File size: 24,388 Bytes
e187916
 
59022ca
 
 
 
 
 
 
e2f048d
 
 
 
 
 
59022ca
 
 
e187916
 
 
 
 
 
 
59022ca
e187916
 
 
e2f048d
e187916
59022ca
 
 
 
e187916
59022ca
 
 
 
e187916
e2f048d
 
3c4fcca
42ee5cf
 
e187916
 
59022ca
e187916
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
59022ca
 
 
 
 
 
 
b038669
 
 
 
e187916
 
 
 
59022ca
 
 
 
 
 
 
57356d8
 
 
 
59022ca
 
e187916
 
3c4fcca
 
 
42ee5cf
 
 
 
 
 
 
3c4fcca
 
 
e187916
 
 
59022ca
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
42ee5cf
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
59022ca
 
 
 
 
 
 
 
 
 
 
 
e2f048d
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
e187916
e2f048d
 
 
e187916
59022ca
 
42ee5cf
 
 
 
 
 
 
 
 
 
 
59022ca
 
 
 
 
 
e187916
 
 
 
 
 
59022ca
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
e187916
 
 
 
 
 
 
 
59022ca
 
e187916
59022ca
 
 
 
 
 
 
 
e187916
 
 
 
 
59022ca
e187916
 
 
 
59022ca
 
 
42ee5cf
 
 
 
59022ca
 
 
 
 
 
 
 
 
 
 
 
 
 
e187916
57356d8
 
 
 
 
 
 
e187916
59022ca
 
 
 
 
 
 
 
e187916
 
59022ca
 
42ee5cf
 
59022ca
 
 
 
 
e187916
 
42ee5cf
 
3c4fcca
 
 
 
 
 
 
 
e187916
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
"""Command line entry point.

    python -m tiny_computer_agent                     # scripted demo, dry-run
    python -m tiny_computer_agent --doctor            # what can this machine do?
    python -m tiny_computer_agent --image example     # replay a screenshot, dry-run
    python -m tiny_computer_agent --image shot.png    # replay your own screenshot
    python -m tiny_computer_agent --live              # your real screen, dry-run
    python -m tiny_computer_agent --live --real-input "click 'OK'"

2.0 adds two subcommands, for everything after that first run:

    python -m tiny_computer_agent skills list                  # what has been learned
    python -m tiny_computer_agent skills learn "click 'Save'" --script '[{"kind":"click","label":"Save"}]' --verify-text Saved
    python -m tiny_computer_agent batch tasks/day.json          # a queue, resumable, reported

Real mouse and keyboard input additionally requires
``TINY_COMPUTER_AGENT_ALLOW_REAL_INPUT=1``. Dry run is the default, so you can read a
whole episode before anything touches your pointer.
"""

from __future__ import annotations

import argparse
import json
import os
import platform
import sys

from tiny_computer_agent.act import DryRunExecutor, PyAutoGuiExecutor
from tiny_computer_agent.diff import ChangeVerifier
from tiny_computer_agent.brain import MockBrain, PlannerBrain
from tiny_computer_agent.demo import fake_desktop
from tiny_computer_agent.desktop import (
    BRAIN_NAMES, DEFAULT_KILL_SWITCH, Check, display_available, run_checks,
)
from tiny_computer_agent.loop import AgentLoop, Step
from tiny_computer_agent.observe import (
    Element, FakeScreen, GrabScreen, ImageScreen, ScreenUnavailable,
)
from tiny_computer_agent.perception import IndexedScreen, detector_available, make_detector
from tiny_computer_agent.safety import Policy
from tiny_computer_agent.runner import Task, TaskRunner
from tiny_computer_agent.skills import DEFAULT_SKILLS_PATH, SkillBrain, SkillLibrary, record_skill
from tiny_computer_agent.trace import Trace, score_trace
from tiny_computer_agent.audit import AuditLog, verify_audit
from tiny_computer_agent.gates import Gate, gate_from_spec

