LowRouter

Claude Code

Claude Code is Anthropic’s CLI agent. It expects an Anthropic API endpoint, which LowRouter exposes via the /api/v1/anthropic prefix.

Configure

Set environment variables before starting Claude Code:

Bash
export ANTHROPIC_BASE_URL=https://lowrouter.ai/api/v1/anthropic
export ANTHROPIC_API_KEY=lr-sk-...
claude

Or persist them in your shell profile (~/.zshrc, ~/.bashrc).

Picking a model

Claude Code uses the model defined in its settings. Edit ~/.claude/settings.json to pin a LowRouter-routed Claude model:

JSON
{
  "model": "anthropic/claude-sonnet-4-5"
}

The model string is the LowRouter ID (anthropic/claude-sonnet-4-5), not Anthropic’s short name. The full list of supported Claude models is on the model browser — filter by provider anthropic.

  • Dedicated key. Same daily-limit advice as the other agents.
  • EU residency: pin the key’s region to eu-west so Claude requests are served from EU endpoints. This survives IDE restarts and machine swaps without per-session config.
  • Audit usage on the dashboard. The transaction detail page shows token counts and cost per generation, which Claude Code itself does not surface in real time.

Troubleshooting

  • Claude Code can’t reach the API: the base URL must end with /anthropic (no trailing slash). Claude Code appends /v1/messages internally.
  • Model “not found”: confirm the model exists on the model browser. Anthropic adds and deprecates models faster than the model browser updates; a 404 usually means the model is no longer routable.
  • The agent stalls during streaming: this is sometimes a network-buffering issue between Claude Code and LowRouter. Setting CLAUDE_CODE_STREAM_BUFFER=0 (if the version you run supports it) disables the client-side buffer.