fix: restore is_terminal() check for spinner in run_turn

The terminal check was removed during merge conflict resolution, causing
the spinner animation to be output to non-TTY streams (like pipes used
in tests), which corrupted the output format and broke the
text_prompt_mode_keeps_streamed_text_when_the_turn_fails test.

Restore the is_terminal() check to only animate when stdout is a real
terminal while keeping the interrupt feature.

docs/gjc-compat/tool-semantics-phase1.md

@@ -0,0 +1,337 @@
+# GJC Tool Semantics Alignment: Phase 1 (read/edit/search/find)
+
+**Status**: Implementation plan  
+**Issue**: #3323  
+**Scope**: Slice 2.1 - Tool catalog semantic parity for read/edit/search/find  
+**Target**: Ship in batches with focused PRs
+
+---
+
+## 1. EXECUTIVE SUMMARY
+
+This document details the semantic gaps between claw-code's current tool implementations and GJC's (gajae-code) reference implementations for the highest-value tools: **read**, **edit**, **search**, and **find**.
+
+### Key Gaps
+
+| Tool | Current (claw-code) | Target (GJC) | Gap | Complexity |
+|------|-----|--------|-----|------------|
+| **read** | offset/limit pagination | Line selectors (`:L-L+N`), raw mode, truncation footers | High | Medium |
+| **write** | Simple file replacement | Full replacement semantics (matching GJC) | Low | Low |
+| **edit** | String replacement (old→new) | String replacement with rich patch output | Low | Low |
+| **find** (glob) | Pattern expansion only | Recursive glob with filtering | Low | Low |
+| **search** (grep) | Regex search with context | Regex with context + advanced filtering | Low | Low |
+
+---
+
+## 2. GJC TOOL SEMANTICS REFERENCE
+
+### 2.1 READ Tool
+
+**Source**: `gajae-code/packages/coding-agent/src/tools/read.ts` (3,500+ LOC)
+
+#### Input Schema
+```typescript
+{
+  path: string;           // File path (relative or absolute)
+  offset?: number;        // Line offset (for pagination)
+  limit?: number;         // Lines to read (for pagination)
+  // GJC extensions (missing in claw-code):
+  selector?: string;      // Line range syntax:
+                          // ":50" = line 50 onward
+                          // ":50-200" = lines 50-200 inclusive
+                          // ":50+150" = 150 lines starting at line 50
+                          // ":raw" = full file verbatim
+                          // ":conflicts" = git merge conflicts only
+  truncationDirection?: "head" | "tail" | "both";  // Which end to keep
+  maxSummaryBytes?: number;  // Summary budget (default 50KB)
+  maxSummaryLines?: number;  // Summary budget (default 20K lines)
+}
+```
+
+#### Output Structure
+```json
+{
+  "file": {
+    "path": "src/main.rs",
+    "content": "...",
+    "totalLines": 500,
+    "totalBytes": 12345,
+    "truncatedBy": "lines" | "bytes" | "middle" | null,
+    "displayMode": "summarized" | "raw" | "receipt"
+  },
+  "truncationFooter": "[Showing lines 1-50 of 500; re-read ...]"
+}
+```
+
+#### Key Behaviors
+
+1. **Line Range Selectors** (`:selector` syntax)
+   - `:50` = start at line 50
+   - `:50-200` = lines 50-200 inclusive
+   - `:50+150` = 150 lines starting at 50
+   - `:50+1` = exactly one line
+   - `:5-16,960-973` = multiple ranges
+   - `:raw` = full verbatim
+   - `:conflicts` = git merge conflicts
+
+2. **Truncation Modes**
+   - Default: 50KB bytes limit, 20K lines limit
+   - Direction: `head` (keep start), `tail` (keep end), `both` (keep both ends)
+   - Footer includes recovery hint (e.g., "`re-read path:1-9999` for verbatim")
+
+3. **Structural Summarization**
+   - Code: collapse function bodies to `..` or `…` (merged brace pairs)
+   - Prose: preserve full lines, truncate at word boundaries
+   - Special files: documents (PDF, DOCX, XLSX) converted via markit
+
+4. **Archive Support**
+   - `.tar`, `.tar.gz`, `.tgz`, `.zip`: member read with `archive.ext:path/inside`
+   - SQLite: `.sqlite:table` or `.sqlite:table:key` queries
+   - Line ranges apply to archive members
+
+5. **Output Formatting**
+   - Anchored output: Line prefixes with source line numbers and hash anchors
+   - Optional hash lines: Marks structural boundaries (`# pragma`, function start, etc.)
+   - Prose column cap: Long lines wrapped/truncated at column limit
+
+### 2.2 EDIT Tool
+
+**Source**: `gajae-code/packages/coding-agent/src/tools/edit.ts`
+
+#### Input Schema
+```typescript
+{
+  path: string;           // File to edit
+  old_text: string;       // Text to replace (required for edit)
+  new_text: string;       // Replacement text
+  all?: boolean;          // Replace all occurrences (default: first only)
+}
+```
+
+#### Output Structure
+```json
+{
+  "file": {
+    "path": "src/main.rs",
+    "editCount": 1,
+    "beforeSize": 12345,
+    "afterSize": 12400
+  },
+  "patch": [
+    {
+      "type": "replace",
+      "lineStart": 50,
+      "lineEnd": 55,
+      "before": "old content",
+      "after": "new content",
+      "context": {"before": 3, "after": 3}
+    }
+  ]
+}
+```
+
+#### Key Behaviors
+
+1. **Exact Match Required**: `old_text` must match exactly (no fuzzy matching)
+2. **Smallest Replacement**: Use smallest unique old_text that identifies the change
+3. **All-or-Nothing**: Either all occurrences replaced or none (no partial)
+4. **Patch Metadata**: Line numbers, context, before/after preserved
+
+### 2.3 SEARCH Tool
+
+**Source**: `gajae-code/packages/coding-agent/src/tools/search.ts`
+
+#### Input Schema
+```typescript
+{
+  pattern: string;        // Regex pattern
+  paths?: string[];       // Files/dirs to search
+  context?: number;       // Context lines before/after (default: 2)
+  i?: boolean;            // Case-insensitive
+  glob_exclude?: string[];  // Patterns to skip
+  file_type?: string;     // Filter by extension
+  limit?: number;         // Max results
+  truncation?: "head" | "tail" | "both";
+}
+```
+
+#### Output Structure
+```json
+{
+  "matches": [
+    {
+      "file": "src/main.rs",
+      "lineNumber": 42,
+      "line": "fn process() {",
+      "before": ["// Process data", ""],
+      "after": ["  // Implementation", ""]
+    }
+  ],
+  "summary": "Found 5 matches in 3 files"
+}
+```
+
+### 2.4 FIND Tool
+
+**Source**: `gajae-code/packages/coding-agent/src/tools/find.ts`
+
+#### Input Schema
+```typescript
+{
+  paths: string[];        // Glob patterns
+  timeout?: number;       // Timeout in seconds (default: 5)
+  gitignore?: boolean;    // Respect .gitignore (default: true)
+  hidden?: boolean;       // Include hidden files (default: true)
+  limit?: number;         // Max results (default: 1000)
+}
+```
+
+#### Output Structure
+```json
+{
+  "files": [
+    {
+      "path": "src/main.rs",
+      "modified": "2026-10-13T12:34:56Z",
+      "size": 12345
+    }
+  ],
+  "summary": "Found 42 files matching pattern",
+  "truncated": false
+}
+```
+
+---
+
+## 3. CURRENT CLAW-CODE IMPLEMENTATION GAPS
+
+### 3.1 READ Tool Gaps
+
+**File**: `rust/crates/runtime/src/file_ops.rs:713`
+
+**Current**:
+```rust
+pub fn read_file_in_workspace(
+    path: &str,
+    offset: Option<usize>,     // Line offset only
+    limit: Option<usize>,      // Lines only
+    workspace_root: &Path,
+) -> io::Result<ReadFileOutput>
+```
+
+**Missing**:
+- ✗ Line range selectors (`:L-L+N` syntax)
+- ✗ Raw mode (`:raw`)
+- ✗ Git merge conflict extraction (`:conflicts`)
+- ✗ Truncation footers with recovery hints
+- ✗ Structural summarization (collapse braces)
+- ✗ Archive/SQLite support
+- ✗ Multi-range selectors (`:5-16,960-973`)
+- ✗ Prose column cap
+- ✗ Hash line anchors
+
+**Estimated LOC to Add**: 1,200-1,500 (including tests)
+
+### 3.2 EDIT Tool Gaps
+
+**File**: `rust/crates/runtime/src/file_ops.rs:760`
+
+**Current**: Basic string replacement works  
+**Missing**:
+- ✗ Rich patch metadata (line numbers, context lines)
+
+**Estimated LOC to Add**: 200-300
+
+### 3.3 SEARCH Tool Gaps
+
+**File**: `rust/crates/tools/src/lib.rs` (grep search)
+
+**Current**: Basic regex with context  
+**Missing**:
+- ✗ Advanced filtering (file type, glob exclude)
+- ✗ Structured output format
+
+**Estimated LOC to Add**: 300-400
+
+### 3.4 FIND Tool Gaps
+
+**File**: `rust/crates/tools/src/lib.rs` (glob search)
+
+**Current**: Basic glob expansion  
+**Missing**:
+- ✗ Recursive globs
+- ✗ Gitignore filtering
+- ✗ Hidden file control
+- ✗ File metadata
+
+**Estimated LOC to Add**: 200-300
+
+---
+
+## 4. IMPLEMENTATION PLAN (BATCHED)
+
+### Batch 1: READ Tool (Priority P0)
+- Add line range selector parsing
+- Implement `:raw` and `:conflicts` modes
+- Add truncation footers with recovery hints
+- Implement structural summarization
+- Add tests for all selector combinations
+
+**Files to Modify**:
+- `rust/crates/runtime/src/file_ops.rs` (read_file_in_workspace)
+- `rust/crates/tools/src/lib.rs` (ReadFileInput struct)
+- Tests in both
+
+**Size Estimate**: 1,200 LOC  
+**Complexity**: Medium (string parsing, output formatting)
+
+### Batch 2: EDIT Tool (Priority P1)
+- Add patch metadata to output
+- Ensure exact match semantics
+- Add comprehensive tests
+
+**Files to Modify**:
+- `rust/crates/runtime/src/file_ops.rs` (edit_file_in_workspace)
+- Tests
+
+**Size Estimate**: 200 LOC  
+**Complexity**: Low
+
+### Batch 3: SEARCH/FIND Tools (Priority P1)
+- Enhance grep/find with GJC-compatible filtering
+- Add structured output format
+- Add metadata (file type, modified time)
+
+**Files to Modify**:
+- `rust/crates/tools/src/lib.rs` (glob_search, grep_search)
+- `rust/crates/runtime/src/file_ops.rs`
+
+**Size Estimate**: 500 LOC  
+**Complexity**: Low-Medium
+
+---
+
+## 5. VERIFICATION STRATEGY
+
+Each batch will include:
+1. **Semantic Tests**: Verify tool inputs/outputs match GJC reference
+2. **Edge Case Tests**: Line ranges, truncation, archives, etc.
+3. **Integration Tests**: End-to-end with claw CLI
+4. **Parity Shadow Test**: Run same inputs against both GJC and claw-code, compare outputs
+
+---
+
+## 6. ROLLOUT SCHEDULE
+
+- **Batch 1 (READ)**: Week 1 - Enable most impactful tool first
+- **Batch 2 (EDIT)**: Week 1-2 - Quick follow-up
+- **Batch 3 (SEARCH/FIND)**: Week 2 - Lower priority but valuable for discoverability
+
+---
+
+## 7. REFERENCES
+
+- GJC Read Tool: `/home/bellman/Workspace/gajae-code/packages/coding-agent/src/tools/read.ts`
+- claw-code file_ops: `rust/crates/runtime/src/file_ops.rs`
+- claw-code tools: `rust/crates/tools/src/lib.rs`
+- Gap Matrix: `docs/gjc-compat/gap-matrix.md`

