> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vh3.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Architecture and APIs

> API surfaces, authentication, and where your data lives.

## Architecture and APIs

<AccordionGroup>
  <Accordion title="What are the main API surfaces?">
    You receive a single VH3 API key during onboarding. It is used across both server-to-server surfaces:

    | API                 | Base URL                                 | Auth                                         |
    | ------------------- | ---------------------------------------- | -------------------------------------------- |
    | VH3 AI Intelligence | `https://api.vh3connect.io/api:kP8T1CK7` | `company_id` + `api_key` in the request body |
    | BigChange API       | `https://api.vh3connect.io/api:YdihQNr3` | `X-API-Key` header only                      |

    Intelligence endpoints require your company ID on every request. BigChange proxy endpoints resolve your tenant from the API key alone.

    For interactive applications and custom portals, users authenticate with email and password. The returned JWT is used for all subsequent calls. No API key is ever involved in client-side code.

    See [Authentication](/authentication) for the complete surface map and code examples.
  </Accordion>

  <Accordion title="Why do the public docs not match an endpoint I see in VH3 Connect?">
    The public API reference documents the customer-facing subset. Additional endpoints exist for platform engineering, pollers, and operational tooling. Those internal endpoints are outside the integration contract. For integrations, use the endpoints documented here or the OpenAPI export your CSM provides.
  </Accordion>

  <Accordion title="Where does my data live?">
    | Layer                 | What is stored                                                                                       |
    | --------------------- | ---------------------------------------------------------------------------------------------------- |
    | Knowledge graph       | Jobs, engineers, customers, outcomes, relationships, and SLA analytics, traversable in any direction |
    | Semantic search index | Intake descriptions and diagnostic outcomes, indexed by meaning for fault discovery                  |
    | Platform data         | Cases, teams, notifications, usage, and configuration                                                |
    | Your FMS              | Your operational system of record for dispatch, scheduling, worksheets, and job execution            |
  </Accordion>
</AccordionGroup>