> For the complete documentation index, see [llms.txt](https://springstreet.gitbook.io/springstreet.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://springstreet.gitbook.io/springstreet.io/api/openapi-specification.md).

# OpenAPI Specification

The Springstreet API is defined using the OpenAPI Specification (OAS)—a machine-readable standard for RESTful interfaces. This specification serves as the formal contract between our backend services and your implementation, ensuring predictable data structures and streamlined integration.

#### Engineering Utility

By utilizing this OpenAPI-compliant documentation, engineering teams can leverage the following workflows:

* Automated SDK Generation: Use tools like `openapi-generator` or `TypeSpec` to automatically produce type-safe client libraries in Python, TypeScript, Go, or Java.
* Mock Server Integration: Spin up local mock servers (using tools like Prism) to develop and test your frontend or middleware logic before making live requests to our production environment.
* Contract Validation: Validate that your request payloads match our expected schemas (e.g., UCC filing models) before transmission, reducing 400-level errors and debugging time.
* Interactive Testing: The "Try It Out" console in these docs allows for real-time interaction with the API, automatically handling header formatting and credential injection.

#### Why This Assists Developers

The OAS removes the guesswork from API consumption by providing a Shared Mental Model:

1. Strict Schema Definitions: Every object—from co-borrower arrays to database statistics—is defined in the `components/schemas` section, detailing specific data types, required fields, and regex constraints.
2. Versioning Transparency: Changes to endpoints or data structures are reflected in the spec versioning, allowing teams to track updates via GitHub diffs.
3. Reduced Onboarding Time: New developers can understand the entire surface area of the Springstreet lending data ecosystem by browsing the structured paths and response codes without needing to deep-dive into source code.

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#### Implementation Note

Our specification is synced directly from our private GitHub repository. This ensures that the documentation you see is always the current "Source of Truth" for the API's behavior.

> Tip: If you are using Postman or Insomnia, you can import our OpenAPI `.yaml` file directly to pre-configure your collections and environment variables.