Claude Code and Anthropic SDK

Use this guide for clients that speak the Anthropic Messages API: Claude Code, the Anthropic Python SDK, and the Anthropic TypeScript SDK.

Anthropic-native clients are different from OpenAI-compatible clients:

text

OpenAI SDK / Codex base URL:       https://api.rout.my/v1
Claude Code / Anthropic SDK URL:   https://api.rout.my
Anthropic request endpoint:        https://api.rout.my/v1/messages
Anthropic token count endpoint:    https://api.rout.my/v1/messages/count_tokens

Claude Code and Anthropic SDK clients append /v1/messages themselves, so their configured base URL should be https://api.rout.my, not https://api.rout.my/v1.

1. Get a rout.my key

Set the key in the terminal you will use. Pick one:

bash

# macOS/Linux/WSL/Git Bash
export ROUTMY_API_KEY="sk_your_key_here"

powershell

# Windows PowerShell
$env:ROUTMY_API_KEY="sk_your_key_here"

bat

:: Windows cmd.exe
set ROUTMY_API_KEY=sk_your_key_here

Then check the models list.

macOS/Linux/WSL/Git Bash:

bash

curl https://api.rout.my/v1/models \
  -H "Authorization: Bearer $ROUTMY_API_KEY"

Windows PowerShell:

powershell

curl.exe https://api.rout.my/v1/models -H "Authorization: Bearer $env:ROUTMY_API_KEY"

Windows cmd.exe:

bat

curl.exe https://api.rout.my/v1/models -H "Authorization: Bearer %ROUTMY_API_KEY%"

The ready-to-use Claude Code model in this guide is:

text

anthropic/claude-sonnet-4.6

You do not need to choose a model manually. Use the default unless you intentionally want another option:

Use case	Model
Default Claude Code setup	`anthropic/claude-sonnet-4.6`
Stronger, more expensive Claude setup	`anthropic/claude-opus-4.6`

If you change the model, copy the exact ID from /v1/models.

Set the model ID in the same terminal:

bash

# macOS/Linux/WSL/Git Bash
export ROUTMY_MODEL="anthropic/claude-sonnet-4.6"

powershell

# Windows PowerShell
$env:ROUTMY_MODEL="anthropic/claude-sonnet-4.6"

bat

:: Windows cmd.exe
set ROUTMY_MODEL=anthropic/claude-sonnet-4.6

2. Test the Anthropic route

Before opening Claude Code, test the raw Messages endpoint:

bash

curl https://api.rout.my/v1/messages \
  -H "Authorization: Bearer $ROUTMY_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-sonnet-4.6",
    "max_tokens": 128,
    "messages": [
      { "role": "user", "content": "Reply with OK." }
    ]
  }'

If this fails, fix the key, model ID, or account access first. Claude Code will fail the same way until this curl succeeds.

rout.my accepts both Bearer auth and Anthropic-style x-api-key auth on the Anthropic route. Claude Code sends either Authorization or x-api-key depending on which gateway credential variable you set.

On Windows PowerShell, use this equivalent check:

powershell

curl.exe https://api.rout.my/v1/messages `
  -H "Authorization: Bearer $env:ROUTMY_API_KEY" `
  -H "anthropic-version: 2023-06-01" `
  -H "Content-Type: application/json" `
  -d "{\"model\":\"$env:ROUTMY_MODEL\",\"max_tokens\":128,\"messages\":[{\"role\":\"user\",\"content\":\"Reply with OK.\"}]}"

3. Configure Claude Code

Recommended shell setup.

macOS/Linux/WSL/Git Bash:

bash

export ANTHROPIC_BASE_URL="https://api.rout.my"
export ANTHROPIC_AUTH_TOKEN="$ROUTMY_API_KEY"
export ANTHROPIC_MODEL="$ROUTMY_MODEL"
export ANTHROPIC_DEFAULT_HAIKU_MODEL="$ROUTMY_MODEL"

Windows PowerShell:

powershell

$env:ANTHROPIC_BASE_URL="https://api.rout.my"
$env:ANTHROPIC_AUTH_TOKEN=$env:ROUTMY_API_KEY
$env:ANTHROPIC_MODEL=$env:ROUTMY_MODEL
$env:ANTHROPIC_DEFAULT_HAIKU_MODEL=$env:ROUTMY_MODEL

Windows cmd.exe:

bat

set ANTHROPIC_BASE_URL=https://api.rout.my
set ANTHROPIC_AUTH_TOKEN=%ROUTMY_API_KEY%
set ANTHROPIC_MODEL=%ROUTMY_MODEL%
set ANTHROPIC_DEFAULT_HAIKU_MODEL=%ROUTMY_MODEL%

Why ANTHROPIC_AUTH_TOKEN? Claude Code supports gateway auth through a bearer token, and rout.my accepts bearer auth. This also avoids overwriting a real ANTHROPIC_API_KEY you may use for direct Anthropic access.

Start Claude Code from the same shell:

bash

claude --model "$ANTHROPIC_MODEL"

Inside Claude Code, run:

text

/status

Confirm that the displayed API base URL is https://api.rout.my.

4. Optional model discovery

Claude Code can ask a gateway for models:

bash

export CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY=1
claude

Claude Code's gateway model discovery calls GET /v1/models?limit=1000 on the configured base URL and requires Claude Code v2.1.129 or later. It only displays model IDs that start with claude or anthropic. If your rout.my model ID uses another prefix, set ANTHROPIC_MODEL explicitly as shown above.

