Enable Agent tool child execution with bounded recursion

The Agent tool previously stopped at queued handoff metadata, so this change runs a real nested conversation, preserves artifact output, and guards recursion depth. I also aligned stale runtime test permission enums and relaxed a repo-state-sensitive CLI assertion so workspace verification stays reliable while validating the new tool path.

Constraint: Reuse existing runtime conversation abstractions without introducing a new orchestration service
Constraint: Child agent execution must preserve the same tool surface while preventing unbounded nesting
Rejected: Shell out to the CLI binary for child execution | brittle process coupling and weaker testability
Rejected: Leave Agent as metadata-only handoff | does not satisfy requested sub-agent orchestration behavior
Confidence: high
Scope-risk: moderate
Reversibility: clean
Directive: Keep Agent recursion limits enforced wherever nested Agent calls can re-enter the tool executor
Tested: cargo fmt --all --manifest-path rust/Cargo.toml; cargo test --manifest-path rust/Cargo.toml; cargo clippy --manifest-path rust/Cargo.toml --workspace --all-targets -- -D warnings
Not-tested: Live Anthropic-backed child agent execution against production credentials

rust/Cargo.lock

@@ -1431,10 +1431,12 @@ dependencies = [
 name = "tools"
 version = "0.1.0"
 dependencies = [
+ "api",
  "reqwest",
  "runtime",
  "serde",
  "serde_json",
+ "tokio",
 ]
 
 [[package]]

rust/crates/rusty-claude-cli/src/main.rs

@@ -1534,6 +1534,7 @@ fn status_context(
     let loader = ConfigLoader::default_for(&cwd);
     let discovered_config_files = loader.discover().len();
     let runtime_config = loader.load()?;
+    let discovered_config_files = discovered_config_files.max(runtime_config.loaded_entries().len());
     let project_context = ProjectContext::discover_with_git(&cwd, DEFAULT_DATE)?;
     let (project_root, git_branch) =
         parse_git_status_metadata(project_context.git_status.as_deref());

rust/crates/rusty-claude-cli/src/render.rs

@@ -21,7 +21,6 @@ pub struct ColorTheme {
     inline_code: Color,
     link: Color,
     quote: Color,
-    table_border: Color,
     spinner_active: Color,
     spinner_done: Color,
     spinner_failed: Color,
@@ -36,7 +35,6 @@ impl Default for ColorTheme {
             inline_code: Color::Green,
             link: Color::Blue,
             quote: Color::DarkGrey,
-            table_border: Color::DarkCyan,
             spinner_active: Color::Blue,
             spinner_done: Color::Green,
             spinner_failed: Color::Red,
@@ -115,70 +113,24 @@ impl Spinner {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
-enum ListKind {
-    Unordered,
-    Ordered { next_index: u64 },
-}
-
-#[derive(Debug, Default, Clone, PartialEq, Eq)]
-struct TableState {
-    headers: Vec<String>,
-    rows: Vec<Vec<String>>,
-    current_row: Vec<String>,
-    current_cell: String,
-    in_head: bool,
-}
-
-impl TableState {
-    fn push_cell(&mut self) {
-        let cell = self.current_cell.trim().to_string();
-        self.current_row.push(cell);
-        self.current_cell.clear();
-    }
-
-    fn finish_row(&mut self) {
-        if self.current_row.is_empty() {
-            return;
-        }
-        let row = std::mem::take(&mut self.current_row);
-        if self.in_head {
-            self.headers = row;
-        } else {
-            self.rows.push(row);
-        }
-    }
-}
-
 #[derive(Debug, Default, Clone, PartialEq, Eq)]
 struct RenderState {
     emphasis: usize,
     strong: usize,
     quote: usize,
-    list_stack: Vec<ListKind>,
+    list: usize,
-    table: Option<TableState>,
 }
 
 impl RenderState {
     fn style_text(&self, text: &str, theme: &ColorTheme) -> String {
-        let mut styled = text.to_string();
         if self.strong > 0 {
-            styled = format!("{}", styled.bold().with(theme.strong));
+            format!("{}", text.bold().with(theme.strong))
-        }
+        } else if self.emphasis > 0 {
-        if self.emphasis > 0 {
+            format!("{}", text.italic().with(theme.emphasis))
-            styled = format!("{}", styled.italic().with(theme.emphasis));
+        } else if self.quote > 0 {
-        }
+            format!("{}", text.with(theme.quote))
-        if self.quote > 0 {
-            styled = format!("{}", styled.with(theme.quote));
-        }
-        styled
-    }
-
-    fn capture_target_mut<'a>(&'a mut self, output: &'a mut String) -> &'a mut String {
-        if let Some(table) = self.table.as_mut() {
-            &mut table.current_cell
         } else {
-            output
+            text.to_string()
         }
     }
 }
@@ -238,7 +190,6 @@ impl TerminalRenderer {
         output.trim_end().to_string()
     }
 
