upd

.env.example

@@ -10,11 +10,20 @@ MODEL=xiaomi/mimo-v2.6-flash
 # Optional: Tavily API key — enables the websearch and browse_url tools
 TAVILY_API_KEY=tvly-dev-...
 
-# Optional: File to persist the undo log (relative to workspace root)
+# Optional: File to persist the undo log (relative to workspace root).
+# When run via the ~/.fido/bin/fido launcher this is overridden to a
+# per-workspace path under ~/.fido/state/<workspace>/undo.json.
 UNDO_FILE=.fido-undo.json
 
-# Optional: Directory for /suspend snapshots, one JSON file each (relative to workspace root)
+# Optional: Directory for /suspend snapshots, one JSON file each (relative to workspace root).
+# When run via the ~/.fido/bin/fido launcher this is overridden to a
+# per-workspace path under ~/.fido/state/<workspace>/suspends.
 SUSPEND_DIR=.fido-suspends
 
 # Optional: Workspace root directory (defaults to cwd when running fido)
 # ROOT_DIR=.
+
+# Optional: Set to 1 to log compaction stats each turn (patch tool calls
+# compacted / stale read_file results invalidated). Useful for observing the
+# between-turns transcript compaction; unset keeps normal runs quiet.
+# COMPACT_DEBUG=1

README.md

@@ -3,6 +3,48 @@
 Fido is a console REPL assistant that inspects files, lists directories, searches file
 contents, applies changes, and runs shell commands (with user approval).
 
+## Install
+
+Installs into `~/.fido` and adds a `fido` launcher to your `PATH` via `~/.bashrc`:
+
+```sh
+git clone <this-repo> ~/src/fidoca
+cd ~/src/fidoca
+./install.sh
+source ~/.bashrc
+```
+
+The installer needs the sibling `llmorbiter` checkout (this project depends on it
+via `file:../llmorbiter`); it is bundled into `~/.fido/llmorbiter`. Override its
+location with `LLMORBITER_SRC=/path/to/llmorbiter`.
+
+Then, from any project directory:
+
+```sh
+fido                    # work on the current directory
+fido /path/to/project   # work on a specific directory
+```
+
+Set `OPENROUTER_API_KEY` (and optionally `TAVILY_API_KEY`) in `~/.fido/.env`.
+
+### Layout
+
+```
+~/.fido/
+  app/                     the fido app (this repo)
+  llmorbiter/              bundled dependency
+  bin/fido                 the launcher (added to PATH)
+  .env                     your config / API keys
+  state/<workspace>/       per-workspace state
+    undo.json
+    suspends/
+```
+
+Undo and `/suspend` state is stored **per workspace** under `~/.fido/state/`, so it
+never mixes between projects and never litters your repositories.
+
+To remove everything: `./install.sh --uninstall`.
+
 ## License
 
 [0BSD](https://opensource.org/license/0bsd)

