Mock sample for your project: link.fish API

This API provides a similarity key used to match with other similar country name data, including for purposes of deduplication, fuzzy matching, or merging of datasets. A much higher match rate will be achieved by matching on the algorithmically generated similarity key rather than the data itself.

Airbyte Configuration API
https://airbyte.io.
This API is a collection of HTTP RPC-style methods. While it is not a REST API, those familiar with REST should find the conventions of this API recognizable.
Here are some conventions that this API follows:
All endpoints are http POST methods.
All endpoints accept data via application/json request bodies. The API does not accept any data via query params.
The naming convention for endpoints is: localhost:8000/{VERSION}/{METHODFAMILY}/{METHODNAME} e.g. localhost:8000/v1/connections/create.
For all update methods, the whole object must be passed in, even the fields that did not change.
Change Management:
The major version of the API endpoint can be determined / specified in the URL localhost:8080/v1/connections/create
Minor version bumps will be invisible to the end user. The user cannot specify minor versions in requests.
All backwards incompatible changes will happen in major version bumps. We will not make backwards incompatible changes in minor version bumps. Examples of non-breaking changes (includes but not limited to...):
Adding fields to request or response bodies.
Adding new HTTP endpoints.

Visual Search API lets you discover insights about an image such as visually similar images, shopping sources, and related searches. The API can also perform text recognition, identify entities (people, places, things), return other topical content for the user to explore, and more. For more information, see Visual Search Overview. NOTE: To comply with the new EU Copyright Directive in France, the Bing Visual Search API must omit some content from certain EU News sources for French users. The removed content may include thumbnail images and videos, video previews, and snippets which accompany search results from these sources. As a consequence, the Bing APIs may serve fewer results with thumbnail images and videos, video previews, and snippets to French users.

Stack Exchange is a network of 130+ Q&A communities including Stack Overflow.

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 News Search API lets you send a search query to Bing and get back a list of news that are relevant to the search query. This section provides technical details about the query parameters and headers that you use to request news and the JSON response objects that contain them. For examples that show how to make requests, see Searching the web for news.

The GeoDB API focuses on getting global city and region data. Easily obtain country, region, and city data for use
in your apps!
Filter cities by name prefix, country, location, time-zone, and even minimum population.
Sort cities by name, country code, elevation, and population - or any combination of these.
Get all country regions. Get all cities in a given region.
Display results in multiple languages. RESTful API adheres to industry best-practices, including
HATEOAS-style links to facilitate paging results.
Backed by cloud-based load-balanced infrastructure for resiliency and performance!
Data is periodically refreshed from GeoNames and WikiData.
Notes:
Since the database is periodically updated, this may very rarely result in certain cities
being marked deleted (e.g., duplicates removed). By default, endpoints returning city data will exclude
cities marked deleted. However, in the unlikely event that this occurs while your app is paging through a set
of affected results - and you care about the paged results suddenly changing underneath - specify
includeDeleted=SINCEYESTERDAY (or SINCELAST_WEEK if you're really paranoid!).
Useful Resources
SDKs
Angular,
Sample App
Java
JavaScript
Swagger Docs
Usage License

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

The Web Search API lets you send a search query to Bing and get back search results that include links to webpages, images, and more.

This API provides current weather information for US Cities, including temperatures, wind speeds, wind direction, relative humidity, and visibility.