Struct ClaudeCodeOptionsBuilder 

pub struct ClaudeCodeOptionsBuilder { /* private fields */ }

Builder for ClaudeCodeOptions

Implementations

impl ClaudeCodeOptionsBuilder

pub fn system_prompt(self, prompt: impl Into<String>) -> Self

Set system prompt

pub fn append_system_prompt(self, prompt: impl Into<String>) -> Self

Set append system prompt

pub fn allowed_tools(self, tools: Vec<String>) -> Self

Set allowed tools (auto-approval permissions only)

IMPORTANT: This only controls which tool invocations bypass permission prompts. It does NOT disable or restrict which tools the AI can use. To completely disable tools, use disallowed_tools() instead.

Example: vec!["Bash(git:*)".to_string()] auto-approves git commands.

pub fn allow_tool(self, tool: impl Into<String>) -> Self

Add a single allowed tool (auto-approval permission)

See allowed_tools() for important usage notes.

pub fn disallowed_tools(self, tools: Vec<String>) -> Self

Set disallowed tools (completely disabled)

IMPORTANT: This completely disables the specified tools. The AI will not be able to use these tools at all. This is the correct way to restrict which tools the AI has access to.

Example: vec!["Bash".to_string(), "WebSearch".to_string()] prevents the AI from using Bash or WebSearch entirely.

pub fn disallow_tool(self, tool: impl Into<String>) -> Self

Add a single disallowed tool (completely disabled)

See disallowed_tools() for important usage notes.

pub fn permission_mode(self, mode: PermissionMode) -> Self

Set permission mode

pub fn add_mcp_server( self, name: impl Into<String>, config: McpServerConfig, ) -> Self

Add MCP server

pub fn mcp_servers(self, servers: HashMap<String, McpServerConfig>) -> Self

Set all MCP servers from a map

pub fn mcp_tools(self, tools: Vec<String>) -> Self

Set MCP tools

pub fn max_turns(self, turns: i32) -> Self

Set max turns

pub fn max_thinking_tokens(self, tokens: i32) -> Self

Set max thinking tokens

pub fn max_output_tokens(self, tokens: u32) -> Self

Set max output tokens (1-32000, overrides CLAUDE_CODE_MAX_OUTPUT_TOKENS env var)

pub fn model(self, model: impl Into<String>) -> Self

Set model

pub fn cwd(self, path: impl Into<PathBuf>) -> Self

Set working directory

pub fn continue_conversation(self, enable: bool) -> Self

Enable continue conversation

pub fn resume(self, id: impl Into<String>) -> Self

Set resume conversation ID

pub fn permission_prompt_tool_name(self, name: impl Into<String>) -> Self

Set permission prompt tool name

pub fn settings(self, settings: impl Into<String>) -> Self

Set settings file path

pub fn add_dirs(self, dirs: Vec<PathBuf>) -> Self

Add directories as working directories

pub fn add_dir(self, dir: impl Into<PathBuf>) -> Self

Add a single directory as working directory

pub fn extra_args(self, args: HashMap<String, Option<String>>) -> Self

Add extra CLI arguments

pub fn add_extra_arg( self, key: impl Into<String>, value: Option<String>, ) -> Self

Add a single extra CLI argument

pub fn control_protocol_format(self, format: ControlProtocolFormat) -> Self

Set control protocol format

pub fn include_partial_messages(self, include: bool) -> Self

Include partial assistant messages in streaming output

pub fn fork_session(self, fork: bool) -> Self

Enable fork_session behavior

pub fn setting_sources(self, sources: Vec<SettingSource>) -> Self

Set setting sources

pub fn agents(self, agents: HashMap<String, AgentDefinition>) -> Self

Define programmatic agents

pub fn cli_channel_buffer_size(self, size: usize) -> Self

Set CLI channel buffer size

Controls the size of internal communication channels (message, control, stdin buffers). Default is 100. Increase for high-throughput scenarios to prevent message lag.

Arguments

• size - Buffer size (number of messages that can be queued)

Example

let options = ClaudeCodeOptions::builder()
    .cli_channel_buffer_size(500)
    .build();

pub fn tools(self, config: ToolsConfig) -> Self

Set tools configuration

Controls the base set of tools available to Claude. This is distinct from allowed_tools which only controls auto-approval permissions.

Examples

// Enable specific tools only
let options = ClaudeCodeOptions::builder()
    .tools(ToolsConfig::list(vec!["Read".into(), "Edit".into()]))
    .build();

pub fn betas(self, betas: Vec<SdkBeta>) -> Self

Add SDK beta features

Enable Anthropic API beta features like extended context window.

pub fn add_beta(self, beta: SdkBeta) -> Self

Add a single SDK beta feature

pub fn max_budget_usd(self, budget: f64) -> Self

Set maximum spending limit in USD

When the budget is exceeded, the session will automatically terminate.

pub fn fallback_model(self, model: impl Into<String>) -> Self

Set fallback model

Used when the primary model is unavailable.

pub fn output_format(self, format: Value) -> Self

Set output format for structured outputs

Enables JSON schema validation for Claude’s responses.

Example

let options = ClaudeCodeOptions::builder()
    .output_format(serde_json::json!({
        "type": "json_schema",
        "schema": {
            "type": "object",
            "properties": {
                "answer": {"type": "string"}
            }
        }
    }))
    .build();

pub fn enable_file_checkpointing(self, enable: bool) -> Self

Enable file checkpointing

When enabled, file changes are tracked and can be rewound to any user message using ClaudeSDKClient::rewind_files().

pub fn sandbox(self, settings: SandboxSettings) -> Self

Set sandbox configuration

Controls bash command sandboxing for filesystem and network isolation.

pub fn plugins(self, plugins: Vec<SdkPluginConfig>) -> Self

Set plugin configurations

pub fn add_plugin(self, plugin: SdkPluginConfig) -> Self

Add a single plugin

pub fn user(self, user: impl Into<String>) -> Self

Set user identifier

pub fn stderr_callback(self, callback: Arc<dyn Fn(&str) + Send + Sync>) -> Self

Set stderr callback

Called with each line of stderr output from the CLI.

pub fn auto_download_cli(self, enable: bool) -> Self

Enable automatic CLI download

When enabled, the SDK will automatically download and cache the Claude Code CLI binary if it’s not found in the system PATH or common installation locations.

Example

let options = ClaudeCodeOptions::builder()
    .auto_download_cli(true)
    .build();

pub fn build(self) -> ClaudeCodeOptions

Build the options

Trait Implementations

impl Debug for ClaudeCodeOptionsBuilder

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ClaudeCodeOptionsBuilder

fn default() -> ClaudeCodeOptionsBuilder

Returns the “default value” for a type.