install.sh

@@ -0,0 +1,174 @@
+#!/usr/bin/env bash
+#
+# install.sh — install Fido into ~/.fido and wire it into your shell.
+#
+# Usage:
+#   ./install.sh                 # install (or re-install) into $FIDO_HOME (default ~/.fido)
+#   FIDO_HOME=/opt/fido ./install.sh
+#   LLMORBITER_SRC=/path/to/llmorbiter ./install.sh
+#   ./install.sh --uninstall     # remove the install and the PATH entry
+#   ./install.sh --help
+#
+# Environment:
+#   FIDO_HOME        install directory               (default: ~/.fido)
+#   LLMORBITER_SRC   path to the llmorbiter checkout (default: sibling of this repo)
+#   BASHRC           shell rc file to edit           (default: ~/.bashrc)
+#   FIDO_SKIP_DEPS=1 skip `npm install` (useful for testing)
+#
+# What it does:
+#   1. Copies the app into        $FIDO_HOME/app
+#   2. Bundles the llmorbiter dep $FIDO_HOME/llmorbiter   (required by "file:../llmorbiter")
+#   3. Copies your config to      $FIDO_HOME/.env
+#   4. Installs the launcher at   $FIDO_HOME/bin/fido
+#   5. Runs `npm install` for the app and for llmorbiter
+#   6. Adds $FIDO_HOME/bin to PATH in ~/.bashrc
+#
+# All undo/suspend state lives under $FIDO_HOME/state/<workspace>/.
+
+set -euo pipefail
+
+FIDO_HOME="${FIDO_HOME:-$HOME/.fido}"
+
+# Directory of this script = the repo root.
+SRC_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# llmorbiter is a sibling checkout by default; override with LLMORBITER_SRC.
+LLMORBITER_SRC="${LLMORBITER_SRC:-$SRC_DIR/../llmorbiter}"
+
+BASHRC="${BASHRC:-$HOME/.bashrc}"
+PATH_MARKER_BEGIN="# >>> fido >>>"
+PATH_MARKER_END="# <<< fido <<<"
+
+info() { printf '\033[36m▸\033[0m %s\n' "$*"; }
+warn() { printf '\033[33m!\033[0m %s\n' "$*" >&2; }
+die()  { printf '\033[31m✖\033[0m %s\n' "$*" >&2; exit 1; }
+
+usage() {
+    sed -n '2,30p' "$0" | sed 's/^# \{0,1\}//'
+}
+
+# Copy a source tree, skipping build/state noise and dotfile cruft.
+copy_tree() {
+    local src="$1" dst="$2"
+    mkdir -p "$dst"
+    if command -v rsync >/dev/null 2>&1; then
+        rsync -a --delete \
+            --exclude 'node_modules' --exclude '.git' \
+            --exclude '.env' --exclude '.fido-*' \
+            "$src/" "$dst/"
+    else
+        local tmp
+        tmp="$(mktemp -d)"
+        tar -C "$src" \
+            --exclude=./node_modules --exclude=./.git \
+            --exclude=./.env --exclude='./.fido-*' \
+            -cf - . | tar -C "$tmp" -xf -
+        rm -rf "$dst"
+        mkdir -p "$dst"
+        cp -a "$tmp/." "$dst/"
+        rm -rf "$tmp"
+    fi
+}
+
+add_to_path() {
+    if [ -f "$BASHRC" ] && grep -qF "$PATH_MARKER_BEGIN" "$BASHRC"; then
+        info "PATH entry already present in $BASHRC"
+        return
+    fi
+    {
+        printf '\n%s\n' "$PATH_MARKER_BEGIN"
+        printf '# Added by the Fido installer — makes the "fido" launcher available.\n'
+        printf 'export PATH="%s/bin:$PATH"\n' "$FIDO_HOME"
+        printf '%s\n' "$PATH_MARKER_END"
+    } >> "$BASHRC"
+    info "Added $FIDO_HOME/bin to PATH in $BASHRC"
+}
+
+remove_from_path() {
+    [ -f "$BASHRC" ] || return
