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

# API Configuration & Technical Integration

## 1. What should I enter for the API base URL?

Depending on the protocol, there are several options:

* OpenAI compatible format: [https://api.myrouter.ai/openai](https://api.myrouter.ai/openai) or [https://api.myrouter.ai/openai/v1/chat/completions](https://api.myrouter.ai/openai/v1/chat/completions)
* Anthropic native protocol: [https://api.myrouter.ai/anthropic](https://api.myrouter.ai/anthropic) (for tools like Claude Code)
* Image/Video generation: [https://api.myrouter.ai/v3/](https://api.myrouter.ai/v3/) (e.g., Gemini, Nano Banana, etc.)

Note: If you encounter a 404 error, check whether there is an extra /v1 at the end of the URL. Different tools have different path concatenation logic.

## 2. What should I do if I get a 401 "invalid token" error?

1. Confirm the API Key has been correctly created: [https://myrouter.ai/settings/key-management](https://myrouter.ai/settings/key-management)
2. Confirm the Authorization header format is: Bearer sk\_xxxxxx
3. If using Claude Code, the environment variable should be set as ANTHROPIC\_AUTH\_TOKEN=sk\_xxxxx (no need to add the Bearer prefix; the tool adds it automatically)

## 3. How do I troubleshoot a 404 "page not found" error?

Common causes:

* Incorrect URL: e.g., typo in /v3/glm-asr
* Model routing error: e.g., Codex models need to use /v1/responses instead of /v1/chat/completions
* Tool auto-concatenation issue: Some tools (e.g., cc-switch) automatically append /chat/completions, in which case the Base URL should not include that path

## 4. How do I configure Myrouter in Claude Code?

Set the environment variables as follows:

Windows cmd:

```
set ANTHROPIC_BASE_URL=https://api.myrouter.ai/anthropic
set ANTHROPIC_AUTH_TOKEN=sk_your_api_key
set ANTHROPIC_MODEL=claude-opus-4-1-20250805
set ANTHROPIC_SMALL_FAST_MODEL=claude-sonnet-4-20250514
```

Mac/Linux bash:

```
export ANTHROPIC_BASE_URL=https://api.myrouter.ai/anthropic
export ANTHROPIC_AUTH_TOKEN=sk_your_api_key
export ANTHROPIC_MODEL=claude-opus-4-1-20250805
export ANTHROPIC_SMALL_FAST_MODEL=claude-sonnet-4-20250514
```

Reference documentation: [https://docs.myrouter.ai/docs/integration/claudecode](https://docs.myrouter.ai/docs/integration/claudecode)

## 5. How do I resolve Claude Code forcing login/requiring verification?

The latest version of Claude Code may require mandatory login. Solutions:

* Use the Cline plugin as an alternative (search in the VSCode plugin marketplace)
* Or use forwarding tools like cc-switch

## 6. How do I call GPT-5.1 / Codex models? Why am I getting a 400 error?

The GPT-5.1 series (including Codex) requires the OpenAI Responses API, not Chat Completions:

```
curl "https://api.myrouter.ai/openai/v1/responses" \
-H "Content-Type: application/json" \
-H "Authorization: Bearer <API Key>" \
-d '{
    "model": "gpt-5.1-codex",
    "input": [...],
    "max_output_tokens": 64000
  }'
```

## 7. What should I do about "thinking block" errors with Claude 4.5?

The error typically says: Expected 'thinking' or 'redacted\_thinking', but found 'text'. This is because after enabling the Thinking feature for Claude 4.5, the context must include a specific thinking block format. Suggestions:

* Clear conversation history and start over
* Or disable the Thinking feature (if not needed)
* Use the native Anthropic protocol instead of the OpenAI compatible protocol (the latter may have incomplete Thinking support)

## 8. Getting an "input too long" error when calling the Claude API?

Claude models have input length limits (typically max\_tokens supports up to 64000). Please check:

* Input text length
* Base64 image size (compress large images first)
* Accumulated conversation history context length

***

**Contact Support**

If the above FAQ does not resolve your issue, please contact technical support through the following channels:

* Email: [support@myrouter.ai](mailto:support@myrouter.ai)
* Please provide the following information:
  * Problem description + screenshots
  * Account ID (UUID)
  * Trace ID (if available, usually found in the error message)
  * Request parameters (with sensitive data redacted)