ALLOW_REAL_INPUT_ENV = "TINY_COMPUTER_AGENT_ALLOW_REAL_INPUT"
EXAMPLE_IMAGE = "example"


def demo_screen() -> FakeScreen:
    """A three-frame desktop: a dialog, then an editor, then a saved file."""
    return FakeScreen(
        [
            (Element("Terminal", x=0, y=0, width=40, height=24),
             Element("Files", x=60, y=0, width=40, height=24)),
            (Element("Name", kind="input", x=100, y=120, width=200, height=24),
             Element("Save", x=320, y=120, width=80, height=24)),
            (Element("Save", x=320, y=120, width=80, height=24),),
        ],
        text="Untitled document - unsaved changes",
    )


def build_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser(
        prog="tiny-computer-agent",
        description="Drive a computer with a tiny local model (dry-run by default).",
    )
    parser.add_argument("goal", nargs="?", default="click 'Save' to save the document")
    parser.add_argument("--max-steps", type=int, default=6)
    parser.add_argument("--script", default=None,
                        help="JSON list of actions to replay instead of using a brain")
    parser.add_argument("--doctor", action="store_true",
                        help="report what this machine can and cannot do, then exit")
    parser.add_argument("--image", default=None,
                        help="replay a screenshot instead of the screen; "
                             f"'{EXAMPLE_IMAGE}' uses the built-in one")
    parser.add_argument("--brain", default="planner", choices=BRAIN_NAMES,
                        help="planner (rule-based, no weights) | text-planner | vlm")
    parser.add_argument("--detector", default="auto",
                        choices=("auto", "best", "atspi", "ocr", "grid"),
                        help="how to build the element index "
                             "(best = accessibility tree, then OCR, then grid)")
    parser.add_argument("--live", action="store_true",
                        help="capture your real screen instead of the scripted demo")
    parser.add_argument("--real-input", action="store_true",
                        help="actually move the mouse and type (requires the allow env var)")
    parser.add_argument("--monitor", type=int, default=1, help="1 is the primary monitor")
    parser.add_argument("--scale", type=float, default=None,
                        help="screen pixels per captured pixel (HiDPI, secondary monitors)")
    parser.add_argument("--no-ocr", action="store_true",
                        help="skip OCR and index a numbered grid instead")
    parser.add_argument("--max-width", type=int, default=1600,
                        help="downscale captures wider than this before indexing")
    parser.add_argument("--verify-text", default=None, metavar="TEXT",
                        help="stop with success once this text appears on screen "
                             "(otherwise a successful action that removes its own "
                             "target is indistinguishable from a failure)")
    parser.add_argument("--allow-grid", action="store_true",
                        help="permit clicks on numbered grid cells with --real-input")
    parser.add_argument("--kill-switch", default=DEFAULT_KILL_SWITCH,
                        help="create this file to abort the run before the next action")
    parser.add_argument("--trace", default=None, metavar="PATH",
                        help="write a portable trace of the run (frames, no pixels) so it "
                             "can be replayed and scored offline")
    parser.add_argument("--gate", default=None,
                        help="the operator's yes, before each action: read-only | interactive "
                             "| labels:Save,Cancel | allow-all")
    parser.add_argument("--audit", default=None, metavar="PATH",
                        help="append a hash-chained record of this run to a JSONL file")
    parser.add_argument("--verify-audit", default=None, metavar="PATH",
                        help="check an audit log's chain and exit (0 intact, 1 tampered)")
    parser.add_argument("--expected", default=None, metavar="LABEL",
                        help="the element label that is the right answer for this goal; "
                             "recorded in the trace so the run can be scored")
    return parser


def report(checks: list[Check]) -> int:
    """Print a preflight report; non-zero when something required is missing."""
    blocking = [c for c in checks if c.required and not c.ok]
    lines = [
        f"tiny-computer-agent preflight ({platform.system()} {platform.machine()}, "
        f"python {platform.python_version()})",
        "",
        *(c.render() for c in checks),
        "",
    ]
    if blocking:
        lines.append(f"NOT READY: {len(blocking)} blocking problem(s): "
                     + ", ".join(c.name for c in blocking))
    else:
        lines.append("READY: the harness can drive this desktop.")
    print("\n".join(lines))
    return 1 if blocking else 0


