---
title: "Hello world"
url: "https://console.9fin.com/apis/demo-api/versions/0f60f9db-1bed-45fa-881c-d4876e2da06f/operations/hello_v0_demo_api_hello_get"
---

> Full API specification: https://console.9fin.com/apis/demo-api/versions/0f60f9db-1bed-45fa-881c-d4876e2da06f.md

# Hello world

`GET` `/v0/demo-api/hello`

Operation ID: `hello_v0_demo_api_hello_get`

Return a simple JSON greeting for smoke tests.

## Responses

- `200` - Successful Response
- `400` - Bad request.
- `500` - Unexpected server error.
- `503` - Service temporarily unavailable.

## OpenAPI definition

```yaml
openapi: 3.1.0
info:
  title: Demo API
  version: 0.3.0
servers:
  - description: Production environment
    url: https://api.9fin.com
paths:
  /v0/demo-api/hello:
    get:
      description: Return a simple JSON greeting for smoke tests.
      operationId: hello_v0_demo_api_hello_get
      responses:
        "200":
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/HelloResponse"
          description: Successful Response
        "400":
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
          description: Bad request.
        "500":
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/InternalServerErrorResponse"
          description: Unexpected server error.
        "503":
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
          description: Service temporarily unavailable.
      security:
        - HTTPBearer: []
      summary: Hello world
      tags:
        - Hello
security:
  - HTTPBearer: []
components:
  schemas:
    HelloResponse:
      description: Hello-world payload for smoke tests.
      properties:
        message:
          description: Greeting message.
          title: Message
          type: string
        service:
          description: Service identifier.
          title: Service
          type: string
      required:
        - message
        - service
      title: HelloResponse
      type: object
    ErrorResponse:
      description: Client-facing error envelope.
      examples:
        - error_code: bad_request
          message: The request could not be understood.
          trace_id: 202bde256c7d446f9623efdc96286c5d
        - error_code: service_unavailable
          message: Service is temporarily unavailable
          trace_id: c2416d52c6d14c8e831aad792407442c
      properties:
        error_code:
          title: Error Code
          type: string
        message:
          title: Message
          type: string
        trace_id:
          anyOf:
            - type: string
            - type: "null"
          title: Trace Id
      required:
        - error_code
        - message
      title: ErrorResponse
      type: object
    InternalServerErrorResponse:
      properties:
        error_code:
          examples:
            - internal_server_error
          title: Error Code
          type: string
        message:
          examples:
            - An unexpected error occurred.
          title: Message
          type: string
        trace_id:
          anyOf:
            - type: string
            - type: "null"
          examples:
            - e7dfd20231374d308f04655eb0538be4
          title: Trace Id
      required:
        - error_code
        - message
        - trace_id
      title: InternalServerErrorResponse
      type: object
  securitySchemes:
    HTTPBearer:
      bearerFormat: JWT
      scheme: bearer
      type: http
```