[jxiwang]

Summary

Introduce the first independently mergeable amp-semantic increment: opt-in amp-semantic/context and amp-semantic/visibility events in the existing rrweb stream. Context is emitted after accepted full snapshots; visibility reports deduplicated hidden/visible transitions. Capture is disabled by default and supports local/remote family controls, additional sampling, per-session caps, and tab/document identity.

The package has separate context and visibility recorders behind an injectable host/runtime boundary. Session Replay and its analytics plugin supply configuration and transport. This increment adds no DOM observer, click hook, navigation observer, or semantic lifecycle events. Dialog/notice and the remaining families remain in #2082 for subsequent increments.

Include a two-family wire schema, documentation, a local-only replay fixture, and unit/browser tests. No prerelease version history or unrelated changes from #2082 are included.

Validation

• Node 24; install and frozen-lockfile verification passed.
• Full workspace build, documentation check, lint, dependency checks, and bundle-size checks passed.
• pnpm test --concurrency=2: 4,831 tests / 269 suites passed across 32 projects. The initial default-concurrency run hit two timing assertions in unchanged Autocapture long-task tests; the isolated file and reduced-concurrency full run passed.
• All affected packages have 100% statements, branches, functions and lines coverage: amp-semantic (29 tests), session-replay-browser (1,112), and plugin-session-replay-browser (65).
• Six Chromium browser tests passed through real replay transport, including timestamps, identity, disabled/sampled-out capture, remote kill switch, and stop/resume. Visibility notification inputs are controlled in these automated tests; native tab timing remains browser-dependent.
• Existing bundle limits remain unchanged: standalone replay 144.16 kB gzip; Unified 232.29 kB gzip.
• Existing repository blocker: pnpm test:examples cannot start because its configured jest.setup.examples.js is absent from main. This PR does not alter the example-test setup.

Checklist

• PR title follows the conventional commit format.
• Breaking change: No stable API is removed; semantic capture is new and opt-in.

[github-actions]

size-limit report 📦

Path	Size
packages/analytics-browser/lib/scripts/amplitude-min.js.gz	68.33 KB (0%)
packages/session-replay-browser/lib/scripts/session-replay-browser-min.js.gz	140.78 KB (+1.85% 🔺)
packages/unified/lib/scripts/amplitude-min.umd.js.gz	226.86 KB (+1.15% 🔺)
@amplitude/element-selector (gzipped esm)	3.48 KB (0%)
@amplitude/analytics-browser/lite (gzipped esm)	21.75 KB (0%)

[github-actions]

Session Replay Browser E2E Results

 157 passed

Details

 157 tests across 18 suites
 4 minutes, 27 seconds
 152ea3c