Providers

Sonzai routes chat completions through one of four providers. The IDs are exported as constants from the sonzai.providers module in the SDKs — import those rather than hand-typing strings, so they stay in sync as the catalog evolves. Use client.list_models() for the live set enabled on your tenant at runtime.

gemini — Google Gemini (default)

The platform default. gemini-3.1-flash-lite-preview is providers.DEFAULT_MODEL, and is also the wildcard fallback for the post-processing cascade.

openai — OpenAI

Default gpt-5.5; the 5.4 family is the cheaper workhorse and 5 / 5-mini / 5-nano cover even cheaper or smaller-context tiers. The fallback chain on quota exhaustion is gpt-5.5 → gpt-5.4 → gpt-5.4-mini → gpt-5.

xai — xAI (Grok)

Reasoning and non-reasoning variants in the Grok 4 family. grok-4-1-fast-non-reasoning is the default; reasoning models are opt-in for tasks that benefit from deeper chain-of-thought.

All Grok 4 entries support streaming, tools, and JSON mode. None support vision today.

custom — bring-your-own-LLM (BYOM)

Point Sonzai at any OpenAI-compatible chat-completions endpoint. The Mind Layer keeps owning memory, personality, mood, and post-processing — only the chat-completion call gets routed through your endpoint.

See Custom LLM for the full setup. This is distinct from BYOK — BYOK uses Sonzai's provider integrations but with your billing key; BYOM uses your own inference stack entirely.

Picking a provider in code

Pass provider and model on the chat call. Both are optional — omit them and Sonzai uses the agent's default, falling back through the scope cascade.

import { Sonzai } from "@sonzai-labs/agents";

const client = new Sonzai({ apiKey: process.env.SONZAI_API_KEY! });

await client.agents.chat({
agent:    "agent_abc",
messages: [{ role: "user", content: "Hello" }],
provider: "openai",
model:    "gpt-5.5",
});

Listing what's available at runtime

client.list_models() (Python / TS / Go expose the same shape) returns the live set of providers and models enabled on your tenant — useful for building a model-picker UI or for asserting that a provider you depend on is wired up before a deploy.

const result = await client.listModels();
for (const p of result.providers) {
console.log(p.provider, p.models.map((m) => m.id));
}

Reference

• BYOK — drop your own provider keys per project.
• Custom LLM — point Sonzai at your own endpoint entirely.
• Model scope — how provider / model is resolved per call.
• Post-processing — what runs in the background, on what model.