Initialize plugins only when their models are used

[polyrand]

I recently started passing API keys as CLI flags instead of storing them in the environment or the keys file. When I try to run llm with a plugin that requires an API key, there's an error even if I'm not using the model from the plugin.

For example, this works as expected:

uvx --with "llm-anthropic" "llm@latest" -m "claude-3.5-sonnet-latest" --key "${KEY:?}" "tell me a joke"

But this breaks:

uvx --with "llm-together" --with "llm-anthropic" "llm@latest" -m "claude-3.5-sonnet-latest" --key "${KEY:?}" "tell me a joke"

llm.errors.NeedsKeyException: No key found - add one using 'llm keys set together' or set the TOGETHER_API_KEY environment variable

I understand this is probably a bug on llm-together because there aren't any errors if I add --with "llm-gemini" or --with "llm-groq" to the command. For example, this works:

uvx --with "llm-gemini" --with "llm-anthropic" "llm@latest" -m "claude-3.5-sonnet-latest" --key "${KEY:?}" "tell me a joke"

But I'm wondering if it would be better to only initialize plugins if the model they are registering is actually used.