Claude Code

Claude Code connects to Fenno using Anthropic Messages. This guide uses environment variables, without a third-party provider switcher or changes to local configuration files.

1. Prepare the client and model

Install the client using the official instructions , then check its version:


claude --version

Prepare a Fenno key and a model supporting Anthropic Messages, streaming and tool calling. Back up existing configuration and avoid multiple tools editing the same provider settings.

2. Configure the current terminal

Use the Bash/Zsh example on macOS, Linux or WSL, or PowerShell on Windows:


export FENNO_API_KEY="<YOUR_FENNO_API_KEY>"
export ANTHROPIC_BASE_URL="https://api.fenno.ai"
export ANTHROPIC_AUTH_TOKEN="$FENNO_API_KEY"
export ANTHROPIC_MODEL="<YOUR_MODEL_ID>"


$env:FENNO_API_KEY = "<YOUR_FENNO_API_KEY>"
$env:ANTHROPIC_BASE_URL = "https://api.fenno.ai"
$env:ANTHROPIC_AUTH_TOKEN = $env:FENNO_API_KEY
$env:ANTHROPIC_MODEL = "<YOUR_MODEL_ID>"

Replace the key and model ID. The base URL is the domain without /v1 or /messages; the client appends /v1/messages.

ANTHROPIC_AUTH_TOKEN sends Bearer authentication; ANTHROPIC_API_KEY sends x-api-key. Choose one as described in authentication, without conflicting credentials.

3. Inspect and verify


cd your-test-project
claude

Run /status in the session to check the API address and model.
Ask “Reply with OK only. Do not read or modify files.”
Match the time, model and usage in the Fenno console.
Test file reads and tool calling separately in a disposable project.

Do not ask the model which API it uses to verify routing: a generated answer cannot reliably identify the actual endpoint.

Persistence and conflicting settings

Variables in one terminal are not automatically available in other windows. For persistent use, add non-sensitive settings to your shell configuration and supply the key through your chosen secure credential mechanism.

The env object in Claude Code’s settings.json can override shell variables. If the old address remains active, check user, project and local settings for the same keys, then start a new session. Do not publish complete environment dumps.

If lightweight background requests use an unavailable model, configure ANTHROPIC_DEFAULT_HAIKU_MODEL with an accessible exact ID following the official model configuration guide. A successful main request does not verify all background model mappings.

Troubleshooting

Symptom	Action
Repeated authentication prompts or 401	Check the active credential source, stale keys and settings overrides
404 / model not found	Remove repeated `/v1` segments and check Messages support
Main session works, background requests fail	Check default model mappings and account permissions
Text works, tool requests fail	Reduce to one tool and inspect arguments and tool-result messages
429 / insufficient quota	Read the error and check quota before retrying a long conversation

See Claude Code’s gateway guide , model configuration , and general troubleshooting.