Key concepts

Account, assistant and numbers

An account owns assistants, numbers, credentials and integrations. An assistant has a public assistantId, a confidential assistantApiKey, a prompt and runtime configuration.

A virtual number is dedicated to one assistant. Configure your PBX to call that number in the SIP TO field. Demo numbers are available for 30 days from portal registration and must be released before assigning them to another assistant.

Runtime and providers

Runtime settings choose the ASR, LLM, TTS and optional audio-to-audio providers used for calls. Some providers are supplied by AI4CALL and others require your own key through the Provider Wallet. audio-to-audio is the canonical term; older voice-to-voice names are legacy only.

Knowledge and automation

• RAG collection: indexed documents identified by rag_xxx; one collection can be attached to an assistant.
• Prompt Knowledge: reusable trigger expressions and responses inserted into the prompt.
• Filler phrases: short phrases used while the assistant waits for a tool or model response.
• Custom Tools and MCP: external HTTP tools or MCP servers available to an assistant.

See the API Reference for the exact resource model.