Struct SubAgentConfig 

pub struct SubAgentConfig {

    pub enabled: bool,
    pub max_concurrent: usize,
    pub extra_dirs: Vec<PathBuf>,
    pub user_agents_dir: Option<PathBuf>,
    pub default_permission_mode: Option<PermissionMode>,
    pub default_disallowed_tools: Vec<String>,
    pub allow_bypass_permissions: bool,
    pub default_memory_scope: Option<MemoryScope>,
    pub hooks: SubAgentLifecycleHooks,
    pub transcript_dir: Option<PathBuf>,
    pub transcript_enabled: bool,
    pub transcript_max_files: usize,
    pub context_window_turns: usize,
    pub max_spawn_depth: u32,
    pub context_injection_mode: ContextInjectionMode,
    pub parent_context_policy: ParentContextPolicy,
    pub max_parent_messages: usize,
    pub summary_max_chars: usize,
}

Sub-agent pool configuration, nested under [agents] in TOML.

When enabled = true, the agent can spawn isolated sub-agent sessions from SKILL.md-based agent definitions. Sub-agents inherit the parent’s provider pool unless overridden by model in their definition frontmatter.

Example (TOML)

[agents]
enabled = true
max_concurrent = 3
max_spawn_depth = 2

Fields

enabled: bool

Enable the sub-agent subsystem. Default: false.

max_concurrent: usize

Maximum number of sub-agents that can run concurrently.

extra_dirs: Vec<PathBuf>

Additional directories to search for .agent.md definition files.

user_agents_dir: Option<PathBuf>

User-level agents directory.

default_permission_mode: Option<PermissionMode>

Default permission mode applied to sub-agents that do not specify one.

default_disallowed_tools: Vec<String>

Global denylist applied to all sub-agents in addition to per-agent tools.except.

allow_bypass_permissions: bool

Allow sub-agents to use bypass_permissions mode.

default_memory_scope: Option<MemoryScope>

Default memory scope applied to sub-agents that do not set memory in their definition.

hooks: SubAgentLifecycleHooks

Lifecycle hooks executed when any sub-agent starts or stops.

transcript_dir: Option<PathBuf>

Directory where transcript JSONL files and meta sidecars are stored.

transcript_enabled: bool

Enable writing JSONL transcripts for sub-agent sessions.

transcript_max_files: usize

Maximum number of .jsonl transcript files to keep.

context_window_turns: usize

Number of recent parent conversation turns to pass to spawned sub-agents. Set to 0 to disable history propagation.

max_spawn_depth: u32

Maximum nesting depth for sub-agent spawns.

context_injection_mode: ContextInjectionMode

How parent context is injected into the sub-agent’s task prompt.

parent_context_policy: ParentContextPolicy

Whether to sanitize parent conversation history before passing to a spawned sub-agent.

Defaults to ParentContextPolicy::InheritSanitized which runs each text message part through the IPI sanitizer, stripping prompt-injection payloads that may have entered the parent history via tool results, web scrapes, or A2A messages.

max_parent_messages: usize

Maximum number of parent messages to inject, independent of context_window_turns.

Acts as a hard upper bound on context propagation volume to limit the blast radius of poisoned histories. When max_parent_messages < context_window_turns * 2 this cap wins and fewer messages are passed; otherwise context_window_turns * 2 is the binding limit. The tighter of the two limits always applies.

summary_max_chars: usize

Maximum character count for the Summary context injection mode.

When context_injection_mode = "summary", the extracted summary is truncated to this many characters at a UTF-8 char boundary before being prepended to the sub-agent’s task prompt. Consistent with the max_state_chars naming convention.

Default: 600 (≈200 tokens at 3 chars/token).

Trait Implementations

impl Clone for SubAgentConfig

fn clone(&self) -> SubAgentConfig

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SubAgentConfig

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

Formats the value using the given formatter.

impl Default for SubAgentConfig

fn default() -> SubAgentConfig

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for SubAgentConfig

where SubAgentConfig: Default,

fn deserialize<__D>( __deserializer: __D, ) -> Result<SubAgentConfig, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for SubAgentConfig

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.