0.38.1

rerun-io/rerun0.38.1Sep 17, 2026by rerun-bot

Upgrading?

AI Summary

This release introduces the Measurements archetype, LeRobot lazy chunk streaming, and gRPC server reflection. It improves time series interactions, adds TIFF support for depth images, and enhances the Viewer with an experimental agent panel and better playhead controls.

Key Highlights

  • Measurements archetype
  • LeRobotReader for lazy chunk streams
  • gRPC server reflection
  • Experimental agent panel
  • Tidier playhead controls

Breaking Changes

  • Chunk API and stable readers moved out of `rerun.experimental`
  • Python 3.10 is deprecated
  • `--connect` also starts a local Viewer server
  • Experimental table blueprint redesigned
  • TUID parsing requires canonical 32-character hexadecimal strings

New Features

  • LeRobotReader
  • gRPC server reflection
  • TIFF support for EncodedDepthImage
  • `rerun --asset` flag
  • Annotation context is a visualizer component source

Full Release Notes

[Rerun](https://www.rerun.io/) is an easy-to-use database and visualization toolbox for multimodal and temporal data.
Try it live at https://rerun.io/viewer.

- Python: `pip install -U rerun-sdk`
- Rust: `cargo add rerun` and `cargo install rerun-cli --locked`
- Online demo: https://rerun.io/viewer
- C++ FetchContent: https://github.com/rerun-io/rerun/releases/download/0.38.1/rerun_cpp_sdk.zip

---

### โœจ Overview & highlights

- Measurements archetype
- Local `.rrd` files load via the Viewer catalog by default
- Live and imported recordings
- `rerun --asset`
- Drive a running Viewer from Python
- Control the Viewer time cursor from Python
- Better time series plot interactions
- Keep following the time cursor after zooming or panning
- Tidier playhead controls
- TIFF support for `EncodedDepthImage`
- `LeRobotReader`: stream LeRobot datasets as lazy chunk streams
- gRPC server reflection
- Experimental agent panel
- More flexible experimental table blueprints
- Annotation context is a visualizer component source
- Server capabilities
- Viewer new-version notice

๐Ÿ“– Release notes: https://rerun.io/docs/changelog/changeset-0-38#highlights

### โš ๏ธ Breaking changes

- Chunk API and stable readers moved out of `rerun.experimental`
- "Log setup for binaries is opt-in with feature `log_setup`"
- `--connect` also starts a local Viewer server
- Experimental table blueprint redesigned
- MCAP importer maps ROS scalar sensor messages to `Measurements`
- Recorded labels no longer mix with annotation labels
- Custom views must now provide reflection metadata
- Python 3.10 is deprecated
- MCAP importer preserves ROS `/tf_static` message timing
- ROS 2 MCAP importer outputs `VideoStream:codec` as temporal data
- TUID parsing requires canonical 32-character hexadecimal strings

๐Ÿงณ Migration guide: https://rerun.io/docs/changelog/changeset-0-38#breaking-changes

### ๐Ÿ”Ž Details

#### ๐Ÿ Python API
- `py-chunk`: Move stable chunk API & readers out of `experimental` into `rerun.chunk` for 0.38 [ccc27e6](https://github.com/rerun-io/rerun/commit/ccc27e6a7b406a580d6784554c3ace35bb2b7842)
- Expose ViewerClient time cursor control to Python [43d8836](https://github.com/rerun-io/rerun/commit/43d88369641b355fd57526d73c37271ced072376) (thanks [@pablovela5620](https://github.com/pablovela5620)!)
- Decode the RRD footer once per `RrdReader` instead of once per `store()` [046bdb6](https://github.com/rerun-io/rerun/commit/046bdb607d411fa62d6a48fe23f7e66919061d17)
- `re_lerobot`: open(),stream() per-episode lazy chunk streaming [7b63de7](https://github.com/rerun-io/rerun/commit/7b63de7ca0c70ab0fca4e42839ba8cfd0d5ac434)
- Generalize the `ViewerControl` API [4bdf267](https://github.com/rerun-io/rerun/commit/4bdf26751395a4255cedaf30c91ac69e436b9d25)

#### ๐Ÿชณ Bug fixes
- Fix cases of component mappings becoming incorrectly transitive [5b1d730](https://github.com/rerun-io/rerun/commit/5b1d730d56ecb97ddd0e57af1cf466d9939b0e4e)
- Make sure old marking missing on just-loaded chunks don't cause warnings [3aa1977](https://github.com/rerun-io/rerun/commit/3aa19770025b5b59c32d9ca60ce0d9649e9bdcbf)
- Fix rare viewer deadlock in renderer [6464bff](https://github.com/rerun-io/rerun/commit/6464bffa99a317d6d64fe81f66b1d1a0ed16a54d)
- Fix parsing of unicode escapes above U+FFFF in entity paths [#12912](https://github.com/rerun-io/rerun/pull/12912) (thanks [@jaideeppyne](https://github.com/jaideeppyne)!)
- Report error for missing required components in mappings [655ac44](https://github.com/rerun-io/rerun/commit/655ac442d2a3aa3d6ad8ffbe906e74d125bf9702)
- Don't display `?url=` with empty url [09f22fd](https://github.com/rerun-io/rerun/commit/09f22fd44d95cb36aaa1acbc97a02a1fd09ba4f1)
- Fix table recognizing URLs embedded in strings too eagerly [be47aed](https://github.com/rerun-io/rerun/commit/be47aed3787042919d9ab2f48a7d909823f7434b)
- Grid map's cell_size can now be edited in the UI [d0bef4f](https://github.com/rerun-io/rerun/commit/d0bef4f5aff79d6525391d1b519ccf2d95244952)
- Enable importers on wasm [ecca42f](https://github.com/rerun-io/rerun/commit/ecca42f7f03d91f77297eed1b1f9be880df28c37)
- Fix missing task labels for LeRobot v3 datasets written with LeRobot 0.5.0+ [f057ae9](https://github.com/rerun-io/rerun/commit/f057ae9a5efd90314a7b9042380db947a147c1bb)
- Fix theme warning for embedded viewers in Python notebooks [45c1135](https://github.com/rerun-io/rerun/commit/45c11358d5c3a9d7b03c4de918d785d09850b92f)
- Fix dataframe UI warning bug [873e86d](https://github.com/rerun-io/rerun/commit/873e86d528d0f51d2edd45f907c6e7c9085e9767)
- Fix: handle `file://` prefixes on paths [e372ae4](https://github.com/rerun-io/rerun/commit/e372ae43600f1871930140609d42f3a4a7513585)

