OpenAPI to Bruno
Convert an OpenAPI specification into a Bruno collection folder you can open in the app or run with the CLI.
bru import openapi --source <openapi.yaml> --output <output-folder>. See bru import. Use the script below when you want to process the collection in your own code.
Convert the specification
1. Read the arguments
Import the converter, the file writers from @usebruno/filestore, and Node's file helpers. Take the paths from the command line and print a usage line if any are missing. format is 'yml' for OpenCollection YAML or 'bru' for classic .bru files.
const [inputFile, outputDir] = process.argv.slice(2);
if (!inputFile || !outputDir) {
console.error('Usage: node convert.mjs <openapi.yaml> <output-folder>');
process.exit(1);
}
const format = 'yml';
2. Add the helpers
safeName strips characters that are not allowed in file names. write saves a file and creates any missing parent folders.
const safeName = (name) => name.replace(/[<>:"/\\|?*\x00-\x1F]/g, '-');
const write = async (file, content) => {
await mkdir(path.dirname(file), { recursive: true });
await writeFile(file, content);
};
3. Convert
openApiToBruno accepts the specification as JSON or YAML and returns the Bruno collection. Pass { groupBy: 'path' } as a second argument to group folders by path instead of tag. See the API Reference for the full signature.
const collection = openApiToBruno(await readFile(inputFile, 'utf8'));
4. Write the collection settings and environments
brunoConfig holds the collection settings. For .bru collections it is written to bruno.json. For yml it is embedded in opencollection.yml. The collection root holds collection-level auth, headers, and scripts. Each environment gets its own file in the environments folder.
const brunoConfig = { version: collection.version, name: collection.name, type: 'collection', ignore: ['node_modules', '.git'] };
const root = stringifyCollection(collection.root || {}, brunoConfig, { format });
if (format === 'yml') {
await write(path.join(outputDir, 'opencollection.yml'), root);
} else {
await write(path.join(outputDir, 'bruno.json'), JSON.stringify(brunoConfig, null, 2));
await write(path.join(outputDir, 'collection.bru'), root);
}
for (const env of collection.environments || []) {
await write(path.join(outputDir, 'environments', `${safeName(env.name)}.${format}`), stringifyEnvironment(env, { format }));
}
5. Write the folders and requests
Each folder becomes a directory and each request a file. Folder-level auth, headers, and scripts go in folder.yml or folder.bru. A stack is used instead of recursion so deeply nested collections are safe.
const stack = collection.items.map((item) => [item, outputDir]);
while (stack.length) {
const [item, parent] = stack.pop();
if (item.type === 'folder') {
const folderDir = path.join(parent, safeName(item.name));
await mkdir(folderDir, { recursive: true });
if (item.root) await write(path.join(folderDir, `folder.${format}`), stringifyFolder(item.root, { format }));
for (const child of item.items || []) stack.push([child, folderDir]);
} else {
await write(path.join(parent, `${safeName(item.name)}.${format}`), stringifyRequest(item, { format }));
}
}
6. Report
Print where the collection was written.
console.log(`Collection written to ${outputDir}`);
7. Run the script
Run the script with Node.js, passing the paths as arguments.
```bash convert.js
node convert.js <openapi.yaml> <output-folder>
Where:
<openapi.yaml>: The OpenAPI specification, as JSON or YAML<output-folder>: The folder to create the Bruno collection in. It is created if it does not exist
The output folder looks like this (with format set to 'bru', the files are bruno.json, collection.bru, folder.bru, and .bru requests instead):
my-collection/
├── opencollection.yml
├── environments/
│ └── Environment 1.yml
└── pets/
├── folder.yml
├── List pets.yml
└── Create pet.yml
One folder per tag, one file per operation, and an environment holding the base URL from the spec's servers.
Full script
The complete script, ready to copy. convert.mjs is an ES module with top-level await. convert.js is the same script as CommonJS, with the steps inside an async main function.