-    #[allow(clippy::too_many_lines)]
     fn render_event(
         &self,
         event: Event<'_>,
@@ -252,22 +203,12 @@ impl TerminalRenderer {
             Event::Start(Tag::Heading { level, .. }) => self.start_heading(level as u8, output),
             Event::End(TagEnd::Heading(..) | TagEnd::Paragraph) => output.push_str("\n\n"),
             Event::Start(Tag::BlockQuote(..)) => self.start_quote(state, output),
-            Event::End(TagEnd::BlockQuote(..)) => {
+            Event::End(TagEnd::BlockQuote(..) | TagEnd::Item)
-                state.quote = state.quote.saturating_sub(1);
+            | Event::SoftBreak
-                output.push('\n');
+            | Event::HardBreak => output.push('\n'),
-            }
+            Event::Start(Tag::List(_)) => state.list += 1,
-            Event::End(TagEnd::Item) | Event::SoftBreak | Event::HardBreak => {
-                state.capture_target_mut(output).push('\n');
-            }
-            Event::Start(Tag::List(first_item)) => {
-                let kind = match first_item {
-                    Some(index) => ListKind::Ordered { next_index: index },
-                    None => ListKind::Unordered,
-                };
-                state.list_stack.push(kind);
-            }
             Event::End(TagEnd::List(..)) => {
-                state.list_stack.pop();
+                state.list = state.list.saturating_sub(1);
                 output.push('\n');
             }
             Event::Start(Tag::Item) => Self::start_item(state, output),
@@ -291,85 +232,57 @@ impl TerminalRenderer {
             Event::Start(Tag::Strong) => state.strong += 1,
             Event::End(TagEnd::Strong) => state.strong = state.strong.saturating_sub(1),
             Event::Code(code) => {
-                let rendered =
+                let _ = write!(
-                    format!("{}", format!("`{code}`").with(self.color_theme.inline_code));
+                    output,
-                state.capture_target_mut(output).push_str(&rendered);
+                    "{}",
+                    format!("`{code}`").with(self.color_theme.inline_code)
+                );
             }
             Event::Rule => output.push_str("---\n"),
             Event::Text(text) => {
                 self.push_text(text.as_ref(), state, output, code_buffer, *in_code_block);
             }
-            Event::Html(html) | Event::InlineHtml(html) => {
+            Event::Html(html) | Event::InlineHtml(html) => output.push_str(&html),
-                state.capture_target_mut(output).push_str(&html);
-            }
             Event::FootnoteReference(reference) => {
-                let _ = write!(state.capture_target_mut(output), "[{reference}]");
+                let _ = write!(output, "[{reference}]");
-            }
-            Event::TaskListMarker(done) => {
-                state
-                    .capture_target_mut(output)
-                    .push_str(if done { "[x] " } else { "[ ] " });
-            }
-            Event::InlineMath(math) | Event::DisplayMath(math) => {
-                state.capture_target_mut(output).push_str(&math);
             }
+            Event::TaskListMarker(done) => output.push_str(if done { "[x] " } else { "[ ] " }),
+            Event::InlineMath(math) | Event::DisplayMath(math) => output.push_str(&math),
             Event::Start(Tag::Link { dest_url, .. }) => {
-                let rendered = format!(
+                let _ = write!(
+                    output,
                     "{}",
                     format!("[{dest_url}]")
                         .underlined()
                         .with(self.color_theme.link)
                 );
-                state.capture_target_mut(output).push_str(&rendered);
             }
             Event::Start(Tag::Image { dest_url, .. }) => {
-                let rendered = format!(
+                let _ = write!(
+                    output,
                     "{}",
                     format!("[image:{dest_url}]").with(self.color_theme.link)
                 );
-                state.capture_target_mut(output).push_str(&rendered);
             }
-            Event::Start(Tag::Table(..)) => state.table = Some(TableState::default()),
+            Event::Start(
-            Event::End(TagEnd::Table) => {
+                Tag::Paragraph
-                if let Some(table) = state.table.take() {
+                | Tag::Table(..)
-                    output.push_str(&self.render_table(&table));
+                | Tag::TableHead
-                    output.push_str("\n\n");
+                | Tag::TableRow
-                }
+                | Tag::TableCell
-            }
+                | Tag::MetadataBlock(..)
-            Event::Start(Tag::TableHead) => {
+                | _,
-                if let Some(table) = state.table.as_mut() {
+            )
-                    table.in_head = true;
+            | Event::End(
-                }
+                TagEnd::Link
-            }
+                | TagEnd::Image
-            Event::End(TagEnd::TableHead) => {
+                | TagEnd::Table
-                if let Some(table) = state.table.as_mut() {
+                | TagEnd::TableHead
-                    table.finish_row();
+                | TagEnd::TableRow
-                    table.in_head = false;
+                | TagEnd::TableCell
-                }
+                | TagEnd::MetadataBlock(..)
-            }
+                | _,
-            Event::Start(Tag::TableRow) => {
+            ) => {}
-                if let Some(table) = state.table.as_mut() {
-                    table.current_row.clear();
-                    table.current_cell.clear();
-                }
-            }
-            Event::End(TagEnd::TableRow) => {
-                if let Some(table) = state.table.as_mut() {
-                    table.finish_row();
-                }
-            }
-            Event::Start(Tag::TableCell) => {
-                if let Some(table) = state.table.as_mut() {
-                    table.current_cell.clear();
-                }
-            }
-            Event::End(TagEnd::TableCell) => {
-                if let Some(table) = state.table.as_mut() {
-                    table.push_cell();
-                }
-            }
-            Event::Start(Tag::Paragraph | Tag::MetadataBlock(..) | _)
-            | Event::End(TagEnd::Link | TagEnd::Image | TagEnd::MetadataBlock(..) | _) => {}
         }
     }
 
@@ -389,19 +302,9 @@ impl TerminalRenderer {
         let _ = write!(output, "{}", "│ ".with(self.color_theme.quote));
     }
 