+    if grep -qF "$PATH_MARKER_BEGIN" "$BASHRC"; then
+        sed -i "/^# >>> fido >>>$/,/^# <<< fido <<<$/d" "$BASHRC"
+        info "Removed PATH entry from $BASHRC"
+    fi
+}
+
+do_install() {
+    command -v node >/dev/null 2>&1 || die "node not found in PATH — install Node.js first."
+    command -v npm  >/dev/null 2>&1 || die "npm not found in PATH."
+
+    [ -f "$SRC_DIR/src/fido.js" ] || die "src/fido.js not found — run this script from the Fido repo root."
+    [ -f "$SRC_DIR/bin/fido" ]    || die "bin/fido not found — is this a complete checkout?"
+    [ -d "$LLMORBITER_SRC" ] || die "llmorbiter dependency not found at: $LLMORBITER_SRC
+Set LLMORBITER_SRC=/path/to/llmorbiter and re-run."
+
+    info "Installing Fido into $FIDO_HOME"
+    mkdir -p "$FIDO_HOME/bin" "$FIDO_HOME/state"
+
+    info "Copying app            -> $FIDO_HOME/app"
+    copy_tree "$SRC_DIR" "$FIDO_HOME/app"
+
+    info "Bundling llmorbiter    -> $FIDO_HOME/llmorbiter"
+    copy_tree "$LLMORBITER_SRC" "$FIDO_HOME/llmorbiter"
+
+    # Config: never clobber an existing install's .env (users edit it in place).
+    if [ -f "$FIDO_HOME/.env" ]; then
+        info "Keeping existing $FIDO_HOME/.env"
+    elif [ -f "$SRC_DIR/.env" ]; then
+        cp "$SRC_DIR/.env" "$FIDO_HOME/.env"
+        info "Copied .env            -> $FIDO_HOME/.env"
+    else
+        cp "$SRC_DIR/.env.example" "$FIDO_HOME/.env"
+        warn "No .env found — wrote $FIDO_HOME/.env from .env.example."
+        warn "Edit it and set OPENROUTER_API_KEY before running fido."
+    fi
+
+    info "Installing launcher     -> $FIDO_HOME/bin/fido"
+    cp "$SRC_DIR/bin/fido" "$FIDO_HOME/bin/fido"
+    chmod +x "$FIDO_HOME/bin/fido"
+
+    if [ "${FIDO_SKIP_DEPS:-0}" = "1" ]; then
+        warn "FIDO_SKIP_DEPS=1 — skipping npm install."
+    else
+        info "Installing dependencies (npm install) — this may take a moment…"
+        ( cd "$FIDO_HOME/llmorbiter" && npm install --no-audit --no-fund )
+        ( cd "$FIDO_HOME/app"        && npm install --no-audit --no-fund )
+    fi
+
+    add_to_path
+
+    cat <<EOF
+
+  ✅ Fido installed.
+
+     Home:      $FIDO_HOME
+     Launcher:  $FIDO_HOME/bin/fido
+     Config:    $FIDO_HOME/.env
+     State:     $FIDO_HOME/state/<workspace>/  (undo.json + suspends/)
+
+  Activate in this shell:  source "$BASHRC"
+  (or just open a new terminal.)
+
+  Then run, from any project directory:
+     fido                    # work on the current directory
+     fido /path/to/project   # work on a specific directory
+
+  Remember to set OPENROUTER_API_KEY in $FIDO_HOME/.env.
+EOF
+}
+
+do_uninstall() {
+    remove_from_path
+    if [ -d "$FIDO_HOME" ]; then
+        info "Removing $FIDO_HOME"
+        rm -rf "$FIDO_HOME"
+    else
+        warn "$FIDO_HOME does not exist — nothing to remove."
+    fi
+    info "Fido uninstalled. Open a new shell (or re-source $BASHRC) to drop the PATH entry."
+}
+
+case "${1:-}" in
+    ""|--install|-i) do_install ;;
+    --uninstall|-u)  do_uninstall ;;
+    --help|-h)       usage ;;
+    *) die "Unknown argument: $1 (try --help)" ;;
+esac

