AI Subscription API

Use your ChatGPT Plus/Pro, Claude Pro/Max, and Gemini subscriptions programmatically. No API keys required.

Installation

bun add ai-subscription-api

Requirements

• Bun runtime (Node.js is not supported)

Quick Start

import { SubscriptionClient } from "ai-subscription-api"

const client = new SubscriptionClient()

// Login (opens browser)
const { session, complete } = await client.login("claude", "browser")
console.log(`Open: ${session.url}`)
// For Claude, paste the code from the browser
const code = "..." // from browser
await complete(code)

// Chat
const response = await client.ask("claude", "What is the meaning of life?")
console.log(response)

Providers

| Provider | ID | Subscription | | -------- | --------- | ----------------- | | Claude | claude | Pro/Max | | ChatGPT | chatgpt | Plus/Pro | | Gemini | gemini | Free/Pro |

Login Methods

Claude

const { session, complete } = await client.login("claude", "browser")
console.log(session.url) // Open this URL
console.log(session.instructions) // "After authorizing, copy and paste the code shown."
Bun.spawn(["open", session.url])
const code = await getCodeFromUser()
await complete(code)

ChatGPT

const { session, complete } = await client.login("chatgpt", "browser")
Bun.spawn(["open", session.url])
await complete() // Waits for OAuth callback

Gemini

const { session, complete } = await client.login("gemini", "browser")
Bun.spawn(["open", session.url])
await complete() // Waits for OAuth callback

Chat

// Simple
const answer = await client.ask("claude", "Hello!")

// With options
const response = await client.chat("claude", [{ role: "user", content: "Hello!" }], {
  model: "claude-sonnet-4-20250514",
  maxTokens: 1024,
  system: "You are a helpful assistant.",
})

console.log(response.content)
console.log(response.usage) // { input: 10, output: 50 }

Streaming

await client.chat("claude", messages, {
  stream: true,
  onChunk: (chunk) => process.stdout.write(chunk),
})

Custom Credential Storage

import {
  SubscriptionClient,
  MemoryCredentialStore,
  FileCredentialStore,
  StaticCredentialStore,
} from "ai-subscription-api"

// In-memory (session only)
const client = new SubscriptionClient({
  store: new MemoryCredentialStore(),
})

// Custom file path
const client = new SubscriptionClient({
  store: new FileCredentialStore("/path/to/auth.json"),
})

// Pre-loaded credentials (read-only)
const client = new SubscriptionClient({
  store: new StaticCredentialStore({
    claude: {
      type: "oauth",
      refresh: "...",
      access: "...",
      expires: Date.now() + 3600000,
    },
  }),
})

Custom Credential Store

Implement the CredentialStore interface:

import type { CredentialStore, Credentials } from "ai-subscription-api"

class RedisCredentialStore implements CredentialStore {
  async get(provider: string): Promise<Credentials | undefined> { ... }
  async set(provider: string, credentials: Credentials): Promise<void> { ... }
  async remove(provider: string): Promise<void> { ... }
  async all(): Promise<Record<string, Credentials>> { ... }
}

const client = new SubscriptionClient({
  store: new RedisCredentialStore()
})

Available Models

Claude

• claude-sonnet-4-5-20250929 (default)
• claude-opus-4-5-20251101
• claude-opus-4-6
• claude-haiku-4-5-20251001

ChatGPT

• gpt-5.2 (default)
• gpt-5.1-codex
• gpt-5.1-codex-mini
• gpt-5.1-codex-max
• gpt-5.2-codex
• gpt-5.3-codex

Gemini

• gemini-3-flash-preview (default)
• gemini-3-pro-preview
• gemini-2.5-pro
• gemini-2.5-flash
• gemini-2.0-flash
• gemini-2.0-flash-lite

Scripts

# Run tests
bun test

# Run interactive CLI example
bun run example

Use bun run example to play with the APIs.

Notes

• Claude OAuth credentials require the claude-cli user agent
• ChatGPT Codex API requires stream: true and store: false
• Credentials are stored in ~/.local/share/subscription-auth/auth.json by default
• Tokens are automatically refreshed when expired