📥 Import OpenAPI and Postman collections

LiveMock can turn an API description into a set of expectations, so you do not have to re-create every endpoint by hand.

Supported formats

Source	Versions
OpenAPI	3.0 / 3.1 (JSON or YAML)
Swagger	2.0 (JSON or YAML, converted to OpenAPI 3 first)
Postman Collection	v2.0 / v2.1 (JSON)

The format is detected automatically. A file that is none of the above is rejected with a message.

Importing

Imported expectations are appended to the currently open project. To start from a clean slate, either import into a new project or delete the existing expectations first.

Upload the file (click or drag it into the drop area) and choose the options:

Option	Default	Effect
Path prefix	off	When on, the path prefix of the first servers entry in an OpenAPI document is kept in front of every path. The host is always ignored; servers entries that still contain an unresolved {variable} are skipped.
Overwrite existing	off	When on, an imported operation replaces an existing expectation with the same method and path. When off, such operations are skipped.

Then click Import. The result dialog lists how many expectations were created, overwritten and skipped, plus the reason for every entry that could not be imported.

What is generated

One expectation per OpenAPI operation

• Matchers - exactly two: method and path.
  • A path without parameters becomes a path IS matcher, for example /users.
  • A path with parameters becomes a path MATCH_GLOB matcher, where each {param} is replaced by *, for example /users/{id} becomes /users/*.
• Status and body - the first 2xx response is used, preferring 200, then 201; when there is no 2xx, default is used (treated as 200), otherwise the first declared response.
• Body source, in order of preference: the first entry of examples, then example, then a value sampled from the schema (formats such as date-time, email, uuid, uri and hostname produce deterministic samples), and finally {}.
• Response type - a JSON media type becomes a JSON response with the value pretty-printed; any other media type becomes plain text. An operation without a body (for example a 204) gets an empty JSON response.
• Name - summary, then operationId, then METHOD /path.
• Other fields - the expectation is active, with delay 0 and priority 0. Deprecated operations are imported like any other.

One expectation per Postman request

• Folders are flattened; disabled items and non-HTTP items (websocket, gRPC, …) are skipped and reported.
• Method comes from the request (default GET).
• Path is the pathname of the URL, so the host and the query string are dropped. Collection variables are resolved with their default values. A path that still contains an unresolved {{variable}} is skipped.
• Placeholders such as :id become *, and a path with * uses MATCH_GLOB (same rule as OpenAPI).
• Status and body come from the first saved 2xx example of the request; without a saved example you get 200 and {}. JSON previews and parseable bodies become JSON responses, everything else plain text.

Duplicates

An import is considered a duplicate when the method value and the path matcher value already exist in the project. With Overwrite existing the existing expectation keeps its id and its timing and state, while its name, matchers and actions are replaced. A failure on one operation does not roll back the rest of the import.