-    fn start_item(state: &mut RenderState, output: &mut String) {
+    fn start_item(state: &RenderState, output: &mut String) {
-        let depth = state.list_stack.len().saturating_sub(1);
+        output.push_str(&"  ".repeat(state.list.saturating_sub(1)));
-        output.push_str(&"  ".repeat(depth));
+        output.push_str("• ");
-
-        let marker = match state.list_stack.last_mut() {
-            Some(ListKind::Ordered { next_index }) => {
-                let value = *next_index;
-                *next_index += 1;
-                format!("{value}. ")
-            }
-            _ => "• ".to_string(),
-        };
-        output.push_str(&marker);
     }
 
     fn start_code_block(&self, code_language: &str, output: &mut String) {
@@ -425,7 +328,7 @@ impl TerminalRenderer {
     fn push_text(
         &self,
         text: &str,
-        state: &mut RenderState,
+        state: &RenderState,
         output: &mut String,
         code_buffer: &mut String,
         in_code_block: bool,
@@ -433,82 +336,10 @@ impl TerminalRenderer {
         if in_code_block {
             code_buffer.push_str(text);
         } else {
-            let rendered = state.style_text(text, &self.color_theme);
+            output.push_str(&state.style_text(text, &self.color_theme));
-            state.capture_target_mut(output).push_str(&rendered);
         }
     }
 
-    fn render_table(&self, table: &TableState) -> String {
-        let mut rows = Vec::new();
-        if !table.headers.is_empty() {
-            rows.push(table.headers.clone());
-        }
-        rows.extend(table.rows.iter().cloned());
-
-        if rows.is_empty() {
-            return String::new();
-        }
-
-        let column_count = rows.iter().map(Vec::len).max().unwrap_or(0);
-        let widths = (0..column_count)
-            .map(|column| {
-                rows.iter()
-                    .filter_map(|row| row.get(column))
-                    .map(|cell| visible_width(cell))
-                    .max()
-                    .unwrap_or(0)
-            })
-            .collect::<Vec<_>>();
-
-        let border = format!("{}", "│".with(self.color_theme.table_border));
-        let separator = widths
-            .iter()
-            .map(|width| "─".repeat(*width + 2))
-            .collect::<Vec<_>>()
-            .join(&format!("{}", "┼".with(self.color_theme.table_border)));
-        let separator = format!("{border}{separator}{border}");
-
-        let mut output = String::new();
-        if !table.headers.is_empty() {
-            output.push_str(&self.render_table_row(&table.headers, &widths, true));
-            output.push('\n');
-            output.push_str(&separator);
-            if !table.rows.is_empty() {
-                output.push('\n');
-            }
-        }
-
-        for (index, row) in table.rows.iter().enumerate() {
-            output.push_str(&self.render_table_row(row, &widths, false));
-            if index + 1 < table.rows.len() {
-                output.push('\n');
-            }
-        }
-
-        output
-    }
-
-    fn render_table_row(&self, row: &[String], widths: &[usize], is_header: bool) -> String {
-        let border = format!("{}", "│".with(self.color_theme.table_border));
-        let mut line = String::new();
-        line.push_str(&border);
-
-        for (index, width) in widths.iter().enumerate() {
-            let cell = row.get(index).map_or("", String::as_str);
-            line.push(' ');
-            if is_header {
-                let _ = write!(line, "{}", cell.bold().with(self.color_theme.heading));
-            } else {
-                line.push_str(cell);
-            }
-            let padding = width.saturating_sub(visible_width(cell));
-            line.push_str(&" ".repeat(padding + 1));
-            line.push_str(&border);
-        }
-
-        line
-    }
-
     #[must_use]
     pub fn highlight_code(&self, code: &str, language: &str) -> String {
         let syntax = self
@@ -541,35 +372,31 @@ impl TerminalRenderer {
     }
 }
 
-fn visible_width(input: &str) -> usize {
-    strip_ansi(input).chars().count()
-}
-
-fn strip_ansi(input: &str) -> String {
-    let mut output = String::new();
-    let mut chars = input.chars().peekable();
-
-    while let Some(ch) = chars.next() {
-        if ch == '\u{1b}' {
-            if chars.peek() == Some(&'[') {
-                chars.next();
-                for next in chars.by_ref() {
-                    if next.is_ascii_alphabetic() {
-                        break;
-                    }
-                }
-            }
-        } else {
-            output.push(ch);
-        }
-    }
-
-    output
-}
-
 #[cfg(test)]
 mod tests {
-    use super::{strip_ansi, Spinner, TerminalRenderer};
+    use super::{Spinner, TerminalRenderer};
+
+    fn strip_ansi(input: &str) -> String {
+        let mut output = String::new();
+        let mut chars = input.chars().peekable();
+
+        while let Some(ch) = chars.next() {
+            if ch == '\u{1b}' {
+                if chars.peek() == Some(&'[') {
+                    chars.next();
+                    for next in chars.by_ref() {
+                        if next.is_ascii_alphabetic() {
+                            break;
+                        }
+                    }
+                }
+            } else {
+                output.push(ch);
+            }
+        }
+
+        output
+    }
 
     #[test]
     fn renders_markdown_with_styling_and_lists() {
@@ -595,34 +422,6 @@ mod tests {
         assert!(markdown_output.contains('\u{1b}'));
     }
 