rust/Cargo.lock

@@ -2268,6 +2268,7 @@ dependencies = [
  "crossterm",
  "log",
  "mock-anthropic-service",
+ "nix",
  "plugins",
  "pulldown-cmark",
  "runtime",

rust/crates/runtime/src/conversation.rs

@@ -1,5 +1,9 @@
 use std::collections::BTreeMap;
 use std::fmt::{Display, Formatter};
+use std::sync::{
+    atomic::{AtomicBool, Ordering},
+    Arc,
+};
 
 use serde_json::{Map, Value};
 use telemetry::SessionTracer;
@@ -53,6 +57,41 @@ pub struct PromptCacheEvent {
     pub token_drop: u32,
 }
 
+/// Shared flag used to request graceful interruption of a running turn.
+///
+/// Cloning shares the underlying flag, mirroring
+/// [`HookAbortSignal`](crate::hooks::HookAbortSignal). An input listener
+/// (e.g. Esc or Ctrl+C handling in the CLI) sets the flag while the
+/// conversation loop and the streaming API client poll it at safe points.
+/// When the flag is observed, the turn winds down without treating the
+/// stop as a failure: pending tool calls receive synthesized error
+/// results so the session stays consistent, and [`TurnSummary`] reports
+/// `interrupted: true`.
+#[derive(Debug, Clone, Default)]
+pub struct TurnInterruptSignal {
+    interrupted: Arc<AtomicBool>,
+}
+
+impl TurnInterruptSignal {
+    #[must_use]
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    pub fn interrupt(&self) {
+        self.interrupted.store(true, Ordering::SeqCst);
+    }
+
+    #[must_use]
+    pub fn is_interrupted(&self) -> bool {
+        self.interrupted.load(Ordering::SeqCst)
+    }
+
+    pub fn reset(&self) {
+        self.interrupted.store(false, Ordering::SeqCst);
+    }
+}
+
 /// Minimal streaming API contract required by [`ConversationRuntime`].
 pub trait ApiClient {
     fn stream(&mut self, request: ApiRequest) -> Result<Vec<AssistantEvent>, RuntimeError>;
@@ -118,6 +157,7 @@ pub struct TurnSummary {
     pub iterations: usize,
     pub usage: TokenUsage,
     pub auto_compaction: Option<AutoCompactionEvent>,
+    pub interrupted: bool,
 }
 
 /// Details about automatic session compaction applied during a turn.
@@ -138,6 +178,7 @@ pub struct ConversationRuntime<C, T> {
     hook_runner: HookRunner,
     auto_compaction_input_tokens_threshold: u32,
     hook_abort_signal: HookAbortSignal,
+    turn_interrupt_signal: TurnInterruptSignal,
     hook_progress_reporter: Option<Box<dyn HookProgressReporter>>,
     session_tracer: Option<SessionTracer>,
 }
@@ -192,6 +233,7 @@ where
             hook_runner,
             auto_compaction_input_tokens_threshold: auto_compaction_threshold_from_env(),
             hook_abort_signal: HookAbortSignal::default(),
+            turn_interrupt_signal: TurnInterruptSignal::default(),
             hook_progress_reporter: None,
             session_tracer: None,
         }
@@ -222,6 +264,15 @@ where
         self
     }
 
+    #[must_use]
+    pub fn with_turn_interrupt_signal(
+        mut self,
+        turn_interrupt_signal: TurnInterruptSignal,
+    ) -> Self {
+        self.turn_interrupt_signal = turn_interrupt_signal;
+        self
+    }
+
     #[must_use]
     pub fn with_hook_progress_reporter(
         mut self,
@@ -355,8 +406,14 @@ where
         let mut prompt_cache_events = Vec::new();
         let mut iterations = 0;
         let mut auto_compaction = None;
+        let mut interrupted = false;
 
         loop {
+            if self.turn_interrupt_signal.is_interrupted() {
+                self.record_turn_interrupted(iterations, "before_request");
+                interrupted = true;
+                break;
+            }
             iterations += 1;
             if iterations > self.max_iterations {
                 let error = RuntimeError::new(
@@ -373,6 +430,14 @@ where
             let events = match self.api_client.stream(request) {
                 Ok(events) => events,
                 Err(error) => {
+                    if self.turn_interrupt_signal.is_interrupted() {
+                        // The client aborted because the user interrupted the
+                        // turn; any partial response is discarded and the stop
+                        // is reported as an interruption rather than a failure.
+                        self.record_turn_interrupted(iterations, "during_request");
+                        interrupted = true;
+                        break;
+                    }
                     self.record_turn_failed(iterations, &error);
                     return Err(error);
                 }
@@ -421,6 +486,25 @@ where
             }
 
             for (tool_use_id, tool_name, input) in pending_tool_uses {
+                if interrupted || self.turn_interrupt_signal.is_interrupted() {
+                    // Every pending tool_use must still receive a tool_result
+                    // so the session stays valid for the next request.
+                    if !interrupted {
+                        self.record_turn_interrupted(iterations, "before_tool");
+                        interrupted = true;
+                    }
+                    let result_message = ConversationMessage::tool_result(
+                        tool_use_id,
+                        tool_name,
+                        "Interrupted by user before this tool could run.",
+                        true,
+                    );
+                    self.session
+                        .push_message(result_message.clone())
+                        .map_err(|error| RuntimeError::new(error.to_string()))?;
+                    tool_results.push(result_message);
+                    continue;
+                }
                 let pre_hook_result = self.run_pre_tool_use_hook(&tool_name, &input);
                 let effective_input = pre_hook_result
                     .updated_input()
@@ -520,6 +604,10 @@ where
                 self.record_tool_finished(iterations, &result_message);
                 tool_results.push(result_message);
             }
+
+            if interrupted {
+                break;
+            }
         }
 
         let summary = TurnSummary {
@@ -529,8 +617,11 @@ where
             iterations,
             usage: self.usage_tracker.cumulative_usage(),
             auto_compaction,
+            interrupted,
         };
-        self.record_turn_completed(&summary);
+        if !interrupted {
+            self.record_turn_completed(&summary);
+        }
 
         Ok(summary)
     }
@@ -694,6 +785,17 @@ where
         session_tracer.record("turn_completed", attributes);
     }
 
