@decartai/langchain

LangChain.js integration for Decart AI - Image Editing.

Installation

npm install @decartai/langchain @langchain/core

Setup

Get your API key from platform.decart.ai and set it as an environment variable:

export DECART_API_KEY="your-api-key"

Or pass it directly to the tool:

const tool = new DecartImageTool({ apiKey: "your-api-key" });

Quick Start

import { DecartImageTool } from "@decartai/langchain";

const tool = new DecartImageTool();
const exampleImageUrl = "https://picsum.photos/id/10/480/360.jpg";

// Image-to-image editing
const editedImage = await tool.invoke({
  prompt: "Change the sky to aurora borealis",
  imageUrl: exampleImageUrl,
});
// Returns: data:image/png;base64,...

Using with LangChain Agents

import { ChatAnthropic } from "@langchain/anthropic";
import { HumanMessage } from "@langchain/core/messages";
import { DecartImageTool } from "@decartai/langchain";

const llm = new ChatAnthropic({ model: "claude-sonnet-4-20250514" });
const tool = new DecartImageTool();
const exampleImageUrl = "https://picsum.photos/id/10/480/360.jpg";

// Bind the tool to the model
const llmWithTools = llm.bindTools([tool]);

// Ask the model to edit an image
const response = await llmWithTools.invoke([
  new HumanMessage(
    `Edit this image to add a futuristic city skyline at night: ${exampleImageUrl}`
  ),
]);

// Execute the tool call if present
if (response.tool_calls?.length > 0) {
  const result = await tool.invoke(response.tool_calls[0].args);
  console.log("Edited image:", result);
}

DecartImageTool

Edit images using Decart AI. Returns base64-encoded PNG images.

Parameters

Parameter	Type	Description
prompt	string	Edit instructions for the image
imageUrl	string	Source image URL (required)
resolution	"480p" | "720p"	Output resolution (default: "720p")
seed	number	Random seed for reproducibility
enhancePrompt	boolean	Auto-enhance prompt (default: true)

Models

• lucy-pro-i2i - Image-to-image editing

Constructor Options

Option	Type	Description
apiKey	string	Decart API key (or use DECART_API_KEY)
baseUrl	string	Custom API base URL

API Reference

For detailed API documentation, see the Decart API Documentation.

License

MIT