> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ai-stats.phaseo.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Migration Guides

> Guides for moving between platforms or upgrading from one model to a newer model.

# Migration Guides

AI Stats migration guides cover two different upgrade problems:

* moving from one platform or gateway to AI Stats
* moving from an older model release to a newer model on the same platform

## 1. Model migrations

Use model migrations when the integration stays broadly the same but the model changes underneath it.

These guides focus on:

* request parameter changes
* prompt and reasoning behavior shifts
* structured output and tool-calling differences
* rollout, fallback, and rollback strategy

Current model migration guides:

* [Anthropic: Claude Opus 4.6 to 4.7](../model-migrations/anthropic-claude-opus-4-6-to-4-7.mdx)
* [Anthropic: Claude Opus 4.5 to 4.6](../model-migrations/anthropic-claude-opus-4-5-to-4-6.mdx)
* [Anthropic: Claude Sonnet 4.5 to 4.6](../model-migrations/anthropic-claude-sonnet-4-5-to-4-6.mdx)
* [OpenAI: Migrating to GPT-5.4](../model-migrations/openai-migrating-to-gpt-5-4.mdx)
* [Google: Migrating to Gemini 3 and 3.1](../model-migrations/google-migrating-to-gemini-3-and-3-1.mdx)
* [Google: Nano Banana 1 to Nano Banana 2](../model-migrations/google-nano-banana-1-to-nano-banana-2.mdx)
* [xAI: Grok 4.20](../model-migrations/xai-grok-4-20.mdx)

## 2. Platform migrations

Use platform migrations when you are changing SDKs, providers, or gateways and need to map your current integration onto AI Stats.

Current platform migration guides:

* [OpenAI SDK Migration](./from-openai.mdx)
* [Anthropic SDK Migration](./from-anthropic.mdx)
* [Migration from OpenRouter](./from-openrouter.mdx)
* [Vercel AI Gateway Migration](./from-vercel.mdx)
* [LLMGateway Migration](./from-llmgateway.mdx)
* [LiteLLM Migration](./from-litellm.mdx)
* [Cloudflare AI Gateway Migration](./from-cloudflare.mdx)
* [Helicone AI Gateway Migration](./from-helicone.mdx)

Supporting review:

* [Gateway Parity Review](./gateway-parity-review.mdx)
* [Feature Parity Matrix](./feature-parity-matrix.mdx)

## How to use these guides

1. Identify whether you are changing the platform, the model, or both.
2. Start with the guide that matches the riskiest part of the migration.
3. Update request shape before comparing output quality.
4. Run production-like evals before shifting live traffic.