> ## Documentation Index > Fetch the complete documentation index at: https://phaseo.app/docs/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Phaseo Gateway base URL: https://api.phaseo.app/v1. Send `Authorization: Bearer $PHASEO_API_KEY` with every request. > Model IDs look like `provider/model`, for example `openai/gpt-6-astra`. Do not guess IDs: list them with `GET /v1/models` or check https://phaseo.app/models. `phaseo/free` routes to an available free model and needs no wallet balance. > For new text integrations prefer `POST /v1/responses`. `POST /v1/chat/completions` (OpenAI format) and `POST /v1/messages` (Anthropic format) suit existing code. > The full API contract is https://phaseo.app/docs/openapi/v1/openapi.yaml. Official SDKs: `@phaseo/sdk` (TypeScript) and `phaseo` (Python), plus Go, C#, PHP, Ruby and Rust. > Search these docs over MCP at https://phaseo.app/docs/mcp, and install Phaseo skills with `npx skills add https://phaseo.app/docs`. If a page is wrong or out of date, report it with the MCP `submit_feedback` tool. > Manage Phaseo accounts with the `phaseo` CLI (`npm install -g @phaseo/cli`, then `phaseo login` or `phaseo login --device-code`), the `/v1` Management API or the MCP server at `https://mcp.phaseo.app/mcp?access=manage`. Do not send users to the dashboard for account tasks. A person is still needed for sign-up, approving a sign-in, paying the first top-up on the checkout link that `phaseo credits add` returns when no card is saved, confirming each saved-card top-up from the emailed link, and account security (password, MFA, passkeys). Create API keys with `phaseo keys create --name --json`; never guess one. Credit top-ups need `phaseo login --scopes billing:write` first. Task map: https://phaseo.app/docs/v1/developers/manage-from-an-agent.md. # Migration Guides > Guides for moving between platforms or adopting a specific model release. Phaseo migration guides cover two different upgrade problems: * moving from one platform or gateway to Phaseo * adopting a specific model release on the same platform > [card] [Model migrations](https://phaseo.app/docs/v1/model-migrations.md) > > Upgrade a model while keeping the surrounding integration broadly the same. > [card] [Platform migrations](https://phaseo.app/docs/v1/migration-guides/gateway-parity-review.md) > > Move an SDK, provider, or gateway integration onto Phaseo. ## Model migrations For a tailored starting checklist, use the [Migration Assistant](https://phaseo.app/migrate). 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 5](https://phaseo.app/docs/v1/model-migrations/anthropic-claude-opus-5.md) * [OpenAI GPT-5.6](https://phaseo.app/docs/v1/model-migrations/openai-migrating-to-gpt-5-6.md) * [Anthropic Claude Opus 4.8](https://phaseo.app/docs/v1/model-migrations/anthropic-claude-opus-4-1-to-4-8.md) * [Anthropic Claude Opus 4.7](https://phaseo.app/docs/v1/model-migrations/anthropic-claude-opus-4-6-to-4-7.md) * [Mistral Small 4](https://phaseo.app/docs/v1/model-migrations/mistral-small-3-2-to-mistral-small-4.md) * [OpenAI GPT-5.4](https://phaseo.app/docs/v1/model-migrations/openai-migrating-to-gpt-5-4.md) * [Google Nano Banana 2](https://phaseo.app/docs/v1/model-migrations/google-nano-banana-1-to-nano-banana-2.md) * [Google Gemini 3.1](https://phaseo.app/docs/v1/model-migrations/google-migrating-to-gemini-3-and-3-1.md) * [Anthropic Claude Sonnet 4.6](https://phaseo.app/docs/v1/model-migrations/anthropic-claude-sonnet-4-5-to-4-6.md) * [SpaceXAI Grok 4.20](https://phaseo.app/docs/v1/model-migrations/xai-grok-4-20.md) * [Anthropic Claude Opus 4.6](https://phaseo.app/docs/v1/model-migrations/anthropic-claude-opus-4-5-to-4-6.md) ## Platform migrations Use platform migrations when you are changing SDKs, providers, or gateways and need to map your current integration onto Phaseo. > [card] [Build a migration checklist](https://phaseo.app/migrate) > > Choose your current integration and open the interactive migration assistant. Ask a coding agent to plan and carry out the migration with you. Migrate this project's AI requests to Phaseo Gateway. 1\. Install the Phaseo skills: npx skills add [https://phaseo.app/docs](https://phaseo.app/docs) Use phaseo-migration, which has a guide for each source platform (and openrouter-to-phaseo-migration for a detailed OpenRouter move). 2\. Find every place the project calls its current provider or gateway (OpenAI, Anthropic, OpenRouter, Vercel AI Gateway, LiteLLM or another), including environment variables, SDK clients, base URLs and model IDs. 3\. Read the matching guide at [https://phaseo.app/docs/v1/migration-guides](https://phaseo.app/docs/v1/migration-guides.md) and map each call to its Phaseo equivalent at [https://api.phaseo.app/v1](https://api.phaseo.app/v1) with a server-side PHASEO\_API\_KEY. 4\. Check every model ID with GET /v1/models. Do not assume IDs carry over unchanged. 5\. List the changes and a rollback plan before editing. After editing, verify one normal request and one streaming request if the project streams. 6\. Never print or commit API keys, and do not switch production traffic without my approval. Current platform migration guides: * [OpenAI SDK Migration](https://phaseo.app/docs/v1/migration-guides/from-openai.md) * [Anthropic SDK Migration](https://phaseo.app/docs/v1/migration-guides/from-anthropic.md) * [OpenRouter Migration](https://phaseo.app/docs/v1/migration-guides/from-openrouter.md) — switch the endpoint and key, verify model IDs, and test streaming and rollback. * [Vercel AI Gateway Migration](https://phaseo.app/docs/v1/migration-guides/from-vercel.md) * [LLMGateway Migration](https://phaseo.app/docs/v1/migration-guides/from-llmgateway.md) * [LiteLLM Migration](https://phaseo.app/docs/v1/migration-guides/from-litellm.md) * [Cloudflare AI Gateway Migration](https://phaseo.app/docs/v1/migration-guides/from-cloudflare.md) * [Helicone AI Gateway Migration](https://phaseo.app/docs/v1/migration-guides/from-helicone.md) Plan and validate the rollout: * [Migration Readiness Review](https://phaseo.app/docs/v1/migration-guides/gateway-parity-review.md) * [Migration Feature Checklist](https://phaseo.app/docs/v1/migration-guides/feature-parity-matrix.md) ## 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. Verify request parameters and endpoint behavior before comparing output quality. 4. Run production-like evals before shifting live traffic. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.