Model Configuration

Configure models at Project (required), Agent, or Sub Agent levels. Settings inherit down the hierarchy.

Configuration Hierarchy

You must configure at least the base model at the project level:

// inkeep.config.ts
export default defineConfig({
  models: {
    base: {
      model: "anthropic/claude-sonnet-4-5",
      providerOptions: { temperature: 0.7, maxOutputTokens: 2048 }
    }
  }
});

Override at agent or sub agent level:

const myAgent = agent({
  models: {
    base: { model: "openai/gpt-4.1" }  // Override project default
  }
});

const mySubAgent = subAgent({
  models: {
    structuredOutput: { model: "openai/gpt-4.1-mini" }  // Override for JSON output
  }
});

Model Types

Type	Purpose	Fallback
`base`	Text generation and reasoning	Required at project level
`structuredOutput`	JSON/structured output only	Falls back to `base`
`summarizer`	Summaries and status updates	Falls back to `base`

Supported Models

Provider	Example Models	API Key
Anthropic	`anthropic/claude-sonnet-4-5` `anthropic/claude-haiku-4-5`	`ANTHROPIC_API_KEY`
OpenAI	`openai/gpt-4.1` `openai/gpt-4.1-mini` `openai/gpt-4.1-nano` `openai/gpt-5`*	`OPENAI_API_KEY`
Google	`google/gemini-2.5-flash` `google/gemini-2.5-flash-lite`	`GOOGLE_GENERATIVE_AI_API_KEY`
OpenRouter	`openrouter/anthropic/claude-sonnet-4-0` `openrouter/meta-llama/llama-3.1-405b`	`OPENROUTER_API_KEY`
Gateway	`gateway/openai/gpt-4.1-mini`	`AI_GATEWAY_API_KEY`

Note

*openai/gpt-5, openai/gpt-5-mini, and openai/gpt-5-nano require a verified OpenAI organization. If your organization is not yet verified, these models will not be available.

Pinned vs Unpinned Models

Pinned models include a specific date or version (e.g., anthropic/claude-sonnet-4-20250514) and always use that exact version.

Unpinned models use generic identifiers (e.g., anthropic/claude-sonnet-4-5) and let the provider choose the latest version, which may change over time as providers update their models.

models: {
  base: {
    model: "anthropic/claude-sonnet-4-5",  // Unpinned - provider chooses version
    // vs
    model: "anthropic/claude-sonnet-4-20250514"  // Pinned - exact version
  }
}

The TypeScript SDK also provides constants for common models:

import { Models } from "@inkeep/agents-sdk";

models: {
  base: {
    model: Models.ANTHROPIC_CLAUDE_SONNET_4_5,  // Type-safe constants
  }
}

Provider Options

Inkeep Agents supports all Vercel AI SDK provider options.

Complete Examples

Basic configuration:

OpenAI with reasoning:

Anthropic with thinking:

Google with thinking:

CLI Defaults

When using inkeep init, defaults are set based on your chosen provider:

Provider	Base	Structured Output	Summarizer
Anthropic	`claude-sonnet-4-5`	`claude-sonnet-4-5`	`claude-sonnet-4-5`
OpenAI	`gpt-4.1`	`gpt-4.1-mini`	`gpt-4.1-nano`
Google	`gemini-2.5-flash`	`gemini-2.5-flash-lite`	`gemini-2.5-flash-lite`