// ---- Arguments ----
const [inputFile, outputDir] = process.argv.slice(2);
if (!inputFile || !outputDir) {
console.error('Usage: node convert.mjs
// 'yml' (OpenCollection YAML) or 'bru' (classic .bru files) const format = 'yml';
// ---- Helpers ----
// Strip characters not allowed in file names const safeName = (name) => name.replace(/[<>:"/\|?*\x00-\x1F]/g, '-');
// Write a file, creating parent folders as needed const write = async (file, content) => { await mkdir(path.dirname(file), { recursive: true }); await writeFile(file, content); };
// ---- Convert ----
// Accepts JSON or YAML. Pass { groupBy: 'path' } as a second argument to group folders by path instead of tag. const collection = openApiToBruno(await readFile(inputFile, 'utf8'));
// ---- Write the collection folder ----
// Collection settings: bruno.json for .bru, embedded in opencollection.yml for yml const brunoConfig = { version: collection.version, name: collection.name, type: 'collection', ignore: ['node_modules', '.git'] };
// Collection-level auth, headers, and scripts const root = stringifyCollection(collection.root || {}, brunoConfig, { format }); if (format === 'yml') { await write(path.join(outputDir, 'opencollection.yml'), root); } else { await write(path.join(outputDir, 'bruno.json'), JSON.stringify(brunoConfig, null, 2)); await write(path.join(outputDir, 'collection.bru'), root); }
// One file per environment
for (const env of collection.environments || []) {
await write(path.join(outputDir, 'environments', ${safeName(env.name)}.${format}), stringifyEnvironment(env, { format }));
}
// Folders become directories, requests become files. A stack avoids recursion on deep trees.
const stack = collection.items.map((item) => [item, outputDir]);
while (stack.length) {
const [item, parent] = stack.pop();
if (item.type === 'folder') {
const folderDir = path.join(parent, safeName(item.name));
await mkdir(folderDir, { recursive: true });
// Folder-level auth, headers, and scripts
if (item.root) await write(path.join(folderDir, folder.${format}), stringifyFolder(item.root, { format }));
for (const child of item.items || []) stack.push([child, folderDir]);
} else {
await write(path.join(parent, ${safeName(item.name)}.${format}), stringifyRequest(item, { format }));
}
}
// ---- Report ----
console.log(Collection written to ${outputDir});
```javascript convert.js
// Converts an OpenAPI specification into a Bruno collection folder.
// Usage: node convert.js <openapi.yaml> <output-folder>
const { openApiToBruno } = require('@usebruno/converters');
const { stringifyCollection, stringifyFolder, stringifyRequest, stringifyEnvironment } = require('@usebruno/filestore');
const { mkdir, readFile, writeFile } = require('fs/promises');
const path = require('path');
// ---- Arguments ----
const [inputFile, outputDir] = process.argv.slice(2);
if (!inputFile || !outputDir) {
console.error('Usage: node convert.js <openapi.yaml> <output-folder>');
process.exit(1);
}
// 'yml' (OpenCollection YAML) or 'bru' (classic .bru files)
const format = 'yml';
// ---- Helpers ----
// Strip characters not allowed in file names
const safeName = (name) => name.replace(/[<>:"/\\|?*\x00-\x1F]/g, '-');
// Write a file, creating parent folders as needed
const write = async (file, content) => {
await mkdir(path.dirname(file), { recursive: true });
await writeFile(file, content);
};
// CommonJS cannot use top-level await, so the steps run inside an async function
async function main() {
// ---- Convert ----
// Accepts JSON or YAML. Pass { groupBy: 'path' } as a second argument to group folders by path instead of tag.
const collection = openApiToBruno(await readFile(inputFile, 'utf8'));
// ---- Write the collection folder ----
// Collection settings: bruno.json for .bru, embedded in opencollection.yml for yml
const brunoConfig = { version: collection.version, name: collection.name, type: 'collection', ignore: ['node_modules', '.git'] };
// Collection-level auth, headers, and scripts
const root = stringifyCollection(collection.root || {}, brunoConfig, { format });
if (format === 'yml') {
await write(path.join(outputDir, 'opencollection.yml'), root);
} else {
await write(path.join(outputDir, 'bruno.json'), JSON.stringify(brunoConfig, null, 2));
await write(path.join(outputDir, 'collection.bru'), root);
}
// One file per environment
for (const env of collection.environments || []) {
await write(path.join(outputDir, 'environments', `${safeName(env.name)}.${format}`), stringifyEnvironment(env, { format }));
}
// Folders become directories, requests become files. A stack avoids recursion on deep trees.
const stack = collection.items.map((item) => [item, outputDir]);
while (stack.length) {
const [item, parent] = stack.pop();
if (item.type === 'folder') {
const folderDir = path.join(parent, safeName(item.name));
await mkdir(folderDir, { recursive: true });
// Folder-level auth, headers, and scripts
if (item.root) await write(path.join(folderDir, `folder.${format}`), stringifyFolder(item.root, { format }));
for (const child of item.items || []) stack.push([child, folderDir]);
} else {
await write(path.join(parent, `${safeName(item.name)}.${format}`), stringifyRequest(item, { format }));
}
}
// ---- Report ----
console.log(`Collection written to ${outputDir}`);
}
main();
Open the collection in the app or run it with the CLI
The spec's servers become an environment holding the base URL. Select it in the app, or pass its name to --env.