> ## 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.

# Coding Assistants

> Add Phaseo as a model provider in Cursor, VS Code, Codex, Claude Code, and other coding tools.

Use this guide to add Phaseo as the model provider in coding assistants that support custom OpenAI-compatible or Anthropic-compatible endpoints.

## Provider settings

Use these values unless the tool asks for a different field name:

| Setting       | Value                                          |
| ------------- | ---------------------------------------------- |
| Provider type | OpenAI Compatible                              |
| Base URL      | `https://api.phaseo.ai/v1`                     |
| API key       | Your Phaseo API key                            |
| Model         | A Phaseo model id, such as `openai/gpt-5-nano` |

For Anthropic-compatible tools, use:

| Setting    | Value                                                    |
| ---------- | -------------------------------------------------------- |
| Base URL   | `https://api.phaseo.ai`                                  |
| Auth token | Your Phaseo API key                                      |
| Model      | A Phaseo model id, such as `anthropic/claude-sonnet-4.5` |

## Cursor

Cursor supports custom OpenAI-compatible endpoints through its OpenAI API key settings.

1. Open `Cursor Settings`.
2. Go to `Models`.
3. Enable or add the `OpenAI API Key` entry.
4. Paste your Phaseo API key.
5. Enable `Override OpenAI Base URL`.
6. Set the base URL to `https://api.phaseo.ai/v1`.
7. Add a custom model using A Phaseo model id, for example `openai/gpt-5-nano`.
8. Enable the model and verify it from the Cursor model picker.

If Cursor rejects a model id with `/`, create the closest local alias the UI allows and route that alias to the Phaseo model in your own config when the client supports aliases.

## VS Code

VS Code supports adding models through the Language Models editor when the OpenAI-compatible provider is available in your VS Code or Insiders build.

1. Open the Command Palette.
2. Run `Chat: Manage Language Models`.
3. Choose `OpenAI Compatible` or `OAI Compatible`.
4. Enter your Phaseo API key.
5. Set the endpoint or base URL to `https://api.phaseo.ai/v1`.
6. Add A Phaseo model id, for example `openai/gpt-5-nano`.
7. Select the new model from the chat model picker.

If your VS Code build does not show an OpenAI-compatible provider, use an extension that supports custom providers, such as Continue, Cline, Roo Code, or Kilo Code.

## Continue

Continue can use Phaseo through its OpenAI provider with a custom API base.

```yaml theme={null}
name: Phaseo
version: 0.0.1
schema: v1

models:
  - name: Phaseo GPT-5 Nano
    provider: openai
    model: openai/gpt-5-nano
    apiKey: ${{ secrets.PHASEO_API_KEY }}
    apiBase: https://api.phaseo.ai/v1
    roles:
      - chat
      - edit
      - apply
```

For models where Continue defaults to Responses but your workflow needs Chat Completions compatibility, set `useResponsesApi: false`.

## Cline, Roo Code, and Kilo Code

These tools expose similar provider settings.

1. Open the extension settings.
2. Choose `OpenAI Compatible` as the provider.
3. Set the base URL to `https://api.phaseo.ai/v1`.
4. Paste your Phaseo API key.
5. Enter A Phaseo model id.
6. Save and run a small chat request before using file-editing tools.

## Aider

Set OpenAI-compatible environment variables and pass the model on launch:

```bash theme={null}
export OPENAI_API_BASE="https://api.phaseo.ai/v1"
export OPENAI_API_KEY="your_phaseo_api_key"
aider --model openai/openai/gpt-5-nano
```

Aider often expects OpenAI-compatible custom models to be prefixed with `openai/`. Because Phaseo model ids already include provider prefixes, the full Aider model string may look like `openai/openai/gpt-5-nano`.

## Codex

Use the dedicated [Codex guide](./codex.mdx) for Codex CLI, Codex App, and the Codex IDE extension. The short version is:

```toml theme={null}
model = "openai/gpt-5.5"
model_provider = "phaseo"

[model_providers.phaseo]
name = "Phaseo"
base_url = "https://api.phaseo.ai/v1"
env_key = "PHASEO_API_KEY"
wire_api = "responses"
```

Codex custom providers use the Responses wire protocol.

## OpenCode

Use the dedicated [OpenCode guide](./opencode.mdx) when you want OpenCode to call Phaseo through an OpenAI-compatible custom provider.

## Claude Code

Use the dedicated [Claude Code guide](./claude-code.mdx). Claude Code uses Anthropic-compatible gateway environment variables:

```bash theme={null}
export ANTHROPIC_BASE_URL="https://api.phaseo.ai"
export ANTHROPIC_AUTH_TOKEN="your_phaseo_api_key"
export ANTHROPIC_API_KEY=""
```

Then start Claude Code from the same shell:

```bash theme={null}
claude
```

## Claude Desktop

Claude Desktop supports MCP servers, but it does not expose the same custom model-provider setup as coding assistants such as Cursor, Codex, or Claude Code. Use [Docs MCP](./docs-mcp.mdx) to add Phaseo documentation context to Claude Desktop. Use Claude Code when you need Phaseo to be the model gateway.

## Deep Agents CLI and LangChain tools

Use the same base URL and API key settings as [LangChain](./langchain.mdx). If the tool reads OpenAI environment variables, set:

```bash theme={null}
export OPENAI_API_KEY="your_phaseo_api_key"
export OPENAI_BASE_URL="https://api.phaseo.ai/v1"
```

Then pass A Phaseo model id in the tool's model field.

## Notes

* Coding assistants vary in how they handle slashes in model ids. If the UI rejects `openai/gpt-5-nano`, create a local alias if the tool supports aliases.
* Test file-editing workflows carefully. `phaseo:apply_patch` is Responses-only.
* Add [Docs MCP](./docs-mcp.mdx) when you want the assistant to read Phaseo docs during a session.
* Prefer Chat Completions for older coding tools unless the tool explicitly supports Responses events and server tools.

## Related

* [Server Tools](../server-tools/index.mdx)
* [Responses](../../api-reference/endpoint/responses.mdx)
* [Chat Completions](../../api-reference/endpoint/chat-completions.mdx)