API archive entry · source-reported

hashlookup CIRCL API

![](https://www.circl.lu/assets/images/circl-logo.png) CIRCL hash lookup is a public API to lookup hash values against known database of files. For more details about all the datasets included visit the website of the project. The API is accessible via HTTP ReST API and the API is also described as an OpenAPI. A documentation is available with with sample queries and software using hashlookup. An offline version as Bloom filter is also available. The API can be tested live in the interface below.

Provider / source website

Plan the first integration safely

The access fields below come from the connected directory. Their likely implementation impact is explained without assuming provider-specific behavior.

Authentication

OAuth is reported. Confirm flows, scopes, consent, token lifetime, and refresh rules.

Transport

HTTPS is not confirmed. Do not send credentials or production data until secure transport is verified.

Browser access

CORS is unknown. Treat direct browser access as unconfirmed and test before choosing a client-only architecture.

First-request sequence

  1. Identify the current base URL, version, and endpoint for the use case.
  2. Confirm how credentials are issued and where they may be stored.
  3. Test success, invalid input, throttling, unavailable data, and timeouts.
  4. Record response fields, pagination, caching, and error shapes.
  5. Add monitoring, retries with backoff, and an appropriate fallback.

Questions to resolve before production

Pricing and quotas

Confirm current plans, free-tier limits, overages, and request ceilings.

Endpoint coverage

Check that the operations and response fields match the intended workload.

Reliability

Look for uptime history, a status page, support routes, and service commitments.

Data and privacy

Review retention, licensing, regional processing, and compliance requirements.

Versioning

Confirm the active version, change policy, deprecation window, and migration guidance.

Developer experience

Validate SDKs, examples, error formats, pagination, and test environments.

Source reference

APIs.guru OpenAPI Directory

This page separates source-reported facts from questions that need live provider verification.