Claude Code

Arbytra connects to Claude Code through environment variables, giving you access to multiple models through a single API key.

Prerequisites

Claude Code installed and working
An Arbytra API key

If you’ve previously logged in to Claude Code with an Anthropic account, cached credentials take precedence over environment variables. Clear them first:

claude auth logout

If you haven’t logged in with Anthropic directly, skip this step.

Set your API key

Add these three lines to your shell profile (~/.zshrc on macOS, ~/.bashrc on Linux):

export ANTHROPIC_BASE_URL="https://api.arbytra.com"
export ANTHROPIC_AUTH_TOKEN="ak_live_..."   # your Arbytra API key
export ANTHROPIC_API_KEY=""

ANTHROPIC_API_KEY="" must be an empty string. If it contains any value, Claude Code uses it directly against Anthropic, bypassing Arbytra. The base URL must not include /v1. Claude Code appends /v1/messages itself. Reload your shell after saving:

source ~/.zshrc   # or: source ~/.bashrc

Or open a new terminal.

Use Arbytra alongside a direct Anthropic subscription

To keep claude connected to your Anthropic account, create a wrapper command instead of modifying your shell profile.Add your Arbytra API key to your shell profile (~/.zshrc or ~/.bashrc):

export ARBYTRA_API_KEY="ak_live_..."

Create the wrapper script:

mkdir -p ~/.local/bin
cat > ~/.local/bin/claude-arbytra << 'EOF'
#!/usr/bin/env bash
export ANTHROPIC_BASE_URL="https://api.arbytra.com"
export ANTHROPIC_AUTH_TOKEN="${ARBYTRA_API_KEY}"
export ANTHROPIC_API_KEY=""
exec claude "$@"
EOF
chmod +x ~/.local/bin/claude-arbytra

Add ~/.local/bin to your PATH if it isn’t already:

export PATH="$HOME/.local/bin:$PATH"

Reload your shell, then verify:

claude-arbytra -p "Say exactly: setup-ok" --model claude-haiku-4-5-20251001

Use claude-arbytra for Arbytra sessions and claude for your Anthropic subscription. You don’t need to clear your Anthropic login.

Model defaults are shared. The /model command saves your choice to ~/.claude/settings.json, which both claude and claude-arbytra read. Setting /model deepseek-v4-pro in an Arbytra session changes the default for your Anthropic subscription too.To avoid this, set a default model in the wrapper script so Arbytra sessions start with the right model without touching settings.json:

#!/usr/bin/env bash
export ANTHROPIC_BASE_URL="https://api.arbytra.com"
export ANTHROPIC_AUTH_TOKEN="${ARBYTRA_API_KEY}"
export ANTHROPIC_API_KEY=""

# Default to deepseek-v4-pro unless --model is passed explicitly
has_model=false
for arg in "$@"; do
  [[ "$arg" == "--model" ]] && has_model=true
done

if $has_model; then
  exec claude "$@"
else
  exec claude --model deepseek-v4-pro "$@"
fi

The --model flag is session-only and does not persist. You can still switch models mid-session with /model, but be aware it saves globally.

Verify

claude -p "Say exactly: setup-ok" --model claude-haiku-4-5-20251001

Claude Code includes a system prompt on every request. The first request in a session costs more than follow-ups due to prompt caching. Factor this into your cost estimates.

Use different models

Pass any Arbytra model ID with the --model flag:

claude --model deepseek-v4-flash
claude --model gemini-2.5-flash
claude --model grok-4.3

Model IDs must be exact. Claude Code requires reasoning support from every model. Models that don’t support reasoning return a 400 error. Browse per-model capabilities in the directory API. These are some of the models available through Arbytra:

Model	Author	Context
`claude-sonnet-4-6`	Anthropic	1M
`claude-opus-4-6`	Anthropic	1M
`claude-opus-4-7`	Anthropic	1M
`deepseek-v4-flash`	DeepSeek	1M
`deepseek-v4-pro`	DeepSeek	1M
`gemini-2.5-flash`	Google	1M
`gemini-2.5-pro`	Google	1M
`gemini-3.1-pro-preview`	Google	1M
`glm-5.1`	Z.AI	200K
`grok-4.3`	xAI	1M
`kimi-k2.5`	Moonshot	262K
`kimi-k2.6`	Moonshot	262K
`minimax-m2-7`	MiniMax	205K
`minimax-m2-7-highspeed`	MiniMax	205K
`qwen-3.6-plus`	Alibaba	1M

To list available models:

curl -s -H "Authorization: Bearer $ANTHROPIC_AUTH_TOKEN" \
  https://api.arbytra.com/v1/models | jq '.data[].id'

The /model picker in interactive sessions lists only Claude tier names (Opus, Sonnet, and Haiku). To switch to a non-Claude model mid-session, type the full ID: /model deepseek-v4-flash. You can also remap the tier aliases (next section) so picker entries route through Arbytra.

Override model tier aliases

Claude Code uses three model tiers (sonnet, opus, haiku). You can override which model each tier maps to:

export ANTHROPIC_DEFAULT_SONNET_MODEL="deepseek-v4-flash"
export ANTHROPIC_DEFAULT_OPUS_MODEL="claude-opus-4-7"
export ANTHROPIC_DEFAULT_HAIKU_MODEL="claude-haiku-4-5-20251001"

Add these to your shell profile alongside the other environment variables. If you’re using the claude-arbytra wrapper, add these exports to the wrapper script instead.

Switch back to direct Anthropic

Remove or comment out the three environment variables from your shell profile, then reload and re-authenticate:

source ~/.zshrc
claude auth login

Troubleshoot

Symptom	Cause	Fix
”model may not exist or you may not have access”	Model ID isn’t exact (e.g., `claude-haiku-4-5` instead of `claude-haiku-4-5-20251001`)	Use the full model ID from `GET /v1/models`
Requests go to Anthropic directly, not Arbytra	`ANTHROPIC_API_KEY` contains a value	Set `ANTHROPIC_API_KEY=""` (empty string, not unset)
“Invalid API Key” or auth errors	Cached Anthropic OAuth credentials	Run `claude auth logout`, then verify env vars are set
Requests hang or timeout	`ANTHROPIC_BASE_URL` includes `/v1`	Use `https://api.arbytra.com` only
”does not support reasoning/extended thinking”	Claude Code requires reasoning support but this model doesn’t have it	Use a reasoning-capable model (see “Use different models” above)
`apiKeySource: none` in session events	Claude Code doesn’t classify `ANTHROPIC_AUTH_TOKEN` as a key source	Expected behavior. Requests authenticate correctly
`/model` in `claude-arbytra` changes the default for `claude` too	Both commands share `~/.claude/settings.json` and `/model` saves globally	Use `--model` in the wrapper script (see wrapper section above)

Get Started

Guides

Response API

Frameworks

Integrations

Specifications

Platform

Changelog

Prerequisites

Set your API key

Verify

Use different models

Override model tier aliases

Switch back to direct Anthropic

Troubleshoot

​Prerequisites

​Clear existing Anthropic login

​Set your API key

​Verify

​Use different models

​Override model tier aliases

​Switch back to direct Anthropic

​Troubleshoot

Prerequisites

Clear existing Anthropic login

Set your API key

Verify

Use different models

Override model tier aliases

Switch back to direct Anthropic

Troubleshoot