prompterizer

Prompterizer

Prompterizer is a Go library for simplifying structured prompt generation and response handling with Google's Gemini AI models. It converts Go structs with tags into genai.Schema for AI interaction.

Features

• Schema from Go Structs: Define AI response formats using Go structs and tags.
• Gemini-Ready: Generates *genai.Content (system instructions), []*genai.Part (prompts), and *genai.Schema.
• Rich Struct Tags: Customize field names, types, descriptions, requirements, and aliases.
• Complex Structures: Supports nested/embedded structs and slices.
• Dynamic Descriptions: Use template variables in field descriptions.
• Easy Unmarshaling: Helper to unmarshal JSON responses to Go structs.

Installation

go get github.com/tenkeylabs/prompterizer

Dependencies (google.golang.org/genai, github.com/samber/lo) are handled by go mod tidy.

Usage

1. Define Response Structure

Use Go structs and prompt tags:

package main

type Address struct {
    Street string `prompt:"street,string,required" prompt_description:"Street name."`
    City   string `prompt:"city,string,required"`
    Country string `prompt:"country,string" prompt_enum:"US,CA,MX,INVALID"`
}

type UserProfile struct {
    FullName    string  `prompt:"full_name,string,required" prompt_description:"User's full name."`
    Age         *int     `prompt:"age,integer"` // Pointer values set the schema to Nullable
    DateOfBirth time.Time  `prompt:"dateOfBirth,string,date-time"`
    Addresses []Address `prompt:"addresses,object,required"`
    TemplatedDescription string `prompt:"templatedDescription,string" prompt_description:"This is a templated description with a variable: {example_detail}"`
}

2. Generate Prompt Components

package main

import (
    "log"
    "github.com/tenkeylabs/prompterizer"
)

func main() {
    params := prompterizer.PromptParams{
        SystemInstructions: []string{"You are a helpful AI."},
        Prompt:             []string{"Extract user profile."},
        ResponseStruct:     prompterizer.UserProfile{}, // Or new(prompterizer.UserProfile)
        TemplateVariables:  map[string]string{"example_detail": "some value"},
    }

    _, _, responseSchema, err := prompterizer.GenerateGeminiParts(params)
    if err != nil {
        log.Fatalf("Error generating Gemini parts: %v", err)
    }
    // Use responseSchema with your Gemini model
}

3. Unmarshal AI Responses

// jsonResponse is the JSON string from the AI
profile, err := prompterizer.Unmarshal[UserProfile](jsonResponse)
if err != nil {
    log.Fatalf("Failed to unmarshal: %v", err)
}
// Use profile

Struct Tag Reference

• prompt:"<name>,<type>[,format][,required]":
  • name: JSON property name.
  • type: string, bool, number, integer, object.
    • For array/slice fields, specify the expected type of the array items e.g.

    Addresses []Address `prompt:"addresses,object`
    Names []string `prompt:"names,string`
    

  • format: (Optional) Describe the expected format of the value to be returned as per OpenApi 3.0 spec e.g. date-time (for ISO 8601)
    • If prompt_enum is present, format enum is automatically set if not explicitly overridden.
    • If type number is present, format float is automatically set if not explicitly overridden.
  • required: (Optional) Marks field as required.
• prompt_enum:"<value1>,<value2>,...": (Optional) Specify an enumeration of possible return values in a comma-separated list.
  • Sets the format to enum if a format is not explicitly set.
• prompt_description:"<text>": (Optional) Field description. Supports {var} templating.
• prompt_aliases:"<alias1>,<alias2>": (Optional) Alternative names, added to description.
• If field is a pointer, it's marked as Nullable

Contributing

Contributions are welcome! Please submit a PR or open an issue.

License

Apache 2.0