def _probe_live(args: argparse.Namespace) -> Check:
    """Actually grab one frame, because only a real capture proves it works."""
    try:
        observation = GrabScreen(
            monitor=args.monitor, max_width=args.max_width, scale=args.scale
        ).capture()
        frame = observation.frame
        return Check("live capture", True, f"captured {frame.width}x{frame.height} pixels")
    except ScreenUnavailable as exc:
        return Check("live capture", False, str(exc),
                     fix="run this on the desktop session itself, not a headless shell")


def _gate_from_spec_arg(args: argparse.Namespace) -> tuple[Gate | None, str | None]:
    """The operator's gate, from the one-line spelling on the command line."""
    spec = getattr(args, "gate", None)
    if not spec:
        return None, None
    try:
        return gate_from_spec(spec), None
    except ValueError as exc:
        return None, f"bad --gate: {exc}"


def _audit_from_arg(args: argparse.Namespace) -> AuditLog | None:
    """Append-only evidence for this run, if the operator asked for it."""
    path = getattr(args, "audit", None)
    return AuditLog(path) if path else None


def _build_screen(args: argparse.Namespace):
    """(screen, description). Raises ScreenUnavailable / OSError on failure."""
    detector_name = "grid" if args.no_ocr else args.detector
    if args.image is not None:
        source = ImageScreen(fake_desktop() if args.image == EXAMPLE_IMAGE else args.image)
        return IndexedScreen(source, make_detector(detector_name)), f"screenshot replay: {args.image}"
    if args.live:
        source = GrabScreen(monitor=args.monitor, max_width=args.max_width, scale=args.scale)
        return IndexedScreen(source, make_detector(detector_name)), f"real desktop (monitor {args.monitor})"
    return demo_screen(), "scripted demo"


SUBCOMMANDS = ("skills", "batch")


def _screen_arguments(parser: argparse.ArgumentParser) -> None:
    """The screen flags the subcommands share with the main parser."""
    parser.add_argument("--image", default=None,
                        help=f"replay a screenshot; '{EXAMPLE_IMAGE}' uses the built-in one")
    parser.add_argument("--live", action="store_true", help="use this machine's real screen")
    parser.add_argument("--detector", default="auto",
                        choices=("auto", "best", "atspi", "ocr", "grid"))
    parser.add_argument("--no-ocr", action="store_true", help="index a numbered grid instead")
    parser.add_argument("--monitor", type=int, default=1)
    parser.add_argument("--scale", type=float, default=None)
    parser.add_argument("--max-width", type=int, default=1600)
    parser.add_argument("--path", default=str(DEFAULT_SKILLS_PATH),
                        help="the skill library to read or write")


def build_skills_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser(
        prog="tiny-computer-agent skills",
        description="Skills are verified runs, written down once, replayed forever.")
    actions = parser.add_subparsers(dest="action", required=True)
    listing = actions.add_parser("list", help="what the library holds")
    show = actions.add_parser("show", help="one skill, step by step")
    show.add_argument("name")
    remove = actions.add_parser("remove", help="forget a skill")
    remove.add_argument("name")
    learn = actions.add_parser("learn", help="run a script once, and keep it if it verifies")
    learn.add_argument("goal")
    learn.add_argument("--script", required=True, help="JSON list of actions to perform once")
    learn.add_argument("--verify-text", default=None, metavar="TEXT",
                       help="what 'it worked' looks like on screen: some text appears")
    learn.add_argument("--verify-gone", default=None, metavar="LABEL",
                       help="or: this element must disappear (the dialog closed)")
    learn.add_argument("--verify-appeared", default=None, metavar="LABEL",
                       help="or: this element must appear (the menu opened)")
    learn.add_argument("--name", default=None, help="name the skill yourself")
    _screen_arguments(learn)                      # which also carries --path
    for read_only in (listing, show, remove):     # these only ever need the library
        read_only.add_argument("--path", default=str(DEFAULT_SKILLS_PATH),
                               help="the skill library to read or write")
    return parser