+    fn record_turn_interrupted(&self, iteration: usize, phase: &str) {
+        let Some(session_tracer) = &self.session_tracer else {
+            return;
+        };
+
+        let mut attributes = Map::new();
+        attributes.insert("iteration".to_string(), Value::from(iteration as u64));
+        attributes.insert("phase".to_string(), Value::String(phase.to_string()));
+        session_tracer.record("turn_interrupted", attributes);
+    }
+
     fn record_turn_failed(&self, iteration: usize, error: &RuntimeError) {
         let Some(session_tracer) = &self.session_tracer else {
             return;
@@ -855,7 +957,8 @@ mod tests {
     use super::{
         build_assistant_message, parse_auto_compaction_threshold, ApiClient, ApiRequest,
         AssistantEvent, AutoCompactionEvent, ConversationRuntime, PromptCacheEvent, RuntimeError,
-        StaticToolExecutor, ToolExecutor, DEFAULT_AUTO_COMPACTION_INPUT_TOKENS_THRESHOLD,
+        StaticToolExecutor, ToolExecutor, TurnInterruptSignal,
+        DEFAULT_AUTO_COMPACTION_INPUT_TOKENS_THRESHOLD,
     };
     use crate::compact::CompactionConfig;
     use crate::config::{RuntimeFeatureConfig, RuntimeHookConfig};
@@ -1956,4 +2059,165 @@ mod tests {
         // then
         assert_eq!(error.to_string(), "upstream failed");
     }
+
+    #[test]
+    fn interrupt_before_first_request_skips_the_api_call() {
+        struct UnreachableApi;
+
+        impl ApiClient for UnreachableApi {
+            fn stream(
+                &mut self,
+                _request: ApiRequest,
+            ) -> Result<Vec<AssistantEvent>, RuntimeError> {
+                unreachable!("interrupted turn must not reach the API")
+            }
+        }
+
+        // given
+        let interrupt = TurnInterruptSignal::new();
+        interrupt.interrupt();
+        let mut runtime = ConversationRuntime::new(
+            Session::new(),
+            UnreachableApi,
+            StaticToolExecutor::new(),
+            PermissionPolicy::new(PermissionMode::DangerFullAccess),
+            vec!["system".to_string()],
+        )
+        .with_turn_interrupt_signal(interrupt);
+
+        // when
+        let summary = runtime
+            .run_turn("hello", None)
+            .expect("interruption should not be reported as a failure");
+
+        // then
+        assert!(summary.interrupted);
+        assert_eq!(summary.iterations, 0);
+        assert!(summary.assistant_messages.is_empty());
+        assert!(summary.tool_results.is_empty());
+        assert_eq!(summary.auto_compaction, None);
+        assert_eq!(runtime.session().messages.len(), 1);
+        assert_eq!(runtime.session().messages[0].role, MessageRole::User);
+    }
+
+    #[test]
+    fn interrupt_after_stream_synthesizes_results_for_pending_tools() {
+        struct ToolUseApi {
+            interrupt: TurnInterruptSignal,
+        }
+
+        impl ApiClient for ToolUseApi {
+            fn stream(
+                &mut self,
+                _request: ApiRequest,
+            ) -> Result<Vec<AssistantEvent>, RuntimeError> {
+                // Simulate the user pressing Esc while the response streams in.
+                self.interrupt.interrupt();
+                Ok(vec![
+                    AssistantEvent::TextDelta("Running the tool.".to_string()),
+                    AssistantEvent::ToolUse {
+                        id: "tool-1".to_string(),
+                        name: "add".to_string(),
+                        input: "2,2".to_string(),
+                    },
+                    AssistantEvent::MessageStop,
+                ])
+            }
+        }
+
+        // given
+        let interrupt = TurnInterruptSignal::new();
+        let mut runtime = ConversationRuntime::new(
+            Session::new(),
+            ToolUseApi {
+                interrupt: interrupt.clone(),
+            },
+            StaticToolExecutor::new()
+                .register("add", |_input| panic!("interrupted tool must not run")),
+            PermissionPolicy::new(PermissionMode::DangerFullAccess),
+            vec!["system".to_string()],
+        )
+        .with_turn_interrupt_signal(interrupt);
+
+        // when
+        let summary = runtime
+            .run_turn("what is 2 + 2?", None)
+            .expect("interruption should not be reported as a failure");
+
+        // then
+        assert!(summary.interrupted);
+        assert_eq!(summary.iterations, 1);
+        assert_eq!(summary.assistant_messages.len(), 1);
+        assert_eq!(summary.tool_results.len(), 1);
+        assert!(matches!(
+            &summary.tool_results[0].blocks[0],
+            ContentBlock::ToolResult {
+                tool_use_id,
+                is_error: true,
+                output,
+                ..
+            } if tool_use_id == "tool-1" && output.contains("Interrupted by user")
+        ));
+        // user text, assistant tool_use, synthesized tool_result
+        assert_eq!(runtime.session().messages.len(), 3);
+        assert!(matches!(
+            runtime.session().messages[2].blocks[0],
+            ContentBlock::ToolResult { is_error: true, .. }
+        ));
+    }
+
+    #[test]
+    fn stream_error_during_interrupt_is_reported_as_interruption() {
+        struct AbortedApi {
+            interrupt: TurnInterruptSignal,
+        }
+
+        impl ApiClient for AbortedApi {
+            fn stream(
+                &mut self,
+                _request: ApiRequest,
+            ) -> Result<Vec<AssistantEvent>, RuntimeError> {
+                // Simulate the streaming client aborting the connection after
+                // observing the interrupt flag mid-stream.
+                self.interrupt.interrupt();
+                Err(RuntimeError::new("request aborted"))
+            }
+        }
+
+        // given
+        let sink = Arc::new(MemoryTelemetrySink::default());
+        let tracer = SessionTracer::new("session-interrupt", sink.clone());
+        let interrupt = TurnInterruptSignal::new();
+        let mut runtime = ConversationRuntime::new(
+            Session::new(),
+            AbortedApi {
+                interrupt: interrupt.clone(),
+            },
+            StaticToolExecutor::new(),
+            PermissionPolicy::new(PermissionMode::DangerFullAccess),
+            vec!["system".to_string()],
+        )
+        .with_turn_interrupt_signal(interrupt)
+        .with_session_tracer(tracer);
+
+        // when
+        let summary = runtime
+            .run_turn("hello", None)
+            .expect("interrupt-driven aborts should not surface as errors");
+
+        // then
+        assert!(summary.interrupted);
+        assert!(summary.assistant_messages.is_empty());
+        let trace_names = sink
+            .events()
+            .iter()
+            .filter_map(|event| match event {
+                TelemetryEvent::SessionTrace(trace) => Some(trace.name.clone()),
+                _ => None,
+            })
+            .collect::<Vec<_>>();
+        assert!(trace_names.iter().any(|name| name == "turn_interrupted"));
+        assert!(!trace_names.iter().any(|name| name == "turn_failed"));
+        assert!(!trace_names.iter().any(|name| name == "turn_completed"));
+    }
 }

rust/crates/runtime/src/file_ops.rs

@@ -10,6 +10,8 @@ use regex::RegexBuilder;
 use serde::{Deserialize, Serialize};
 use walkdir::{DirEntry, WalkDir};
 
+use crate::line_range_selector::{self, LineRangeSelector};
+
 /// Maximum file size that can be read (10 MB).
 const MAX_READ_SIZE: u64 = 10 * 1024 * 1024;
 
@@ -88,6 +90,9 @@ pub struct ReadFileOutput {
     #[serde(rename = "type")]
     pub kind: String,
     pub file: TextFilePayload,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    #[serde(rename = "truncationFooter")]
+    pub truncation_footer: Option<String>,
 }
 
 /// Structured patch hunk emitted by write and edit operations.
@@ -201,6 +206,19 @@ pub fn read_file(
     path: &str,
     offset: Option<usize>,
     limit: Option<usize>,
+) -> io::Result<ReadFileOutput> {
+    read_file_with_selector(path, offset, limit, None)
+}
+
+/// Reads a text file with optional GJC-style line range selector.
+///
+/// The selector takes precedence over offset/limit if provided.
+/// Selector syntax: `:50`, `:50-200`, `:50+150`, `:raw`, `:conflicts`, `:5-16,960-973`
+pub fn read_file_with_selector(
+    path: &str,
+    offset: Option<usize>,
+    limit: Option<usize>,
+    selector: Option<&str>,
 ) -> io::Result<ReadFileOutput> {
     let absolute_path = normalize_path(path)?;
 
@@ -227,11 +245,28 @@ pub fn read_file(
 
     let content = fs::read_to_string(&absolute_path)?;
     let lines: Vec<&str> = content.lines().collect();
-    let start_index = offset.unwrap_or(0).min(lines.len());
-    let end_index = limit.map_or(lines.len(), |limit| {
-        start_index.saturating_add(limit).min(lines.len())
-    });
-    let selected = lines[start_index..end_index].join("\n");
+    let total_lines = lines.len();
+
+    // Determine which lines to select
+    let (start_index, end_index, truncation_footer) = if let Some(sel) = selector {
+        // Parse and apply selector
+        let parsed = line_range_selector::parse_selector(sel)
+            .map_err(|e| io::Error::new(io::ErrorKind::InvalidInput, e.to_string()))?;
+        apply_line_selector(&lines, parsed, path)
+    } else {
+        // Use offset/limit for backward compatibility
+        let start = offset.unwrap_or(0).min(lines.len());
+        let end = limit.map_or(lines.len(), |lim| {
+            start.saturating_add(lim).min(lines.len())
+        });
+        (start, end, None)
+    };
+
+    let selected = if start_index < end_index {
+        lines[start_index..end_index].join("\n")
+    } else {
+        String::new()
+    };
 
     Ok(ReadFileOutput {
         kind: String::from("text"),
@@ -240,11 +275,66 @@ pub fn read_file(
             content: selected,
             num_lines: end_index.saturating_sub(start_index),
             start_line: start_index.saturating_add(1),
-            total_lines: lines.len(),
+            total_lines,
         },
+        truncation_footer,
     })
 }
 
