browser4-experience

Progressive Experience Memory (PEM)

The PEM system makes Browser4 progressively smarter: each successfully completed task deposits reusable knowledge so that future tasks — identical, similar, or on similar sites — complete faster with fewer steps.

1. Core Loop

Before task ──▶ experience_query ──▶ Get stored selectors, steps, blockers
    │                                      │
    ▼                                      ▼
Execute task                        P1: Replay directly
    │                               P2: Verify then replay
    ▼                               P3: Hint mode (verify all)
After task  ──▶ experience_save ──▶ P4: Advisory only
                                      P5: Cold start (no knowledge)

Copy-Paste Template

The experience tools are MCP tools called by the agent during browser4-cli agent run. The agent should call them as part of its tool set:

# Before starting a task — the agent calls experience_query to check prior knowledge
# After completing a task — the agent calls experience_save to persist what it learned
browser4-cli agent run "Go to https://amazon.com/dp/test and extract product details"

# To inspect stored knowledge, the agent calls experience_list
browser4-cli agent run "List experience knowledge entries for amazon"

2. Key Concepts

• Knowledge store — a local directory tree of memory artifacts (tasks, traces, index); the store layout is described in section 6.
• experience_save — persist a completed task's trace (selectors, steps, blockers) into the store.
• experience_query — retrieve relevant past traces before starting a new task; returns a replay tier P1-P5.
• experience_list — inspect what is stored, per domain.
• Replay tiers — P1 (replay directly) → P5 (cold start), the confidence ladder used by the Decision Tree in section 2.

3. Command Map

experience_save

Persists a task execution trace to the knowledge store.

Argument	Required	Description
url	Yes	The URL the task operated on
trace	Yes	JSON-encoded ExecutionTrace (steps, selectors, extraction results)
outcome	No	"success" (default) or "failure"
task_type	No	One of the 12 canonical task types (e.g., extract_product_list)
intent	No	Free-text description of what the task was trying to do