Arcflow

Claude Code CLI

Configure Claude Code with Arcflow as an Anthropic Messages API base URL.

Claude Code can talk to an API base URL that implements the Anthropic Messages surface. Arcflow exposes the expected endpoints:

  • POST /v1/messages
  • POST /v1/messages/count_tokens
  • GET /v1/models

The simplest setup is to edit ~/.claude/settings.json with the base URL, key, and the model ids you want Claude Code to use:

{
  "env": {
    "ANTHROPIC_AUTH_TOKEN": "sk-...",
    "ANTHROPIC_BASE_URL": "https://api.tryarcflow.com",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "claude-opus-4-8",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "claude-sonnet-4-6",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "claude-haiku-4-5",
    "ANTHROPIC_SMALL_FAST_MODEL": "claude-haiku-4-5",
    "CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC": "1"
  },
  "hasCompletedOnboarding": true
}

The base URL is the bare host https://api.tryarcflow.com; the Anthropic SDK appends /v1/messages. Then run claude.

Alternative: environment variables

You can also configure Claude Code with environment variables instead of the settings file.

1. Export the base URL

export ANTHROPIC_BASE_URL="https://api.tryarcflow.com"

2. Export the Arcflow key

export ANTHROPIC_AUTH_TOKEN="sk-..."

Claude Code sends this value as Authorization: Bearer ....

3. Enable model discovery

export CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY=1

Discovery queries /v1/models at startup. If the model you want does not appear in the picker, launch Claude Code with the model explicitly:

ANTHROPIC_MODEL="claude-sonnet-4-6" claude

4. Run Claude Code

claude

Direct HTTP test

curl https://api.tryarcflow.com/v1/messages \
  -H "Authorization: Bearer $ANTHROPIC_AUTH_TOKEN" \
  -H "Content-Type: application/json" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "claude-sonnet-4-6",
    "max_tokens": 128,
    "messages": [{ "role": "user", "content": "Reply with ok" }]
  }'

Source: Claude Code base URL configuration.

On this page

Recommended: ~/.claude/settings.json
Alternative: environment variables
1. Export the base URL
2. Export the Arcflow key
3. Enable model discovery
4. Run Claude Code
Direct HTTP test