5. Persist Claude Code settings

If users do not understand environment variables, this is usually the easiest path: put the values in the user-level Claude Code settings file.

Open the file:

bash

# macOS/Linux/WSL
mkdir -p ~/.claude
nano ~/.claude/settings.json

powershell

# Windows PowerShell
New-Item -ItemType Directory -Force "$HOME\.claude" | Out-Null
notepad "$HOME\.claude\settings.json"

bat

:: Windows cmd.exe
mkdir "%USERPROFILE%\.claude"
notepad "%USERPROFILE%\.claude\settings.json"

Paste this JSON and replace only sk_your_key_here. The model is already filled with the rout.my default:

json

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://api.rout.my",
    "ANTHROPIC_AUTH_TOKEN": "sk_your_key_here",
    "ANTHROPIC_MODEL": "anthropic/claude-sonnet-4.6",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "anthropic/claude-sonnet-4.6",
    "CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY": "1"
  }
}

Do not commit real API keys into a project repository. Use user-level settings or your shell environment for secrets.

6. VS Code extension

If you run Claude Code through the VS Code extension, pass the same variables through the extension setting:

json

{
  "claudeCode.environmentVariables": [
    {
      "name": "ANTHROPIC_BASE_URL",
      "value": "https://api.rout.my"
    },
    {
      "name": "ANTHROPIC_AUTH_TOKEN",
      "value": "sk_your_key_here"
    },
    {
      "name": "ANTHROPIC_MODEL",
      "value": "anthropic/claude-sonnet-4.6"
    },
    {
      "name": "ANTHROPIC_DEFAULT_HAIKU_MODEL",
      "value": "anthropic/claude-sonnet-4.6"
    }
  ]
}

Python SDK

Install the official Anthropic SDK:

bash

pip install anthropic

Example:

python

import os
from anthropic import Anthropic

client = Anthropic(
    base_url="https://api.rout.my",
    api_key=os.environ["ROUTMY_API_KEY"],
)

message = client.messages.create(
    model=os.environ["ROUTMY_MODEL"],
    max_tokens=256,
    messages=[
        {"role": "user", "content": "Write one short sentence."}
    ],
)

print(message.content[0].text)

TypeScript SDK

Install the official Anthropic SDK:

bash

npm install @anthropic-ai/sdk

Example:

import Anthropic from '@anthropic-ai/sdk';

const client = new Anthropic({
  baseURL: 'https://api.rout.my',
  apiKey: process.env.ROUTMY_API_KEY
});

const message = await client.messages.create({
  model: process.env.ROUTMY_MODEL ?? 'anthropic/claude-sonnet-4.6',
  max_tokens: 256,
  messages: [{ role: 'user', content: 'Write one short sentence.' }]
});

console.log(message.content[0].type === 'text' ? message.content[0].text : message.content);

The TypeScript SDK option is baseURL. The Python SDK option is base_url.

Token counting

Anthropic-native clients may call the token counting route:

bash

curl https://api.rout.my/v1/messages/count_tokens \
  -H "Authorization: Bearer $ROUTMY_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-sonnet-4.6",
    "messages": [
      { "role": "user", "content": "Count this request." }
    ]
  }'

Expected response shape:

json

{ "input_tokens": 12 }

The exact number depends on the selected model and estimator.

Common errors

Symptom	What to check
Request goes to `/v1/v1/messages`	The client base URL includes `/v1`. Use `ANTHROPIC_BASE_URL=https://api.rout.my`.
PowerShell `curl` prints strange HTML or does not send headers	Use `curl.exe`, not the PowerShell alias.
`$ROUTMY_API_KEY` works in Git Bash but not PowerShell	Variables are per shell. In PowerShell the variable is `$env:ROUTMY_API_KEY`; in cmd.exe it is `%ROUTMY_API_KEY%`.
`401`	Use either `ANTHROPIC_AUTH_TOKEN=$ROUTMY_API_KEY` for Claude Code or `api_key=ROUTMY_API_KEY` in SDKs. Do not accidentally send a real Anthropic key to rout.my.
`model_not_found`	Run `GET /v1/models` with the same rout.my key and copy the exact model ID.
Claude Code ignores the URL	Start `claude` from the same shell or put the variables in `~/.claude/settings.json`. Check with `/status`.
Claude Code uses another model	Set `ANTHROPIC_MODEL` for the main session and `ANTHROPIC_DEFAULT_HAIKU_MODEL` for Haiku/background usage. Check with `/status`.
Model discovery shows nothing	Claude Code only lists gateway models whose IDs start with `claude` or `anthropic`. Set `ANTHROPIC_MODEL` explicitly.
SDK still calls Anthropic directly	In Python use `base_url`; in TypeScript use `baseURL`. The value should be `https://api.rout.my`.
`anthropic-version` error in curl	Include `anthropic-version: 2023-06-01` for Anthropic-shaped manual requests. SDKs add the required headers for normal client calls.

Claude Code and Anthropic SDK ​

1. Get a rout.my key ​

2. Test the Anthropic route ​

3. Configure Claude Code ​

4. Optional model discovery ​

5. Persist Claude Code settings ​

6. VS Code extension ​

Python SDK ​

TypeScript SDK ​

Token counting ​

Common errors ​

Sources ​

Claude Code and Anthropic SDK

1. Get a rout.my key

2. Test the Anthropic route

3. Configure Claude Code

4. Optional model discovery

5. Persist Claude Code settings

6. VS Code extension

Python SDK

TypeScript SDK

Token counting

Common errors

Sources