#### ๐ŸŒ Viewer improvements
- Add Measurement Archetype [a1c8501](https://github.com/rerun-io/rerun/commit/a1c850176b869954ddb51b1f63c44d79199a7766)
- Add version check on viewer startup [cb5e9d6](https://github.com/rerun-io/rerun/commit/cb5e9d6da5571003d587f995843ca7ac5ec1c463)
- Overhaul table blueprint datastructures & start making them more powerful [c1ea47a](https://github.com/rerun-io/rerun/commit/c1ea47a3b80b3eb00f2b0e54c8887b589728bec6)
- Use server capabilities in UI to know what can be registered to the server [bab02d7](https://github.com/rerun-io/rerun/commit/bab02d75f368bc28cefe99d3b5ac655fa36440d7)
- Improve playhead navigation controls [bc395cc](https://github.com/rerun-io/rerun/commit/bc395cc561eb011ea7848bcd939d73317fe40075)
- Distinguish between Live and Imported recordings [e926710](https://github.com/rerun-io/rerun/commit/e926710925659d3f220d198d23bd901d3d132b01)
- Add TIFF support to `EncodedDepthImage` [6f95c34](https://github.com/rerun-io/rerun/commit/6f95c341cbfe128e0c32a992d5bdb6d1f6e290d2)
- Fix how visualizer menu shows annotation context data & allow selecting it in the ui (and blueprint!) [392b05c](https://github.com/rerun-io/rerun/commit/392b05cc3af46d3649dc315f4baf3afcdbf4d534)
- Preserve relative time cursor on pan/zoom in time series & state timeline views [8097444](https://github.com/rerun-io/rerun/commit/80974444c39f4a1a67eede8feec6c71511905bed)
- Add experimental agent panel to the viewer [4ded82a](https://github.com/rerun-io/rerun/commit/4ded82a104fa79a7eb810034d59db3f0af6aa15d)
- Spawn all viewer services, even for `--connect` (under free port) [785d27c](https://github.com/rerun-io/rerun/commit/785d27c3a13a46ca9fc606f25d4594427cc45837)

#### ๐Ÿ—„๏ธ OSS server
- Serve gRPC server reflection from all open-source gRPC servers [b9ffa9c](https://github.com/rerun-io/rerun/commit/b9ffa9c1387ce50d1264f9ec4f7a4221d7cda0ce)

#### ๐Ÿš€ Performance improvements
- Speed up common entity path ancestor lookup [#12910](https://github.com/rerun-io/rerun/pull/12910) (thanks [@pnn64](https://github.com/pnn64)!)
- Losslessly compress all non-snapshot PNGs [099aa62](https://github.com/rerun-io/rerun/commit/099aa6294d8779d5b357c5733260b5148c1672ca)
- Avoid allocations when resolving archetype field names [#12921](https://github.com/rerun-io/rerun/pull/12921) (thanks [@pnn64](https://github.com/pnn64)!)
- Enable the Viewer catalog by default (and allow opt-out) [3008fb0](https://github.com/rerun-io/rerun/commit/3008fb0d7f571ddd89c8bde81ca73ef26a7e9447)

#### ๐Ÿ–ผ UI improvements
- Time series tooltip: add option to display all series values at once [eb8d373](https://github.com/rerun-io/rerun/commit/eb8d373698963ef19f4b860d1cf0db3b492275bc)

#### ๐Ÿงข MCAP
- Move ROS `TFMessage` to lens & remove `/tf_static` special-casing [2c7a86b](https://github.com/rerun-io/rerun/commit/2c7a86b108595a72d7cb5476c604b6256f08c776)
- convert ROS2 scalar sensor parsers to Measurements lenses [e6f461f](https://github.com/rerun-io/rerun/commit/e6f461fa112bc1b9c3b42d586a7842148d008d88)
- MCAP: Port ROS compressed image decoding to lenses [833c268](https://github.com/rerun-io/rerun/commit/833c268bd0b2a1969a41da0cc997052a4f3d01fe)

#### ๐Ÿ“ฆ Dependencies
- `python`: A deprecation notice for Python 3.10 [dac09e2](https://github.com/rerun-io/rerun/commit/dac09e29c07f89aead640d0bcb3deb80a69059e2)

#### ๐Ÿคทโ€ Other
- Make `tracing-subscriber` an optional dependency of `re_log` [#12909](https://github.com/rerun-io/rerun/pull/12909) (thanks [@CattleProdigy](https://github.com/CattleProdigy)!)
- --asset flag to register asset to the viewer catalog [96d4950](https://github.com/rerun-io/rerun/commit/96d49503c712a831f8267a0a5195fa64dee432a5)

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