Jake WriterandClaude Opus 5.5
d3d9d73c2d
- AGENTS.md holds the engineering rules for any coding agent, plus the
repo map, build, patch and test commands that CLAUDE.md used to carry.
CLAUDE.md now only imports it, so there is one set of rules.
ci/tribal-rules.yml is the record of settled decisions it points to.
- ROADMAP.md lists planned work, each item linked to its issue.
- README:
- fpgen and the coherence check replace BrowserForge;
- the patch workflow uses the make targets instead of the removed
developer UI;
- letter-spacing noise is described as off by default, as it is.
- docs/:
- beta-testing-ff146.md removed;
- patch-upgrading-guide rewritten around the make targets;
- per-context-patches without the canvas patch that no longer exists,
and with measured preset counts;
- playwright-maintenance without the JSM wrapper that does not exist;
- smaller fixes in MEDIA-DEVICES, input-dispatch and FONTS.
- ci/README: every job, and the real shard, skiplist and entry-point lists.
- pythonlib, tester and patch-dependency READMEs corrected against the code.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2.8 KiB
Media devices
How Camoufox presents navigator.mediaDevices (media-device-spoofing.patch,
pythonlib/camoufox/media-devices.json, draw_media_devices()).
What a page can see
Stock Firefox exposes, before any getUserMedia grant, at most one device
per input kind with empty label/deviceId/groupId and no audiooutput.
After a grant (or while capturing) it lists every device with the OS's own
names, per-origin hashed ids, and shared groupIds for devices of the same
hardware. The captured track's label and getSettings().deviceId/groupId
are those of one listed device.
Camoufox reproduces exactly that for a spoofed machine:
- The fake media engine (
MediaEngineFake::EnumerateDevices) emits the identity's microphones, cameras and speakers, with labels, raw ids and groups from the config, andMediaManageruses it for mics/cams and for the outputs whenevermediaDevices:enabledis set.MediaDevices.cppis stock, so the pre-/post-grant rules, feature policy, permission prompts, the capture indicator and the camera/microphonegroupIdcorrelation all run unchanged. getUserMedia()therefore succeeds iff the identity has the requested device kind (a claimed camera captures the fake engine's test pattern; a camera-less identity getsNotFoundError, like a real machine without one).- The patch treats the identity's devices (
LocalMediaDevice::IsIdentityDevice()) as real hardware, so they get the permission prompt, count as capturing and expose their labels after a grant.media.navigator.permission.fakestays off, as in stock Firefox, because a page can detect it.
Config keys
| key | meaning |
|---|---|
mediaDevices:enabled |
use the identity's devices instead of the host's |
mediaDevices:micros / webcams / speakers |
counts |
mediaDevices:microphoneLabels / webcamLabels / speakerLabels |
labels, aligned with the counts |
mediaDevices:microphoneGroups / webcamGroups / speakerGroups |
raw group ids (same string = same groupId) |
The Python package draws all of them from media-devices.json, seeded by the
identity, unless the caller set any mediaDevices: key. Label styles follow
the OS: Windows WASAPI friendly names (Microphone Array (Realtek(R) Audio)),
macOS CoreAudio names (MacBook Pro Microphone, FaceTime HD Camera), Linux
PulseAudio/PipeWire descriptions plus v4l2 card names with the USB id, and a
Monitor of … source per output as PulseAudio exposes.
Guard
tests/patches/media-devices-coherence.py checks the pre-grant shape, that
capture succeeds exactly for listed kinds, that captured tracks match listed
devices, that labels are never the fake engine's, and that a camera-only
identity does not crash the content process (it did, before build12).