@cgaravitoq/claude-code-core

Framework-agnostic core for using the Claude Code OAuth subscription as an Anthropic provider. No Pi, no LangChain — just the native stack, with zero runtime dependencies.

It exists so the Claude Code internals live in one place and are shared by @cgaravitoq/open-langchain-ts and the pi-claude-code-auth Pi extension.

What's inside

• creds — read/refresh ~/.claude/.credentials.json (and macOS Keychain), with a claude CLI fallback and a force-refresh path for 401s.
• signing — the reverse-engineered x-anthropic-billing-header.
• model-config — ccVersion, beta computation (computeBetas/requestBetas) and frozen per-model overrides (adaptive thinking, long context, etc.).
• transforms — Claude Code payload reshaping: billing header injection, identity split, mcp_<PascalCase> tool prefixing, and orphan tool-pair repair.

Install

npm install @cgaravitoq/claude-code-core

ESM-only, Node >= 22.19.0.

Usage

import {
  readClaudeCodeCreds,
  refreshClaudeCodeCreds,
  applyClaudeCodeTransforms,
  requestBetas,
} from "@cgaravitoq/claude-code-core";

const creds = readClaudeCodeCreds();
if (creds) {
  const fresh = await refreshClaudeCodeCreds(creds);
  // build your Anthropic request, then:
  const params = applyClaudeCodeTransforms(rawParams);
  // send with "anthropic-beta": requestBetas(model, longContext).join(",")
}

This is the building block, not a chat client — see the consumers above for ready-to-use LangChain chat models or a Pi provider.

Notes

Using a subscription OAuth session from a third-party app may violate Anthropic's terms and risk your account.

License

MIT