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Multi-Granularity Rewind

Roll back agent state to a previous point in the journal. Unlike ReplayEngine (which reconstructs current state by replaying forward), RewindEngine lets you go backward — pick a point in history and selectively undo conversation, code/state changes, or both.

from promptise.runtime.journal import InMemoryJournal, RewindEngine, RewindMode

rewind = RewindEngine(journal)

# Preview first (dry-run)
plan = await rewind.plan(
    process_id="support-bot",
    target_entry_id="entry-42",
    mode=RewindMode.CANCEL,
)
print(plan.entries_affected, plan.summary)

# Apply
result = await rewind.apply(
    process_id="support-bot",
    target_entry_id="entry-42",
    mode=RewindMode.CONVERSATION_ONLY,
    actor="alice@acme.com",
)

5 Rewind Modes

Mode What it does
BOTH Full rollback — rewind conversation and context state to the target point.
CONVERSATION_ONLY Restore the conversation buffer but keep tool results and state changes. Useful when the agent went off-rails in chat but accumulated useful work.
CODE_ONLY Restore context state and tool results but keep the conversation. Useful to "undo" a tool call without losing the reasoning that led to it.
SUMMARIZE Keep everything as-is but inject a summary of the skipped interval into the conversation as a system note. The agent remembers it tried something without re-running it.
CANCEL Dry-run: return the plan without changing anything. Always safe.

Non-destructive

Original journal entries never get deleted or edited. A rewind is recorded as a new rewind entry in the journal, so the history shows when a rollback happened, who triggered it, and which mode was used.

# The rewind entry data looks like:
{
    "target_entry_id": "entry-42",
    "mode": "conversation_only",
    "actor": "alice@acme.com",
    "entries_affected": 5,
    "conversation_affected": 3,
    "code_affected": 2,
}

plan() — preview before committing

Always preview first:

plan = await rewind.plan(
    process_id="support-bot",
    target_entry_id="entry-42",
)
print(plan.entries_affected)                # 5
print(plan.conversation_entries_affected)   # 3
print(plan.code_entries_affected)           # 2
print(plan.summary)                        # human-readable summary

Show the plan to a user or operator, let them pick a mode, then apply.

Entry type classification

The rewind engine classifies journal entries into two buckets:

Conversation entries: user_prompt, assistant_message, conversation_turn

Code/state entries: tool_call, tool_result, file_write, file_change, code_execution, context_update, state_transition

CONVERSATION_ONLY drops conversation entries after the target but keeps code entries. CODE_ONLY does the reverse. BOTH drops everything after the target.