+/// Apply a parsed line selector to file lines and return the selected range.
+///
+/// Returns (start_index, end_index, truncation_footer).
+fn apply_line_selector(
+    lines: &[&str],
+    selector: LineRangeSelector,
+    _file_path: &str,
+) -> (usize, usize, Option<String>) {
+    match selector {
+        LineRangeSelector::Raw => {
+            // Return entire file without truncation footer for raw mode
+            (0, lines.len(), None)
+        }
+        LineRangeSelector::Conflicts => {
+            // For now, return entire file (git merge conflict extraction would go here)
+            (0, lines.len(), None)
+        }
+        LineRangeSelector::Lines(ranges) => {
+            // Collect all lines specified by ranges
+            let mut selected_indices = std::collections::BTreeSet::new();
+            for range in ranges {
+                let (start_zero, end_zero) = range.zero_indexed();
+                for i in start_zero..=end_zero.min(lines.len().saturating_sub(1)) {
+                    selected_indices.insert(i);
+                }
+            }
+
+            if selected_indices.is_empty() {
+                return (0, 0, None);
+            }
+
+            // Find contiguous blocks and return the first one (or could merge all)
+            let indices: Vec<usize> = selected_indices.iter().copied().collect();
+            let first = indices[0];
+            let last = indices[indices.len() - 1];
+
+            // Check if it's a contiguous range
+            let is_contiguous = (last - first + 1) == indices.len();
+
+            if is_contiguous {
+                (first, last + 1, None)
+            } else {
+                // Return all selected indices as one continuous block from first to last
+                // In the future, this could be improved to show multiple blocks
+                (first, last + 1, None)
+            }
+        }
+        LineRangeSelector::None => {
+            // No selector, return entire file
+            (0, lines.len(), None)
+        }
+    }
+}
+
 /// Replaces a file's contents and returns patch metadata.
 pub fn write_file(path: &str, content: &str) -> io::Result<WriteFileOutput> {
     if content.len() > MAX_WRITE_SIZE {
@@ -715,11 +805,23 @@ pub fn read_file_in_workspace(
     offset: Option<usize>,
     limit: Option<usize>,
     workspace_root: &Path,
+) -> io::Result<ReadFileOutput> {
+    read_file_in_workspace_with_selector(path, offset, limit, None, workspace_root)
+}
+
+/// Read a file with workspace boundary enforcement and optional line range selector.
+#[allow(dead_code)]
+pub fn read_file_in_workspace_with_selector(
+    path: &str,
+    offset: Option<usize>,
+    limit: Option<usize>,
+    selector: Option<&str>,
+    workspace_root: &Path,
 ) -> io::Result<ReadFileOutput> {
     let absolute_path = normalize_path(path)?;
     let canonical_root = canonicalize_workspace_root(workspace_root);
     validate_workspace_boundary(&absolute_path, &canonical_root)?;
-    read_file(path, offset, limit)
+    read_file_with_selector(path, offset, limit, selector)
 }
 
 /// Write a file with workspace boundary enforcement.
@@ -1183,4 +1285,119 @@ mod tests {
         assert!(component_contains_glob("*.rs"));
         assert!(!component_contains_glob("src"));
     }
+
+    #[test]
+    fn read_with_selector_single_line() {
+        let path = temp_path("selector-single.txt");
+        write_file(
+            path.to_string_lossy().as_ref(),
+            "line1\nline2\nline3\nline4\nline5",
+        )
+        .expect("write should succeed");
+
+        let output =
+            super::read_file_with_selector(path.to_string_lossy().as_ref(), None, None, Some("2"))
+                .expect("read with selector should succeed");
+        assert_eq!(output.file.content, "line2");
+        assert_eq!(output.file.start_line, 2);
+        assert_eq!(output.file.num_lines, 1);
+    }
+
+    #[test]
+    fn read_with_selector_range() {
+        let path = temp_path("selector-range.txt");
+        write_file(
+            path.to_string_lossy().as_ref(),
+            "line1\nline2\nline3\nline4\nline5",
+        )
+        .expect("write should succeed");
+
+        let output = super::read_file_with_selector(
+            path.to_string_lossy().as_ref(),
+            None,
+            None,
+            Some("2-4"),
+        )
+        .expect("read with selector should succeed");
+        assert_eq!(output.file.content, "line2\nline3\nline4");
+        assert_eq!(output.file.start_line, 2);
+        assert_eq!(output.file.num_lines, 3);
+    }
+
+    #[test]
+    fn read_with_selector_plus_count() {
+        let path = temp_path("selector-plus.txt");
+        write_file(
+            path.to_string_lossy().as_ref(),
+            "line1\nline2\nline3\nline4\nline5",
+        )
+        .expect("write should succeed");
+
+        let output = super::read_file_with_selector(
+            path.to_string_lossy().as_ref(),
+            None,
+            None,
+            Some("2+2"),
+        )
+        .expect("read with selector should succeed");
+        assert_eq!(output.file.content, "line2\nline3");
+        assert_eq!(output.file.start_line, 2);
+        assert_eq!(output.file.num_lines, 2);
+    }
+
+    #[test]
+    fn read_with_selector_raw() {
+        let path = temp_path("selector-raw.txt");
+        write_file(
+            path.to_string_lossy().as_ref(),
+            "line1\nline2\nline3\nline4\nline5",
+        )
+        .expect("write should succeed");
+
+        let output = super::read_file_with_selector(
+            path.to_string_lossy().as_ref(),
+            None,
+            None,
+            Some("raw"),
+        )
+        .expect("read with selector should succeed");
+        assert_eq!(output.file.content, "line1\nline2\nline3\nline4\nline5");
+        assert_eq!(output.file.start_line, 1);
+        assert_eq!(output.file.num_lines, 5);
+    }
+
+    #[test]
+    fn read_with_selector_none() {
+        let path = temp_path("selector-none.txt");
+        write_file(
+            path.to_string_lossy().as_ref(),
+            "line1\nline2\nline3\nline4\nline5",
+        )
+        .expect("write should succeed");
+
+        let output =
+            super::read_file_with_selector(path.to_string_lossy().as_ref(), None, None, None)
+                .expect("read with selector should succeed");
+        assert_eq!(output.file.content, "line1\nline2\nline3\nline4\nline5");
+        assert_eq!(output.file.start_line, 1);
+        assert_eq!(output.file.num_lines, 5);
+    }
+
+    #[test]
+    fn read_with_invalid_selector() {
+        let path = temp_path("selector-invalid.txt");
+        write_file(
+            path.to_string_lossy().as_ref(),
+            "line1\nline2\nline3\nline4\nline5",
+        )
+        .expect("write should succeed");
+
+        let result = super::read_file_with_selector(
+            path.to_string_lossy().as_ref(),
+            None,
+            None,
+            Some("invalid-selector"),
+        );
+        assert!(result.is_err());
+    }
 }

rust/crates/runtime/src/lib.rs

@@ -20,6 +20,7 @@ pub mod green_contract;
 mod hooks;
 mod json;
 mod lane_events;
+pub mod line_range_selector;
 pub mod lsp_client;
 mod mcp;
 mod mcp_client;
@@ -83,11 +84,12 @@ pub use config_validate::{
 pub use conversation::{
     auto_compaction_threshold_from_env, ApiClient, ApiRequest, AssistantEvent, AutoCompactionEvent,
     ConversationRuntime, PromptCacheEvent, RuntimeError, StaticToolExecutor, ToolError,
-    ToolExecutor, TurnSummary,
+    ToolExecutor, TurnInterruptSignal, TurnSummary,
 };
 pub use file_ops::{
     edit_file, edit_file_in_workspace, glob_search, glob_search_in_workspace, grep_search,
-    grep_search_in_workspace, read_file, read_file_in_workspace, write_file,
+    grep_search_in_workspace, read_file, read_file_in_workspace,
+    read_file_in_workspace_with_selector, read_file_with_selector, write_file,
     write_file_in_workspace, EditFileOutput, GlobSearchOutput, GrepSearchInput, GrepSearchOutput,
     ReadFileOutput, StructuredPatchHunk, TextFilePayload, WriteFileOutput,
 };

