Claude Code

Claude Code is the terminal agent from Anthropic. It uses the Anthropic Messages format and reads its endpoint from environment variables.

The quickest way is the Liquid CLI. Use the manual steps only when you must keep the settings in your own files.

Start with the Liquid CLI

The Liquid CLI starts Claude Code with the exchange as its provider. It sets the base URL, the key and the model for that process only. It writes no file of yours.

curl -fsSL https://inference.ai.exchange/cli/install.sh | bash
liquid login
liquid claude

By default, Opus runs the main agent and liquid.auto runs subagents and background calls.

liquid claude reads --model, --cap and --filter. It sends all other arguments to Claude Code.

A separate config directory

liquid claude sets CLAUDE_CONFIG_DIR to ~/.config/liquid/claude. That directory holds the settings, history and MCP servers of the Liquid sessions.

• A /model choice in a Liquid session stays there, so a plain claude keeps its own model.
• When the session ends, liquid claude saves the choice as liquid model. The next Liquid session starts with it.

At its first start at a terminal, liquid claude asks which parts of ~/.claude to share:

Without a terminal, it shares instructions. To change the answer, run one of these commands:

liquid config claude-share instructions,plugins
liquid config claude-share none

The MCP server of the exchange

Each liquid claude session has the Liquid MCP server with the key of the session. Claude can buy images, speech and video within the limits of the key.

• liquid mcp claude adds the server to both directories, with a key that you approve in the browser.
• To add another MCP server to the Liquid sessions, run liquid claude mcp add ….

Before you start

• A workspace with a balance and a spend key. See API keys.

• The key exported in your shell, so it never appears in a file:

  export LIQUID_API_KEY=sk-liquid-...
  

• Claude Code installed. Install it with the native installer or with npm:

# native installer (macOS, Linux, WSL)
curl -fsSL https://claude.ai/install.sh | bash

# or with npm
npm install -g @anthropic-ai/claude-code

1. Point it at the exchange

Set these variables in the shell that starts Claude Code. To keep them, add them to ~/.zshrc or ~/.bashrc. The second block has the same variables in .claude/settings.json, for one project.

Shell

export ANTHROPIC_AUTH_TOKEN=$LIQUID_API_KEY
export ANTHROPIC_BASE_URL=https://router.inference.ai.exchange
export ANTHROPIC_DEFAULT_HAIKU_MODEL=cc.anthropic/liquid.auto
export ANTHROPIC_DEFAULT_OPUS_MODEL=cc.anthropic/liquid.auto
export ANTHROPIC_DEFAULT_SONNET_MODEL=cc.anthropic/liquid.auto
export ANTHROPIC_MODEL=cc.anthropic/liquid.auto
export CLAUDE_CODE_ATTRIBUTION_HEADER=0
export CLAUDE_CODE_AUTO_MODE_SERVER=0
export CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY=1
export CLAUDE_CODE_MAX_OUTPUT_TOKENS=16384
export CLAUDE_CODE_SUBAGENT_MODEL=cc.anthropic/liquid.auto

.claude/settings.json

{
  "env": {
    "ANTHROPIC_AUTH_TOKEN": "sk-liquid-...",
    "ANTHROPIC_BASE_URL": "https://router.inference.ai.exchange",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "cc.anthropic/liquid.auto",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "cc.anthropic/liquid.auto",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "cc.anthropic/liquid.auto",
    "ANTHROPIC_MODEL": "cc.anthropic/liquid.auto",
    "CLAUDE_CODE_ATTRIBUTION_HEADER": "0",
    "CLAUDE_CODE_AUTO_MODE_SERVER": "0",
    "CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY": "1",
    "CLAUDE_CODE_MAX_OUTPUT_TOKENS": "16384",
    "CLAUDE_CODE_SUBAGENT_MODEL": "cc.anthropic/liquid.auto"
  }
}

Set LIQUID_API_KEY before this block. If a profile sets the key on a later line, the token is empty and each request fails with 401.

The project file holds the key in plain text. Use .claude/settings.local.json and keep it out of version control.

2. Keep your existing login

Do not sign out of Claude Code. The variables apply only to the process that you start with them. A plain claude in another shell still uses Anthropic.

ANTHROPIC_API_KEY has priority over ANTHROPIC_AUTH_TOKEN. Clear it in the shell that starts Claude Code:

unset ANTHROPIC_API_KEY

To keep the variables out of your normal shell, use a wrapper:

claude-liquid() {
  ANTHROPIC_BASE_URL=... ANTHROPIC_AUTH_TOKEN="$LIQUID_API_KEY" \
    CLAUDE_CONFIG_DIR="$HOME/.config/liquid/claude" \
    env -u ANTHROPIC_API_KEY claude "$@"
}

Add the other variables from step 1 to the same line. Keep CLAUDE_CONFIG_DIR, the directory that liquid claude uses. Without it, Claude Code saves a /model choice of the exchange in ~/.claude, and a plain claude uses it.