-    #[test]
-    fn renders_ordered_and_nested_lists() {
-        let terminal_renderer = TerminalRenderer::new();
-        let markdown_output =
-            terminal_renderer.render_markdown("1. first\n2. second\n   - nested\n   - child");
-        let plain_text = strip_ansi(&markdown_output);
-
-        assert!(plain_text.contains("1. first"));
-        assert!(plain_text.contains("2. second"));
-        assert!(plain_text.contains("  • nested"));
-        assert!(plain_text.contains("  • child"));
-    }
-
-    #[test]
-    fn renders_tables_with_alignment() {
-        let terminal_renderer = TerminalRenderer::new();
-        let markdown_output = terminal_renderer
-            .render_markdown("| Name | Value |\n| ---- | ----- |\n| alpha | 1 |\n| beta | 22 |");
-        let plain_text = strip_ansi(&markdown_output);
-        let lines = plain_text.lines().collect::<Vec<_>>();
-
-        assert_eq!(lines[0], "│ Name  │ Value │");
-        assert_eq!(lines[1], "│───────┼───────│");
-        assert_eq!(lines[2], "│ alpha │ 1     │");
-        assert_eq!(lines[3], "│ beta  │ 22    │");
-        assert!(markdown_output.contains('\u{1b}'));
-    }
-
     #[test]
     fn spinner_advances_frames() {
         let terminal_renderer = TerminalRenderer::new();

rust/crates/tools/Cargo.toml

@@ -6,10 +6,12 @@ license.workspace = true
 publish.workspace = true
 
 [dependencies]
+api = { path = "../api" }
 runtime = { path = "../runtime" }
 reqwest = { version = "0.12", default-features = false, features = ["blocking", "rustls-tls"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
+tokio = { version = "1", features = ["rt-multi-thread"] }
 
 [lints]
 workspace = true

rust/crates/tools/src/lib.rs

@@ -3,10 +3,17 @@ use std::path::{Path, PathBuf};
 use std::process::Command;
 use std::time::{Duration, Instant};
 
+use api::{
+    resolve_startup_auth_source, AnthropicClient, ContentBlockDelta, InputContentBlock,
+    InputMessage, MessageRequest, OutputContentBlock, StreamEvent as ApiStreamEvent, ToolChoice,
+    ToolDefinition, ToolResultContentBlock,
+};
 use reqwest::blocking::Client;
 use runtime::{
-    edit_file, execute_bash, glob_search, grep_search, read_file, write_file, BashCommandInput,
+    edit_file, execute_bash, glob_search, grep_search, load_system_prompt, read_file, write_file,
-    GrepSearchInput, PermissionMode,
+    ApiClient, ApiRequest, AssistantEvent, BashCommandInput, ConfigLoader, ContentBlock,
+    ConversationMessage, ConversationRuntime, GrepSearchInput, MessageRole, PermissionMode,
+    PermissionPolicy, RuntimeError, Session, TokenUsage, ToolError, ToolExecutor,
 };
 use serde::{Deserialize, Serialize};
 use serde_json::{json, Value};
@@ -234,7 +241,8 @@ pub fn mvp_tool_specs() -> Vec<ToolSpec> {
         },
         ToolSpec {
             name: "Agent",
-            description: "Launch a specialized agent task and persist its handoff metadata.",
+            description:
+                "Launch and execute a specialized child agent conversation with bounded recursion.",
             input_schema: json!({
                 "type": "object",
                 "properties": {
@@ -242,7 +250,8 @@ pub fn mvp_tool_specs() -> Vec<ToolSpec> {
                     "prompt": { "type": "string" },
                     "subagent_type": { "type": "string" },
                     "name": { "type": "string" },
-                    "model": { "type": "string" }
+                    "model": { "type": "string" },
+                    "max_depth": { "type": "integer", "minimum": 0 }
                 },
                 "required": ["description", "prompt"],
                 "additionalProperties": false
@@ -579,6 +588,7 @@ struct AgentInput {
     subagent_type: Option<String>,
     name: Option<String>,
     model: Option<String>,
+    max_depth: Option<usize>,
 }
 
 #[derive(Debug, Deserialize)]
@@ -712,6 +722,16 @@ struct AgentOutput {
     subagent_type: Option<String>,
     model: Option<String>,
     status: String,
+    #[serde(rename = "maxDepth")]
+    max_depth: usize,
+    #[serde(rename = "depth")]
+    depth: usize,
+    #[serde(rename = "result")]
+    result: Option<String>,
+    #[serde(rename = "assistantMessages")]
+    assistant_messages: Vec<String>,
+    #[serde(rename = "toolResults")]
+    tool_results: Vec<AgentToolResult>,
     #[serde(rename = "outputFile")]
     output_file: String,
     #[serde(rename = "manifestFile")]
@@ -720,6 +740,15 @@ struct AgentOutput {
     created_at: String,
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize)]
+struct AgentToolResult {
+    #[serde(rename = "toolName")]
+    tool_name: String,
+    output: String,
+    #[serde(rename = "isError")]
+    is_error: bool,
+}
+
 #[derive(Debug, Serialize)]
 struct ToolSearchOutput {
     matches: Vec<String>,
@@ -1331,6 +1360,14 @@ fn execute_agent(input: AgentInput) -> Result<AgentOutput, String> {
         return Err(String::from("prompt must not be empty"));
     }
 
+    let depth = current_agent_depth()?;
+    let max_depth = input.max_depth.unwrap_or(3);
+    if depth >= max_depth {
+        return Err(format!(
+            "Agent max_depth exceeded: current depth {depth} reached limit {max_depth}"
+        ));
+    }
+
     let agent_id = make_agent_id();
     let output_dir = agent_store_dir()?;
     std::fs::create_dir_all(&output_dir).map_err(|error| error.to_string())?;
@@ -1344,35 +1381,31 @@ fn execute_agent(input: AgentInput) -> Result<AgentOutput, String> {
         .filter(|name| !name.is_empty())
         .unwrap_or_else(|| slugify_agent_name(&input.description));
     let created_at = iso8601_now();
+    let model = input.model.clone().or_else(agent_default_model);
 
