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Using Claude Code with ToxPipe models

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Parker Combs edited this page May 20, 2026 · 10 revisions

Using ToxPipe models with Claude Code

ToxPipe's Anthropic models are compatible with the Claude Code desktop and command line applications.

(The following guide was written by Jennifer Serafini and edited for formatting by Parker Combs)

Setting Up Claude Code via ToxPipe LiteLLM Proxy

Documented by Jennifer Serafini, April 2026 For use by other NIEHS/AFDS developers on Windows GFE. Special thanks to Benjamin Petersen and Rich Ogin, for discovering the correct JSON keynames:values for sending the API key to LiteLLM, disabling Claude's AutoUpdater, and additional troubleshooting contributions.

A note on authorship: This document was developed collaboratively with Claude (Anthropic), an AI assistant, which assisted with drafting, structure, and technical documentation. All decisions, testing, and validation reflect the judgment and domain expertise of the author. The author takes full responsibility for the content of this document.

Overview

This document covers two installation methods: Method A: Native (recommended) - requires Node.js installed by IT Method B: Docker - use if Node.js is not available

Both methods connect Claude Code to the ToxPipe LiteLLM proxy instead of directly to Anthropic’s API.

Prerequisites

  • ToxPipe API key
  • NIH CA Bundle PEM file (certs/NIH_CA_Bundle.pem)
  • Node.js installed (Method A) or Docker Desktop 27.0.3+ (Method B)

Step 1: Verify the /v1/messages Endpoint is Working

PowerShell encodes strings with a BOM by default which breaks JSON parsing. Write the body to a file first: 1a. Write request body to file:

'{"model":"claude-4.6-sonnet","max_tokens":100,"messages":[{"role":"user","content":"hello"}]}' | Out-File -FilePath test_body.json -Encoding ascii -NoNewline

1b. Send the request:

curl.exe -v -X POST "https://litellm.toxpipe.niehs.nih.gov/v1/messages" -H "x-api-key: your_key_here" -H "Content-Type: application/json" --cacert "certs/NIH_CA_Bundle.pem" -d "@test_body.json"

Expected result: HTTP 200 with JSON response containing “role”:“assistant”

Troubleshooting notes:

  • Use curl.exe not curl - PowerShell aliases curl to Invoke-WebRequest
  • SSL cert warning lines (did not match against certificate name) are normal
  • Empty response with no error = BOM encoding issue, use the file approach above
  • Content-Length: 2 in verbose output = same issue

Step 2: Check Available Models

curl.exe -X GET "https://litellm.toxpipe.niehs.nih.gov/v1/models" -H "x-api-key: your_key_here" --cacert "certs/NIH_CA_Bundle.pem"

Use the exact model string from this response in all requests. At time of writing: claude-4.6-sonnet

Method A: Native Installation (Recommended)

Use this method if IT has installed Node.js on your GFE. No Docker required.

Step 3A: Confirm Node.js is installed

Run from PyCharm terminal (not a standalone PowerShell window - execution policy may block npm outside PyCharm):

node --version 
npm --version

Both should return version numbers.

Step 4A: Install Claude Code

Important: Pin to version 2.1.45. Newer versions have a known incompatibility with the ToxPipe LiteLLM proxy that causes every prompt to fail with API Error: Content block is not a text block.

npm install -g @anthropic-ai/claude-code@2.1.45

Prevent auto-updates: Claude Code may auto-update to a newer incompatible version. To prevent this, run once after installing:

New-Item -ItemType Directory -Force "$env:USERPROFILE\.claude" 
'{"env": {"DISABLE_AUTOUPDATER": "1"}}' | Out-File -FilePath "$env:USERPROFILE\.claude\settings.json" -Encoding utf8

Step 5A: Set Environment Variables

Option 1: Persistent (recommended) - skip to Step 6A to set these as permanent user environment variables. This is the recommended approach. Do not set both persistent and session variables - this causes a conflict warning.

Option 2: Session only (for testing) - set in the current terminal session only. Variables will be lost when the terminal closes: In Powershell (or compatible style, i.e., PyCharm) terminal:

$env:ANTHROPIC_BASE_URL = "https://litellm.toxpipe.niehs.nih.gov" 
$env:ANTHROPIC_AUTH_TOKEN = "your_key_here" 
$env:NODE_EXTRA_CA_CERTS = "C:\path\to\your\project\certs\NIH_CA_Bundle.pem"
$env:CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS = "1"

Replace the NODE_EXTRA_CA_CERTS path with the actual path to your NIH CA Bundle file. Setting CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS to 1 fixes an issue where updates to ToxPipe's LiteLLM instance breaks compatibility with Claude Code.