def skills_main(argv: list[str]) -> int:
    args = build_skills_parser().parse_args(argv)
    library = SkillLibrary.load(args.path)
    if args.action == "list":
        if not library:
            print(f"no skills in {args.path} yet. Learn one with:\n"
                  f"  python -m tiny_computer_agent skills learn \"click 'Save'\" "
                  f"--script '[{{\"kind\": \"click\", \"label\": \"Save\"}}]' --verify-text Saved")
            return 0
        rows = library.to_rows()
        widths = {key: max(len(key), *(len(str(row[key])) for row in rows)) for key in rows[0]}
        print(f"{len(rows)} skill(s) in {args.path}")
        print("  " + "  ".join(key.ljust(widths[key]) for key in rows[0]))
        for row in rows:
            print("  " + "  ".join(str(row[key]).ljust(widths[key]) for key in row))
        return 0
    if args.action == "show":
        skill = library.get(args.name)
        if skill is None:
            print(f"no skill named {args.name!r} in {args.path}", file=sys.stderr)
            return 1
        print(skill.line())
        print(f"  verify: {skill.verification()}")
        print(f"  entry:  {', '.join(skill.preconditions()) or '(none - no label to re-ground)'}")
        for index, step in enumerate(skill.steps, 1):
            print(f"  {index}. {step.describe()}")
        return 0
    if args.action == "remove":
        library = SkillLibrary.load(args.path)
        if not library.remove(args.name):
            print(f"no skill named {args.name!r} in {args.path}", file=sys.stderr)
            return 1
        print(f"removed {args.name!r}; {len(library)} left in {library.save()}")
        return 0

    # learn: the first run is scripted, and only a verified one becomes a skill
    if not (args.verify_text or args.verify_gone or args.verify_appeared):
        print("refusing to learn: pass --verify-text (or --verify-gone / --verify-appeared) so "
              "the run has evidence. A skill recorded from a brain's own 'done' would be a "
              "guess with a name.", file=sys.stderr)
        return 2
    try:
        screen, description = _build_screen(args)
    except ScreenUnavailable as exc:
        print(f"cannot see the screen: {exc}", file=sys.stderr)
        return 3
    try:
        script = json.loads(args.script)
    except json.JSONDecodeError as exc:
        print(f"--script is not valid JSON: {exc}", file=sys.stderr)
        return 2
    _, index_detail = detector_available("grid" if args.no_ocr else args.detector)
    print(f"learning {args.goal!r} on {description} ({index_detail})")
    if args.verify_text:
        needle = args.verify_text.lower()
        verify: object = lambda observation: needle in observation.text.lower()
    else:
        verify = ChangeVerifier(appeared=(args.verify_appeared,) if args.verify_appeared else (),
                                disappeared=(args.verify_gone,) if args.verify_gone else ())
    loop = AgentLoop(screen=screen, brain=MockBrain(script), executor=DryRunExecutor(),
                     policy=Policy(dry_run=True, step_budget=len(script) + 2),
                     on_step=lambda step: print("  " + step.line()),
                     verify=verify)
    episode = loop.run(args.goal)
    print()
    print(episode.render())
    skill = record_skill(episode, name=args.name, library=library, verify_text=args.verify_text or "",
                         verify_gone=args.verify_gone or "",
                         verify_appeared=args.verify_appeared or "")
    if skill is None:
        print("\nnot learned: the run did not end verified, so there is nothing worth keeping.",
              file=sys.stderr)
        return 1
    print(f"\nlearned {skill.name!r} ({len(skill.steps)} step(s)) -> {library.save()}")
    return 0


