Importing OpenAPI Specs

Import Methods

Import an OpenAPI or Swagger specification to create a new project. All endpoints, schemas, and security configurations are converted automatically.

From URL

Enter a URL to a hosted spec file

Upload File

Select a local .json, .yaml, or .yml file

Paste Content

Paste YAML or JSON directly

How to Import

1

Open New Project Dialog

Click "New Project" in the Projects section of the sidebar.

2

Select "Import OpenAPI" Tab

Switch from "From Scratch" to "Import OpenAPI".

3

Choose Import Method

Select URL, File, or Paste and provide your spec.

4

Click "Import & Open"

Tigrister parses the spec, creates the project, and opens the Designer.

Create New Project×
From ScratchImport OpenAPI
URLFilePaste

Enter a URL to a JSON or YAML OpenAPI spec

What Gets Imported

Everything in your OpenAPI spec is converted to Tigrister's project structure:

API Structure
  • Info - Title, description, version, contact
  • Tags - Become Modules in Tigrister
  • Paths - Become Endpoints with full configuration
  • Servers - Base URLs for the API
Components
  • Schemas - Data models for request/response
  • Security Schemes - API Key, OAuth2, etc.
  • Parameters - Query, header, path, cookie params
  • Webhooks - OpenAPI 3.1 webhook definitions

Swagger 2.0 Auto-Conversion

Automatic

When you import a Swagger 2.0 specification, Tigrister automatically converts it to OpenAPI 3.0.3.

Conversion includes:
  • host + basePath + schemesservers array
  • definitionscomponents/schemas
  • securityDefinitionscomponents/securitySchemes
  • Body parameters → requestBody
  • consumes/produces → Content-Type in operations

Note

After import, a badge shows "Swagger 2.0 → 3.0" in the toolbar. The converted spec can then be exported as OpenAPI 3.0 or 3.1.

Common Import Errors

If import fails, check for these common issues:

Invalid YAML/JSON Syntax

Error: YAML parsing failed at line 15
Unexpected token '}' at position 234

Fix: Check for missing colons, wrong indentation, or unclosed brackets.

Not a Valid OpenAPI Spec

Error: Missing required field 'openapi' or 'swagger'
Error: Missing required field 'info'

Fix: Ensure file has openapi: "3.x.x" or swagger: "2.0" at root.

URL Fetch Failed

Error: Failed to fetch from URL
Error: CORS policy blocked the request

Fix: Download the file manually and use "Upload File" instead.

Invalid $ref Reference

Warning: Could not resolve $ref '#/components/schemas/Missing'

Fix: Ensure all referenced schemas exist in components/schemas.

Post-Import Checklist

After importing, verify everything looks correct:

Structure

All modules (tags) appear in sidebar
Endpoints are grouped correctly
Server URLs are set in environments

Content

Security schemes appear in Authorize
Parameters have correct types
Request/response schemas visible

Quick Test

Try sending a request to a simple GET endpoint to verify the base URL and auth work correctly.

Handling Large Specs

Large API specs (1000+ endpoints) may take longer to import. Tips for best results:

Use File Upload for Large Specs

Downloading locally first avoids timeout issues with URL import.

Consider Splitting by Tag

If you only need certain endpoints, extract those paths into a smaller spec.

Be Patient with GitHub/Stripe APIs

These specs have 500+ endpoints and may take 10-20 seconds to fully load.

Spec SizeEndpointsExpected Load Time
Small< 50< 1 second
Medium50-2001-3 seconds
Large200+5-20 seconds

Try It Out

Import a popular public API spec to explore the feature:

Petstore (OpenAPI 3.0)

https://petstore3.swagger.io/api/v3/openapi.json

Recommended

GitHub API

https://raw.githubusercontent.com/github/rest-api-description/main/descriptions/api.github.com/api.github.com.json

Large

Stripe API

https://raw.githubusercontent.com/stripe/openapi/master/openapi/spec3.json

Large

Twilio API

https://raw.githubusercontent.com/twilio/twilio-oai/main/spec/json/twilio_api_v2010.json

Slack Web API

https://raw.githubusercontent.com/slackapi/slack-api-specs/master/web-api/slack_web_openapi_v2.json

Swagger 2.0