[kernel-1310] browser telemetry - CLI integration

[archandatta]

Adds browser telemetry to the CLI:

• kernel browsers create --telemetry=all|off|<list>
• kernel browsers update <id> --telemetry=all|off|<list> (partial — unspecified categories retain state)
• kernel browsers telemetry stream <id> with --categories, --types, --seq (Last-Event-ID resume), -o json (NDJSON)

Full test matrix → https://gist.github.com/archandatta/f27eb3ea93d58e932b9fd9a7b7b9090f

Essential run steps to validate

Build:

go build -o /tmp/kernel ./cmd/kernel
export KERNEL_API_KEY=<your key>

1. Config (create / update / get):

# create with all categories enabled
ID=$(/tmp/kernel browsers create --telemetry=all -o json | jq -r .session_id)

# verify on the session
/tmp/kernel browsers get $ID -o json | jq .telemetry

# partial update — only network is changed, others retain state
/tmp/kernel browsers update $ID --telemetry=network=off
/tmp/kernel browsers get $ID -o json | jq .telemetry

# disable everything
/tmp/kernel browsers update $ID --telemetry=off

2. Live stream (text + JSON):

# in terminal A — start streaming
/tmp/kernel browsers update $ID --telemetry=all
/tmp/kernel browsers telemetry stream $ID

# in terminal B — drive traffic via CDP (use any Playwright/CDP client) to https://kernel.sh
# events appear in terminal A: 15:04:05<TAB>[network]<TAB>network_response

3. Filters:

/tmp/kernel browsers telemetry stream $ID --categories=network
/tmp/kernel browsers telemetry stream $ID --categories=system   # monitor_* events
/tmp/kernel browsers telemetry stream $ID --types=network_response
/tmp/kernel browsers telemetry stream $ID -o json                # NDJSON envelopes

4. Resume from sequence:

# pull a seq from JSON output, then resume
/tmp/kernel browsers telemetry stream $ID --seq=0     # from beginning of retention
/tmp/kernel browsers telemetry stream $ID --seq=574   # from a specific event

5. Validation paths (all should error cleanly):

/tmp/kernel browsers create --telemetry=garbage          # invalid assignment
/tmp/kernel browsers create --telemetry=foo=on           # unknown category
/tmp/kernel browsers create --telemetry=network=yes      # invalid value
/tmp/kernel browsers telemetry stream $ID --seq=-50      # negative seq rejected
/tmp/kernel browsers telemetry stream $ID --output=yaml  # unsupported output

Cleanup:

/tmp/kernel browsers delete $ID

Tests

• 14 unit tests under cmd/browsers_telemetry_test.go (go test ./cmd/...)
• Full end-to-end matrix run against prod API → see linked gist

---

Note

Medium Risk
Enables collection and live streaming of browser activity (network, console, page, etc.); behavior depends on correct API merge semantics for partial --telemetry updates.

Overview
Adds browser telemetry to the CLI: configure it on session create and update via --telemetry=all, --telemetry=off, or per-category lists like network=on,page=off (partial updates only touch named categories; all/off reset the whole config).

Introduces kernel browsers telemetry stream <id> for live SSE events with optional --categories, --types, --seq (Last-Event-ID resume), human-readable lines or -o json NDJSON via new PrintCompactJSONLine. README documents the commands and flags; unit tests cover parsing, wire encoding, streaming, and create/update wiring.

^{Reviewed by Cursor Bugbot for commit 93d3168. Bugbot is set up for automated code reviews on this repo. Configure here.}

[firetiger-agent]

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Any PR that changes the kernel API. Monitor changes to API endpoints (packages/api/cmd/api/) and Temporal workflows (packages/api/lib/temporal) in the kernel repo

Reason: PR modifies CLI commands (cmd/kernel) for browser telemetry, not the kernel API endpoints (packages/api/cmd/api/) or Temporal workflows (packages/api/lib/temporal) specified in the filter.

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[cursor]

Function shouldEmit defined but never called in production

Low Severity

The shouldEmit helper function is defined and unit-tested but never called from production code. TelemetryStream duplicates the exact same filtering logic inline (checking in.Categories and in.Types with slices.Contains) instead of calling shouldEmit. This means the tested function and the actual streaming behavior can drift independently — a fix applied to one won't propagate to the other.

Additional Locations (1)

• cmd/browsers_telemetry.go#L133-L139

 

^{Reviewed by Cursor Bugbot for commit 26e6b5b. Configure here.}

[Sayan-]

integration looks good overall!

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

There are 2 total unresolved issues (including 1 from previous review).

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit 93d3168. Configure here.}

[cursor]

Telemetry stream uses inline output flag instead of shared helper

Low Severity

The telemetry stream command defines its output flag inline via StringP("output", "o", "", "Output format: json for newline-delimited JSON envelopes") and validates it with a hand-rolled check (if in.Output != "" && in.Output != "json"). Every other command in cmd/ uses addJSONOutputFlag(cmd) for flag registration and validateJSONOutput(output) for validation. The error message also drifts from the standard format used by ValidateJSONOutput.

Additional Locations (1)

• cmd/browsers_telemetry.go#L134-L136

 

^{Triggered by learned rule: Use shared JSON output helpers in CLI commands}

^{Reviewed by Cursor Bugbot for commit 93d3168. Configure here.}