def build_batch_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser(
        prog="tiny-computer-agent batch",
        description="Run a queue of goals, resuming what already finished, and report on it.")
    parser.add_argument("tasks", help="JSON: a list of {goal, name?, verify_text?, budget?}")
    parser.add_argument("--state", default=None,
                        help="JSONL file appended as each task finishes (resume from it)")
    parser.add_argument("--report", default=None, help="write the report as JSON here")
    parser.add_argument("--max-steps", type=int, default=6)
    parser.add_argument("--real-input", action="store_true",
                        help="actually drive the mouse (requires the allow env var)")
    parser.add_argument("--brain", default="planner", choices=BRAIN_NAMES)
    _screen_arguments(parser)
    return parser


def batch_main(argv: list[str]) -> int:
    args = build_batch_parser().parse_args(argv)
    try:
        payload = json.loads(open(args.tasks).read())
    except (OSError, json.JSONDecodeError) as exc:
        print(f"cannot read {args.tasks}: {exc}", file=sys.stderr)
        return 2
    if not isinstance(payload, list) or not payload:
        print(f"{args.tasks} should hold a non-empty list of tasks", file=sys.stderr)
        return 2
    try:
        from_args = [Task(goal=entry["goal"], name=entry.get("name", ""),
                          budget=entry.get("budget"), verify_text=entry.get("verify_text", ""),
                          verify_gone=entry.get("verify_gone", ""),
                          verify_appeared=entry.get("verify_appeared", ""))
                     for entry in payload]
    except (TypeError, KeyError) as exc:
        print(f"a task needs at least a 'goal': {exc}", file=sys.stderr)
        return 2

    if args.real_input and os.environ.get(ALLOW_REAL_INPUT_ENV) != "1":
        print(f"refusing --real-input: set {ALLOW_REAL_INPUT_ENV}=1 first.", file=sys.stderr)
        return 2
    try:
        screen, description = _build_screen(args)
    except ScreenUnavailable as exc:
        print(f"cannot see the screen: {exc}", file=sys.stderr)
        return 3

    def make_loop(task: Task) -> AgentLoop:
        from tiny_computer_agent.models import make_model_brain
        brain = PlannerBrain() if args.brain == "planner" else make_model_brain(args.brain)
        return AgentLoop(screen=screen, brain=brain,
                         executor=PyAutoGuiExecutor() if args.real_input else DryRunExecutor(),
                         policy=Policy(dry_run=not args.real_input, step_budget=task.budget or args.max_steps))

    print(f"batch: {len(from_args)} task(s) on {description}, "
          f"{'REAL INPUT' if args.real_input else 'dry-run'}")
    report = TaskRunner(make_loop, state_path=args.state,
                        on_task=lambda outcome: print("  " + outcome.line())).run(from_args)
    print()
    print(report.render())
    if args.report:
        print(f"report: wrote {report.save(args.report)}")
    return 0 if report.failed == 0 else 1


def main(argv: list[str] | None = None) -> int:
    argv = list(sys.argv[1:] if argv is None else argv)
    if argv and argv[0] in SUBCOMMANDS:
        return skills_main(argv[1:]) if argv[0] == "skills" else batch_main(argv[1:])
    args = build_parser().parse_args(argv)
    detector_name = "grid" if args.no_ocr else args.detector

    if args.verify_audit:
        intact, detail = verify_audit(args.verify_audit)
        print(f"{'ok  ' if intact else 'FAIL'} audit chain: {detail}")
        return 0 if intact else 1

    gate, gate_error = _gate_from_spec_arg(args)
    if gate_error is not None:
        print(gate_error, file=sys.stderr)
        return 2
    audit = _audit_from_arg(args)

    if args.doctor:
        checks = run_checks(brain=args.brain, detector=detector_name,
                            real_input=args.real_input, kill_switch_path=args.kill_switch)
        if args.live:
            checks.append(_probe_live(args))
        return report(checks)

    if args.real_input and os.environ.get(ALLOW_REAL_INPUT_ENV) != "1":
        print(f"refusing --real-input: set {ALLOW_REAL_INPUT_ENV}=1 to confirm you "
              f"understand this will drive your actual mouse and keyboard.", file=sys.stderr)
        return 2

    if args.brain == "vlm" and not (args.live or args.image):
        print("the vlm brain needs --live (or --image) so it has pixels to look at; "
              "use --brain planner to exercise the harness offline.", file=sys.stderr)
        return 2

