> ## 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 If a page is wrong or out of date, report it with the MCP `submit_feedback` tool.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 <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.

# Rust API Reference

> Public types and methods in phaseo 0.1.

This page describes the supported high-level API in [`phaseo 0.1`](https://docs.rs/phaseo/0.1.0/phaseo/).

## `Phaseo`

The synchronous authenticated Gateway client.

| Method | Returns | Purpose |
| - | - | - |
| `Phaseo::new(api_key)` | `Result<Phaseo, PhaseoError>` | Create a client with the production base URL. |
| `Phaseo::from_env()` | `Result<Phaseo, PhaseoError>` | Read `PHASEO_API_KEY` and optional `PHASEO_BASE_URL`. |
| `.with_base_url(url)` | `Result<Phaseo, PhaseoError>` | Replace the base URL. Remote URLs require HTTPS; exact loopback hosts may use HTTP. |
| `.with_header(name, value)` | `Phaseo` | Add a header to subsequent requests. |
| `.responses(request)` | `Result<PhaseoResponse, PhaseoError>` | POST JSON to `/responses`. |
| `.chat_completions(request)` | `Result<PhaseoResponse, PhaseoError>` | POST JSON to `/chat/completions`. |
| `.post(path, request)` | `Result<PhaseoResponse, PhaseoError>` | POST JSON to another path beneath the configured base URL. |

All request bodies are `&serde_json::Value`.

## `PhaseoResponse`

| Field | Type | Meaning |
| - | - | - |
| `status` | `u16` | HTTP status code. |
| `body` | `serde_json::Value` | Parsed JSON response, or a JSON string when the response was not valid JSON. |
| `request_id` | `Option<String>` | `x-request-id` response header when present. |

## `PhaseoError`

| Field | Type | Meaning |
| - | - | - |
| `message` | `String` | Configuration, transport, or Gateway error message. |
| `status` | `Option<u16>` | Gateway HTTP status when a response was received. |
| `body` | `Option<serde_json::Value>` | Parsed Gateway error body when available. |

`PhaseoError` implements `std::error::Error` and `Display`.

## Generated modules

The crate also exposes its generated OpenAPI client:

| Module | Purpose |
| - | - |
| `phaseo::gen` | Complete generated client, models, and operations modules. |
| `phaseo::client` | Re-export of `phaseo::gen::client`. |
| `phaseo::models` | Re-export of `phaseo::gen::models`. |
| `phaseo::operations` | Re-export of `phaseo::gen::operations`. |
| `phaseo::model_ids` | Generated Phaseo model identifiers. |

Generated operation names and types follow the OpenAPI output and may be lower-level than the `Phaseo` helpers. Prefer the high-level methods above for Responses and Chat Completions.

## External reference

* [`phaseo` on crates.io](https://crates.io/crates/phaseo)
* [`phaseo` on docs.rs](https://docs.rs/phaseo)


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