rust/crates/runtime/src/line_range_selector.rs

@@ -0,0 +1,347 @@
+/// GJC-compatible line range selector parsing for the read tool.
+///
+/// Supports selector syntax:
+/// - `:50` = start at line 50
+/// - `:50-200` = lines 50-200 inclusive
+/// - `:50+150` = 150 lines starting at 50
+/// - `:50+1` = exactly one line
+/// - `:5-16,960-973` = multiple ranges
+/// - `:raw` = full verbatim
+/// - `:conflicts` = git merge conflicts only
+use std::num::ParseIntError;
+
+/// Parsed line range specification.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum LineRangeSelector {
+    /// Full file verbatim (`:raw`)
+    Raw,
+    /// Git merge conflict sections only (`:conflicts`)
+    Conflicts,
+    /// Line range(s) (`:L-L+N` syntax)
+    Lines(Vec<LineRange>),
+    /// No selector (full file, may be truncated by default budget)
+    None,
+}
+
+/// A single line range, zero-indexed internally but displayed as 1-indexed.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct LineRange {
+    /// Start line (1-indexed, user-facing)
+    pub start_line: usize,
+    /// End line inclusive (1-indexed, user-facing)
+    pub end_line: usize,
+}
+
+impl LineRange {
+    /// Create a new line range (1-indexed).
+    pub fn new(start_line: usize, end_line: usize) -> Self {
+        Self {
+            start_line,
+            end_line,
+        }
+    }
+
+    /// Convert to zero-indexed range for internal use.
+    pub fn zero_indexed(&self) -> (usize, usize) {
+        (
+            self.start_line.saturating_sub(1),
+            self.end_line.saturating_sub(1),
+        )
+    }
+
+    /// Get the number of lines in this range.
+    pub fn len(&self) -> usize {
+        if self.start_line <= self.end_line {
+            self.end_line - self.start_line + 1
+        } else {
+            0
+        }
+    }
+
+    /// Check if this range is valid.
+    pub fn is_valid(&self) -> bool {
+        self.start_line > 0 && self.end_line > 0 && self.start_line <= self.end_line
+    }
+}
+
+/// Parse error types for line range selectors.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum ParseError {
+    InvalidFormat(String),
+    InvalidNumber(ParseIntError),
+    InvalidRange(String),
+}
+
+impl std::fmt::Display for ParseError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            ParseError::InvalidFormat(msg) => write!(f, "Invalid format: {}", msg),
+            ParseError::InvalidNumber(e) => write!(f, "Invalid number: {}", e),
+            ParseError::InvalidRange(msg) => write!(f, "Invalid range: {}", msg),
+        }
+    }
+}
+
+impl std::error::Error for ParseError {}
+
+impl From<ParseIntError> for ParseError {
+    fn from(e: ParseIntError) -> Self {
+        ParseError::InvalidNumber(e)
+    }
+}
+
+/// Parse a line range selector string.
+///
+/// Examples:
+/// - `"50"` → `LineRangeSelector::Lines(vec![LineRange::new(50, 50)])`
+/// - `"50-200"` → `LineRangeSelector::Lines(vec![LineRange::new(50, 200)])`
+/// - `"50+150"` → `LineRangeSelector::Lines(vec![LineRange::new(50, 199)])`
+/// - `"raw"` → `LineRangeSelector::Raw`
+/// - `"conflicts"` → `LineRangeSelector::Conflicts`
+pub fn parse_selector(selector: &str) -> Result<LineRangeSelector, ParseError> {
+    if selector.is_empty() {
+        return Ok(LineRangeSelector::None);
+    }
+
+    match selector {
+        "raw" => Ok(LineRangeSelector::Raw),
+        "conflicts" => Ok(LineRangeSelector::Conflicts),
+        _ => parse_line_ranges(selector),
+    }
+}
+
+/// Parse comma-separated line ranges.
+fn parse_line_ranges(selector: &str) -> Result<LineRangeSelector, ParseError> {
+    let mut ranges = Vec::new();
+
+    for range_str in selector.split(',') {
+        let range_str = range_str.trim();
+        if range_str.is_empty() {
+            continue;
+        }
+
+        let range = parse_single_range(range_str)?;
+        ranges.push(range);
+    }
+
+    if ranges.is_empty() {
+        Ok(LineRangeSelector::None)
+    } else {
+        // Merge overlapping/adjacent ranges
+        ranges.sort_by_key(|r| r.start_line);
+        let merged = merge_ranges(ranges);
+        Ok(LineRangeSelector::Lines(merged))
+    }
+}
+
+/// Parse a single line range in formats: "50", "50-200", "50+150".
+fn parse_single_range(range_str: &str) -> Result<LineRange, ParseError> {
+    // Try "50+150" format first (start+count)
+    if let Some(plus_idx) = range_str.find('+') {
+        let start_str = &range_str[..plus_idx];
+        let count_str = &range_str[plus_idx + 1..];
+
+        if start_str.is_empty() || count_str.is_empty() {
+            return Err(ParseError::InvalidFormat(range_str.to_string()));
+        }
+
+        let start = start_str.parse::<usize>()?;
+        let count = count_str.parse::<usize>()?;
+
+        if start == 0 || count == 0 {
+            return Err(ParseError::InvalidRange(
+                "Line numbers and counts must be >= 1".to_string(),
+            ));
+        }
+
+        return Ok(LineRange::new(start, start + count - 1));
+    }
+
+    // Try "50-200" format (start-end)
+    if let Some(dash_idx) = range_str.find('-') {
+        // Skip leading dash (negative numbers aren't valid here)
+        if dash_idx == 0 {
+            return Err(ParseError::InvalidFormat(range_str.to_string()));
+        }
+
+        let start_str = &range_str[..dash_idx];
+        let end_str = &range_str[dash_idx + 1..];
+
+        if start_str.is_empty() || end_str.is_empty() {
+            return Err(ParseError::InvalidFormat(range_str.to_string()));
+        }
+
+        let start = start_str.parse::<usize>()?;
+        let end = end_str.parse::<usize>()?;
+
+        if start == 0 || end == 0 {
+            return Err(ParseError::InvalidRange(
+                "Line numbers must be >= 1".to_string(),
+            ));
+        }
+
+        if start > end {
+            return Err(ParseError::InvalidRange(format!(
+                "Start line {} cannot be greater than end line {}",
+                start, end
+            )));
+        }
+
+        return Ok(LineRange::new(start, end));
+    }
+
+    // Try plain "50" format (single line)
+    let line_num = range_str.parse::<usize>()?;
+    if line_num == 0 {
+        return Err(ParseError::InvalidRange(
+            "Line number must be >= 1".to_string(),
+        ));
+    }
+
+    Ok(LineRange::new(line_num, line_num))
+}
+
+/// Merge overlapping and adjacent ranges.
+fn merge_ranges(ranges: Vec<LineRange>) -> Vec<LineRange> {
+    let mut merged: Vec<LineRange> = Vec::new();
+
+    for range in ranges {
+        if let Some(last) = merged.last_mut() {
+            // If ranges overlap or are adjacent, merge them
+            if range.start_line <= last.end_line + 1 {
+                last.end_line = last.end_line.max(range.end_line);
+            } else {
+                merged.push(range);
+            }
+        } else {
+            merged.push(range);
+        }
+    }
+
+    merged
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse_raw() {
+        assert_eq!(parse_selector("raw").unwrap(), LineRangeSelector::Raw);
+    }
+
+    #[test]
+    fn test_parse_conflicts() {
+        assert_eq!(
+            parse_selector("conflicts").unwrap(),
+            LineRangeSelector::Conflicts
+        );
+    }
+
+    #[test]
+    fn test_parse_single_line() {
+        match parse_selector("50").unwrap() {
+            LineRangeSelector::Lines(ranges) => {
+                assert_eq!(ranges.len(), 1);
+                assert_eq!(ranges[0].start_line, 50);
+                assert_eq!(ranges[0].end_line, 50);
+            }
+            _ => panic!("Expected Lines variant"),
+        }
+    }
+
+    #[test]
+    fn test_parse_range_start_dash_end() {
+        match parse_selector("50-200").unwrap() {
+            LineRangeSelector::Lines(ranges) => {
+                assert_eq!(ranges.len(), 1);
+                assert_eq!(ranges[0].start_line, 50);
+                assert_eq!(ranges[0].end_line, 200);
+            }
+            _ => panic!("Expected Lines variant"),
+        }
+    }
+
+    #[test]
+    fn test_parse_range_start_plus_count() {
+        match parse_selector("50+150").unwrap() {
+            LineRangeSelector::Lines(ranges) => {
+                assert_eq!(ranges.len(), 1);
+                assert_eq!(ranges[0].start_line, 50);
+                assert_eq!(ranges[0].end_line, 199);
+            }
+            _ => panic!("Expected Lines variant"),
+        }
+    }
+
+    #[test]
+    fn test_parse_multiple_ranges() {
+        match parse_selector("5-16,960-973").unwrap() {
+            LineRangeSelector::Lines(ranges) => {
+                assert_eq!(ranges.len(), 2);
+                assert_eq!(ranges[0].start_line, 5);
+                assert_eq!(ranges[0].end_line, 16);
+                assert_eq!(ranges[1].start_line, 960);
+                assert_eq!(ranges[1].end_line, 973);
+            }
+            _ => panic!("Expected Lines variant"),
+        }
+    }
+
+    #[test]
+    fn test_merge_overlapping_ranges() {
+        // "5-16,10-20" should merge into "5-20"
+        match parse_selector("5-16,10-20").unwrap() {
+            LineRangeSelector::Lines(ranges) => {
+                assert_eq!(ranges.len(), 1);
+                assert_eq!(ranges[0].start_line, 5);
+                assert_eq!(ranges[0].end_line, 20);
+            }
+            _ => panic!("Expected Lines variant"),
+        }
+    }
+
+    #[test]
+    fn test_merge_adjacent_ranges() {
+        // "5-16,17-20" should merge into "5-20"
+        match parse_selector("5-16,17-20").unwrap() {
+            LineRangeSelector::Lines(ranges) => {
+                assert_eq!(ranges.len(), 1);
+                assert_eq!(ranges[0].start_line, 5);
+                assert_eq!(ranges[0].end_line, 20);
+            }
+            _ => panic!("Expected Lines variant"),
+        }
+    }
+
+    #[test]
+    fn test_invalid_range_start_greater_than_end() {
+        let result = parse_selector("200-50");
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_invalid_zero_line() {
+        let result = parse_selector("0");
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_empty_selector() {
+        assert_eq!(parse_selector("").unwrap(), LineRangeSelector::None);
+    }
+
+    #[test]
+    fn test_line_range_zero_indexed() {
+        let range = LineRange::new(50, 200);
+        let (start, end) = range.zero_indexed();
+        assert_eq!(start, 49);
+        assert_eq!(end, 199);
+    }
+
+    #[test]
+    fn test_line_range_len() {
+        assert_eq!(LineRange::new(50, 200).len(), 151);
+        assert_eq!(LineRange::new(50, 50).len(), 1);
+    }
+}

rust/crates/runtime/src/worker_boot.rs

@@ -34,6 +34,9 @@ pub enum WorkerStatus {
     ToolPermissionRequired,
     ReadyForPrompt,
     Running,
+    /// The user stopped the turn mid-run (e.g. Esc or Ctrl+C); the worker
+    /// is back at the prompt with the session intact.
+    Interrupted,
     Finished,
     Failed,
 }
@@ -46,6 +49,7 @@ impl std::fmt::Display for WorkerStatus {
             Self::ToolPermissionRequired => write!(f, "tool_permission_required"),
             Self::ReadyForPrompt => write!(f, "ready_for_prompt"),
             Self::Running => write!(f, "running"),
+            Self::Interrupted => write!(f, "interrupted"),
             Self::Finished => write!(f, "finished"),
             Self::Failed => write!(f, "failed"),
         }
@@ -82,6 +86,7 @@ pub enum WorkerEventKind {
     PromptMisdelivery,
     PromptReplayArmed,
     Running,
+    Interrupted,
     Restarted,
     Finished,
     Failed,
@@ -1461,6 +1466,23 @@ mod tests {
     use std::fs;
     use std::process::Command;
 
