data-api-builder

Supports Mcp

Data API builder (DAB) is an open-source, no-code tool that creates secure, full-featured REST and GraphQL endpoints for your database. It’s a CRUD data API engine that runs in a container—on Azure, any other cloud, or on-premises. DAB is built for developers with integrated tooling, telemetry, and other productivity features.

[!IMPORTANT] Data API builder (DAB) is open source and always free.

Which databases does Data API builder support?

Which environments does Data API builder support?

Which endpoints does Data API builder support?

Use the Getting Started tutorial to quickly explore the core tools and concepts.

1. Install the dotnet command line

https://get.dot.net

[!NOTE] You may already have .NET installed!

The Data API builder (DAB) command line requires the .NET runtime version 8 or later.

Validate your installation

dotnet --version

2. Install the dab command line

The Data API builder (DAB) command line is cross-platform and intended for local developer use.

dotnet tool install microsoft.dataapibuilder -g

Validate your installation

dab --version

3. Create your database (example: Azure SQL database / T-SQL)

This example uses a single table for simplicity.

CREATE TABLE dbo.Todo
(
    Id INT PRIMARY KEY IDENTITY,
    Title NVARCHAR(500) NOT NULL,
    IsCompleted BIT NOT NULL DEFAULT 0
);
INSERT dbo.Todo (Title, IsCompleted)
VALUES
    ('Walk the dog', 0),
    ('Feed the fish', 0),
    ('Clean the cat', 1);

4. Prepare your connection string

Data API builder (DAB) supports .env files for testing process-level environment variables.

PowerShell (Windows)

echo "my-connection-string=$env:database_connection_string" > .env

cmd.exe (Windows)

echo my-connection-string=%database_connection_string% > .env

bash (macOS/Linux)

echo "my-connection-string=$database_connection_string" > .env

Resulting .env file

The file .env is automatically created through this process. These are the resulting contents:

"my-connection-string=$env:database_connection_string" 

[!NOTE] Be sure and replace database_connection_string with your actual database connection string.

[!IMPORTANT] Adding .env to your .gitignore file will help ensure your secrets are not added to source control.

5. Create your initial configuration file

Data API builder (DAB) requires a JSON configuration file. Use dab --help for syntax options.

dab init
  --database-type mssql
  --connection-string "@env('my-connection-string')"
  --host-mode development

[!NOTE] Including --host-mode development enables Swagger for REST and Nitro for GraphQL.

Resulting configuration

The file dab-config.json is automatically created through this process. These are the resulting contents:

{
  "$schema": "https://github.com/Azure/data-api-builder/releases/download/v1.5.56/dab.draft.schema.json",
  "data-source": {
    "database-type": "mssql",
    "connection-string": "@env('my-connection-string')",
    "options": {
      "set-session-context": false
    }
  },
  "runtime": {
    "rest": {
      "enabled": true,
      "path": "/api",
      "request-body-strict": true
    },
    "graphql": {
      "enabled": true,
      "path": "/graphql",
      "allow-introspection": true
    },
    "host": {
      "cors": {
        "origins": [],
        "allow-credentials": false
      },
      "authentication": {
        "provider": "AppService"
      },
      "mode": "development"
    }
  },
  "entities": { }
}

6. Add your table to the configuration

dab add Todo
  --source "dbo.Todo"
  --permissions "anonymous:*"

[!NOTE] DAB supports tables, views, and stored procedures. When the type is not specified, the default is table.

Resulting configuration

The entities section of the configuration is no longer empty:

{
  "entities": {
    "Todo": {
      "source": {
        "object": "dbo.Todo",
        "type": "table"
      },
      "graphql": {
        "enabled": true,
        "type": {
          "singular": "Todo",
          "plural": "Todos"
        }
      },
      "rest": {
        "enabled": true
      },
      "permissions": [
        {
          "role": "anonymous",
          "actions": [
            {
              "action": "*"
            }
          ]
        }
      ]
    }
  }
}

7. Run Data API builder

In production, DAB runs in a container. In development, it’s locally self-hosted.

dab start

[!IMPORTANT] The DAB CLI assumes your configuration file is called dab-config.json and is in the local folder.

8. Access your data!

By default, DAB enables both REST and GraphQL.

GET http://localhost:5000/api/Todo

[!NOTE] Change the URL to match your port if it is different.

Other things you should try

• DAB’s Health endpoint: http://localhost:5000/health
• DAB’s Swagger UI: http://localhost:5000/swagger
• DAB’s Nitro UI: http://localhost:5000/graphql