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Mindcache

A TypeScript library for managing short-term memory in AI agents through an LLM-friendly key-value repository.

Motivation

MindCache was born from three core motivations:
  1. Learning by Doing: Building real-world AI agent applications reveals patterns and challenges that theoretical knowledge alone cannot provide. This library captures those learnings.
  1. Code Mutualization: Instead of rewriting memory management logic for each project, MindCache provides a shared foundation that can be reused across various AI agent applications.
  1. Pattern Discovery: Through practical use, MindCache explores and implements patterns that are essential for effective context window management and tools orchestration in AI systems.

What Problem Does It Solve?

AI agents need to maintain context during conversations and across tool calls. MindCache provides:
  • Short-term memory management for session-based context
  • LLM-optimized storage that agents can easily read and write
  • Automatic tool generation so agents can interact with memory without manual tool definitions
  • System prompt generation that summarizes memory state efficiently
  • Context window optimization through visibility controls and smart formatting
Note: Cross-session persistence is out of scope. MindCache focuses on short-term memory within a single session.

Core Concepts

Universal Storage

Store any data type an LLM can process: text, JSON, images, and files. All data is stored in an LLM-friendly format.

LLM-Native Interface

  • Readable: Memory is formatted for easy LLM consumption
  • Writable: Agents can directly modify memory through automatically generated tools
  • Template Injection: Use {{key}} syntax to inject memory values into prompts and templates

Smart Context Management

  • Visibility Controls: Mark keys as visible/invisible to control what appears in system prompts
  • Read-only Keys: Protect certain values from modification
  • Tags: Organize and filter memory entries by category
  • Templates: Enable dynamic value resolution with circular reference protection

Automatic Tool Generation

Tools are automatically generated for each writable key, allowing agents to read and write memory without manual tool definitions. Tools integrate seamlessly with Vercel AI SDK.

Quick Start

import { mindcache } from 'mindcache'; // Store values mindcache.set_value('userName', 'Alice'); mindcache.set_value('favoriteColor', 'blue'); // Generate system prompt for your AI agent const systemPrompt = mindcache.get_system_prompt(); // "userName: Alice. You can rewrite \\"userName\\" by using the write_userName tool..." // Generate tools for Vercel AI SDK const tools = mindcache.get_aisdk_tools(); // { write_userName: {...}, write_favoriteColor: {...} } // Use with AI SDK import { generateText } from 'ai'; const { text } = await generateText({ model: openai('gpt-4'), tools: tools, system: systemPrompt, prompt: 'Remember that I love green now, not blue.' }); // AI automatically calls write_favoriteColor('green')

Key Features

Template Injection

mindcache.set_value('name', 'Alice'); mindcache.set_value('city', 'New York'); const message = mindcache.injectSTM('Hello {{name}} from {{city}}!'); // "Hello Alice from New York!"

Attributes & Metadata

// Set with attributes mindcache.set_value('apiKey', 'secret123', { readonly: true, visible: false, tags: ['credentials'] }); // Mark as template for dynamic resolution mindcache.set_value('greeting', 'Hello {{name}}!', { template: true });

Image & File Support

// Store images mindcache.add_image('profilePic', base64Data, 'image/png'); // Store files mindcache.set_base64('document', base64Data, 'application/pdf', 'file'); // Get as data URL const imageUrl = mindcache.get_data_url('profilePic');

Tag-Based Organization

mindcache.set_value('userName', 'Alice', { tags: ['user'] }); mindcache.set_value('userRole', 'developer', { tags: ['user'] }); mindcache.set_value('tempNote', 'Meeting at 3pm'); // No tags // Get only tagged entries const userData = mindcache.getTagged('user'); // "userName: Alice, userRole: developer"

Markdown Serialization

// Export to markdown const markdown = mindcache.toMarkdown(); // Import from markdown mindcache.fromMarkdown(markdown);

Temporal Context

Built-in $date and $time keys provide current date and time:
mindcache.get('$date'); // "2025-01-15" mindcache.get('$time'); // "14:30:00"

Integration

Vercel AI SDK

import { streamText } from 'ai'; import { mindcache } from 'mindcache'; const tools = mindcache.get_aisdk_tools(); const systemPrompt = mindcache.get_system_prompt(); const result = await streamText({ model: openai('gpt-4'), tools: tools, system: systemPrompt, prompt: userMessage });

Next.js

See the Next.js example for a complete integration.

Framework Agnostic

MindCache works in any TypeScript/JavaScript environment, including:
  • Serverless functions
  • Edge runtimes
  • Browser applications
  • Node.js servers

API Reference

Core Methods

  • set_value(key, value, attributes?) - Store a value with optional attributes
  • get_value(key) - Retrieve a value (supports template processing)
  • delete(key) - Remove a key-value pair
  • has(key) - Check if a key exists
  • clear() - Clear all memory

Memory Management

  • get_system_prompt() - Generate system prompt from visible keys
  • get_aisdk_tools() - Generate tools for Vercel AI SDK
  • injectSTM(template) - Inject memory values into template strings
  • getSTM() - Get formatted string of all visible entries

Serialization

  • toJSON() - Serialize to JSON string
  • fromJSON(jsonString) - Deserialize from JSON string
  • toMarkdown() - Export to markdown format
  • fromMarkdown(markdown) - Import from markdown format
  • serialize() - Get complete state object
  • deserialize(data) - Restore complete state

Attributes & Tags

  • set_attributes(key, attributes) - Update key attributes
  • get_attributes(key) - Get key attributes
  • addTag(key, tag) - Add a tag to a key
  • removeTag(key, tag) - Remove a tag from a key
  • getTags(key) - Get all tags for a key
  • getTagged(tag) - Get all entries with a specific tag

Event System

  • subscribe(key, listener) - Subscribe to changes for a specific key
  • unsubscribe(key, listener) - Unsubscribe from key changes
  • subscribeToAll(listener) - Subscribe to all changes
  • unsubscribeFromAll(listener) - Unsubscribe from all changes

Examples

See the examples directory for complete implementations:
  • Form management with AI assistant
  • Image processing workflows
  • Multi-step workflows with memory persistence
  • Client-side STM editor

Installation

npm install mindcache

Requirements

  • Node.js >= 18.0.0
  • TypeScript >= 5.0.0
  • Optional: ai package >= 3.0.0 for Vercel AI SDK integration

License

MIT License - see LICENSE for details.
 
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