---
title: Types
description: RunOptions, CliName, McpServer, and provider-specific option structs
generated: true
---

# Types

All types are re-exported from the crate root and implement `Serialize`/`Deserialize` for easy JSON interop.

## CliName

Enum of supported CLI agents.

```rust
pub enum CliName {
    Claude,
    Codex,
    Gemini,
}
```

Serializes to lowercase strings: `"claude"`, `"codex"`, `"gemini"`. Implements `Display` with the same output.

## RunOptions

Configuration for a single `run()` call. All fields except `task` are optional.

```rust
pub struct RunOptions {
    pub cli: Option<CliName>,
    pub task: String,
    pub system_prompt: Option<String>,
    pub system_prompt_file: Option<String>,
    pub mcp_servers: Option<HashMap<String, McpServer>>,
    pub cwd: Option<String>,
    pub model: Option<String>,
    pub idle_timeout_ms: Option<u64>,
    pub total_timeout_ms: Option<u64>,
    pub max_consecutive_tool_failures: Option<u32>,
    pub env: Option<HashMap<String, String>>,
    pub executable_path: Option<String>,
    pub resume_session_id: Option<String>,
    pub max_output_bytes: Option<usize>,
    pub skip_permissions: bool,
    pub providers: Option<ProviderOptions>,
}
```

| Field | Default | Description |
|-------|---------|-------------|
| `cli` | `None` (auto-discover) | Which CLI to use |
| `task` | required | The prompt/task to send to the agent |
| `system_prompt` | `None` | Inline system prompt |
| `system_prompt_file` | `None` | Path to a system prompt file (takes precedence over `system_prompt`) |
| `mcp_servers` | `None` | MCP servers to connect |
| `cwd` | `"."` | Working directory for the CLI process |
| `model` | `None` | Model name (e.g. `"sonnet"`, `"o3"`, `"gemini-2.0-flash"`) |
| `idle_timeout_ms` | 300,000 | Idle timeout in milliseconds |
| `total_timeout_ms` | `None` | Total timeout in milliseconds |
| `max_consecutive_tool_failures` | 3 | Max consecutive tool failures before aborting |
| `env` | `None` | Extra environment variables for the CLI process |
| `executable_path` | `None` | Explicit path to the CLI binary (skips discovery — requires `cli` to be set) |
| `resume_session_id` | `None` | Session ID to resume a previous conversation |
| `max_output_bytes` | 10 MB | Max stdout buffer before aborting |
| `skip_permissions` | `false` | Bypass CLI permission prompts |
| `providers` | `None` | Provider-specific options |

Serializes with `camelCase` field names and implements `Default`.

## McpServer

Configuration for an MCP (Model Context Protocol) server.

```rust
pub struct McpServer {
    // Stdio transport
    pub command: Option<String>,
    pub args: Option<Vec<String>>,
    pub env: Option<HashMap<String, String>>,
    pub cwd: Option<String>,

    // HTTP/SSE transport
    pub url: Option<String>,
    pub transport_type: Option<McpTransport>,
    pub headers: Option<HashMap<String, String>>,

    // Tool filtering
    pub include_tools: Option<Vec<String>>,
    pub exclude_tools: Option<Vec<String>>,

    // Timeouts
    pub timeout: Option<u64>,
}
```

Use either stdio fields (`command`, `args`) or HTTP/SSE fields (`url`, `transport_type`), not both.

## McpTransport

```rust
pub enum McpTransport {
    Stdio,
    Sse,
    Http,
}
```

## ProviderOptions

Container for provider-specific option structs:

```rust
pub struct ProviderOptions {
    pub claude: Option<ClaudeOptions>,
    pub codex: Option<CodexOptions>,
    pub gemini: Option<GeminiOptions>,
}
```

Only the options matching the active CLI are used. You can safely set options for all providers.

## ClaudeOptions

```rust
pub struct ClaudeOptions {
    pub allowed_tools: Option<String>,
    pub disallowed_tools: Option<String>,
    pub tools: Option<String>,
    pub append_system_prompt: Option<String>,
    pub max_turns: Option<u32>,
    pub max_budget_usd: Option<f64>,
    pub max_thinking_tokens: Option<u32>,
    pub continue_session: Option<bool>,
    pub include_partial_messages: Option<bool>,
    pub effort: Option<String>,
    pub agents: Option<serde_json::Value>,
}
```

| Field | Description |
|-------|-------------|
| `allowed_tools` | Comma-separated list of allowed tools |
| `disallowed_tools` | Comma-separated list of disallowed tools |
| `tools` | Comma-separated list of tools to make available |
| `append_system_prompt` | Text appended to the system prompt |
| `max_turns` | Maximum number of agent turns |
| `max_budget_usd` | Spending limit in USD |
| `max_thinking_tokens` | Cap on thinking/reasoning tokens |
| `continue_session` | Continue the last session |
| `include_partial_messages` | Include partial messages in streaming |
| `effort` | Effort level (`"low"`, `"medium"`, `"high"`) |
| `agents` | Agent configuration as JSON |

## CodexOptions

```rust
pub struct CodexOptions {
    pub approval_policy: Option<String>,
    pub sandbox_mode: Option<String>,
    pub additional_directories: Option<Vec<String>>,
    pub images: Option<Vec<String>>,
    pub output_schema: Option<String>,
}
```

| Field | Description |
|-------|-------------|
| `approval_policy` | `"full-auto"`, `"suggest"`, or `"auto-edit"` |
| `sandbox_mode` | Sandbox mode (e.g. `"workspace-write"`) |
| `additional_directories` | Extra directories Codex can access |
| `images` | Image file paths to include |
| `output_schema` | JSON schema for structured output |

## GeminiOptions

```rust
pub struct GeminiOptions {
    pub approval_mode: Option<String>,
    pub sandbox: Option<bool>,
    pub extra_args: Option<Vec<String>>,
}
```

| Field | Description |
|-------|-------------|
| `approval_mode` | Approval mode (e.g. `"auto"`) |
| `sandbox` | Enable sandbox mode |
| `extra_args` | Additional CLI arguments passed directly to the Gemini binary |