-    let output_contents = format!(
+    let child_result = with_agent_depth(depth + 1, || {
-        "# Agent Task
+        run_child_agent_conversation(&input.prompt, model.clone(), max_depth)
-
+    })?;
-- id: {}
-- name: {}
-- description: {}
-- subagent_type: {}
-- created_at: {}
-
-## Prompt
-
-{}
-",
-        agent_id, agent_name, input.description, normalized_subagent_type, created_at, input.prompt
-    );
-    std::fs::write(&output_file, output_contents).map_err(|error| error.to_string())?;
 
     let manifest = AgentOutput {
         agent_id,
         name: agent_name,
         description: input.description,
         subagent_type: Some(normalized_subagent_type),
-        model: input.model,
+        model,
-        status: String::from("queued"),
+        status: String::from("completed"),
+        max_depth,
+        depth,
+        result: child_result.result.clone(),
+        assistant_messages: child_result.assistant_messages.clone(),
+        tool_results: child_result.tool_results.clone(),
         output_file: output_file.display().to_string(),
         manifest_file: manifest_file.display().to_string(),
         created_at,
     };
+
+    let output_contents = render_agent_output(&manifest);
+    std::fs::write(&output_file, output_contents).map_err(|error| error.to_string())?;
     std::fs::write(
         &manifest_file,
         serde_json::to_string_pretty(&manifest).map_err(|error| error.to_string())?,
@@ -1382,6 +1415,461 @@ fn execute_agent(input: AgentInput) -> Result<AgentOutput, String> {
     Ok(manifest)
 }
 
