Configure Claude Code

Claude Code reads its API connection when the process starts. These variables belong to Claude Code, not to the proxy server.

Minimal client contract

ANTHROPIC_BASE_URL=http://127.0.0.1:18765 \
ANTHROPIC_AUTH_TOKEN=unused \
ANTHROPIC_MODEL=gpt-5.6-sol[1m] \
ANTHROPIC_SMALL_FAST_MODEL=gpt-5.6-luna[1m] \
CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC=1 \
CLAUDE_CODE_DISABLE_NONSTREAMING_FALLBACK=1 \
  claude

Claude Code variable	Purpose
ANTHROPIC_BASE_URL	Sends Anthropic API requests to the local proxy.
ANTHROPIC_AUTH_TOKEN	Satisfies Claude Code’s client credential requirement. The proxy does not use it for upstream auth.
ANTHROPIC_MODEL	Selects the main request model and therefore the provider.
ANTHROPIC_SMALL_FAST_MODEL	Selects the model for title generation, token-related background work, and other small requests. Use a model the proxy routes.
CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC=1	Reduces background traffic sent to the subscription provider.
CLAUDE_CODE_DISABLE_NONSTREAMING_FALLBACK=1	Prevents Claude Code from retrying a partially completed stream as non-streaming, which can duplicate tool calls.

The proxy always makes streaming upstream requests. It can still accumulate a non-streaming Anthropic response when the client requests one.

Compaction settings

A trailing [1m] tells Claude Code to use its larger local context policy. The proxy strips the suffix before upstream routing. It does not enlarge the provider’s context window.

For Codex GPT-5.6 subscription models, set the threshold explicitly:

CLAUDE_CODE_AUTO_COMPACT_WINDOW=272000

For a provider and model with a different real context limit, choose a safe value or omit the override. DISABLE_AUTO_COMPACT=1 disables automatic compaction while preserving manual /compact, but the session can then hit the upstream limit.

Persistent Claude Code settings

If every Claude Code session should use the proxy, put client variables in ~/.claude/settings.json:

{
  "env": {
    "ANTHROPIC_BASE_URL": "http://127.0.0.1:18765",
    "ANTHROPIC_AUTH_TOKEN": "unused",
    "ANTHROPIC_MODEL": "gpt-5.6-sol[1m]",
    "ANTHROPIC_SMALL_FAST_MODEL": "gpt-5.6-luna[1m]",
    "CLAUDE_CODE_AUTO_COMPACT_WINDOW": 272000,
    "CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC": 1,
    "CLAUDE_CODE_DISABLE_NONSTREAMING_FALLBACK": 1
  }
}

Use process-level variables or a wrapper when you also launch Claude Code directly against Anthropic. See Switching models and backends.

Proxy settings are separate

CCP_*, PORT, and config.json configure the claude-code-proxy server process. They control the listener, provider endpoints, transport, credentials, and diagnostics. They do not belong in Claude Code’s client environment unless the same shell also starts the proxy.

See Configuration for the canonical server setting table.