Lichtblick

Lichtblick is an open-source (MPL-2.0), Foxglove-compatible MCAP / ROS-bag / robotics log viewer. It is the browser-based analog of rerun-viewer: a static web viewer that opens artifacts, with no GPU. The image ships Lichtblick (lichtblick-suite/lichtblick), the actively maintained community fork of the archived, relicensed Foxglove Studio. It is a distinct product from the now-proprietary Foxglove; no Foxglove account or proprietary component is required.

• Tool name: lichtblick — Image: npa-lichtblick — Port: 8080 — Tier: service.
• Pinned OSS version: Lichtblick 1.26.0 ([tool.npa.supported-tools]).
• CPU-only; not part of the cuda12 / cuda13-b300 tag families.

Related: skills/tools/foxglove/SKILL.md covers the official Foxglove app embedded with the @foxglove/embed SDK, the MCAP converter (npa workbench foxglove convert-run), and the agent's Foxglove pane — which falls back to this viewer when no Foxglove account is configured.

Interfaces

CLI:

# View an existing MCAP (plan only by default; --execute stages + launches):
npa workbench lichtblick serve --input-path s3://bucket/run/recording.mcap --execute

# Pack a robot camera-frame sequence (e.g. sim2real rollout/augment frames) into
# a real MCAP of foxglove.CompressedImage messages, then serve it:
npa workbench lichtblick serve \
  --input-path s3://bucket/sim2real-b/<run-id>/augment/frames/ \
  --from-frames --fps 10 --topic /sim2real/augment/camera --execute

npa workbench lichtblick launch  # alias for serve
npa workbench lichtblick status
npa workbench lichtblick list

# Decode an MCAP into a native Rerun .rrd so Rerun renders it too (Rerun's built-in
# MCAP loader keeps foxglove/JSON messages as raw blobs; this maps the well-known
# schemas to archetypes). Open the result with `rerun x.rrd` or `sim2real rerun serve`.
npa workbench lichtblick to-rerun \
  --input-path s3://bucket/sim2real-b/<run-id>/reports/sim2real.mcap \
  --output-path <run-id>.rrd --execute

SDK: npa.sdk.workbench.lichtblick (serve, launch, status, list).

Container: caddy file-server serves the static Lichtblick bundle on :8080 (default CMD), with a HEALTHCHECK on /. Final USER nobody; Caddy's XDG data/config dirs are owned by that user so the server starts cleanly.

What it does (tangible)

Lichtblick consumes real Physical AI workflow artifacts from S3 (mirroring how rerun-viewer consumes sim2real.rrd — a separate viewer, not embedded in the pipeline):

• MCAP export (--from-frames): build_mcap_from_frames turns the Sim2Real pipeline's rollouts/.../camera and augment/frames image artifacts into a real MCAP of foxglove.CompressedImage messages at a chosen --fps, so the robot camera stream plays on a timeline. PNG/JPEG frames are packed byte-for-byte; raw .ppm rollout dumps (and other PIL-readable formats) are transcoded to PNG first (via encode_frame_to_compressed_bytes), so genuine rollout cameras render instead of being silently skipped. Verified end-to-end: 32 Cosmos-Transfer2.5 augment frames → a 9.5 MB MCAP → rendered in a headless browser on topic /sim2real/augment/camera (200 + 206 range fetches, 0 console errors).
• Native Sim2Real MCAP (finalize stage): the Sim2Real viz/finalize stage (sim2real_viz.emit_sim2real_mcap, gated by NPA_SIM2REAL_MCAP, default on when rerun is on) natively emits reports/sim2real.mcap alongside reports/sim2real.rrd from the same rollout data — camera frames as foxglove.CompressedImage, VLM critiques as foxglove.Log, and reward/advantage/score signals as numeric samples a Plot panel can chart. Open it with npa workbench lichtblick serve --input-path s3://bucket/sim2real-b/<run-id>/reports/sim2real.mcap --execute.
• Staging + launch (--execute): serve_viewer stages the artifact from S3 (stage_input_to_mcap) and runs the npa-lichtblick container so the log is live at the returned URL. Without --execute it prints the plan (infra-free).
• MCAP → Rerun (to-rerun / build_rerun_rrd_from_mcap): Rerun can open an MCAP (rerun mcap convert), but its decoders target ROS2/protobuf, so our JSON/foxglove messages land as raw McapMessage:data blobs (topics + timeline, no image/scalar/log panels). build_rerun_rrd_from_mcap decodes the well-known schemas into native archetypes — foxglove.CompressedImage → rr.EncodedImage, foxglove.Log → rr.TextLog, numeric JSON (value) → rr.Scalars — so the same MCAP renders with full fidelity in Rerun. Complements the natively-emitted reports/sim2real.rrd; useful for any MCAP (incl. real-robot logs) → Rerun.

Deploy / launch contract

• Cross-tool data flows through S3 only. serve/launch take --input-path (S3 or local MCAP/bag/db3, or a camera-frames prefix with --from-frames) and optional --output-path; the artifact is staged into the viewer's own origin (/srv/data/<name>, served by the same Caddy on :8080) and opened via a deep-linked ?ds=remote-file&ds.url=... URL.
• Because the MCAP is co-served from the viewer origin, the browser fetch is same-origin: no bucket CORS, no pre-signed URL, and no http/https mixed-content block are involved. (Pointing ds.url directly at an S3 URL instead would require bucket CORS + a presigned URL + an https viewer — that is deliberately not this tool's path.) Caddy serves the MCAP with Accept-Ranges: bytes, so Lichtblick streams it via HTTP range requests.
• The deep link always targets the app root / (data source in the query string), never a client-routed sub-path, so caddy file-server needs no SPA fallback: GET / always returns index.html.
• --host / --port control the bind (default 127.0.0.1:8080). The standalone viewer has no authentication and co-serves the selected artifact. Use a verified SSH forward or authenticated proxy for remote viewing; an explicit non-loopback --host publishes the artifact to everyone who can reach that interface.
• The CLI resolves the npa-lichtblick image via npa.deploy.images.container_image_for_tool (the supported default is public GHCR; a custom image must be explicit) and emits the container run command + viewer URL. Container launch itself is performed by the deploy/workflow path, mirroring how rerun-viewer is workflow-launched.

Source of truth

Launch logic lives in npa/src/npa/workbench/lichtblick/; the CLI and SDK call into it. The Dockerfile is npa/docker/workbench/lichtblick/Dockerfile (multi-stage node:22-bookworm build of the pinned OSS tag → caddy:2.11.4-alpine runtime, both digest-pinned). Golden eval and safety posture: lichtblick in npa/src/npa/smoke/golden_evals.yaml (kind build-import, gpu: none).