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# OpenAPI mock data generator

Generate seeded, schema-valid example requests and responses from an OpenAPI document and download them as test fixtures.
OpenAPI 2.0, 3.0 or 3.1 document, JSON or YAMLLoad a file instead

Paste a document to generate mocks.

Everything runs in this tab; the document is not uploaded. The tool reads OpenAPI 2.0, 3.0 and 3.1 in JSON or YAML and resolves only local #/ references: remote and file references are reported, not fetched. Validation covers required properties, enums, const, numeric bounds and multiples, string lengths, patterns and common formats; it is not a full JSON Schema checker. Determinism holds per engine version, not forever: the same document, options and seed give the same bytes for this version, so pin the downloaded fixtures file rather than the seed.
Options

## More regex & cron tools

- [JSON schema validator](/json/schema)
- [JSON schema generator](/json/schema-generator)
- [JSON formatter](/json/formatter)
[All regex & cron tools](/dev)

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Canonical HTML: https://nutter.tools/dev/openapi-mock-data-generator
Markdown version: https://nutter.tools/dev/openapi-mock-data-generator.md
Plain-text version: https://nutter.tools/dev/openapi-mock-data-generator.txt
Agent index: https://nutter.tools/llms.txt