Budibase/budibase · error · Error

Empty OpenAPI document

Error message

Empty OpenAPI document

What it means

prepareDocument is the first step of OpenAPI parsing: it trims the raw input and rejects empty input with 'Empty OpenAPI document' before attempting YAML/JSON parsing. This gives a clear early error instead of a confusing parser failure downstream.

Source

Thrown at packages/server/src/api/controllers/query/import/sources/base/openapi.ts:17

import SwaggerParser from "@apidevtools/swagger-parser"
import { load as loadYaml } from "js-yaml"
import isObject from "lodash/isObject"
import { OpenAPI } from "openapi-types"
import { ImportSource } from "."

const isYamlDocument = (loaded: unknown): loaded is OpenAPI.Document => {
  if (isObject(loaded)) {
    return true
  }
  return false
}

const prepareDocument = (raw: string): string | OpenAPI.Document => {
  const trimmed = raw.trim()
  if (!trimmed) {
    throw new Error("Empty OpenAPI document")
  }

  try {
    const yamlDocument = loadYaml(trimmed, {
      // allow duplicate keys so large vendor specs (e.g. Okta) still parse
      json: true,
    })
    if (isYamlDocument(yamlDocument)) {
      return yamlDocument
    }
  } catch (err) {
    // fall through to allow swagger parser to attempt parsing
  }

  return raw
}

export abstract class OpenAPISource extends ImportSource {

View on GitHub (pinned to a81a902e9a)

Solutions

1. Verify the input string is non-empty and contains the actual YAML/JSON spec before loading
2. If loading via URL, curl the URL and check the body is not empty (a 200 with empty content)
3. Fix file reading so the spec content is actually read and passed, not an empty string

Example fix

// before
const data = fs.readFileSync(path, "utf8") // wrong path, ''
await RestImporter.init(data, "openapi3.0")
// after
const data = fs.readFileSync(correctPath, "utf8")
if (!data.trim()) throw new Error("spec file is empty")
await RestImporter.init(data, "openapi3.0")

if (!data || !data.trim()) {
  throw new Error("Spec content is empty — provide the OpenAPI YAML/JSON body")
}

const isNonEmptyString = (v: unknown): v is string =>
  typeof v === "string" && v.trim().length > 0

null

When it happens

Trigger: Loading an OpenAPI source with data that is empty or whitespace-only — e.g. an empty file, a spec fetched as an empty body, or a variable that was never assigned.

Common situations: URL import returned 200 with an empty body (misconfigured server); reading a file with the wrong path yielding ''; a form submission where the paste box was blank but whitespace satisfied a naive check.

Related errors

• Unsupported import data
• Selected endpoint could not be imported
• Unsupported method: ${method}
• Failed to load OpenAPI 2 document
• Failed to load OpenAPI 3 document

AI-assisted analysis of Budibase/budibase@a81a902e9a (2026-08-29). Data as JSON: /api/errors/526b74e7549fdddb. Report an issue: GitHub.