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

# Overall architecture

> How the Bridger Gateway connects OpenAPI sources to MCP clients.

Bridger converts OpenAPI-based data sources into MCP tools and handles authentication, routing, and
auditing in a single Gateway. Users call the Gateway endpoint without operating any servers of their own.

## Components

<CardGroup cols={2}>
  <Card title="Gateway" icon="cloud">
    The execution layer that exposes MCP JSON-RPC, SSE, and the Registry API.
  </Card>

  <Card title="Tool Registry" icon="boxes-stacked">
    Manages schemas, permissions, and routing for preset and BYOAPI-registered tools.
  </Card>

  <Card title="Public Data Adapter" icon="building-columns">
    Handles public-data service-key injection, coordinate conversion, XML/JSON normalization, and error mapping.
  </Card>

  <Card title="Admin Dashboard" icon="key">
    Manages API keys, Provider Keys, and audit logs.
  </Card>
</CardGroup>

## Runtime data flow

```text theme={null}
   Client (Claude · Cursor · ChatGPT · custom app)
        │
        │  MCP JSON-RPC / SSE / REST
        ▼
   ┌──────────────────────────────────────────────┐
   │            Bridger Gateway               │
   ├──────────────────────────────────────────────┤
   │  1. Authentication  (API Key / OAuth 2.0)     │
   │  2. Tenant isolation                           │
   │  3. Request control                            │
   │  4. JSON-RPC dispatch                          │
   │     ├─ tools/list → Registry lookup            │
   │     └─ tools/call → ID routing → Upstream Proxy│
   │  5. Public Data Adapter                        │
   │     ├─ ServiceKey auto-injection               │
   │     ├─ lat/lon → grid conversion               │
   │     └─ XML/JSON normalization                  │
   │  6. PII filtering                              │
   │  7. Audit logging                              │
   │  8. SSE event delivery (per tenant)            │
   └──────────────────────────────────────────────┘
        │
        ▼
   External APIs (data.go.kr · 3rd-party SaaS · self-registered APIs)
```

## Preset structure

A preset is a tool definition that carries both an OpenAPI spec and public-data metadata.

```yaml theme={null}
openapi: "3.0.3"
info:
  title: KMA Ultra-Short-Term Forecast API
  description: ...
  version: "1.0"
x-publicdata:
  provider: KMA
  dataGoKrId: "15070051"
servers:
  - url: https://apis.data.go.kr/...
paths:
  /getUltraSrtFcst:
    get:
      operationId: getUltraSrtFcst
      summary: Ultra-short-term forecast lookup
      parameters: [...]
```

## Next steps

<CardGroup cols={2}>
  <Card title="BYOAPI" icon="plug" href="/en/concepts/byoapi">
    How to register an arbitrary OpenAPI spec as a tool.
  </Card>

  <Card title="Auth & security" icon="shield" href="/en/concepts/auth-and-security">
    API keys, secrets, PII filtering, audit logs.
  </Card>
</CardGroup>