Mock sample for your project: httpbin.org API

This API provides the two-letter state abbreviation (or the province abbreviation for Canada) for the purposes of standardizing state name data, improving query results, analytics, and data merging.

This API provides area code information for a given telephone area code.

The REST API for LGTM provides data so that you can customize how you integrate LGTM analysis into your workflow. It includes the following resources:
/ (API root)—get version information or download the specification in OpenAPI format.
/projects (Projects)—list projects, get a summary of the current status for a project, or add new projects.
/analyses (Analyses)—get a summary of results, download all the alerts, or trigger analysis for a specific commit.
/codereviews (Code reviews)—trigger code review for a patch, and view the results.
/operations (Operations)—get information about long-running tasks, for example, analyses or code reviews that you've requested.
/snapshots (Snapshots)—download and upload databases representing a snapshot of a codebase.
/queryjobs (Query jobs)—submit queries to evaluate against existing projects, and download their results.
/system (System)—get information on the health or usage of the system.
For an overview and getting started topics, see API for LGTM.

The Computer Vision API provides state-of-the-art algorithms to process images and return information. For example, it can be used to determine if an image contains mature content, or it can be used to find all the faces in an image. It also has other features like estimating dominant and accent colors, categorizing the content of images, and describing an image with complete English sentences. Additionally, it can also intelligently generate images thumbnails for displaying large images effectively.

This API provides XML to JSON, JSON to XML transformations.

This API retrieves the current time for a city or geographic location around the globe.

vRealize Network Insight API Reference

The Snyk API is available to customers on paid plans and allows you to programatically integrate with Snyk.
API vs CLI vs Snyk integration
The API detailed below has the ability to test a package for issues, as they are defined by Snyk. It is important to note that for many package managers, using this API will be less accurate than running the Snyk CLI as part of your build pipe, or just using it locally on your package. The reason for this is that more than one package version fit the requirements given in manifest files. Running the CLI locally tests the actual deployed code, and has an accurate snapshot of the dependency versions in use, while the API can only infer it, with inferior accuracy. It should be noted that the Snyk CLI has the ability to output machine-readable JSON output (with the --json flag to snyk test).
A third option, is to allow Snyk access to your development flow via the existing Snyk integrations. The advantage to this approach is having Snyk monitor every new pull request, and suggest fixes by opening new pull requests. This can be achieved either by integrating Snyk directly to your source code management (SCM) tool, or via a broker to allow greater security and auditability.
If those are not viable options, this API is your best choice.
API url
The base URL for all API endpoints is https://snyk.io/api/v1/
Authorization
To use this API, you must get your token from Snyk. It can be seen on https://snyk.io/account/ after you register with Snyk and login.
The token should be supplied in an Authorization header with the token, preceded by token:

The CircleCI API is a RESTful, fully-featured API that allows you to do almost anything in CircleCI.
You can access all information and trigger all actions.
The only thing we don’t provide access to is billing functions, which must be done from the CircleCI web UI.

Microsoft Visual Studio App Center API

This is a REST API reference for the Keycloak Admin