package.json

@@ -8,7 +8,7 @@
   "main": "src/fido.js",
   "scripts": {
     "start": "node src/fido.js",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "node --test"
   },
   "dependencies": {
     "@inquirer/core": "^10.3.2",

src/autocomplete-input.js

@@ -21,6 +21,7 @@ import {
     createPrompt,
     useState,
     useKeypress,
+    useEffect,
     usePrefix,
     isEnterKey,
     isTabKey,
@@ -55,9 +56,10 @@ function replaceBuffer(rl, nextValue) {
 
 export const autocompleteInput = createPrompt((config, done) => {
     const theme = makeTheme({}, config.theme);
+    const initial = typeof config.default === 'string' ? config.default : '';
     const [status, setStatus] = useState('idle');
-    const [value, setValue] = useState('');
+    const [value, setValue] = useState(initial);
-    const [term, setTerm] = useState(null); // frozen filter term while the menu is open
+    const [term, setTerm] = useState(termFrom(initial)); // frozen filter term while the menu is open
     const [active, setActive] = useState(0); // highlighted suggestion index
 
     const prefix = usePrefix({ status, theme });
@@ -100,6 +102,13 @@ export const autocompleteInput = createPrompt((config, done) => {
         setActive(0);
     });
 
+    // Prefill the editable readline buffer (and mirror it into `value`) when an
+    // initial value is supplied — used to restore a message that a Ctrl+C
+    // cancelled back into the prompt so it can be edited and resent.
+    useEffect((rl) => {
+        if (initial) rl.write(initial);
+    }, []);
+
     const message = theme.style.message(config.message);
     const formattedValue = status === 'done' ? theme.style.answer(value) : value;
 

src/compact.js

@@ -10,8 +10,18 @@
  * are never needed again. `compactPatchToolCalls` rewrites each `patch` tool
  * call in the transcript so its long text fields keep only a head/tail excerpt,
  * with a marker noting how many lines were elided.
+ *
+ * `invalidateStaleReadResults` attacks the same problem from the other side:
+ * a `read_file` result carries a whole file body, and once a later `patch`
+ * writes that file the body no longer matches what is on disk. Keeping it is
+ * both a token waste and a correctness hazard (the model may reason from stale
+ * contents). The stale result is replaced by a short "file was overwritten
+ * meanwhile" marker that tells the model to re-read if it needs the file.
  */
 
+import path from 'path';
+import { ROOT_DIR } from './config.js';
+
 // Lines kept from the top and bottom of each long text field.
 const HEAD_LINES = 5;
 const TAIL_LINES = 5;
@@ -92,3 +102,145 @@ export function compactPatchToolCalls(messages) {
     }
     return compacted;
 }
+
+// ─── Stale read_file results ────────────────────────────────────────────────────
+
+// Marker carried by a replaced read_file result. Detected verbatim so repeated
+// passes over the transcript stay idempotent (an already-invalidated result is
+// left as-is instead of being wrapped again).
+const STALE_MARKER = 'file was overwritten meanwhile';
+
+// Explanatory text carried by the replacement. Like the omission marker above,
+// this is written by the memory-management system, not by the model — the note
+// says so explicitly so the model does not mistake it for its own earlier
+// output or for real file contents.
+const STALE_NOTE =
+    `${STALE_MARKER} — stale contents elided by the memory management system ` +
+    'to save tokens; re-read with read_file for the current contents';
+
+// `applyOperations` tags each change it makes as either an overwrite or a
+// search/replace; both mean the file body a prior read returned is now stale.
+const APPLIED_RE = /^(?:CREATE\/WRITE|PATCH in) (.+)$/;
+
+/**
+ * Canonical key for a workspace-relative path, so a path the model wrote as
+ * "src/x.js" matches one written as "./src/x.js" or with different separators.
+ */
+function canonicalPath(p) {
+    if (typeof p !== 'string' || !p) return null;
+    try {
+        return path.resolve(ROOT_DIR, p);
+    } catch {
+        return p;
+    }
+}
+
+/** The replacement payload handed to the model in place of a stale read. */
+function staleReadResult(filename) {
+    return JSON.stringify({ filename, note: STALE_NOTE });
+}
+
+/**
+ * Extract the files a `patch` result actually wrote. Both successful results
+ * (`applied`) and partially-failed ones (`appliedSoFar`) list the mutations, so
+ * files that were never touched are correctly left alone. Returns canonical
+ * path keys; an unparseable result yields an empty list.
+ */
+function filesWrittenByPatch(resultContent) {
+    let res = resultContent;
+    if (typeof res === 'string') {
+        try {
+            res = JSON.parse(res);
+        } catch {
+            return [];
+        }
+    }
+    if (!res || typeof res !== 'object') return [];
+    const applied = Array.isArray(res.applied)
+        ? res.applied
+        : Array.isArray(res.appliedSoFar)
+            ? res.appliedSoFar
+            : [];
+    const files = new Set();
+    for (const entry of applied) {
+        if (typeof entry !== 'string') continue;
+        const hit = APPLIED_RE.exec(entry);
+        if (hit) {
+            const key = canonicalPath(hit[1]);
+            if (key) files.add(key);
+        }
+    }
+    return [...files];
+}
+
+/**
+ * Replace `read_file` tool results in `messages` with a short "file was
+ * overwritten meanwhile" marker whenever a later `patch` wrote the same file.
+ *
+ * A read result is stale only if the file changed *after* it was read, so we
+ * compare transcript positions: a read is invalidated when a successful patch
+ * write sits at a later index. Reads taken after their last patch (which still
+ * reflect disk) are left untouched, as are reads for files no patch ever wrote.
+ *
+ * The rewrite only fires when it strictly shrinks the payload, so a tiny read
+ * result is never traded for a longer marker. Repeated passes are idempotent.
+ * Returns the number of results invalidated.
+ */
+export function invalidateStaleReadResults(messages) {
+    if (!Array.isArray(messages)) return 0;
+
+    // Index every tool call so a tool result can be mapped back to (name, args).
+    const callInfo = new Map();
+    for (const m of messages) {
+        if (!m || m.role !== 'assistant' || !Array.isArray(m.tool_calls)) continue;
+        for (const tc of m.tool_calls) {
+            if (!tc || !tc.id) continue;
+            let args = {};
+            try {
+                args = JSON.parse(tc.function?.arguments || '{}');
+            } catch {
+                // Malformed arguments: the call stays indexed but argless.
+            }
+            callInfo.set(tc.id, { name: tc.function?.name, args });
+        }
+    }
+
+    // Every place a patch wrote a file, keyed by transcript position.
+    const writes = [];
+    for (let i = 0; i < messages.length; i++) {
+        const m = messages[i];
+        if (!m || m.role !== 'tool') continue;
+        if (callInfo.get(m.tool_call_id)?.name !== 'patch') continue;
+        const files = filesWrittenByPatch(m.content);
+        if (files.length) writes.push({ index: i, files });
+    }
+    if (writes.length === 0) return 0;
+
+    let invalidated = 0;
+    for (let i = 0; i < messages.length; i++) {
+        const m = messages[i];
+        if (!m || m.role !== 'tool') continue;
+        const info = callInfo.get(m.tool_call_id);
+        if (info?.name !== 'read_file') continue;
+
+        const key = canonicalPath(info.args?.filename);
+        if (!key) continue;
+
+        const content = typeof m.content === 'string' ? m.content : '';
+        // Already replaced on an earlier pass — leave it alone.
+        if (content.includes(STALE_MARKER)) continue;
+
+        // Stale only if some patch wrote this file after the read happened.
+        const stale = writes.some((w) => w.index > i && w.files.includes(key));
+        if (!stale) continue;
+
+        const replacement = staleReadResult(info.args.filename);
+        // Never grow the payload: only swap when the marker is actually smaller.
+        if (replacement.length >= content.length) continue;
+
+        m.content = replacement;
+        invalidated++;
+    }
+    return invalidated;
+}
+