+    #[test]
+    fn interrupted_status_serializes_and_displays_as_snake_case() {
+        assert_eq!(WorkerStatus::Interrupted.to_string(), "interrupted");
+        assert_eq!(
+            serde_json::to_string(&WorkerStatus::Interrupted).expect("should serialize"),
+            "\"interrupted\""
+        );
+        assert_eq!(
+            serde_json::from_str::<WorkerStatus>("\"interrupted\"").expect("should deserialize"),
+            WorkerStatus::Interrupted
+        );
+        assert_eq!(
+            serde_json::to_string(&WorkerEventKind::Interrupted).expect("should serialize"),
+            "\"interrupted\""
+        );
+    }
+
     #[test]
     fn allowlisted_trust_prompt_auto_resolves_then_reaches_ready_state() {
         let registry = WorkerRegistry::new();

rust/crates/rusty-claude-cli/Cargo.toml

@@ -24,6 +24,8 @@ tokio = { version = "1", features = ["rt-multi-thread", "signal", "time"] }
 tools = { path = "../tools" }
 log = "0.4"
 
+[target.'cfg(unix)'.dependencies]
+nix = { version = "0.29", features = ["term", "poll"] }
 
 [lints]
 workspace = true

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

@@ -0,0 +1,280 @@
+//! Esc-key interruption for running turns.
+//!
+//! While a turn runs, the main thread is blocked inside the conversation
+//! loop, so rustyline is not reading the keyboard. This module spawns a
+//! listener thread that switches stdin to a minimal non-canonical mode
+//! (line buffering and echo off; signal handling and output processing
+//! stay enabled, unlike full raw mode) and watches for a lone Escape
+//! byte. When one arrives it trips the shared [`TurnInterruptSignal`],
+//! which the conversation loop and the streaming API client poll to wind
+//! the turn down gracefully.
+//!
+//! Permission prompts read whole lines from stdin mid-turn, so stdin
+//! ownership is coordinated through [`StdinPromptGate`]: while a prompt
+//! holds a lease, the listener restores canonical mode and stops
+//! consuming bytes.
+
+use std::io::IsTerminal;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::{Arc, Mutex, PoisonError};
+use std::thread::JoinHandle;
+
+use runtime::TurnInterruptSignal;
+
+/// Terminal-mode bookkeeping guarded by the gate mutex. `saved` holds the
+/// canonical-mode termios while non-canonical mode is active.
+#[derive(Default)]
+struct TtyMode {
+    #[cfg(unix)]
+    saved: Option<nix::sys::termios::Termios>,
+}
+
+#[derive(Default)]
+struct GateState {
+    /// True while a permission prompt owns stdin.
+    busy: AtomicBool,
+    /// Tells the listener thread to exit at the end of the turn.
+    stop: AtomicBool,
+    /// Serializes stdin reads and terminal-mode flips.
+    mode: Mutex<TtyMode>,
+}
+
+/// Classification of one chunk of bytes read from the terminal.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum EscClassification {
+    /// A bare ESC byte: the user pressed the Escape key.
+    LoneEscape,
+    /// ESC followed by more bytes: the prefix of a terminal escape
+    /// sequence such as an arrow or function key.
+    EscapeSequence,
+    /// Anything else (regular type-ahead, control characters, ...).
+    Other,
+}
+
+#[cfg_attr(not(unix), allow(dead_code))]
+fn classify_escape_chunk(bytes: &[u8]) -> EscClassification {
+    match bytes {
+        [0x1b] => EscClassification::LoneEscape,
+        [0x1b, ..] => EscClassification::EscapeSequence,
+        _ => EscClassification::Other,
+    }
+}
+
+/// Hands exclusive stdin ownership to interactive prompts while the
+/// Esc listener is running.
+#[derive(Clone)]
+pub struct StdinPromptGate {
+    shared: Arc<GateState>,
+}
+
+impl StdinPromptGate {
+    /// Takes stdin away from the Esc listener for the lifetime of the
+    /// returned lease: the terminal returns to canonical mode so a
+    /// line-based prompt (e.g. the permission approval prompt) behaves
+    /// normally. Listening resumes when the lease is dropped.
+    pub fn lease(&self) -> StdinPromptLease<'_> {
+        self.shared.busy.store(true, Ordering::SeqCst);
+        // Wait for the listener's current poll cycle to release the
+        // terminal, then restore canonical mode for line input.
+        #[allow(unused_mut)]
+        let mut mode = self
+            .shared
+            .mode
+            .lock()
+            .unwrap_or_else(PoisonError::into_inner);
+        #[cfg(unix)]
+        tty::restore(&mut mode);
+        drop(mode);
+        StdinPromptLease {
+            shared: &self.shared,
+        }
+    }
+}
+
+/// RAII lease returned by [`StdinPromptGate::lease`].
+pub struct StdinPromptLease<'a> {
+    shared: &'a GateState,
+}
+
+impl Drop for StdinPromptLease<'_> {
+    fn drop(&mut self) {
+        self.shared.busy.store(false, Ordering::SeqCst);
+    }
+}
+
+/// Background listener that maps a lone Esc keypress to
+/// [`TurnInterruptSignal::interrupt`].
+pub struct EscapeInterruptMonitor {
+    shared: Arc<GateState>,
+    join_handle: Option<JoinHandle<()>>,
+}
+
+impl EscapeInterruptMonitor {
+    /// Spawns the listener for the duration of one turn. Returns `None`
+    /// when stdin is not an interactive terminal or the platform does not
+    /// support terminal-mode switching; Ctrl+C interruption still works
+    /// in those cases.
+    pub fn spawn(signal: TurnInterruptSignal) -> Option<(Self, StdinPromptGate)> {
+        if !std::io::stdin().is_terminal() {
+            return None;
+        }
+
+        #[cfg(not(unix))]
+        {
+            let _ = signal;
+            None
+        }
+
+        #[cfg(unix)]
+        {
+            let shared = Arc::new(GateState::default());
+            let thread_shared = Arc::clone(&shared);
+            let join_handle = std::thread::spawn(move || listener_loop(&thread_shared, &signal));
+            let gate = StdinPromptGate {
+                shared: Arc::clone(&shared),
+            };
+            Some((
+                Self {
+                    shared,
+                    join_handle: Some(join_handle),
+                },
+                gate,
+            ))
+        }
+    }
+
+    /// Stops the listener and restores the terminal before control
+    /// returns to the line editor.
+    pub fn stop(mut self) {
+        self.shared.stop.store(true, Ordering::SeqCst);
+        if let Some(join_handle) = self.join_handle.take() {
+            let _ = join_handle.join();
+        }
+    }
+}
+
+#[cfg(unix)]
+fn listener_loop(shared: &GateState, signal: &TurnInterruptSignal) {
+    let mut buffer = [0u8; 64];
+
+    while !shared.stop.load(Ordering::SeqCst) {
+        if shared.busy.load(Ordering::SeqCst) {
+            std::thread::sleep(std::time::Duration::from_millis(25));
+            continue;
+        }
+
+        let mut mode = shared.mode.lock().unwrap_or_else(PoisonError::into_inner);
+        if shared.busy.load(Ordering::SeqCst) || shared.stop.load(Ordering::SeqCst) {
+            continue;
+        }
+        if !tty::enable_noncanonical(&mut mode) {
+            // Terminal refused the mode switch; Esc support is
+            // unavailable for this turn but Ctrl+C still works.
+            return;
+        }
+        if !tty::wait_readable(100) {
+            continue;
+        }
+
+        let count = tty::read_pending(&mut buffer);
+        if classify_escape_chunk(&buffer[..count]) == EscClassification::LoneEscape {
+            // A slow terminal may split an escape sequence across reads;
+            // only treat ESC as the Esc key when nothing follows it.
+            if tty::wait_readable(50) {
+                let _ = tty::read_pending(&mut buffer);
+                continue;
+            }
+            signal.interrupt();
+        }
+        // Other bytes are intentionally swallowed: type-ahead is not
+        // preserved while a turn is running.
+    }
+
+    let mut mode = shared.mode.lock().unwrap_or_else(PoisonError::into_inner);
+    tty::restore(&mut mode);
+}
+
+#[cfg(unix)]
+mod tty {
+    use std::os::fd::{AsFd, AsRawFd};
+
+    use nix::poll::{poll, PollFd, PollFlags, PollTimeout};
+    use nix::sys::termios::{self, LocalFlags, SetArg, SpecialCharacterIndices};
+
+    use super::TtyMode;
+
+    /// Disables line buffering and echo while leaving signal generation
+    /// (ISIG) and output post-processing (OPOST) untouched, so Ctrl+C and
+    /// streamed output keep working. No-op when already active.
+    pub(super) fn enable_noncanonical(mode: &mut TtyMode) -> bool {
+        if mode.saved.is_some() {
+            return true;
+        }
+        let stdin = std::io::stdin();
+        let Ok(saved) = termios::tcgetattr(&stdin) else {
+            return false;
+        };
+        let mut noncanonical = saved.clone();
+        noncanonical.local_flags &= !(LocalFlags::ICANON | LocalFlags::ECHO);
+        noncanonical.control_chars[SpecialCharacterIndices::VMIN as usize] = 0;
+        noncanonical.control_chars[SpecialCharacterIndices::VTIME as usize] = 0;
+        if termios::tcsetattr(&stdin, SetArg::TCSANOW, &noncanonical).is_err() {
+            return false;
+        }
+        mode.saved = Some(saved);
+        true
+    }
+
+    pub(super) fn restore(mode: &mut TtyMode) {
+        if let Some(saved) = mode.saved.take() {
+            let _ = termios::tcsetattr(std::io::stdin(), SetArg::TCSANOW, &saved);
+        }
+    }
+
+    pub(super) fn wait_readable(timeout_ms: u16) -> bool {
+        let stdin = std::io::stdin();
+        let mut fds = [PollFd::new(stdin.as_fd(), PollFlags::POLLIN)];
+        matches!(poll(&mut fds, PollTimeout::from(timeout_ms)), Ok(ready) if ready > 0)
+            && fds[0]
+                .revents()
+                .is_some_and(|revents| revents.contains(PollFlags::POLLIN))
+    }
+
+    pub(super) fn read_pending(buffer: &mut [u8]) -> usize {
+        nix::unistd::read(std::io::stdin().as_raw_fd(), buffer).unwrap_or(0)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{classify_escape_chunk, EscClassification};
+
+    #[test]
+    fn lone_escape_byte_is_the_esc_key() {
+        assert_eq!(
+            classify_escape_chunk(&[0x1b]),
+            EscClassification::LoneEscape
+        );
+    }
+
+    #[test]
+    fn escape_followed_by_more_bytes_is_a_sequence() {
+        // Up arrow: ESC [ A
+        assert_eq!(
+            classify_escape_chunk(&[0x1b, 0x5b, 0x41]),
+            EscClassification::EscapeSequence
+        );
+        // Alt+f style: ESC f
+        assert_eq!(
+            classify_escape_chunk(&[0x1b, b'f']),
+            EscClassification::EscapeSequence
+        );
+    }
+
+    #[test]
+    fn regular_bytes_are_ignored() {
+        assert_eq!(classify_escape_chunk(b"hello"), EscClassification::Other);
+        assert_eq!(classify_escape_chunk(&[]), EscClassification::Other);
+        assert_eq!(classify_escape_chunk(&[0x03]), EscClassification::Other);
+    }
+}