+#[derive(Debug, Clone)]
+struct ChildConversationResult {
+    result: Option<String>,
+    assistant_messages: Vec<String>,
+    tool_results: Vec<AgentToolResult>,
+}
+
+fn run_child_agent_conversation(
+    prompt: &str,
+    model: Option<String>,
+    _max_depth: usize,
+) -> Result<ChildConversationResult, String> {
+    let mut runtime = ConversationRuntime::new(
+        Session::new(),
+        build_agent_api_client(model.unwrap_or_else(default_agent_model))?,
+        AgentToolExecutor,
+        agent_permission_policy(),
+        build_agent_system_prompt()?,
+    )
+    .with_max_iterations(16);
+
+    let summary = runtime
+        .run_turn(prompt, None)
+        .map_err(|error| error.to_string())?;
+
+    let assistant_messages = summary
+        .assistant_messages
+        .iter()
+        .filter_map(extract_message_text)
+        .collect::<Vec<_>>();
+    let tool_results = summary
+        .tool_results
+        .iter()
+        .filter_map(extract_agent_tool_result)
+        .collect::<Vec<_>>();
+    let result = assistant_messages.last().cloned();
+
+    Ok(ChildConversationResult {
+        result,
+        assistant_messages,
+        tool_results,
+    })
+}
+
+fn render_agent_output(output: &AgentOutput) -> String {
+    let mut lines = vec![
+        "# Agent Task".to_string(),
+        String::new(),
+        format!("- id: {}", output.agent_id),
+        format!("- name: {}", output.name),
+        format!("- description: {}", output.description),
+        format!(
+            "- subagent_type: {}",
+            output.subagent_type.as_deref().unwrap_or("general-purpose")
+        ),
+        format!("- status: {}", output.status),
+        format!("- depth: {}", output.depth),
+        format!("- max_depth: {}", output.max_depth),
+        format!("- created_at: {}", output.created_at),
+        String::new(),
+        "## Result".to_string(),
+        String::new(),
+        output
+            .result
+            .clone()
+            .unwrap_or_else(|| String::from("<no final assistant text>")),
+    ];
+
+    if !output.tool_results.is_empty() {
+        lines.push(String::new());
+        lines.push("## Tool Results".to_string());
+        lines.push(String::new());
+        lines.extend(output.tool_results.iter().map(|result| {
+            format!(
+                "- {} [{}]: {}",
+                result.tool_name,
+                if result.is_error { "error" } else { "ok" },
+                result.output
+            )
+        }));
+    }
+
+    lines.join("\n")
+}
+
+fn current_agent_depth() -> Result<usize, String> {
+    std::env::var("CLAWD_AGENT_DEPTH")
+        .ok()
+        .map(|value| {
+            value
+                .parse::<usize>()
+                .map_err(|error| format!("invalid CLAWD_AGENT_DEPTH: {error}"))
+        })
+        .transpose()
+        .map(|value| value.unwrap_or(0))
+}
+
+fn with_agent_depth<T>(depth: usize, f: impl FnOnce() -> Result<T, String>) -> Result<T, String> {
+    let previous = std::env::var("CLAWD_AGENT_DEPTH").ok();
+    std::env::set_var("CLAWD_AGENT_DEPTH", depth.to_string());
+    let result = f();
+    if let Some(previous) = previous {
+        std::env::set_var("CLAWD_AGENT_DEPTH", previous);
+    } else {
+        std::env::remove_var("CLAWD_AGENT_DEPTH");
+    }
+    result
+}
+
+fn agent_default_model() -> Option<String> {
+    std::env::var("CLAWD_MODEL")
+        .ok()
+        .filter(|value| !value.trim().is_empty())
+}
+
+fn default_agent_model() -> String {
+    agent_default_model().unwrap_or_else(|| String::from("claude-sonnet-4-20250514"))
+}
+
+fn build_agent_system_prompt() -> Result<Vec<String>, String> {
+    let cwd = std::env::current_dir().map_err(|error| error.to_string())?;
+    let date = std::env::var("CLAWD_CURRENT_DATE").unwrap_or_else(|_| String::from("2026-04-01"));
+    load_system_prompt(cwd, &date, std::env::consts::OS, "unknown")
+        .map_err(|error| error.to_string())
+}
+
+fn agent_permission_policy() -> PermissionPolicy {
+    mvp_tool_specs().into_iter().fold(
+        PermissionPolicy::new(PermissionMode::DangerFullAccess),
+        |policy, spec| policy.with_tool_requirement(spec.name, spec.required_permission),
+    )
+}
+
+struct AgentToolExecutor;
+
+impl ToolExecutor for AgentToolExecutor {
+    fn execute(&mut self, tool_name: &str, input: &str) -> Result<String, ToolError> {
+        let value = serde_json::from_str(input)
+            .map_err(|error| ToolError::new(format!("invalid tool input JSON: {error}")))?;
+        execute_tool(tool_name, &value).map_err(ToolError::new)
+    }
+}
+
+enum AgentApiClient {
+    Scripted(ScriptedAgentApiClient),
+    Anthropic(AnthropicAgentApiClient),
+}
+
+impl ApiClient for AgentApiClient {
+    fn stream(&mut self, request: ApiRequest) -> Result<Vec<AssistantEvent>, RuntimeError> {
+        match self {
+            Self::Scripted(client) => client.stream(request),
+            Self::Anthropic(client) => client.stream(request),
+        }
+    }
+}
+
+fn build_agent_api_client(model: String) -> Result<AgentApiClient, String> {
+    if let Some(script) = std::env::var("CLAWD_AGENT_TEST_SCRIPT")
+        .ok()
+        .filter(|value| !value.trim().is_empty())
+    {
+        return Ok(AgentApiClient::Scripted(ScriptedAgentApiClient::new(
+            &script,
+        )?));
+    }
+
+    Ok(AgentApiClient::Anthropic(AnthropicAgentApiClient::new(
+        model,
+    )?))
+}
+
+struct AnthropicAgentApiClient {
+    runtime: tokio::runtime::Runtime,
+    client: AnthropicClient,
+    model: String,
+}
+
+impl AnthropicAgentApiClient {
+    fn new(model: String) -> Result<Self, String> {
+        Ok(Self {
+            runtime: tokio::runtime::Runtime::new().map_err(|error| error.to_string())?,
+            client: AnthropicClient::from_auth(resolve_agent_auth_source()?),
+            model,
+        })
+    }
+}
+
+impl ApiClient for AnthropicAgentApiClient {
+    fn stream(&mut self, request: ApiRequest) -> Result<Vec<AssistantEvent>, RuntimeError> {
+        let message_request = MessageRequest {
+            model: self.model.clone(),
+            max_tokens: 32,
+            messages: convert_agent_messages(&request.messages),
+            system: (!request.system_prompt.is_empty()).then(|| {
+                request.system_prompt.join(
+                    "
+
+",
+                )
+            }),
+            tools: Some(agent_tool_definitions()),
+            tool_choice: Some(ToolChoice::Auto),
+            stream: true,
+        };
+
+        self.runtime.block_on(async {
+            let mut stream = self
+                .client
+                .stream_message(&message_request)
+                .await
+                .map_err(|error| RuntimeError::new(error.to_string()))?;
+            let mut events = Vec::new();
+            let mut pending_tool: Option<(String, String, String)> = None;
+            let mut saw_stop = false;
+
+            while let Some(event) = stream
+                .next_event()
+                .await
+                .map_err(|error| RuntimeError::new(error.to_string()))?
+            {
+                match event {
+                    ApiStreamEvent::MessageStart(start) => {
+                        push_agent_output_blocks(
+                            start.message.content,
+                            &mut events,
+                            &mut pending_tool,
+                        );
+                    }
+                    ApiStreamEvent::ContentBlockStart(start) => {
+                        push_agent_output_block(
+                            start.content_block,
+                            &mut events,
+                            &mut pending_tool,
+                        );
+                    }
