Time-Travel

Overview

The Time-Travel Agent implements execution replay capabilities inspired by LangGraph's time-travel debugging. It enables:

• Execution Replay: Step through past agent runs
• State Modification: Change variables at any checkpoint
• Branch Exploration: Fork from checkpoint with different inputs
• Comparative Analysis: Compare outcomes of different paths
• Root Cause Discovery: Trace issues back to originating state

Timeline Visualization

PAST ◀════════════════════════════════════════════▶ PRESENT

┌─────┐   ┌─────┐   ┌─────┐   ┌─────┐   ┌─────┐
│ CP1 │──▶│ CP2 │──▶│ CP3 │──▶│ CP4 │──▶│ CP5 │
└─────┘   └─────┘   └──┬──┘   └─────┘   └─────┘
                       │
                       │ [MODIFY STATE]
                       ▼
                    ┌─────┐   ┌─────┐   ┌─────┐
                    │CP3' │──▶│CP4' │──▶│CP5' │
                    └─────┘   └─────┘   └─────┘
                    (Branch)  (New)     (New)

Commands

/timetravel list

/timetravel list

Execution Timeline: wf_conductor_auth
Total Checkpoints: 12 | Duration: 45 min

Step | Checkpoint | Agent     | Action           | Time
-----|------------|-----------|------------------|-------
1    | cp_001     | architect | design_start     | 20:00
2    | cp_002     | architect | design_complete  | 20:15
3    | cp_003     | auto-code | impl_start       | 20:16
4    | cp_004     | auto-code | impl_50%         | 20:25
5    | cp_005     | auto-code | impl_complete    | 20:35  ← ERROR
...

/timetravel goto

/timetravel goto cp_004

Jumped to cp_004
Agent: auto-code
Action: Implementation 50% complete
Timestamp: 20:25 (20 min ago)

State at this point:
- Files created: 2 (/src/auth/jwt.ts, /src/auth/types.ts)
- Tests: 0
- Decisions: JWT, bcrypt, refresh tokens

Available: replay | modify | inspect | compare

/timetravel modify

/timetravel modify cp_004
> Change decision from JWT to Sessions

Branch Created: br_002
Original: decisions.auth_method = "JWT"
Modified: decisions.auth_method = "Sessions"

Replaying from cp_004 with Sessions auth...
[New execution with modified state]

/timetravel compare

/timetravel compare cp_012 br_002_cp_012

Comparison: Original vs Sessions Branch

Aspect       | Original (JWT) | Branch (Sessions)
-------------|----------------|------------------
Status       | ✓ Complete     | ✓ Complete
Duration     | 45 min         | 52 min
Files        | 8              | 10
Tests        | 6 pass         | 8 pass
Coverage     | 85%            | 92%

Use Cases

• Debugging Failed Execution: Jump to just before failure, inspect state, identify cause
• Exploring Alternatives: "What if we had chosen OAuth instead of JWT?"
• Understanding Decisions: Trace back through checkpoint history to see why choices were made
• A/B Testing Approaches: Run same task with different strategies, compare outcomes

Integration Points

System	Integration
Checkpoint	Uses checkpoints as replay starting points
Episode	Records full execution context for replay
Memory	Stores timeline and branch data
Tracing	Visualizes execution paths