@tanstack/ai-code-mode-skills

Persistent skill library for TanStack AI Code Mode - LLM-created reusable code snippets.

Overview

The Skills System extends Code Mode with persistent, LLM-creatable reusable code snippets. Skills are TypeScript functions that the LLM can create, catalog, and invoke across sessions—enabling compounding capability over time.

Installation

pnpm add @tanstack/ai-code-mode-skills

Usage

import {
  codeModeWithSkills,
  createFileSkillStorage,
  createAlwaysTrustedStrategy,
} from '@tanstack/ai-code-mode-skills'
import { createNodeIsolateDriver } from '@tanstack/ai-isolate-node'

// Create skill storage
const skillStorage = createFileSkillStorage({
  directory: './.skills',
  trustStrategy: createAlwaysTrustedStrategy(),
})

// Create code mode config
const codeModeConfig = {
  driver: createNodeIsolateDriver(),
  tools: allTools, // Your external tools
  timeout: 60000,
  memoryLimit: 128,
}

// Build a dynamic registry and system prompt with skills
const { registry, systemPrompt, selectedSkills } = await codeModeWithSkills({
  config: codeModeConfig,
  adapter: anthropic('claude-3-haiku'), // Cheap model for skill selection
  skills: {
    storage: skillStorage,
    maxSkillsInContext: 5,
  },
  messages,
})

// Use in chat
const stream = chat({
  adapter: anthropic('claude-sonnet-4-20250514'), // Main model
  toolRegistry: registry,
  messages,
  systemPrompts: [basePrompt, systemPrompt],
})

Testing

This package includes a CLI for testing the skills system. The tests verify the complete skills lifecycle:

1. First run (Skill Creation): LLM uses execute_typescript to solve a problem and registers a reusable skill
2. Second run (Skill Reuse): LLM calls the saved skill directly without needing execute_typescript

Running the Simulated Test

The simulated test uses a mock adapter with predetermined responses for fully deterministic testing. No API key required.

# From the package directory
cd packages/typescript/ai-code-mode-skills

# Run the simulated test
pnpm test:cli:simulated

Running the Live Test

The live test uses a real LLM (OpenAI or Anthropic) to verify the skills flow with actual LLM responses.

Setup

1. Copy the environment example file:

   cp test-cli/env.example test-cli/.env.local

2. Edit test-cli/.env.local and add your API key:

   OPENAI_API_KEY=sk-...
   # or
   ANTHROPIC_API_KEY=sk-ant-...

Run the test

# Run with OpenAI (default)
pnpm test:cli:live

# Run with Anthropic
pnpm test:cli:live --provider anthropic

# Run with a specific model
pnpm test:cli:live --model gpt-4o-mini

# Run with verbose output
pnpm test:cli:live -v

CLI Commands

# Show help
pnpm test:cli --help

# Run simulated test (deterministic, no API key)
pnpm test:cli simulated

# Run live test (requires API key)
pnpm test:cli live [options]

Options:
  --provider <provider>  LLM provider: openai or anthropic (default: openai)
  --model <model>        Model to use (default depends on provider)
  -v, --verbose          Enable verbose output

API Reference

codeModeWithSkills(options)

Creates Code Mode tools and system prompt with skills integration.

Options:

• config - Code Mode tool configuration (driver, tools, timeout, memoryLimit)
• adapter - Text adapter for skill selection (should be a cheap/fast model)
• skills.storage - Skill storage implementation
• skills.maxSkillsInContext - Maximum skills to load into context (default: 5)
• messages - Current conversation messages
• skillsAsTools - Whether to include skills as direct tools (default: true)

Returns:

• registry - Mutable ToolRegistry containing execute_typescript, skill management tools, and selected skill tools
• systemPrompt - System prompt documenting available skills and external functions
• selectedSkills - Skills that were selected for this request

Storage

Storage is available from both the root export and the explicit storage subpath:

import { createFileSkillStorage } from '@tanstack/ai-code-mode-skills'
// or
import { createFileSkillStorage } from '@tanstack/ai-code-mode-skills/storage'

createFileSkillStorage(options)

Git-friendly file-based storage:

.skills/
├── compare_react_state_libraries/
│   ├── meta.json      # Metadata, schemas, stats
│   └── code.ts        # TypeScript implementation
└── fetch_github_stats/
    ├── meta.json
    └── code.ts

createMemorySkillStorage(options)

In-memory storage for testing.

Trust Strategies

Skills track execution success and promote trust levels over time:

Available strategies:

• createDefaultTrustStrategy() - Earn trust through successful executions
• createAlwaysTrustedStrategy() - Trust immediately (dev/testing)
• createRelaxedTrustStrategy() - Faster promotion
• createCustomTrustStrategy(options) - Custom thresholds

License

MIT