shunt

A local proxy that pools multiple Claude accounts behind a single endpoint, routing requests across accounts to maximize your available rate limits.

  ─┐    shunt  v0.1.0
  ─┼─▶  2 accounts  ·  http://127.0.0.1:8082
  ─┘    Proxying Claude API across multiple accounts

What it does

Claude's rate limits are per-account. If you hit your 5-hour or weekly limit on one account, you're stuck waiting. Shunt sits in front of the Anthropic API and automatically routes each request to whichever account has the most remaining capacity — so you get the combined limits of all your accounts.

• Least-utilization routing — tracks live anthropic-ratelimit-unified-* headers and always picks the account with the most headroom
• Auto-failover — if one account is rate-limited, the next request goes to another
• Transparent — drop-in replacement for api.anthropic.com; works with Claude Code, the SDK, or any tool that speaks the Anthropic API
• Account management — add or remove accounts without restarting manually

Install

curl -sSf https://raw.githubusercontent.com/ramc10/shunt/main/install.sh | sh

This downloads the right pre-built binary for your OS and arch — no Rust or other dependencies needed.

Or via cargo:

cargo install shunt-proxy

Setup

Shunt uses OAuth — the same session Claude Code uses — so there's no API key to manage.

Step 1: Import your existing Claude Code session

shunt setup

This auto-imports the credentials Claude Code already has on disk. Takes a second.

Step 2: Add a second account

Log out of Claude Code, log in with your second Claude account, then:

shunt add-account secondary

Or give it any name you want (work, personal, etc.):

shunt add-account work

This opens a browser for OAuth authorization.

Step 3: Start the proxy

shunt start

The proxy starts in the background and your terminal is immediately returned. To point Claude Code at it:

export ANTHROPIC_BASE_URL=http://127.0.0.1:8082

Add that to your .zshrc / .bashrc (shunt setup offers to do this automatically).

Usage

shunt start              # Start (or restart) the proxy in the background
shunt start --foreground # Keep it in the terminal (for debugging)
shunt status             # Show accounts, rate limit bars, reset times
shunt add-account <name> # Add another Claude account
shunt remove-account <name> # Remove an account
shunt setup              # First-time setup

Status output

── ACCOUNTS ────────────────────────────────────────────────

  ✓  work        Claude Pro  you@example.com          available     1.2M tok
          5h window  ████████░░░░░░░░░░  61% remaining  ok  resets in 2h 14m
          7d window  ███░░░░░░░░░░░░░░░  79% remaining  ok  resets in 4d 6h
          Extra usage  available

  ✓  personal    Claude Pro  alt@example.com          available     fresh
          5h window  ░░░░░░░░░░░░░░░░░░  100% remaining  ok

How routing works

Every response from the Anthropic API includes anthropic-ratelimit-unified-5h-utilization headers (a float from 0–1). Shunt captures these and always routes the next request to the account with the lowest 5-hour utilization. Fresh accounts (no data yet) are treated as 0% utilized and get highest priority.

If a request returns 429 or 529, shunt marks that account as cooling and retries with the next-best account automatically.

Configuration

Config lives at ~/Library/Application Support/shunt/config.toml (macOS) or ~/.config/shunt/config.toml (Linux):

[server]
host = "127.0.0.1"
port = 8082
log_level = "info"

[[accounts]]
name = "work"
plan_type = "pro"

[[accounts]]
name = "personal"
plan_type = "pro"

Credentials are stored separately in credentials.json (never in the config file).

Files

Requirements

• Rust 1.75+
• One or more Claude Pro / Max accounts
• Claude Code installed (shunt borrows its OAuth credentials)

Notes

• Both accounts need to be different Claude logins — two sessions from the same account won't double your limits
• Shunt only proxies /v1/messages and /v1/messages/count_tokens — everything else passes through untouched
• shunt start automatically kills and replaces any running instance