Rewind to any step. Let another agent take it from there.

01Fork and compare

# pick the step to start from, say 12
$ rewindagents replay
# ../<project>-try2 with step 12's files
$ rewindagents fork 12 --name try2
# run any agent with a hook here, or edit by hand
$ cd ../your-project-try2
$ cd - && rewindagents compare --check "python3 -m pytest -q"
# how two runs differ, as a git diff
$ rewindagents compare --diff your-project try2

$ rewindagents compare --diff shop clamp
diff --git a/cart.py b/cart.py
--- a/cart.py
+++ b/cart.py
@@ -1,2 +1,2 @@
 def total(prices, discount=0):
-    return sum(prices) - discount  # TODO clamp
+    return max(0, sum(prices) - discount)

Every option, and how a fork works in a git repository, is on the docs page.

02Undo, the base

03The timeline

$ pipx install git+https://github.com/Johnbjoseph-cybersec/rewindagents && cd your-project && rewindagents init

# opens the timeline in your browser; Ctrl+C stops it
$ rewindagents ui

# what taking it back to step 12 would change
$ rewindagents diff 12
# take back just that file
$ rewindagents rewind 12 --only src/db.py

04Install

$ pipx install git+https://github.com/Johnbjoseph-cybersec/rewindagents
# or: pip install git+https://...
$ rewindagents --version

$ cd /path/to/your/project
# adds the hook to .claude/settings.json in this project
$ rewindagents install
# or for every project
$ rewindagents install --settings ~/.claude/settings.json

# adds the hook to .codex/hooks.json in this project
$ rewindagents install --agent codex
# adds the hook to .cursor/hooks.json in this project
$ rewindagents install --agent cursor
# or for every project
$ rewindagents install --agent cursor --settings ~/.cursor/hooks.json

05How it works

1. Record

   Every call gets a pre record (tool and input) and a post record (tool and response) in .rewindagents/log.jsonl. Each record carries the SHA-256 of the one before it, so editing, deleting or reordering any record makes verify fail and name the first bad record. Appends are locked, so several processes can write to one log.

2. Checkpoint

   Before Write, Edit, MultiEdit and NotebookEdit, the current bytes of the target file go to .rewindagents/objects/<sha256>. Around a Bash command, the project's files are saved first and scanned after, and only the files the command changed, created or deleted are checkpointed. Copies are stored by hash, so an unchanged file is stored once.

3. Rewind

   rewind N puts back every file a later step changed and deletes the files later steps created. It first checks the hash chain and the hash of every stored copy; if the chain is broken it changes nothing. A rewind saves the current files and records itself as a new step, so a rewind is undone with another rewind.

06Tested

• Every line in the fork and compare panels is what ux-review/try-runs.sh printed.tests/test_runs_demo.py test_every_quoted_line_is_what_the_script_prints
• fork rebuilds the step's files and leaves the project, its HEAD and index alone.tests/test_runs.py test_fork_holds_the_files_as_they_were_right_after_the_step_and_leaves_the_project_alone
• An agent in the run records into the run's own log, not the project's.tests/test_runs.py test_an_agent_in_the_run_records_into_the_run_not_into_the_project
• compare --check runs your command in each run and reports its exit code.tests/test_runs.py test_check_runs_in_each_run_and_reports_its_exit_code
• compare --diff is a diff git apply takes: the first run's files become the second's.tests/test_runs.py test_diff_between_two_runs_applies_with_git
• A tampered log or a step that cannot be rebuilt exactly is refused, and nothing is left behind.tests/test_runs.py test_a_tampered_log_is_refusedtests/test_runs.py test_a_step_that_cannot_be_rebuilt_exactly_is_refusedtests/test_runs.py test_refusals_leave_nothing_behind
• Every terminal line on this page and in the clip is what the CLI printed.tests/test_demo.py test_every_shown_command_replays_exactlytests/test_demo.py test_installed_binary_prints_the_rewind_the_clip_shows
• Editing, deleting or reordering a record makes verify fail.tests/test_log.py test_edited_args_detectedtests/test_log.py test_deleted_middle_record_detectedtests/test_log.py test_reordered_records_detected
• Records cut off the end are caught only against a pinned head.tests/test_log.py test_truncated_tail_caught_only_with_pinned_head
• rewind refuses a tampered log and changes nothing.tests/test_rewind.py test_tampered_log_is_refused_and_nothing_changes
• A rewind can itself be rewound.tests/test_rewind.py test_rewind_can_itself_be_rewound
• A real sed and rm, run through the installed command, are put back.tests/test_bashscan.py test_real_sed_and_rm_undone_through_the_installed_command_path
• The hook prints nothing and exits 0, even on garbage input or a store it cannot write.tests/test_hook.py test_garbage_input_exits_zero_silentlytests/test_hook.py test_unwritable_store_exits_zero
• branch keeps the current files without touching HEAD or the index.tests/test_rewind.py test_git_branch_keeps_the_current_files_without_touching_head_or_index
• A file outside the project is never touched.tests/test_rewind.py test_file_outside_the_project_is_never_touched

$ python3 -m unittest discover -s tests -v

07Limits

• 4,000 charactersA tool response longer than this is cut in the log, with its full length noted.
• 20 MBA file over this size is noted and not copied, so it is reported and not restored.
• 20,000 filesA project with more than this many files is not scanned around Bash commands. The call is still recorded, and rewind says the step was not scanned.
• the project directoryOnly files inside it are scanned, saved or restored. In a git repository, the scan is what git ls-files --cached --others --exclude-standard lists: tracked and untracked files, not git-ignored ones. Outside git, every file except under .git, .rewindagents, .venv, __pycache__, node_modules, venv.
• symlinks, directoriesSymlinks are not saved. Directories created by later steps stay, empty, after a rewind.
• the end of the logA hash chain proves the records are unchanged relative to each other. It cannot tell that records were cut off the end or that the whole file was rewritten and re-hashed. Pin the head hash somewhere the agent cannot write and check against it with verify --head.

08Commands

# one line per step: number, tool, file or command
$ rewindagents replay
# step 12 in full: input, checkpoints, result
$ rewindagents replay --step 12
# what would change
$ rewindagents rewind 12 --dry-run
# the same files, as a unified diff: now -> step 12
$ rewindagents diff 12
# only that file (a directory means every file under it)
$ rewindagents diff 12 src/db.py
# files back to how they were right after step 12
$ rewindagents rewind 12
# put back only these
$ rewindagents rewind 12 --only src/db.py --only tests/
# keep the current files, then rewind to step 12
$ rewindagents branch 12 --name try2

# writes .rewindagents/replay-<session>.html
$ rewindagents export
# a given session, to a given file
$ rewindagents export --session abc --out replay.html
# steps, tools and paths only: no inputs, results or diffs
$ rewindagents export --no-contents
# keep secrets as recorded (they are replaced by default)
$ rewindagents export --no-redact

# every session in the log: id, first and last time, steps, files touched
$ rewindagents sessions
# only sessions with a step that mentions it, and those steps
$ rewindagents sessions --grep config.py

$ rewindagents verify --head <pinned-hash>

09Pricing

Details on the pricing page.

10Questions