Step 6A: Make Environment Variables Persistent

To avoid setting environment variables every session, add them to your PyCharm run configuration or Windows user environment variables:

  1. Search “environment variables” in Windows Start
  2. Click “Edit environment variables for your account”
  3. Add each variable under User variables
  4. No admin rights required for user-level variables
  5. Enter variable values without surrounding quotes - Windows handles quoting automatically
  6. If Git Bash is installed, add this additional variable: Variable: CLAUDE_CODE_GIT_BASH_PATH Value: C:\Users<your-username>\AppData\Local\Programs\Git\git-bash.exe

Alternatively, to set environment variables on a per-project or per-repository basis, you can create a .claude directory in your project file and create a .claude/settings.local.json configuration file there. This file should contain the environment variable assignments as follows:

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://litellm.toxpipe.niehs.nih.gov" ,
    "ANTHROPIC_AUTH_TOKEN": "your_key_here", 
    "NODE_EXTRA_CA_CERTS": "C:\path\to\your\project\certs\NIH_CA_Bundle.pem",
    "CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS": "1"
  }
}

Step 7A: Launch Claude Code

claude --model claude-4.6-sonnet

Method B: Docker Installation

Use this method if Node.js is not available on your GFE.

Step 3B: Add .env File to Project Root

Create .env at project root. Never commit this file:

ANTHROPIC_AUTH_TOKEN=your_key_here

Confirm .gitignore includes:

.env 
config.json

Step 4B: Create Dockerfile.claudecode

Create a file named Dockerfile.claudecode at your project root:

FROM node:20-slim 
 
COPY certs/NIH_CA_Bundle.pem /usr/local/share/ca-certificates/NIH_CA_Bundle.crt 
RUN apt-get update && apt-get install -y --no-install-recommends ca-certificates \ 
    && update-ca-certificates \ 
    && rm -rf /var/lib/apt/lists/* 
 
RUN npm install -g @anthropic-ai/claude-code@2.1.45 
 
WORKDIR /app

Notes:

  • PEM format is what update-ca-certificates expects - renaming to .crt requires no conversion
  • Version pinned to 2.1.45 - see Known Issues

Step 5B: Add claude_code Service to docker-compose.yml

claude_code: 
  build: 
    context: . 
    dockerfile: Dockerfile.claudecode 
  image: genai-pipeline-claudecode:latest 
  volumes: 
    - "./:/app" 
  environment: 
    - ANTHROPIC_BASE_URL=https://litellm.toxpipe.niehs.nih.gov 
    - ANTHROPIC_AUTH_TOKEN 
    - NODE_EXTRA_CA_CERTS=/usr/local/share/ca-certificates/NIH_CA_Bundle.crt
    - CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS=1
  stdin_open: true 
  tty: true 
  command: claude --model claude-4.6-sonnet

Notes:

  • ANTHROPIC_BASE_URL does not include the path. Claude Code appends /v1/messages automatically
  • ANTHROPIC_AUTH_TOKEN with no value tells Compose to pull from .env
  • NODE_EXTRA_CA_CERTS is the Node.js equivalent of curl’s –cacert flag
  • CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS must be set to 1 to fix an issue where updates to ToxPipe's LiteLLM instance breaks compatibility with Claude Code
  • stdin_open and tty make the container interactive
  • ANTHROPIC_MODEL environment variable is not reliable - always use –model flag

Step 6B: Build the Image

docker-compose build claude_code

Expected build time: approximately 4 minutes. All steps should complete with no ERR! lines.

Step 7B: Launch Claude Code

docker-compose run --rm claude_code

Session Management (Both Methods)

Method A - Resume after disconnect:

claude --model claude-4.6-sonnet --continue 
claude --model claude-4.6-sonnet --resume

Method B - Resume after disconnect:

docker-compose run --rm claude_code claude --model claude-4.6-sonnet --continue 
docker-compose run --rm claude_code claude --model claude-4.6-sonnet --resume

First Launch Setup

On first launch Claude Code will:

  1. Ask you to select a color theme - choose your preference
  2. If ANTHROPIC_AUTH_TOKEN and ANTHROPIC_BASE_URL are set as persistent environment variables, Claude Code will connect to ToxPipe and drop into a prompt ready for use. If an auth screen appears, see Known Issues: Auth screen on first launch.