3. Run it

claude

4. Check it works

1. Run /status. The API base URL and the model must be the values that you set.
2. Send one message.
3. Read the receipt on the Overview or Credits page of the console. See Quickstart.

Model discovery

Claude Code drops each model id that does not contain "claude" or "anthropic". The cc.anthropic/ prefix keeps the models of the exchange in the picker.

Add the [1m] suffix if the input window of the model is one million tokens or more:

export ANTHROPIC_MODEL=cc.anthropic/liquid.auto[1m]

Use any model, router model or preset on the book. For names, use GET /v1/models. See Market data.

Output token limit

At high effort, Claude Code asks for 32,000 output tokens by default.

• If no offer allows that many, the exchange lowers the request to the largest limit of the offers that can take it. See Errors.
• The exchange does not halve the limit to fit your balance. If the balance does not cover 32,000 tokens, the request gets 402 insufficient_balance. Add funds or lower CLAUDE_CODE_MAX_OUTPUT_TOKENS.
• An answer that reaches the limit stops with stop_reason: "max_tokens".

The block in step 1 sets 16384. A lower value gives a lower cap for each request.

A different model per task

Claude Code has a model variable for each type of work. The block in step 1 sets all of them to one model. Background work and subagents send many requests, so you can send them to liquid.auto:economy:

export ANTHROPIC_DEFAULT_HAIKU_MODEL=cc.anthropic/liquid.auto:economy
export CLAUDE_CODE_SUBAGENT_MODEL=cc.anthropic/liquid.auto:economy

To pick the ranking, add an axis to the name, such as cc.anthropic/liquid.auto:fastest. With the CLI, run liquid claude --model liquid/auto:fastest. See Axis routing.

The cap

liquid.auto has a cap of its own, so Claude Code needs to send nothing. GET /v1/exchange/routers shows its cap_usd.

To set your own cap, send it as a header, because Claude Code cannot send the exchange object. Set this variable, then start Claude Code again:

export ANTHROPIC_CUSTOM_HEADERS="x-liquid-cap-usd: 1.00"

In a settings file, add "ANTHROPIC_CUSTOM_HEADERS": "x-liquid-cap-usd: 1.00" to the env object. The header sets a cap on each request, for all models. Auto buys only from offers whose worst-case charge is within the cap.

You can link the key to a preset that sets a price bound instead (see Purchasing rules).

Purchasing rules

Send the cost cap, the first-token limit and the Auto preference as headers in ANTHROPIC_CUSTOM_HEADERS. Put a newline between two headers.

export ANTHROPIC_CUSTOM_HEADERS="x-liquid-cap-usd: 0.50
x-liquid-policy: economy"

• If the estimated charge is more than the cap, the exchange refuses the request. It does not shrink it.
• x-liquid-policy applies only to requests that Auto ranks. It needs Claude Code v2.1.227 or later.

For any other rule, such as exchange.privacy.regions, send the exchange block as JSON in one header:

export ANTHROPIC_CUSTOM_HEADERS='x-liquid-rules: {"privacy":{"regions":["eu"]}}'

With the CLI, run liquid config rules '{"region_policy":["eu"]}'. See Rules in one header.

No header sets the models. Save a preset on the Presets page and set a model variable to it:

export CLAUDE_CODE_SUBAGENT_MODEL=cc.anthropic/background

See Purchasing rules for each rule.

Zero retention

If nothing sets exchange.privacy.retention, Auto can send your prompt to its classifier. To stop this, send the rule as a header. Only providers that agree not to retain a request can then take it.

export ANTHROPIC_CUSTOM_HEADERS="x-liquid-retention: none"

To set the rule for every client of the key, use a preset with exchange.privacy.retention: "none". See Data handling.

Auto mode checks

Set CLAUDE_CODE_AUTO_MODE_SERVER=0. Without it, the first action of each session stops with a notice that the session is not eligible for no-charge classifier requests. Auto mode works in both cases.

The auto in opus/auto is the Auto Router, not this mode.

In auto mode, Claude Code checks an action, such as a shell command, before it runs. With Anthropic, the server does that check at no charge. The exchange works differently:

• It returns no verdict. It ignores the safeguards field, because a provider could otherwise allow any action.
• Claude Code checks the action with its own request. The exchange auctions, caps and charges it like any other request.

The attribution block

Set CLAUDE_CODE_ATTRIBUTION_HEADER=0. Claude Code adds a version block to the start of the system prompt. Anthropic removes it by position. The exchange does not, so the block goes to the provider and you pay for its tokens.

Troubleshooting

See also Codex and Prompt caching.