openapi-mergeMerge OpenAPI documents, deterministically

Combine multiple OpenAPI 3.0, 3.1 or 3.2 files into one — from the command line or from TypeScript — for the common case of exposing several microservices behind a single API gateway.

Which package do I want?

CLI reference

Library reference

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Deterministic merging

The first input always takes precedence for element-level conflicts (info, servers, security schemes), while paths, components and tags are merged so nothing is silently dropped.

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CLI or library

Merge from a YAML/JSON config file with openapi-merge-cli, or call merge() directly from TypeScript/JavaScript with openapi-merge — the CLI is a thin wrapper around the library.

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OpenAPI 3.0, 3.1 and 3.2

Merges webhooks, components.pathItems, additionalOperations custom verbs, and the other constructs newer OpenAPI versions introduce — not just the 3.0 subset.

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Safe by default for untrusted input

inputRoot / outputRoot (and their CLI flags) bound where the CLI will read from and write to, for the case where the configuration or inputs aren't fully trusted.