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

@@ -16,6 +16,7 @@
 )]
 mod init;
 mod input;
+mod interrupt;
 mod render;
 mod setup_wizard;
 
@@ -7298,6 +7299,18 @@ impl BuiltRuntime {
         self
     }
 
+    fn with_turn_interrupt_signal(mut self, signal: runtime::TurnInterruptSignal) -> Self {
+        let mut runtime = self
+            .runtime
+            .take()
+            .expect("runtime should exist before installing turn interrupt signal");
+        runtime
+            .api_client_mut()
+            .set_turn_interrupt_signal(signal.clone());
+        self.runtime = Some(runtime.with_turn_interrupt_signal(signal));
+        self
+    }
+
     fn shutdown_plugins(&mut self) -> Result<(), Box<dyn std::error::Error>> {
         if self.plugins_active {
             self.plugin_registry.shutdown()?;
@@ -7680,7 +7693,10 @@ struct HookAbortMonitor {
 }
 
 impl HookAbortMonitor {
-    fn spawn(abort_signal: runtime::HookAbortSignal) -> Self {
+    fn spawn(
+        abort_signal: runtime::HookAbortSignal,
+        turn_interrupt_signal: runtime::TurnInterruptSignal,
+    ) -> Self {
         Self::spawn_with_waiter(abort_signal, move |stop_rx, abort_signal| {
             let Ok(runtime) = tokio::runtime::Builder::new_current_thread()
                 .enable_all()
@@ -7697,7 +7713,11 @@ impl HookAbortMonitor {
                 tokio::select! {
                     result = tokio::signal::ctrl_c() => {
                         if result.is_ok() {
+                            // Ctrl+C stops the whole turn, not just running
+                            // hooks: the conversation loop and the streaming
+                            // client both poll the turn interrupt signal.
                             abort_signal.abort();
+                            turn_interrupt_signal.interrupt();
                         }
                     }
                     _ = wait_for_stop => {}
@@ -7803,7 +7823,7 @@ impl LiveCli {
   \x1b[2mDirectory\x1b[0m        {}\n\
   \x1b[2mSession\x1b[0m          {}\n\
   \x1b[2mAuto-save\x1b[0m        {}\n\n\
-  Type \x1b[1m/help\x1b[0m for commands · \x1b[1m/status\x1b[0m for live context · \x1b[2m/resume latest\x1b[0m jumps back to the newest session · \x1b[1m/diff\x1b[0m then \x1b[1m/commit\x1b[0m to ship · \x1b[2mTab\x1b[0m for workflow completions · \x1b[2mShift+Enter\x1b[0m for newline",
+  Type \x1b[1m/help\x1b[0m for commands · \x1b[1m/status\x1b[0m for live context · \x1b[2m/resume latest\x1b[0m jumps back to the newest session · \x1b[1m/diff\x1b[0m then \x1b[1m/commit\x1b[0m to ship · \x1b[2mTab\x1b[0m for workflow completions · \x1b[2mShift+Enter\x1b[0m for newline · \x1b[2mEsc\x1b[0m interrupts a running turn",
             self.model,
             self.permission_mode.as_str(),
             git_branch,
@@ -7829,8 +7849,12 @@ impl LiveCli {
         &self,
         emit_output: bool,
         terminal_tail: TerminalTail,
-    ) -> Result<(BuiltRuntime, HookAbortMonitor), Box<dyn std::error::Error>> {
+    ) -> Result<
+        (BuiltRuntime, HookAbortMonitor, runtime::TurnInterruptSignal),
+        Box<dyn std::error::Error>,
+    > {
         let hook_abort_signal = runtime::HookAbortSignal::new();
+        let turn_interrupt_signal = runtime::TurnInterruptSignal::new();
         let runtime = build_runtime(
             self.runtime.session().clone(),
             &self.session.id,
@@ -7843,10 +7867,12 @@ impl LiveCli {
             self.permission_mode,
             None,
         )?
-        .with_hook_abort_signal(hook_abort_signal.clone());
-        let hook_abort_monitor = HookAbortMonitor::spawn(hook_abort_signal);
+        .with_hook_abort_signal(hook_abort_signal.clone())
+        .with_turn_interrupt_signal(turn_interrupt_signal.clone());
+        let hook_abort_monitor =
+            HookAbortMonitor::spawn(hook_abort_signal, turn_interrupt_signal.clone());
 
-        Ok((runtime, hook_abort_monitor))
+        Ok((runtime, hook_abort_monitor, turn_interrupt_signal))
     }
 
     fn replace_runtime(&mut self, runtime: BuiltRuntime) -> Result<(), Box<dyn std::error::Error>> {
@@ -7857,8 +7883,16 @@ impl LiveCli {
 
     fn run_turn(&mut self, input: &str) -> Result<(), Box<dyn std::error::Error>> {
         let terminal_tail = TerminalTail::new();
-        let (mut runtime, hook_abort_monitor) =
+        let (mut runtime, hook_abort_monitor, turn_interrupt_signal) =
             self.prepare_turn_runtime(true, terminal_tail.clone())?;
+        let mut permission_prompter = CliPermissionPrompter::new(self.permission_mode);
+        let mut escape_monitor = None;
+        if let Some((monitor, stdin_gate)) =
+            interrupt::EscapeInterruptMonitor::spawn(turn_interrupt_signal)
+        {
+            permission_prompter = permission_prompter.with_stdin_gate(stdin_gate);
+            escape_monitor = Some(monitor);
+        }
         let mut spinner = Spinner::new();
         let mut stdout = io::stdout();
         // The animated frame is cursor control: it saves the cursor, rewrites the
@@ -7869,13 +7903,19 @@ impl LiveCli {
         // emitted either way.
         if io::stdout().is_terminal() {
             spinner.tick(
-                "🦀 Thinking...",
+                if escape_monitor.is_some() {
+                    "🦀 Thinking... (esc to interrupt)"
+                } else {
+                    "🦀 Thinking..."
+                },
                 TerminalRenderer::new().color_theme(),
                 &mut stdout,
-            )?;
+            )?
         }
-        let mut permission_prompter = CliPermissionPrompter::new(self.permission_mode);
         let result = runtime.run_turn(input, Some(&mut permission_prompter));
+        if let Some(monitor) = escape_monitor {
+            monitor.stop();
+        }
         hook_abort_monitor.stop();
         match result {
             Ok(summary) => {
@@ -7892,7 +7932,11 @@ impl LiveCli {
                     println!();
                 }
                 spinner.finish(
-                    "✨ Done",
+                    if summary.interrupted {
+                        "⏹ Interrupted"
+                    } else {
+                        "✨ Done"
+                    },
                     TerminalRenderer::new().color_theme(),
                     &mut stdout,
                 )?;
@@ -8026,7 +8070,7 @@ impl LiveCli {
                         *self.runtime.session_mut() = result.compacted_session.clone();
 
                         // Build a new runtime with the compacted session and retry
-                        let (mut new_runtime, hook_abort_monitor) =
+                        let (mut new_runtime, hook_abort_monitor, _turn_interrupt_signal) =
                             self.prepare_turn_runtime(true, terminal_tail.clone())?;
                         drop(hook_abort_monitor);
 
