Build n8n nodes from OpenAPI specs and custom API mappings
by Iván Ovejero

Installation • Operation • Custom Spec Syntax

Nodebuilder is a utility to generate n8n node files from

• OpenAPI specs in JSON and YAML and
• custom API mappings in YAML.

Developed to automate the node creation process for:

• *.node.ts, logic for a regular node,
• GenericFunctions.ts, helper functions, and
• *Description.ts, parameter descriptions.

$ git clone https://github.com/ivov/nodebuilder.git
$ cd nodebuilder && npm i

1. Place the input file in src/input/openApi/
2. Run npm run generate
3. Inspect src/output/

Notes:

• OpenAPI parsing may fail at undetected edge cases. If your spec cannot be parsed, please open an issue.
• OpenAPI parsing needs to be adjusted to respect n8n's resources-and-operations format. Work in progress.

1. Write a YAML file in src/input/custom/
2. Run npm run generate
3. Inspect src/output/

For a full description of how to describe an API in YAML, refer to this explanation.

For a full example of an API description in YAML, refer to copper.yaml.

Run npm run place to place the output files in:

• an n8n clone dir (located alongside the nodebuilder dir), or
• the default custom nodes dir at ~/.n8n/custom.

OpenAPI:

• Add intermediate step to structure the result.
• Add support for more content types.

YAML:

• Add support for multiOptions

Generator:

• Add resource loaders to the TypeScript generator.
• Generate *.credentials.ts

Extras:

• Implement testing with git.js
• Explore integration with VSCode YAML

© 2021 Iván Ovejero

Distributed under the MIT License. See LICENSE.md.