy a balance up front, or receive one with a plan. Each call to the API draws it down by an amount the provider sets: one credit per request, one per result, or more for a costly endpoint such as a phone number. When the balance is empty, calls stop or are billed as overage until you buy more.

The model is popular because one balance can pay for very different endpoints. The price of a credit, though, says little on its own. What a job will cost depends on what each call consumes.

What does one call cost in API credits?

Two rules decide what one call costs in API credits, and both are in the provider’s documentation rather than on its pricing page.

  • What is counted. A request, a result, or a field. A search that matches 252 job postings and returns 3 costs one unit under a per-request meter and three under a per-result meter, like the first call above.
  • Whether a miss is counted. A lookup that finds nothing, like the third call above, costs nothing on some APIs and a full credit on others. On a cold list, misses can be a large part of the calls.
Check yourselfA search matches 252 job postings and you ask for 3. Under a per-result meter, how many units does the call use?
Show the answer key
  1. 252That is how many postings matched the filters. A per-result meter counts what comes back, not what matched.
  2. 3Three results came back, so three units are counted. The 249 others were never returned.
  3. 1One is the count under a per-request meter, where every call costs the same whatever it returns.
  4. 0A call that returns results always uses something. Zero is what a lookup that finds nothing can cost, on APIs that do not charge misses.

API credits, usage-based pricing and flat plans: what is the difference?

API credits, usage-based pricing and flat plans differ in when you pay and in what sets the bill:

API credits Usage-based pricing Flat plan
How you pay A prepaid balance An invoice after the period A fixed monthly price
What sets the bill The credits each call draws The units you consumed The plan: a request rate and a monthly volume
What to watch Expiry, the cost of misses Spikes from a runaway script The volume the plan covers

Usage-based pricing is the same meter billed afterwards. A flat plan moves the question from “how much will this job cost?” to “does this plan cover the job?”, which is easier to forecast. Requests per second, the other meter of a data API, are covered on the API rate limit page.

Why are API credits hard to forecast?

API credits are hard to forecast because the cost of a job depends on numbers you only know after running it: how many lookups come back empty, how many results each search returns, how many calls a retry adds. A team that budgets from the list size alone will be off by the share of misses, in one direction or the other.

The fix is a small test batch on a sample of the real list. Count what came back, what was charged, and what was usable, then scale. The same habit helps whatever the meter, including the agent purchases described in agentic commerce.

How does BlitzAPI count usage instead of API credits?

BlitzAPI counts usage in records, not credits. One record is one item the API returns to you: one company, one person, one email address, one phone number or one job posting. A call that finds nothing counts nothing. Each plan covers a number of records a month, its fair use policy, and a number of requests per second on each endpoint: the pricing page lists them.

Every metered response returns the records it used, so the cost of a job can be read call by call, and GET /v2/account/key-info returns the records left before a large run, at no cost (API reference).

  • Full definitionAPI rate limit

    A cap on how many requests a program may send to a service in a second or a minute. Above it, the service turns requests away for a moment.

  • OverviewB2B data API

    A service your software calls to get facts about companies and the people who work there, such as a company's size or a person's current role, at the moment it needs them, instead of a list bought once and left to age.

  • Full definitionData as a service

    Getting data from a provider's servers when your software needs it, instead of buying a large file and storing it yourself.

  • GuideAgentic commerce

    Buying and selling where the buyer is an AI agent: it finds a product, reads the price, pays and uses what it bought, without a person filling in forms on its behalf.

All terms in the glossary

Sources and method

Written by
Antoine Blitz, Founder, BlitzAPI
Published
API calls run on

The calls ran on October 28, 2026 through the BlitzAPI MCP server, which calls the same endpoints; they are shown here as the equivalent REST requests. Only the per-call count is shown: the balance of the account used for this glossary is not a public plan.

Credits are described here as other providers use them. BlitzAPI does not sell credits: its plans count records against a fair use policy.

Questions people ask

Which enrichment APIs don't charge per credit?

The ones sold on flat plans: a fixed monthly price for a request rate and a monthly volume, instead of a balance that each lookup draws down. BlitzAPI is one of them. Its plans count records, one per item returned, and a lookup that finds nothing counts nothing.

Do API credits expire?

Often, yes. Many credit plans reset at the end of each billing period, and prepaid balances can carry an expiry date. Read the terms before you buy a large balance, and compare the price per credit with the share of your expected volume you will really use.

Are empty lookups charged in API credits?

It depends on the provider. Some charge every request, found or not; others charge only the results they return. On a list where many lookups come back empty, that single rule can change the cost of a job more than the price of a credit does.

Is usage-based pricing the same as consumption-based pricing?

Yes, the two names describe the same model: you pay for what you consume, counted in a unit the provider defines, such as requests, results, records or compute time, and billed after the period. Prepaid credits are its cousin: the same meter, paid in advance.

How do I check my API credit balance?

Most APIs show it in the account dashboard, and many also return it in each response, in a header or a field, or from an account endpoint. Check it before a large job and after a small test batch, so you know what one useful result really costs.

With BlitzAPI

Put it to work

PricingBlitzAPI Pricing: B2B Data API Plans From $99 a MonthEvery endpoint on every plan. Start at $99 a month for 10 requests per second per endpoint, Scale at $499 for 25, Build Your Infra on a call.

For your team

For builders

The calls behind the real data on this page, as REST requests. Send them with your API key, from any language or workflow tool.

The job search

curl -X POST https://api.blitz-api.ai/v2/jobs/search \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "job": {
      "title": {"include": ["Revenue Operations Manager"]},
      "location": {"country_code": {"include": ["US"]}},
      "date_posted": {"last_days": 30}
    },
    "max_results": 3
  }'

API reference

The domain lookup that finds Stripe

curl -X POST https://api.blitz-api.ai/v2/enrichment/domain-to-linkedin \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"domain":"stripe.com"}'

API reference

The domain lookup that finds nothing

curl -X POST https://api.blitz-api.ai/v2/enrichment/domain-to-linkedin \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"domain":"no-company-here-blitz-glossary.com"}'

API reference

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