Register Model Providers with Correct Format Identifiers

Plano translates requests between its internal format and each provider's API. The model field uses provider/model-name syntax which determines both the upstream endpoint and the request/response translation layer. Some providers require an explicit provider_interface override.

Provider format reference:

Model prefix	Wire format	Example
`openai/*`	OpenAI	`openai/gpt-4o`
`anthropic/*`	Anthropic	`anthropic/claude-sonnet-4-20250514`
`gemini/*`	Google Gemini	`gemini/gemini-2.0-flash`
`mistral/*`	Mistral	`mistral/mistral-large-latest`
`groq/*`	Groq	`groq/llama-3.3-70b-versatile`
`deepseek/*`	DeepSeek	`deepseek/deepseek-chat`
`xai/*`	Grok (OpenAI-compat)	`xai/grok-2`
`together_ai/*`	Together.ai	`together_ai/meta-llama/Llama-3`
`custom/*`	Requires `provider_interface`	`custom/my-local-model`

Incorrect (missing provider prefix, ambiguous format):

yaml

model_providers:
  - model: gpt-4o            # Missing openai/ prefix — Plano cannot route this
    access_key: $OPENAI_API_KEY

  - model: claude-3-5-sonnet # Missing anthropic/ prefix
    access_key: $ANTHROPIC_API_KEY

Correct (explicit provider prefixes):

yaml

model_providers:
  - model: openai/gpt-4o
    access_key: $OPENAI_API_KEY
    default: true

  - model: anthropic/claude-sonnet-4-20250514
    access_key: $ANTHROPIC_API_KEY

  - model: gemini/gemini-2.0-flash
    access_key: $GOOGLE_API_KEY

For local or self-hosted models (Ollama, LiteLLM, vLLM):

yaml

model_providers:
  - model: custom/llama3
    base_url: http://host.docker.internal:11434/v1   # Ollama endpoint
    provider_interface: openai                        # Ollama speaks OpenAI format
    default: true

Always set default: true on exactly one provider per listener so Plano has a fallback when routing preferences do not match.

Reference: https://github.com/katanemo/archgw