Glossary

Two kinds of term are mixed together below: general vocabulary, and words that mean something particular at APIVerve. Where the two differ, the APIVerve meaning is the one stated.

A

API (Application Programming Interface) — a contract letting one piece of software call another. Everything here is a REST API called over HTTPS.

API key — the credential identifying your account. It is a bearer credential: whoever holds it can spend your credits. See authentication.

Asynchronous — a call that does not block while waiting for the response. Every SDK here supports it; nothing about the API requires it.

Authentication — proving who you are. Here that is the API key, and nothing else.

Authorization — what you are allowed to do once identified. Determined by your plan and by any restrictions on the key. Worth keeping distinct from authentication: the two fail for different reasons and are fixed in different places.

B

Base URL — https://api.apiverve.com/v1/. Endpoint paths hang off it.

Batch — sending several inputs in one request instead of one call each. Available per endpoint at POST /v1/<endpoint>/batch; see batch requests.

Billing cycle — the month your allowance is counted over. It runs from your signup date on the free plan and from your subscription date on a paid one, not from the first of the month.

Body — the content of a request or response. Endpoints that take a body take JSON.

C

Cache — keeping a response so you do not fetch it again. The single most effective way to cut usage, because most integrations look up the same values repeatedly.

Concurrency — how many of your requests may be in flight at the same moment. A separate limit from the per-minute rate; see rate limits.

Client — the code making the request. Yours.

Content-Type — the header describing the format of a body. application/json for requests that have one.

CORS (Cross-Origin Resource Sharing) — the browser mechanism deciding whether a page may call another origin. The API does not permit browser calls, deliberately: a key in a page is readable by anyone who loads it. Call from your backend, or use an embedded form. See CORS.

Credit — the unit of usage. Most calls cost one credit and some cost more; each reference page states its own. Failed calls are not billed.

cURL — the command-line HTTP client. The examples throughout these docs start with it because it is the shortest complete way to state a request.

D

Dashboard — dashboard.apiverve.com, where keys, usage and billing live.

Deprecation — announcing that something will be removed while it still works. Deprecated things keep functioning until a stated date.

E

Endpoint — one callable path, and the unit everything else is counted in. /v1/emailvalidator is an endpoint; it has its own parameters, response fields, credit cost and reference page.

Envelope — the three keys wrapping every response: status, error and data. It is the same on every endpoint, which is why one response handler covers your whole integration. See response format.

Environment variable — a value supplied to your program from outside its source. Where your API key should live. See security.

Error handling — deciding what happens on each failure. The distinction that matters is which failures are worth retrying and which are identical on the next attempt. See errors.

F–G

Free plan — a real plan that renews monthly, not a trial that expires. It is also the test environment, since every source behaves identically on every plan.

GET — the HTTP method for retrieving something. Most endpoints here are GET, with parameters in the query string.

GraphQL — a query language letting one request ask for exactly what it needs, across several endpoints at once. In alpha; see GraphQL.

H

Header — metadata on a request or response. x-api-key on the way out; x-api-remaining-credits and, when a limit is hit, the x-rate-limit-* family on the way back. See request headers.

HTTPS — HTTP over TLS. The only way to reach the API; plain HTTP is not served.

I–J

Idempotent — safe to repeat with the same result. The lookups here are, in the sense that repeating one returns the same answer — but each repeat still costs a credit, so idempotent does not mean free.

Integration — connecting your system to the API, whether in code or through a platform like Zapier or Make. See integrations.

JSON — the default response format, and the one every example uses.

JSON bin — a small hosted store for JSON, useful as workflow state or configuration. Part of VerveKit.

L–M

Latency — how long a call takes. Varies by source — a lookup answers far faster than something that renders a page — and each reference page shows its own typical figure.

MCP (Model Context Protocol) — the standard letting an AI assistant call tools. Endpoints are exposed as MCP tools, so a model can use them directly. See MCP.

Mock endpoint — a URL you define that returns a response you choose. For building against a shape before the real call exists, and for testing error paths without provoking real errors. Free. See mock endpoints.

O–P

OAuth — a framework for delegated access. You sign in once and the client holds a token, so no key is written into a config file or a workbook.

OpenAPI — the standard for describing a REST API in a machine-readable document. Every endpoint publishes one, which is what generates the SDKs, the Postman collection and the connector definitions.

Parameter — an input to an endpoint, required or optional, in the query string or the body. The reference page for each endpoint lists them with types and constraints.

Plan — your subscription level. It sets your monthly allowance, rate limit, concurrency and which features are available:

POST — the HTTP method for sending data. Used by endpoints that take more input than fits comfortably in a URL.

Postman — an API client. The whole catalog is published as a Postman collection.

Premium field — a response field included on higher plans. Premium fields are absent rather than null on plans without them.

Primary key — the account's main API key, as distinct from a sub-key.

Q–R

Query string — parameters after the ? in a URL. How GET endpoints take their input. Values with spaces or special characters must be URL-encoded.

Quota — your monthly credit allowance. Exhausting it looks like a rate limit and is not one; see rate limits.

Rate limit — the ceiling on calls per minute, set by your plan. Distinct from your quota: the rate limit resets every minute, the quota every billing cycle. See rate limits.

Reference page — the per-source page carrying parameters, response fields, credit cost, latency and examples. The authoritative description of any source.

Request — one call: a URL, a method, headers, and parameters or a body.

Response — what comes back, always in the envelope described above.

REST — the architectural style the API follows: ordinary HTTP methods, stateless requests, no session to maintain.

Retry logic — automatically re-sending a failed request after a delay. Use exponential backoff, and only for 429 and 5xx — retrying a 400 re-sends a request that was wrong the first time.

Rotation — replacing your API key with a new one. Instant, with no grace period, so every system holding the old key stops working at once. See key rotation.

S

Schema — the formal description of a source's inputs and outputs. What the platform validates against, and what everything generated — reference pages, tool definitions, argument autocomplete — is generated from.

SDK — a generated client package for one endpoint in one language. Published to npm, NuGet, PyPI, Go, Maven, Packagist and pub.dev. See SDKs.

Status code — the HTTP result. 200 success, 400 bad parameter, 401 invalid key, 403 key not permitted for this call, 404 no such endpoint on this door, 413 payload too large, 429 rate limit or out of credits, 5xx our problem.

Sub-key — an additional credential billing to the same account, individually scopable and revocable. The right credential for a per-environment, per-client or per-agent integration. See sub-keys.

T–U

Throttling — limiting call rate to protect a service. When you are throttled, waiting is the whole fix.

Timeout — how long you wait before abandoning a request. Set it generously for endpoints that render or convert; note that calls made through an integration connector are cut off at 25 seconds regardless of what you set.

TLS — the encryption underneath HTTPS. All traffic uses it.

URL encoding — escaping characters that are not safe in a URL. Necessary for any parameter containing a space, an ampersand or a +, and a common cause of a 400 that looks inexplicable.

V–X

Versioning — keeping old behaviour working while new behaviour ships.

VerveKit — the developer tools alongside the API: MCP, JSON bins, mock endpoints and embedded forms. See VerveKit.

Webhook — a URL a service calls when something happens. Endpoints here are request/response and do not call you; to react to events, trigger the call from a platform that has triggers. See integrations.

Workspace — one account's view of the dashboard. You always have your own, and joining a team gives you access to theirs. See workspaces.

x-api-key — the request header carrying your key. The only authentication the API needs.

XML — an alternative response serialisation, available through the Accept header alongside YAML, CSV and Markdown. All of them carry the same envelope.

Next

Quickstart puts most of these into one working example, and the FAQ answers the questions that come after it.