> ## Documentation Index
> Fetch the complete documentation index at: https://docs.llmeasy.ru/llms.txt
> Use this file to discover all available pages before exploring further.

# How should I fill in the Base URL?

> Learn how Base URL, /v1 paths, API Key, and Model ID should match in Claude Code, Codex CLI, Cursor, Cline, and other tools.

## Short answer

The Base URL must match the protocol expected by your tool. Claude Code usually uses the Anthropic-compatible root address. Codex CLI, Cursor, Cline, OpenCode, OpenClaw, and other external tools usually use the OpenAI-compatible `/v1` address.

In LLMEasy:

| Use case                           | Base URL                    |
| ---------------------------------- | --------------------------- |
| Claude Code / Anthropic-compatible | `https://www.llmeasy.ru`    |
| Codex CLI / OpenAI-compatible      | `https://www.llmeasy.ru/v1` |
| Cursor, Cline, OpenCode, OpenClaw  | `https://www.llmeasy.ru/v1` |

Do not guess the path. API Key, Base URL, and Model ID must come from the same provider or gateway.

## Why there are different Base URLs

Different SDKs append paths in different ways.

| Protocol or tool type    | Common behavior                                                                  |
| ------------------------ | -------------------------------------------------------------------------------- |
| OpenAI-compatible SDK    | Usually calls resources such as chat completions or responses under `/v1`        |
| Anthropic-compatible SDK | Usually appends message endpoint paths itself, so you should not add `/v1` again |
| Built-in tool provider   | May append paths automatically, or may ask you for a complete Base URL           |

The same model name does not mean the same Base URL works everywhere. The real match is between tool protocol, Base URL, API Key, Key group, and Model ID.

## Quick reference

| Tool                   | Recommended setup                                                |
| ---------------------- | ---------------------------------------------------------------- |
| Claude Code            | `https://www.llmeasy.ru`, with a Claude group API Key            |
| Claude Desktop Gateway | Follow the Gateway page, including the auth scheme               |
| Codex CLI              | `https://www.llmeasy.ru/v1`, with a GPT group API Key            |
| Cursor                 | `https://www.llmeasy.ru/v1`, with a GPT group API Key            |
| Cline                  | `https://www.llmeasy.ru/v1`, using an OpenAI Compatible provider |
| OpenCode / OpenClaw    | `https://www.llmeasy.ru/v1`, with a GPT group API Key            |

## Common errors

| Error or symptom                                   | Possible cause                                                                        |
| -------------------------------------------------- | ------------------------------------------------------------------------------------- |
| `404 Not Found`                                    | The Base URL path does not match the SDK’s expected path                              |
| `model not found`                                  | The Model ID does not belong to the current Key group or provider                     |
| `invalid_api_key`                                  | The API Key and Base URL are from different services                                  |
| Authentication works, but the model is unavailable | The Key group and Model ID do not match                                               |
| Requests keep failing                              | An Anthropic-compatible address was used in an OpenAI-compatible tool, or the reverse |

## Recommended troubleshooting order

1. Confirm whether the tool expects OpenAI-compatible or Anthropic-compatible API.
2. Check whether the Base URL matches that protocol.
3. Check whether the API Key is from the same service.
4. Check whether the Model ID comes from the <a href={"https://www.llmeasy.ru/pricing"}>model plaza</a> and belongs to the current Key group.
5. Send a minimal test request, such as `hello`.

## Code examples

OpenAI-compatible tools usually use the `/v1` address:

```python theme={null}
from openai import OpenAI

client = OpenAI(
    api_key="YOUR_API_KEY",
    base_url="https://www.llmeasy.ru/v1"
)

response = client.chat.completions.create(
    model="your-model-id",
    messages=[{"role": "user", "content": "hello"}]
)
```

Claude / Anthropic-compatible setups usually use the root address:

```python theme={null}
import anthropic

client = anthropic.Anthropic(
    api_key="YOUR_API_KEY",
    base_url="https://www.llmeasy.ru"
)

message = client.messages.create(
    model="your-claude-model-id",
    max_tokens=1024,
    messages=[{"role": "user", "content": "hello"}]
)
```

## About LLMEasy

LLMEasy provides both Anthropic-compatible and OpenAI-compatible access. You can manage API Keys, balance, and usage records in the same dashboard, but each client still needs the protocol address it supports.

Quick rule: Claude Code uses `https://www.llmeasy.ru`; Codex CLI, Cursor, Cline, OpenCode, and OpenClaw use `https://www.llmeasy.ru/v1`.

## Related docs

* [What is the difference between OpenAI-compatible API and Anthropic-compatible API?](/en/faq/concepts/openai-compatible-vs-anthropic-compatible)
* [How do I choose the right AI model?](/en/faq/model-calling/model-selection-guide)
* [What are model\_provider, base\_url, and wire\_api in Codex CLI?](/en/faq/codex/model-provider-base-url-wire-api)
* [How do I configure an OpenAI-compatible API in Cline?](/en/faq/cline/openai-compatible-api)