Useful Claude Code Commands

  • Exit Claude Code: /exit
  • Change color theme: /theme
  • Interrupt current operation: Ctrl+C

How It Works

Your codebase 
      | 
      v 
Claude Code (native or container) 
      | 
      v 
ANTHROPIC_BASE_URL -> litellm.toxpipe.niehs.nih.gov/v1/messages 
      | 
      v 
LiteLLM proxy -> Anthropic Claude API 
      | 
      v 
Response back through proxy -> Claude Code

All traffic routes through ToxPipe. No direct Anthropic API calls.

Known Issues

Issue Symptom Resolution
Claude Code version incompatibility API Error: Content block is not a text block on every prompt Pin to v2.1.45: npm install -g @anthropic-ai/claude-code@2.1.45. Versions above 2.1.45 have a known incompatibility with ToxPipe LiteLLM proxy.
Claude Code auto-update Reverts to incompatible version after install; Content block is not a text block returns after previously working Disable auto-update - see Troubleshooting: My Version Keeps Auto-Updating below
Corrupted resume session 400: Invalid model name passed in model=claude-sonnet-4-6 after using --resume Do not use --resume with a session ID from a crashed session. Start a fresh session instead.
BOM encoding in PowerShell Content-Length: 2 or empty response from curl Use Out-File -Encoding ascii -NoNewline approach in Step 1
Wrong model name Invalid model name passed in model=claude-sonnet-4-6 Always use --model flag at launch. Never rely on ANTHROPIC_MODEL env var.
npm blocked outside PyCharm running scripts is disabled on this system Run npm from PyCharm terminal only. PowerShell execution policy blocks it in standalone windows.
Docker - ANTHROPIC_MODEL ignored Model name not passed correctly Use --model flag in command, not environment variable
Auth screen on first launch Three login options appear; none accept ToxPipe API key directly Ensure ANTHROPIC_AUTH_TOKEN is set as a persistent user environment variable before launching. Do not use ANTHROPIC_API_KEY - ToxPipe requires the Bearer token header sent by ANTHROPIC_AUTH_TOKEN. If both are set, unset ANTHROPIC_API_KEY.
SSL certificate error Unable to connect to API: Self-signed certificate detected Ensure NODE_EXTRA_CA_CERTS is set to the full path of your NIH CA Bundle PEM file. Required for both native and Docker methods. See Step 5A / Step 7A.
Git Bash not found Claude Code cannot locate Git Bash Add user environment variable CLAUDE_CODE_GIT_BASH_PATH pointing to your git-bash.exe. See Step 7A.

Troubleshooting: Which Version Am I Running?

claude --version

If above 2.1.45:

npm install -g @anthropic-ai/claude-code@2.1.45

Troubleshooting: My Version Keeps Auto-Updating

Claude Code has a built-in auto-updater that can override your pinned version. If you find it keeps updating past 2.1.45:

Step 1: Check your current version

claude --version

Step 2: Reinstall the pinned version

npm install -g @anthropic-ai/claude-code@2.1.45

Step 3: Disable auto-updates permanently

New-Item -ItemType Directory -Force "$env:USERPROFILE\.claude" 
'{"env": {"DISABLE_AUTOUPDATER": "1"}}' | Out-File -FilePath "$env:USERPROFILE\.claude\settings.json" -Encoding utf8

Step 4: Verify the settings file was created

Get-Content "$env:USERPROFILE\.claude\settings.json"

Should return:

{"env": {"DISABLE_AUTOUPDATER": "1"}}

Step 5: Launch and verify version again

claude --version

Should still show 2.1.45 after the next launch.

Troubleshooting: API Error 400: text content blocks must contain non-whitespace text

You can sometimes get a API Error 400: text content blocks must contain non-whitespace text error if you have previous failed queries in Claude Code's conversation history. To fix this, you can manually edit the conversation history .jsonl file (or delete it outright) to remove the offending entries. The conversation history files are typically stored at:

<user_home_directory>/.claude/projects/<project_name>/

Tested on: Windows GFE, Node.js v24.14.1, npm 11.11.0, Claude Code v2.1.45, LiteLLM proxy, April 2026

Docker tested on: Docker Desktop 27.0.3, Docker Compose v2.28.1

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