---
url: https://docs.freetheai.org/guides/claude-code.md
description: >-
  Run Claude Code with free models like GLM 5.3 and Kimi K3 through FreeTheAI.
  Tested settings.json and environment variables.
---

# Claude Code

Claude Code can run on FreeTheAI's Anthropic-compatible Messages endpoint. Point `ANTHROPIC_BASE_URL` at FreeTheAI and choose which model fills each Claude slot.

Category: [Coding tools](/guides/#coding-tools). Before you start, you need a FreeTheAI account, an API key, and today's [check-in](/getting-started/check-in).

## Settings

| Setting | Value |
| --- | --- |
| ANTHROPIC_BASE_URL | `https://api.freetheai.org` |
| ANTHROPIC_AUTH_TOKEN | Your FreeTheAI key (`ftai_...`, 53 characters) |
| ANTHROPIC_MODEL | `fta/zai/glm-5.3` |

## Steps

### Add the settings

Put this in `~/.claude/settings.json` (on Windows, `%USERPROFILE%\.claude\settings.json`). Never put your key in a project's shared .claude/settings.json.

```json
{
  "env": {
    "ANTHROPIC_BASE_URL": "https://api.freetheai.org",
    "ANTHROPIC_AUTH_TOKEN": "ftai_your_key_here",
    "ANTHROPIC_MODEL": "fta/zai/glm-5.3",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "fta/zai/glm-5.3",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "fta/zai/glm-5.3",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "fta/zai/glm-5.3-flash",
    "CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC": "1"
  }
}
```

### Start Claude Code

Run claude, then /status. The Anthropic base URL line should show [api.freetheai.org](https://api.freetheai.org).

### Check in daily

Free models need one check-in a day at [freetheai.org/checkin](https://freetheai.org/checkin), or requests are refused.

## Tips

* Claude Code warns that fta/ models are not in its model catalog. That is expected; it still works and assumes a 200K context.
* The HAIKU model runs background tasks such as titles, so a fast model fits there.
* If a model answers 400 about unknown fields, add "`CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS`": "1".

## Common questions

### Is using Claude Code with FreeTheAI official?

No. Claude Code supports custom gateways through `ANTHROPIC_BASE_URL`, but Anthropic does not support non-Claude models behind one, so some Claude-only features may not work.

### Does Claude Code tool use work on FreeTheAI?

Yes. File reading and other tools were tested on 2026-09-29 with `fta/zai/glm-5.3` and `fta/kimi/k3`.

### Does it use my Claude subscription?

No. While `ANTHROPIC_AUTH_TOKEN` is set, requests go to FreeTheAI with your FreeTheAI key and do not count against a claude.ai plan.

## More help

* [Every API error and its fix](/errors)
* [Limits and the daily reset](/concepts/limits)
* [Claude Code website](https://code.claude.com)

::: info How this guide was checked
Tested end to end with Claude Code 2.1.284 on 2026-09-29 (reads a file with its Read tool on three FreeTheAI models).
:::