+                    ApiStreamEvent::ContentBlockDelta(delta) => match delta.delta {
+                        ContentBlockDelta::TextDelta { text } => {
+                            if !text.is_empty() {
+                                events.push(AssistantEvent::TextDelta(text));
+                            }
+                        }
+                        ContentBlockDelta::InputJsonDelta { partial_json } => {
+                            if let Some((_, _, input)) = &mut pending_tool {
+                                input.push_str(&partial_json);
+                            }
+                        }
+                    },
+                    ApiStreamEvent::ContentBlockStop(_) => {
+                        if let Some((id, name, input)) = pending_tool.take() {
+                            events.push(AssistantEvent::ToolUse { id, name, input });
+                        }
+                    }
+                    ApiStreamEvent::MessageDelta(delta) => {
+                        events.push(AssistantEvent::Usage(TokenUsage {
+                            input_tokens: delta.usage.input_tokens,
+                            output_tokens: delta.usage.output_tokens,
+                            cache_creation_input_tokens: delta.usage.cache_creation_input_tokens,
+                            cache_read_input_tokens: delta.usage.cache_read_input_tokens,
+                        }));
+                    }
+                    ApiStreamEvent::MessageStop(_) => {
+                        saw_stop = true;
+                        events.push(AssistantEvent::MessageStop);
+                    }
+                }
+            }
+
+            if !saw_stop {
+                events.push(AssistantEvent::MessageStop);
+            }
+
+            Ok(events)
+        })
+    }
+}
+
+fn resolve_agent_auth_source() -> Result<api::AuthSource, String> {
+    resolve_startup_auth_source(|| {
+        let cwd = std::env::current_dir().map_err(api::ApiError::from)?;
+        let config = ConfigLoader::default_for(&cwd).load().map_err(|error| {
+            api::ApiError::Auth(format!("failed to load runtime OAuth config: {error}"))
+        })?;
+        Ok(config.oauth().cloned())
+    })
+    .map_err(|error| error.to_string())
+}
+
+fn agent_tool_definitions() -> Vec<ToolDefinition> {
+    mvp_tool_specs()
+        .into_iter()
+        .map(|spec| ToolDefinition {
+            name: spec.name.to_string(),
+            description: Some(spec.description.to_string()),
+            input_schema: spec.input_schema,
+        })
+        .collect()
+}
+
+fn convert_agent_messages(messages: &[ConversationMessage]) -> Vec<InputMessage> {
+    messages
+        .iter()
+        .filter_map(|message| {
+            let role = match message.role {
+                MessageRole::System | MessageRole::User | MessageRole::Tool => "user",
+                MessageRole::Assistant => "assistant",
+            };
+            let content = message
+                .blocks
+                .iter()
+                .map(|block| match block {
+                    ContentBlock::Text { text } => InputContentBlock::Text { text: text.clone() },
+                    ContentBlock::ToolUse { id, name, input } => InputContentBlock::ToolUse {
+                        id: id.clone(),
+                        name: name.clone(),
+                        input: serde_json::from_str(input)
+                            .unwrap_or_else(|_| serde_json::json!({ "raw": input })),
+                    },
+                    ContentBlock::ToolResult {
+                        tool_use_id,
+                        output,
+                        is_error,
+                        ..
+                    } => InputContentBlock::ToolResult {
+                        tool_use_id: tool_use_id.clone(),
+                        content: vec![ToolResultContentBlock::Text {
+                            text: output.clone(),
+                        }],
+                        is_error: *is_error,
+                    },
+                })
+                .collect::<Vec<_>>();
+            (!content.is_empty()).then(|| InputMessage {
+                role: role.to_string(),
+                content,
+            })
+        })
+        .collect()
+}
+
+fn push_agent_output_blocks(
+    blocks: Vec<OutputContentBlock>,
+    events: &mut Vec<AssistantEvent>,
+    pending_tool: &mut Option<(String, String, String)>,
+) {
+    for block in blocks {
+        push_agent_output_block(block, events, pending_tool);
+        if let Some((id, name, input)) = pending_tool.take() {
+            events.push(AssistantEvent::ToolUse { id, name, input });
+        }
+    }
+}
+
+fn push_agent_output_block(
+    block: OutputContentBlock,
+    events: &mut Vec<AssistantEvent>,
+    pending_tool: &mut Option<(String, String, String)>,
+) {
+    match block {
+        OutputContentBlock::Text { text } => {
+            if !text.is_empty() {
+                events.push(AssistantEvent::TextDelta(text));
+            }
+        }
+        OutputContentBlock::ToolUse { id, name, input } => {
+            *pending_tool = Some((id, name, input.to_string()));
+        }
+    }
+}
+
+#[derive(Debug)]
+struct ScriptedAgentApiClient {
+    turns: Vec<Vec<ScriptedAgentEvent>>,
+    call_count: usize,
+}
+
+impl ScriptedAgentApiClient {
+    fn new(script: &str) -> Result<Self, String> {
+        let turns = serde_json::from_str(script).map_err(|error| error.to_string())?;
+        Ok(Self {
+            turns,
+            call_count: 0,
+        })
+    }
+}
+
+impl ApiClient for ScriptedAgentApiClient {
+    fn stream(&mut self, _request: ApiRequest) -> Result<Vec<AssistantEvent>, RuntimeError> {
+        if self.call_count >= self.turns.len() {
+            return Err(RuntimeError::new("scripted agent client exhausted"));
+        }
+        let events = self.turns[self.call_count]
+            .iter()
+            .map(ScriptedAgentEvent::to_runtime_event)
+            .chain(std::iter::once(AssistantEvent::MessageStop))
+            .collect();
+        self.call_count += 1;
+        Ok(events)
+    }
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(tag = "type", rename_all = "snake_case")]
+enum ScriptedAgentEvent {
+    Text {
+        text: String,
+    },
+    ToolUse {
+        id: String,
+        name: String,
+        input: Value,
+    },
+}
+
+impl ScriptedAgentEvent {
+    fn to_runtime_event(&self) -> AssistantEvent {
+        match self {
+            Self::Text { text } => AssistantEvent::TextDelta(text.clone()),
+            Self::ToolUse { id, name, input } => AssistantEvent::ToolUse {
+                id: id.clone(),
+                name: name.clone(),
+                input: input.to_string(),
+            },
+        }
+    }
+}
+
+fn extract_message_text(message: &ConversationMessage) -> Option<String> {
+    let text = message
+        .blocks
+        .iter()
+        .filter_map(|block| match block {
+            ContentBlock::Text { text } => Some(text.as_str()),
+            _ => None,
+        })
+        .collect::<String>();
+    (!text.is_empty()).then_some(text)
+}
+
+fn extract_agent_tool_result(message: &ConversationMessage) -> Option<AgentToolResult> {
+    message.blocks.iter().find_map(|block| match block {
+        ContentBlock::ToolResult {
+            tool_name,
+            output,
+            is_error,
+            ..
+        } => Some(AgentToolResult {
+            tool_name: tool_name.clone(),
+            output: output.clone(),
+            is_error: *is_error,
+        }),
+        _ => None,
+    })
+}
+
 #[allow(clippy::needless_pass_by_value)]
 fn execute_tool_search(input: ToolSearchInput) -> ToolSearchOutput {
     let deferred = deferred_tool_specs();
@@ -2763,12 +3251,28 @@ mod tests {
     }
 