src/config.js

@@ -22,9 +22,10 @@ import dotenv from 'dotenv';
 const __dirname = path.dirname(fileURLToPath(import.meta.url));
 
 // Load .env from the fido project root (one level up from src/)
-dotenv.config({ path: path.resolve(__dirname, '..', '.env') });
+// `quiet: true` suppresses dotenv's "injected env (N) from .env" banner.
+dotenv.config({ path: path.resolve(__dirname, '..', '.env'), quiet: true });
 // Also try cwd-relative .env
-dotenv.config({ path: path.resolve(process.cwd(), '.env') });
+dotenv.config({ path: path.resolve(process.cwd(), '.env'), quiet: true });
 
 export const API_KEY = process.env.OPENROUTER_API_KEY;
 export const MODEL = process.env.MODEL || 'xiaomi/mimo-v2.6-flash';
@@ -32,6 +33,14 @@ export const UNDO_FILE = process.env.UNDO_FILE || '.fido-undo.json';
 export const SUSPEND_DIR = process.env.SUSPEND_DIR || '.fido-suspends';
 export const TAVILY_API_KEY = process.env.TAVILY_API_KEY;
 
+// When set to a truthy value (1/true/yes/on), the REPL logs how many transcript
+// entries each between-turns compaction pass rewrote. Useful for verifying that
+// stale read_file results are being elided, and that repeated passes are
+// idempotent (they report 0). Off by default so normal runs stay quiet.
+export const COMPACT_DEBUG = ['1', 'true', 'yes', 'on'].includes(
+    (process.env.COMPACT_DEBUG || '').toLowerCase()
+);
+
 // Root dir: first positional arg wins, then env ROOT_DIR, then cwd
 const args = process.argv.slice(2);
 export const ROOT_DIR = path.resolve(

src/fido.js

@@ -22,13 +22,13 @@
 
 import path from 'path';
 import chalk from 'chalk';
-import { editor, input, select } from '@inquirer/prompts';
+import { editor, input, select, confirm } from '@inquirer/prompts';
 import { marked } from 'marked';
 import { markedTerminal } from 'marked-terminal';
 
 import { LLMOrbiter, OpenRouterProvider } from 'llmorbiter';
 
