Input Formats

Overview

SemanticTest supports three different input formats for passing data to blocks. This flexibility lets you write cleaner, more readable tests.

1. String Format (Simple)

Pass a single value from the DataBus:

{
  "block": "JsonParser",
  "input": "${response.body}"
}

What happens:

The value from response.body is wrapped in an object
Becomes: { body: "the actual value" }
The block receives it as inputs.body

When to use:

Single value input
Quick and simple syntax
Most common format

2. From/As Format (Mapping)

Map a DataBus slot to a specific parameter name:

{
  "block": "ValidateContent",
  "input": {
    "from": "parsed.message",
    "as": "text"
  }
}

What happens:

Value from parsed.message is mapped to parameter text
The block receives it as inputs.text

When to use:

Block expects a specific parameter name
You need to rename the data
More explicit about what data goes where

Example:

{
  "pipeline": [
    {
      "block": "HttpRequest",
      "input": { "url": "https://api.example.com/users" },
      "output": "response"
    },
    {
      "block": "JsonParser",
      "input": "${response.body}",
      "output": "parsed"
    },
    {
      "block": "ValidateContent",
      "input": {
        "from": "parsed.users[0].email",
        "as": "text"
      },
      "config": {
        "matches": ".*@.*\\.com"
      }
    }
  ]
}

3. Object Format (Full Control)

Pass multiple values with deep variable resolution:

{
  "block": "HttpRequest",
  "input": {
    "url": "${BASE_URL}/users",
    "method": "POST",
    "headers": {
      "Authorization": "Bearer ${token}",
      "Content-Type": "application/json"
    },
    "body": {
      "name": "John Doe",
      "email": "${userEmail}"
    },
    "timeout": 5000
  }
}

What happens:

All ${} variables are resolved from the DataBus
The entire object is passed to the block
Nested objects are fully resolved

When to use:

Multiple parameters needed
Complex nested data structures
Mix of static and dynamic values

Comparison

String Format
From/As Format
Object Format

// Simplest - single value
"input": "${response.body}"

// Block receives:
{
  body: "actual response body content"
}

// Map to specific parameter
"input": {
  "from": "response.body",
  "as": "text"
}

// Block receives:
{
  text: "actual response body content"
}

// Full control
"input": {
  "url": "${API_URL}",
  "method": "POST",
  "data": "${payload}"
}

// Block receives:
{
  url: "https://api.example.com",
  method: "POST",
  data: { name: "John" }
}

Variable Resolution

All formats support ${} syntax for reading from the DataBus:

// Simple property access
"${response.status}"

// Nested properties
"${user.profile.email}"

// Array access
"${users[0].name}"

// From context
"${BASE_URL}"

// From environment
"${env.API_KEY}"

Best Practices

Use String Format for Simple Cases

// Good - clear and simple
{
  "block": "JsonParser",
  "input": "${response.body}"
}

// Unnecessary complexity
{
  "block": "JsonParser",
  "input": {
    "from": "response.body",
    "as": "body"
  }
}

Use From/As When Names Matter

// ValidateContent expects 'text' parameter
{
  "block": "ValidateContent",
  "input": {
    "from": "response.message",
    "as": "text"
  }
}

Use Object Format for Complex Blocks

// HttpRequest needs multiple parameters
{
  "block": "HttpRequest",
  "input": {
    "url": "${BASE_URL}/users",
    "method": "POST",
    "headers": {
      "Authorization": "Bearer ${token}"
    },
    "body": {
      "name": "${userName}",
      "email": "${userEmail}"
    }
  }
}

Don't Mix Formats

// Bad - confusing
{
  "input": {
    "from": "response.body",
    "as": "text",
    "url": "${API_URL}"  // ❌ Mixing from/as with object format
  }
}

// Good - use one format
{
  "input": {
    "text": "${response.body}",
    "url": "${API_URL}"
  }
}

Common Patterns

API Requests with Auth

{
  "block": "HttpRequest",
  "input": {
    "url": "${BASE_URL}/protected",
    "method": "GET",
    "headers": {
      "Authorization": "Bearer ${authToken}"
    }
  }
}

Validation with Specific Field

{
  "block": "ValidateContent",
  "input": {
    "from": "user.profile.bio",
    "as": "text"
  },
  "config": {
    "minLength": 10,
    "maxLength": 500
  }
}

Tool Validation

{
  "block": "ValidateTools",
  "input": {
    "from": "parsed.toolCalls",
    "as": "toolCalls"
  },
  "config": {
    "expected": ["search_database", "send_email"]
  }
}

Overview

1. String Format (Simple)

2. From/As Format (Mapping)

3. Object Format (Full Control)

Comparison

Variable Resolution

Best Practices

Common Patterns

API Requests with Auth

Validation with Specific Field

Tool Validation

Next Steps

Output Formats

Data Flow

​Overview

​1. String Format (Simple)

​2. From/As Format (Mapping)

​3. Object Format (Full Control)

​Comparison

​Variable Resolution

​Best Practices

​Common Patterns

​API Requests with Auth

​Validation with Specific Field

​Tool Validation

​Next Steps

Output Formats

Data Flow

Overview

1. String Format (Simple)

2. From/As Format (Mapping)

3. Object Format (Full Control)

Comparison

Variable Resolution

Best Practices

Common Patterns

API Requests with Auth

Validation with Specific Field

Tool Validation

Next Steps