    if args.live:
        available, detail = display_available()
        if not available:
            print(f"live capture needs a display session: {detail}")
            print(f"refusing to run live: {detail}. Try --image to replay a screenshot, "
                  f"or --doctor to diagnose.", file=sys.stderr)
            return 2

    try:
        screen, description = _build_screen(args)
    except ScreenUnavailable as exc:
        print(f"cannot see the screen: {exc}", file=sys.stderr)
        return 3
    except Exception as exc:
        print(f"could not start the screen: {type(exc).__name__}: {exc}", file=sys.stderr)
        return 2

    if args.script:
        try:
            script = json.loads(args.script)
        except json.JSONDecodeError as exc:
            print(f"--script is not valid JSON: {exc}", file=sys.stderr)
            return 2
        brain = MockBrain(script)
    elif args.brain == "planner":
        brain = PlannerBrain()
    else:
        from tiny_computer_agent.models import make_model_brain

        try:
            brain = make_model_brain(args.brain)
        except Exception as exc:
            print(f"could not load the {args.brain} brain: {type(exc).__name__}: {exc}",
                  file=sys.stderr)
            return 2

    policy = Policy(
        dry_run=not args.real_input,
        step_budget=args.max_steps,
        kill_switch_path=args.kill_switch,
        allow_grid_clicks=args.allow_grid,
    )
    executor = PyAutoGuiExecutor() if args.real_input else DryRunExecutor()

    mode = "REAL INPUT (mouse and keyboard live)" if args.real_input else "dry-run"
    print(f"goal: {args.goal}")
    print(f"mode: {mode}  |  screen: {description}  |  brain: {args.brain}  |  "
          f"kill switch: create {args.kill_switch} to stop")
    if gate is not None:
        print(f"gate: {args.gate} - every action needs the operator's yes")
    if audit is not None:
        print(f"audit: recording this run to {audit.path}")
    if args.image is not None or args.live:
        _, index_detail = detector_available(detector_name)
        print(f"index: {detector_name} - {index_detail}")
    if args.image is not None:
        # One read, so the header can state how big the action space is.
        try:
            preview = screen.capture()
        except ScreenUnavailable as exc:
            print(f"cannot see the screen: {exc}", file=sys.stderr)
            return 3
        print(f"elements detected: {len(preview.elements)}")
    print()

    warned = False

    verify = None
    if args.verify_text:
        _needle = args.verify_text.lower()

        def verify(observation) -> bool:  # noqa: F811 - the loop calls this
            return _needle in observation.text.lower()

    def on_step(step: Step) -> None:
        nonlocal warned
        elements = step.observation.elements
        if not warned and elements and all(e.kind == "grid" for e in elements):
            warned = True
            _, index_detail = detector_available(detector_name)
            print(f"warning: no text was found on screen, so the index is "
                  f"{len(elements)} numbered grid cells and the agent is choosing "
                  f"blind ({index_detail})", file=sys.stderr)
        print("  " + step.line())

    try:
        episode = AgentLoop(screen=screen, brain=brain, executor=executor,
                            policy=policy, on_step=on_step, verify=verify,
                            gate=gate, audit=audit).run(args.goal)
    except ScreenUnavailable as exc:
        print(f"cannot see the screen: {exc}", file=sys.stderr)
        print("run `python -m tiny_computer_agent --doctor --live` for details.", file=sys.stderr)
        return 3

    print()
    print(episode.render())
    if audit is not None:
        print(audit.render())

    if args.trace:
        trace = Trace.record(episode, expected=args.expected, brain=args.brain,
                             scenario=args.goal)
        print(f"trace: wrote {trace.save(args.trace)} ({trace.frames} frames)")
        if args.expected:
            print("score: " + score_trace(trace).line().strip())
            print(f"       replay it later: Trace.load({str(args.trace)!r}).render()")
    return 0 if episode.success else 1


if __name__ == "__main__":
    raise SystemExit(main())