-import { API_KEY, MODEL, UNDO_FILE, SUSPEND_DIR, ROOT_DIR } from './config.js';
+import { API_KEY, MODEL, UNDO_FILE, SUSPEND_DIR, ROOT_DIR, COMPACT_DEBUG } from './config.js';
 import { listDir } from './dir-listing.js';
 import { loadUndoLog, getUndoLog } from './undo.js';
 import { loadSuspends, addSuspend, getSuspends } from './suspend.js';
@@ -36,7 +36,7 @@ import { tools, toolCallNotifications, toolResultNotifications } from './tools/i
 import { printToolCall, emitGenericToolResult } from './tools/notify.js';
 import { autocompleteInput } from './autocomplete-input.js';
 import { COMMANDS, findCommand } from './slash-commands.js';
-import { compactPatchToolCalls } from './compact.js';
+import { compactPatchToolCalls, invalidateStaleReadResults } from './compact.js';
 
 // ─── Markdown → console renderer ───────────────────────────────────────────────
 
@@ -221,11 +221,23 @@ function printToolError(name, error) {
     console.log(chalk.red(`  ✖  Tool error [${name}]: ${error}`));
 }
 
-function printUsage(u) {
+function printUsage(u, totals) {
     const parts = [`in=${u.input}`, `out=${u.output}`];
     if (u.cached) parts.push(`cached=${u.cached}`);
     if (u.cost) parts.push(`cost=$${u.cost.toFixed(5)}`);
-    console.log(chalk.dim(`     📊 ${parts.join('  ')}`));
+    let line = `     📊 ${parts.join('  ')}`;
+    if (totals) {
+        totals.calls += 1;
+        totals.input += u.input || 0;
+        totals.output += u.output || 0;
+        totals.cached += u.cached || 0;
+        totals.cost += u.cost || 0;
+        const acc = [`in=${totals.input}`, `out=${totals.output}`];
+        if (totals.cached) acc.push(`cached=${totals.cached}`);
+        if (totals.cost) acc.push(`cost=$${totals.cost.toFixed(5)}`);
+        line += `  [(${totals.calls}) ${acc.join(', ')}]`;
+    }
+    console.log(chalk.dim(line));
 }
 
 function formatWhen(iso) {
@@ -271,10 +283,20 @@ async function main() {
     loadSuspends();
     printBanner();
 
+    // Most recent reasoning the model streamed during the active turn. The
+    // provider reports reasoning cumulatively, so we keep the latest value. If a
+    // turn is cancelled mid-flight this is offered back to the user so it can be
+    // preserved in the transcript instead of being discarded.
+    let turnReasoning = '';
+
     const provider = new OpenRouterProvider({ apiKey: API_KEY });
 
+    // Running totals across the session, echoed after each per-call usage line.
+    const usageTotals = { calls: 0, input: 0, output: 0, cached: 0, cost: 0 };
+
     const orbiter = new LLMOrbiter(provider, {
         onStatus: (s) => printStatus(s),
+        onReasoning: (text) => { turnReasoning = text; },
         onToolCall: (c) => {
             const notify = toolCallNotifications[c.name];
             if (notify) notify(c.args);
@@ -287,20 +309,26 @@ async function main() {
             printToolResult(r.name, r.result);
         },
         onToolError: (e) => printToolError(e.name, e.error),
-        onUsage: (u) => printUsage(u),
+        onUsage: (u) => printUsage(u, usageTotals),
     });
 
     // Conversation state: persisted across turns
     const systemPrompt = buildSystemPrompt();
     let messages = [{ role: 'system', content: systemPrompt }];
 