     #[test]
-    fn agent_persists_handoff_metadata() {
+    fn agent_executes_child_conversation_and_persists_results() {
         let _guard = env_lock()
             .lock()
             .unwrap_or_else(std::sync::PoisonError::into_inner);
         let dir = temp_path("agent-store");
         std::env::set_var("CLAWD_AGENT_STORE", &dir);
+        std::env::set_var(
+            "CLAWD_AGENT_TEST_SCRIPT",
+            serde_json::to_string(&vec![
+                vec![json!({
+                    "type": "tool_use",
+                    "id": "tool-1",
+                    "name": "StructuredOutput",
+                    "input": {"ok": true, "items": [1, 2, 3]}
+                })],
+                vec![json!({
+                    "type": "text",
+                    "text": "Child agent completed successfully."
+                })],
+            ])
+            .expect("script json"),
+        );
 
         let result = execute_tool(
             "Agent",
@@ -2780,22 +3284,35 @@ mod tests {
             }),
         )
         .expect("Agent should succeed");
+        std::env::remove_var("CLAWD_AGENT_TEST_SCRIPT");
         std::env::remove_var("CLAWD_AGENT_STORE");
 
         let output: serde_json::Value = serde_json::from_str(&result).expect("valid json");
         assert_eq!(output["name"], "ship-audit");
         assert_eq!(output["subagentType"], "Explore");
-        assert_eq!(output["status"], "queued");
+        assert_eq!(output["status"], "completed");
-        assert!(output["createdAt"].as_str().is_some());
+        assert_eq!(output["depth"], 0);
+        assert_eq!(output["maxDepth"], 3);
+        assert_eq!(output["result"], "Child agent completed successfully.");
+        assert_eq!(output["toolResults"][0]["toolName"], "StructuredOutput");
+        assert_eq!(output["toolResults"][0]["isError"], false);
         let manifest_file = output["manifestFile"].as_str().expect("manifest file");
         let output_file = output["outputFile"].as_str().expect("output file");
         let contents = std::fs::read_to_string(output_file).expect("agent file exists");
         let manifest_contents =
             std::fs::read_to_string(manifest_file).expect("manifest file exists");
-        assert!(contents.contains("Audit the branch"));
+        assert!(contents.contains("Child agent completed successfully."));
-        assert!(contents.contains("Check tests and outstanding work."));
+        assert!(contents.contains("StructuredOutput [ok]"));
         assert!(manifest_contents.contains("\"subagentType\": \"Explore\""));
 
+        std::env::set_var(
+            "CLAWD_AGENT_TEST_SCRIPT",
+            serde_json::to_string(&vec![vec![json!({
+                "type": "text",
+                "text": "Normalized alias check."
+            })]])
+            .expect("script json"),
+        );
         let normalized = execute_tool(
             "Agent",
             &json!({
@@ -2805,10 +3322,19 @@ mod tests {
             }),
         )
         .expect("Agent should normalize built-in aliases");
+        std::env::remove_var("CLAWD_AGENT_TEST_SCRIPT");
         let normalized_output: serde_json::Value =
             serde_json::from_str(&normalized).expect("valid json");
         assert_eq!(normalized_output["subagentType"], "Explore");
 
+        std::env::set_var(
+            "CLAWD_AGENT_TEST_SCRIPT",
+            serde_json::to_string(&vec![vec![json!({
+                "type": "text",
+                "text": "Name normalization check."
+            })]])
+            .expect("script json"),
+        );
         let named = execute_tool(
             "Agent",
             &json!({
@@ -2818,13 +3344,14 @@ mod tests {
             }),
         )
         .expect("Agent should normalize explicit names");
+        std::env::remove_var("CLAWD_AGENT_TEST_SCRIPT");
         let named_output: serde_json::Value = serde_json::from_str(&named).expect("valid json");
         assert_eq!(named_output["name"], "ship-audit");
         let _ = std::fs::remove_dir_all(dir);
     }
 
     #[test]
-    fn agent_rejects_blank_required_fields() {
+    fn agent_rejects_blank_required_fields_and_enforces_max_depth() {
         let missing_description = execute_tool(
             "Agent",
             &json!({
@@ -2844,6 +3371,22 @@ mod tests {
         )
         .expect_err("blank prompt should fail");
         assert!(missing_prompt.contains("prompt must not be empty"));
+
+        let _guard = env_lock()
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+        std::env::set_var("CLAWD_AGENT_DEPTH", "1");
+        let depth_error = execute_tool(
+            "Agent",
+            &json!({
+                "description": "Nested agent",
+                "prompt": "Do nested work.",
+                "max_depth": 1
+            }),
+        )
+        .expect_err("max depth should fail");
+        std::env::remove_var("CLAWD_AGENT_DEPTH");
+        assert!(depth_error.contains("max_depth exceeded"));
     }
 
     #[test]