[STG-2450] feat(cli): browse snapshot lean by default, add --full for ref maps

[shrey150]

Summary

browse snapshot now prints the formatted accessibility tree only by default, omitting the xpathMap/urlMap ref maps that were previously included on every call.

• browse snapshot (default): formatted tree only (~14KB on a content-heavy page).
• browse snapshot --full: tree + xpathMap + urlMap.
• browse snapshot --compact: deprecated no-op alias of the default (prints a stderr-only, TTY-gated deprecation notice).
• browse refs: prints the cached maps on demand.

Ref-based element commands (click, fill, select, …) are unaffected — the maps are still captured and cached server-side, so refs resolve exactly as before.

Why

The default snapshot emitted ~241KB (~60K tokens) on a content-heavy page, of which ~217KB (90%) is the xpathMap (a ref→XPath entry for every node) + urlMap. The tree an agent actually reasons over is only ~13.5KB.

Because refs resolve from a server-side cache (not from stdout), the printed maps were dead weight in the context of any agent consuming browse snapshot output. Making the tree lean by default cuts the default payload ~17× with no loss to element interaction; --full and browse refs recover the maps when needed.

E2E Test Matrix

Behavior + size (local build, live session on capeair.com)

Verified against packages/cli/bin/run.js (the local build), not the published browse.

Command / flow	Observed output	Confidence / sufficiency
browse snapshot (default)	13,845 bytes, keys = tree only, hasMaps=false	Lean default; ~17× smaller than before
browse snapshot --full	241,104 bytes, keys = tree,urlMap,xpathMap (1,640 entries)	--full returns the full tree + maps
browse snapshot --compact (piped)	13,868 bytes, hasMaps=false, 0 bytes stderr	Deprecated alias == default; no noise on non-TTY
browse refs	count=1640	Maps still captured + retrievable on demand
browse click @0-1588 after a lean snapshot	{"clicked": true} → navigated to /about_us/	Ref interaction unaffected by dropping maps from stdout
default tree vs --full tree	identical (341 lines both)	Lean mode omits only the maps; it does not prune tree content
pnpm --dir packages/cli build (tsc) + evals tsc --noEmit	success / clean	Typechecks
driver-commands unit test	15/15 pass	Locks in: default omits maps, --full includes them, maps cached in both modes

Agent task-success A/B (lean vs full)

Controlled A/B — same task / model (Sonnet) / session per pair; the only variable is snapshot mode (--full = maps vs default = lean), against the local build.

Task	Arm	Outcome	Snapshots	Agent tokens
capeair (regional booking)	full (maps)	✅ SUCCESS	9	109.8K
capeair	lean	✅ SUCCESS	8	93.5K
Google Flights	full (maps)	✅ SUCCESS	15	85.3K
Google Flights	lean	✅ SUCCESS	15	86.4K

4/4 success — lean-by-default held task success with zero capability loss. (A standard-benchmark A/B via the evals package is in progress and will be added here.)

What's in the diff

• packages/cli/src/commands/snapshot.ts — lean default (compact decoupled from map omission); add --full; deprecate --compact.
• packages/cli/src/lib/driver/commands/snapshot.ts — driver handler emits the full tree and includes ref maps only when full is requested.
• packages/cli/skills/browse/SKILL.md — document lean default + --full.
• packages/cli/tests/driver-commands.test.ts — test the default/--full/caching behavior.
• packages/evals/core/tools/browse_cli.ts — derive refCount from the tree when maps are absent.
• .changeset/lean-browse-snapshot.md — browse patch.

Linear: STG-2450

[changeset-bot]

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Latest commit: c05d2a4

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[cubic-dev-ai]

2 issues found across 4 files

Confidence score: 3/5

• In packages/cli/src/commands/snapshot.ts, the new default path still applies the old compact tree filter, so lean mode may remove accessibility-tree lines (not just ref maps), which can change snapshot content unexpectedly for users — split “omit maps” logic from “compact tree” before merging the default switch.
• In packages/cli/src/commands/snapshot.ts, the default flip plus new --full flag and deprecated flag behavior are untested, so regressions in typical CLI usage could ship unnoticed — add unit tests for default lean output, --full, and deprecated-flag compatibility before merging.

Architecture diagram

sequenceDiagram
    participant Agent as Agent (LLM/Client)
    participant CLI as CLI (browse commands)
    participant Session as Session Manager
    participant Daemon as Driver Daemon
    participant Cache as Refs Cache (in-memory)

    Note over Agent,Cache: NEW: Lean snapshot flow

    Agent->>CLI: browse snapshot
    CLI->>CLI: Parse flags (--full default=false)
    alt --full flag absent (default)
        CLI->>CLI: Set compact=true (lean output)
        CLI->>Daemon: snapshot(compact=true)
        Daemon->>Daemon: Capture accessibility tree only
        Daemon-->>CLI: { tree: formattedTree }
        CLI-->>Agent: JSON with tree only (hasMaps=false)
    else --full flag present
        CLI->>CLI: Set compact=false
        CLI->>Daemon: snapshot(compact=false)
        Daemon->>Daemon: Capture tree + xpathMap + urlMap
        Daemon-->>CLI: { tree, xpathMap, urlMap }
        CLI-->>Agent: JSON with tree + ref maps
    end

    Note over CLI,Daemon: --compact deprecation path (TTY only)

    opt --compact flag AND stderr is TTY
        CLI->>CLI: Print deprecation warning to stderr
    end

    Note over Agent,Cache: CHANGED: Refs still cached server-side

    Agent->>CLI: browse click @0-1588
    CLI->>Daemon: click(ref="0-1588")
    Daemon->>Cache: Resolve ref to XPath
    Cache-->>Daemon: XPath
    Daemon->>Daemon: Execute click on element
    Daemon-->>CLI: { clicked: true }
    CLI-->>Agent: Result

    Note over Agent,Cache: CHANGED: browse refs still works

    Agent->>CLI: browse refs
    CLI->>Daemon: getRefs()
    Daemon->>Cache: Retrieve cached maps
    Cache-->>Daemon: { xpathMap, urlMap }
    Daemon-->>CLI: Maps
    CLI-->>Agent: Formatted ref maps

    Note over Agent,Cache: Eval represent() with BROWSE_SNAPSHOT_FULL toggle

    alt BROWSE_SNAPSHOT_FULL=1
        Agent->>CLI: represent() → snapshot --full
        CLI-->>Agent: { tree, xpathMap, urlMap }
        Agent->>Agent: refCount = Object.keys(xpathMap).length
    else default (lean)
        Agent->>CLI: represent() → snapshot
        CLI-->>Agent: { tree }
        Agent->>Agent: refCount = count refs in tree text
    end

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[cubic-dev-ai]

1 issue found across 5 files (changes from recent commits).

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="packages/cli/tests/driver-commands.test.ts">

<violation number="1" location="packages/cli/tests/driver-commands.test.ts:363">
P3: `toHaveBeenCalledWith` doesn't verify caching happens on the lean call specifically. If the handler is refactored to only cache maps in the `--full` path the test would still pass.</violation>
</file>

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>