-    console.log(chalk.dim('  Type your request below. Type / for commands, /paste for multiline. Press Ctrl+C to exit.\n'));
+    console.log(chalk.dim('  Type your request below. Type / for commands, /paste for multiline.'));
+    console.log(chalk.dim('  Ctrl+C exits at the prompt; while the model is running it cancels the turn.\n'));
+
+    // Restored into the prompt after a Ctrl+C cancels a running turn, so the
+    // message can be edited and resent instead of retyped.
+    let draft = '';
 
     while (true) {
         let userInput;
         try {
             userInput = await autocompleteInput({
                 message: chalk.bold.cyan('You'),
+                default: draft,
                 theme: {
                     prefix: chalk.cyan('›'),
                     style: {
@@ -314,6 +342,7 @@ async function main() {
             console.log(chalk.dim('\n  Goodbye! 🐕\n'));
             break;
         }
+        draft = '';
 
         if (!userInput.trim()) continue;
 
@@ -436,6 +465,15 @@ async function main() {
 
         console.log('');
 
+        // No prompt owns the terminal while the model works, so a Ctrl+C would
+        // otherwise hit Node's default handler and kill the process. Catch it
+        // here instead: abort the active run and fall back through to the prompt
+        // (prefilled with the message) rather than exiting.
+        // Fresh reasoning buffer for this turn.
+        turnReasoning = '';
+
+        const onSigint = () => orbiter.abort('cancelled by user');
+        process.on('SIGINT', onSigint);
         try {
             const result = await orbiter.run({
                 prompt: userInput,
@@ -450,11 +488,61 @@ async function main() {
             // Token savings: the patch tool's arguments carry whole file bodies
             // (search/replace). Once applied they are dead weight, so shrink each
             // patch tool call in the transcript to a head/tail excerpt.
-            compactPatchToolCalls(messages);
+            const compactedPatches = compactPatchToolCalls(messages);
+            // And the other half of the same problem: a read_file result carries a
+            // whole file body that a later patch made stale. Replace it with a
+            // short "file was overwritten meanwhile" marker so the old contents are
+            // not re-sent every turn (nor mistaken for the current file).
+            const invalidatedReads = invalidateStaleReadResults(messages);
+            if (COMPACT_DEBUG) {
+                console.log(chalk.dim(
+                    `  [compact] patch tool calls compacted: ${compactedPatches} · ` +
+                    `stale read results invalidated: ${invalidatedReads}`
+                ));
+            }
 
             printAssistant(result.content);
         } catch (err) {
-            console.log(chalk.red(`\n  ✖  Error: ${err.message}\n`));
+            if (err && err.name === 'AbortError') {
+                // Ctrl+C cancelled the run — put the message back in the prompt
+                // so it can be edited and resent. The aborted transcript is
+                // discarded, so `messages` is untouched and the turn is not lost.
+                draft = userInput;
+                console.log(chalk.dim('\n  ⏹  Cancelled — your message is back in the prompt; edit it and press Enter to resend.\n'));
+
+                // If the model already produced reasoning before the cancel,
+                // offer to keep it. Kept reasoning is added to the transcript
+                // exactly like normal reasoning (an assistant message carrying
+                // the reasoning text), tagged with a marker at the end so it's
+                // clear the turn was cut short.
+                const reasoning = turnReasoning.trim();
+                if (reasoning) {
+                    let keep = false;
+                    try {
+                        keep = await confirm({
+                            message: chalk.bold.cyan('Keep the reasoning the model produced before cancelling?'),
+                            default: true,
+                            theme: {
+                                prefix: chalk.cyan('›'),
+                                style: { message: chalk.bold.cyan },
+                            },
+                        });
+                    } catch {
+                        keep = false; // prompt dismissed (e.g. Ctrl+C) — don't keep
+                    }
+                    if (keep) {
+                        messages.push({
+                            role: 'assistant',
+                            content: `${reasoning}\n---USER-CANCELLED---`,
+                        });
+                        console.log(chalk.dim('  ↗  Reasoning kept in the transcript.\n'));
+                    }
+                }
+            } else {
+                console.log(chalk.red(`\n  ✖  Error: ${err.message}\n`));
+            }
+        } finally {
+            process.removeListener('SIGINT', onSigint);
         }
     }
 }