Model Provider

The Federation AIService abstracts over multiple AI model providers. A model provider is any backend that can serve model requests — OpenAI, Anthropic, Google, or a local inference server.

Registration

Providers register with City by exposing:

• Available model IDs
• Capability flags (streaming, tool use, vision, etc.)
• Authentication requirements

Unified API

Regardless of the backend, the Federation AIService exposes a unified API to Agents. This means:

• Agents do not need provider-specific code
• Switching providers is a configuration change, not a code change
• New providers can be added without modifying Agents

Capability discovery

When an Agent binds to a model ID, City reports:

• Whether the model supports streaming
• Whether the model supports tool use
• Maximum context length
• Pricing per token

Continue with:

• Service
• Action