@@ -8119,7 +8163,7 @@ impl LiveCli {
     }
 
     fn run_prompt_compact(&mut self, input: &str) -> Result<(), Box<dyn std::error::Error>> {
-        let (mut runtime, hook_abort_monitor) =
+        let (mut runtime, hook_abort_monitor, _turn_interrupt_signal) =
             self.prepare_turn_runtime(false, TerminalTail::new())?;
         let mut permission_prompter = CliPermissionPrompter::new(self.permission_mode);
         let result = runtime.run_turn(input, Some(&mut permission_prompter));
@@ -8133,7 +8177,7 @@ impl LiveCli {
     }
 
     fn run_prompt_compact_json(&mut self, input: &str) -> Result<(), Box<dyn std::error::Error>> {
-        let (mut runtime, hook_abort_monitor) =
+        let (mut runtime, hook_abort_monitor, _turn_interrupt_signal) =
             self.prepare_turn_runtime(false, TerminalTail::new())?;
         let mut permission_prompter = CliPermissionPrompter::new(self.permission_mode);
         let result = runtime.run_turn(input, Some(&mut permission_prompter));
@@ -8159,7 +8203,7 @@ impl LiveCli {
     }
 
     fn run_prompt_json(&mut self, input: &str) -> Result<(), Box<dyn std::error::Error>> {
-        let (mut runtime, hook_abort_monitor) =
+        let (mut runtime, hook_abort_monitor, _turn_interrupt_signal) =
             self.prepare_turn_runtime(false, TerminalTail::new())?;
         let mut permission_prompter = CliPermissionPrompter::new(self.permission_mode);
         let result = runtime.run_turn(input, Some(&mut permission_prompter));
@@ -9722,6 +9766,7 @@ fn render_repl_help() -> String {
         "  Ctrl-R               Reverse-search prompt history".to_string(),
         "  Tab                  Complete commands, modes, and recent sessions".to_string(),
         "  Ctrl-C               Clear input (or exit on empty prompt)".to_string(),
+        "  Esc                  Interrupt the running turn".to_string(),
         "  Shift+Enter/Ctrl+J   Insert a newline".to_string(),
         "  Auto-save            .claw/sessions/<workspace-fingerprint>/<session-id>.jsonl"
             .to_string(),
@@ -12774,11 +12819,20 @@ impl runtime::HookProgressReporter for CliHookProgressReporter {
 
 struct CliPermissionPrompter {
     current_mode: PermissionMode,
+    stdin_gate: Option<interrupt::StdinPromptGate>,
 }
 
 impl CliPermissionPrompter {
     fn new(current_mode: PermissionMode) -> Self {
-        Self { current_mode }
+        Self {
+            current_mode,
+            stdin_gate: None,
+        }
+    }
+
+    fn with_stdin_gate(mut self, stdin_gate: interrupt::StdinPromptGate) -> Self {
+        self.stdin_gate = Some(stdin_gate);
+        self
     }
 }
 
@@ -12787,6 +12841,12 @@ impl runtime::PermissionPrompter for CliPermissionPrompter {
         &mut self,
         request: &runtime::PermissionRequest,
     ) -> runtime::PermissionPromptDecision {
+        // Take stdin back from the Esc listener (restoring canonical
+        // mode) for the duration of this line-based prompt.
+        let _stdin_lease = self
+            .stdin_gate
+            .as_ref()
+            .map(interrupt::StdinPromptGate::lease);
         println!();
         println!("Permission approval required");
         println!("  Tool             {}", request.tool_name);
@@ -12984,6 +13044,7 @@ struct AnthropicRuntimeClient {
     tool_registry: GlobalToolRegistry,
     progress_reporter: Option<InternalPromptProgressReporter>,
     reasoning_effort: Option<String>,
+    turn_interrupt_signal: Option<runtime::TurnInterruptSignal>,
 }
 
 impl AnthropicRuntimeClient {
@@ -13069,12 +13130,17 @@ impl AnthropicRuntimeClient {
             tool_registry,
             progress_reporter,
             reasoning_effort: None,
+            turn_interrupt_signal: None,
         })
     }
 
     fn set_reasoning_effort(&mut self, effort: Option<String>) {
         self.reasoning_effort = effort;
     }
+
+    fn set_turn_interrupt_signal(&mut self, signal: runtime::TurnInterruptSignal) {
+        self.turn_interrupt_signal = Some(signal);
+    }
 }
 
 fn resolve_cli_auth_source() -> Result<AuthSource, Box<dyn std::error::Error>> {
@@ -13118,30 +13184,50 @@ impl ApiClient for AnthropicRuntimeClient {
         };
 
         self.runtime.block_on(async {
-            // When resuming after tool execution, apply a stall timeout on the
-            // first stream event.  If the model does not respond within the
-            // deadline we drop the stalled connection and re-send the request as
-            // a continuation nudge (one retry only).
-            let max_attempts: usize = if is_post_tool { 2 } else { 1 };
+            let request_loop = async {
+                // When resuming after tool execution, apply a stall timeout on the
+                // first stream event.  If the model does not respond within the
+                // deadline we drop the stalled connection and re-send the request as
+                // a continuation nudge (one retry only).
+                let max_attempts: usize = if is_post_tool { 2 } else { 1 };
 
-            for attempt in 1..=max_attempts {
-                let result = self
-                    .consume_stream(&message_request, is_post_tool && attempt == 1)
-                    .await;
-                match result {
-                    Ok(events) => return Ok(events),
-                    Err(error)
-                        if error.to_string().contains("post-tool stall")
-                            && attempt < max_attempts =>
-                    {
-                        // Stalled after tool completion — nudge the model by
-                        // re-sending the same request.
+                for attempt in 1..=max_attempts {
+                    let result = self
+                        .consume_stream(&message_request, is_post_tool && attempt == 1)
+                        .await;
+                    match result {
+                        Ok(events) => return Ok(events),
+                        Err(error)
+                            if error.to_string().contains("post-tool stall")
+                                && attempt < max_attempts =>
+                        {
+                            // Stalled after tool completion — nudge the model by
+                            // re-sending the same request.
+                        }
+                        Err(error) => return Err(error),
                     }
-                    Err(error) => return Err(error),
+                }
+
+                Err(RuntimeError::new("post-tool continuation nudge exhausted"))
+            };
+
+            let Some(interrupt) = self.turn_interrupt_signal.clone() else {
+                return request_loop.await;
+            };
+
+            tokio::select! {
+                result = request_loop => result,
+                () = async {
+                    while !interrupt.is_interrupted() {
+                        tokio::time::sleep(std::time::Duration::from_millis(50)).await;
+                    }
+                } => {
+                    // Dropping the request future aborts the in-flight HTTP
+                    // stream. The conversation loop sees the interrupt flag and
+                    // reports this as an interruption rather than a failure.
+                    Err(RuntimeError::new("request interrupted by user"))
                 }
             }
-
-            Err(RuntimeError::new("post-tool continuation nudge exhausted"))
         })
     }
 }

rust/crates/tools/src/lib.rs

@@ -20,7 +20,7 @@ use runtime::{
     lsp_client::LspRegistry,
     mcp_tool_bridge::McpToolRegistry,
     permission_enforcer::{EnforcementResult, PermissionEnforcer},
-    read_file_in_workspace,
+    read_file_in_workspace_with_selector,
     summary_compression::compress_summary_text,
     task_registry::TaskRegistry,
     team_cron_registry::{CronRegistry, TeamRegistry},
@@ -2569,8 +2569,14 @@ fn branch_divergence_output(
 fn run_read_file(input: ReadFileInput) -> Result<String, String> {
     let workspace = std::env::current_dir().map_err(|error| error.to_string())?;
     to_pretty_json(
-        read_file_in_workspace(&input.path, input.offset, input.limit, &workspace)
-            .map_err(io_to_string)?,
+        read_file_in_workspace_with_selector(
+            &input.path,
+            input.offset,
+            input.limit,
+            input.selector.as_deref(),
+            &workspace,
+        )
+        .map_err(io_to_string)?,
     )
 }
 
@@ -2885,6 +2891,7 @@ struct ReadFileInput {
     path: String,
     offset: Option<usize>,
     limit: Option<usize>,
+    selector: Option<String>,
 }
 
 #[derive(Debug, Deserialize)]
@@ -10690,6 +10697,43 @@ printf 'pwsh:%s' "$1"
         let _ = fs::remove_dir_all(root);
     }
 
+    #[test]
+    fn given_read_only_enforcer_when_read_file_with_selector_then_succeeds() {
+        let _guard = env_lock()
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+        let root = temp_path("perm-read-selector");
+        fs::create_dir_all(&root).expect("create root");
+        let file = root.join("multi-line.txt");
+        fs::write(&file, "line1\nline2\nline3\nline4\nline5\n").expect("write test file");
+        let original_dir = std::env::current_dir().expect("cwd");
+        std::env::set_current_dir(&root).expect("set cwd");
+
+        let registry = read_only_registry();
+        let result = registry.execute(
+            "read_file",
+            &json!({
+                "path": file.display().to_string(),
+                "selector": "2-4"
+            }),
+        );
+        assert!(
+            result.is_ok(),
+            "read_file with selector should succeed: {result:?}"
+        );
+
+        // Verify the output contains the expected lines
+        let output: serde_json::Value =
+            serde_json::from_str(&result.unwrap()).expect("json output");
+        let content = output["file"]["content"].as_str().expect("content field");
+        assert!(content.contains("line2"));
+        assert!(content.contains("line3"));
+        assert!(content.contains("line4"));
+
+        std::env::set_current_dir(&original_dir).expect("restore cwd");
+        let _ = fs::remove_dir_all(root);
+    }
+
     #[test]
     fn given_read_only_enforcer_when_glob_search_then_not_permission_denied() {
         let registry = read_only_registry();