Coding tools

Goose

Add Deference to Goose as a custom OpenAI-compatible provider.

Goose loads custom providers from a JSON file. The openai engine speaks Chat Completions, so the base URL is https://deference.si/v1.

Set up

Create a key in API keys and export it as DEFERENCE_API_KEY in the shell that starts Goose.
Create deference.json in the custom providers folder: ~/.config/goose/custom_providers/ on macOS and Linux, and %APPDATA%\Block\goose\config\custom_providers\ on Windows.

{
  "name": "deference",
  "engine": "openai",
  "display_name": "Deference",
  "api_key_env": "DEFERENCE_API_KEY",
  "base_url": "https://deference.si/v1",
  "supports_streaming": true,
  "dynamic_models": true,
  "models": [
    {
      "name": "anthropic/claude-sonnet-5.5",
      "context_limit": 200000,
      "max_tokens": 32000
    }
  ]
}

Select the provider and model.

export GOOSE_PROVIDER=deference
export GOOSE_MODEL=anthropic/claude-sonnet-5.5
goose session

$env:GOOSE_PROVIDER = "deference"
$env:GOOSE_MODEL = "anthropic/claude-sonnet-5.5"
goose session

In Goose Desktop, open Settings, then Models, then Configure providers, and choose Add Custom Provider. It takes the same fields. Desktop keeps the key in your system keychain.

name can use lowercase letters, digits, _ and -. Keep the key out of config.yaml: Goose ignores a key stored there.

Verify

Run goose info -v. It shows the config locations and active settings.
Run a one-off prompt.

GOOSE_PROVIDER=deference GOOSE_MODEL=anthropic/claude-sonnet-5.5 \
  goose run -t "Reply with exactly: gateway-ok"

$env:GOOSE_PROVIDER = "deference"
$env:GOOSE_MODEL = "anthropic/claude-sonnet-5.5"
goose run -t "Reply with exactly: gateway-ok"

Open Activity. The request is the top row, with the model you chose.

Pick a model

With dynamic_models on, Goose fills its model list from GET /v1/models. Your models entries supply the context and output limits.
Limits come from context_limit and max_tokens. GOOSE_CONTEXT_LIMIT and GOOSE_MAX_TOKENS override them for a session.
For Messages, set engine to anthropic and base_url to https://deference.si, without /v1.
GOOSE_PROVIDER and GOOSE_MODEL override the saved choice for one process. Start sessions with them, because the --provider flag is documented for goose run only.

Troubleshooting

You see	Cause	Fix
`missing required key DEFERENCE_API_KEY`	The variable is not set where Goose starts	Export it in that shell, or store the key in Desktop
`401 invalid_api_key`	The key sits in `config.yaml`, which Goose ignores	Use the environment variable or Desktop
The provider is not listed	The file name or `name` is invalid, or the JSON is broken	Check `name` and the JSON syntax
`404 model_not_found`	A `models` name differs from the catalog id	Copy the id from the Models page
`402 insufficient_credit`	No available credit	Add credit
`402 free_credit_not_eligible`	The account has only free credit, and this model or request does not qualify	Use an open-weight text model, set a lower `max_tokens`, or add credit
`402 key_limit_reached`	The key reached the credit limit set on it	Raise the key's limit in API keys, or use another key