Model Routing - PraisonAI

PraisonAI picks the vendor from your model string, so claude-3-5-sonnet-latest goes to Anthropic and gemini-2.0-flash goes to Google — no prefix required.

Quick Start

Just name the model

Name the model and PraisonAI routes it to the right vendor.

import { Agent } from 'praisonai';

const openai = new Agent({ instructions: 'x', llm: 'gpt-4o-mini' });
const claude = new Agent({ instructions: 'x', llm: 'claude-3-5-sonnet-latest' });
const gemini = new Agent({ instructions: 'x', llm: 'gemini-2.0-flash' });

await claude.chat('Hello!');

Be explicit when the name isn't enough

Add a provider/ prefix for custom-named or gateway models the bare name would not resolve.

import { Agent } from 'praisonai';

const anthropic = new Agent({ instructions: 'x', llm: 'anthropic/my-custom-claude' });
const openai    = new Agent({ instructions: 'x', llm: 'openai/gpt-4o' });
const google    = new Agent({ instructions: 'x', llm: 'google/gemini-2.0-flash' });

How It Works

PraisonAI runs four checks in order to resolve every model string. An explicit provider/model prefix wins over everything, including a custom baseURL.

Routing Decision Table

This table is the single source of truth for user-visible routing behaviour.

`llm` string	`baseURL` set?	Resolved provider	Backend used
`gpt-4o-mini`	no	openai	OpenAI (native)
`claude-3-5-sonnet-latest`	no	anthropic	AI SDK
`gemini-2.0-flash`	no	google	AI SDK
`some-local-model` (unknown bare)	no	openai	OpenAI (native)
`openai/gpt-4o`	no	openai	OpenAI (native)
`anthropic/claude-3-5-sonnet-latest`	no	anthropic	AI SDK
`claude-3-5-sonnet-latest`	yes	openai	OpenAI-compatible (baseURL)
`anthropic/claude-3-5-sonnet-latest`	yes	anthropic	AI SDK (explicit prefix wins)

The baseURL Exception

Pointing at a proxy that serves claude-* over an OpenAI-shaped API is a real deployment, so a bare name plus a custom baseURL stays on the OpenAI-compatible path — prefix inference would otherwise route it away from the endpoint you explicitly asked for. An explicit provider/model prefix still wins, because that request is unambiguous.

import { Agent } from 'praisonai';

// Bare name + baseURL → stays OpenAI-compatible (proxy case)
new Agent({ llm: 'claude-3-5-sonnet-latest',
            baseURL: 'https://my-gateway.example/v1' });

// Explicit prefix + baseURL → explicit prefix wins (unambiguous)
new Agent({ llm: 'anthropic/claude-3-5-sonnet-latest',
            baseURL: 'https://my-gateway.example/v1' });

Per-Agent Credentials

Pass apiKey on the agent and PraisonAI honours it for whichever provider the model routes to.

import { Agent } from 'praisonai';

const agent = new Agent({
  instructions: 'You are helpful.',
  llm: 'claude-3-5-sonnet-latest',
  apiKey: process.env.MY_ANTHROPIC_KEY,   // no ANTHROPIC_API_KEY needed
});

A programmatically-passed apiKey is honoured for every provider — env vars are optional, not required.

Best Practices

Prefer the bare name for major models

claude-3-5-sonnet-latest reads more clearly than anthropic/claude-3-5-sonnet-latest and routes the same way.

Add the provider/ prefix when you're using a gateway

A baseURL keeps a bare name on the OpenAI-compatible path; an explicit provider/model prefix overrides that.

Pass apiKey per agent when running multiple tenants

No env-var juggling, no cross-tenant leakage — each agent carries its own key.

Do not name your own model claude-... or gemini-... unless you mean it

The prefix inference is deliberate — a custom model with that name will route to Anthropic or Google.

Providers

Full provider reference and configuration

Multi-Provider Agents (AI SDK)

Build agents across 30+ providers

​Quick Start

​How It Works

​Routing Decision Table

​The baseURL Exception

​Per-Agent Credentials

​Best Practices

​Related

Providers

Multi-Provider Agents (AI SDK)

Quick Start

How It Works

Routing Decision Table

The baseURL Exception

Per-Agent Credentials

Best Practices

Related