muesli-studio

Replay and monitor behaviour trees.

muesli-studio is the inspector for muesli-bt. Open a recorded run, scrub ticks, inspect node state, examine state changes, or follow live events over WebSocket.

Try the demo · Download releases · Read the docs

Studio overview during replanning.

try it now

From the repo root:

pnpm install && ./start-studio.sh

Starts the studio with a deterministic Webots-flavoured demo bundle preloaded in the browser.

pnpm demo remains available as a shorthand for the same path.

what you can do

replay runs

Open a recorded run, scrub through ticks, and inspect behaviour tree execution over time.

inspect state

See the run summary first, inspect node statuses, examine blackboard diffs, and check exactly what changed at the selected tick.

capture and share

Switch into presentation mode, export clean PNG or SVG figures, and write a compact publication bundle with replay data, summary metadata, and screenshots.

follow live

Connect to a running system over WebSocket and follow new events as they arrive through the same inspector.

built for muesli-bt

muesli-studio is the visual inspector for muesli-bt. Replay and live monitoring use the same canonical event stream, so a recorded run and a live session share the same inspection model.

why this is reliable

• deterministic fixture bundles drive the demo, screenshot capture, and regression checks
• replay and live monitoring share the same @muesli/replay event model
• schema and contract sync are checked against the resolved muesli-bt source in CI
• the runtime-backed inspector proves WebSocket and JSONL payload parity in deterministic integration tests
• tagged releases publish source archives plus prebuilt Linux Intel and macOS Apple Silicon bundles

more views

Run summary:

Run summary with tree identity, timing, warnings, and event-family counts.

Node inspector:

Node history for the controller branch.

Blackboard diff at the selected tick:

Blackboard diff for the selected tick.

Refresh the README screenshots with:

pnpm docs:screenshots

releases

Tagged releases matching v* publish these artefacts:

• source (.tar.gz and .zip)
• Linux Intel binary bundle
• macOS Apple Silicon binary bundle

First release: v0.1.0.

See GitHub releases and release targets for workflow and asset naming.

After unpacking a binary bundle, start the packaged UI with:

./start-studio.sh

documentation

• consumer contract checklist
• fixture bundle workflow and CLI
• publication workflow
• large log workflow
• sidecar tick-index format and usage
• release targets and artefacts
• release notes
• studio replay mode
• studio live monitoring

installation and development

pnpm install
pnpm inspector:configure
pnpm sync:schema
pnpm sync:contract
pnpm gen:types
pnpm check:fixtures
pnpm test
pnpm build
pnpm --filter @muesli/studio dev

inspect fixture bundles

pnpm studio inspect tests/fixtures/determinism_replay --out /tmp/run_summary.json

This validates the bundle, prints a concise summary, and writes run_summary.json when --out is provided. When a bundle sits under tests/fixtures/<name>, the CLI auto-uses tests/fixtures/schema/mbt.evt.v1.schema.json.

For the canonical UI demo fixture:

pnpm studio inspect tests/fixtures/studio_demo

To refresh the large deterministic stress fixture used for sidecar planning:

pnpm fixtures:large
pnpm studio inspect tests/fixtures/large_replay --out /tmp/large_run_summary.json
pnpm bench:sidecar

replay mode

Load either:

• a canonical JSONL fixture (tools/fixtures/minimal_run.jsonl)
• a validated bundle event log (tests/fixtures/*/events.jsonl) after running studio inspect

Studio replay load supports the optional sidecar index file events.sidecar.tick-index.v1.json. The UI shows load progress, indexed or unindexed state, and warns when large logs fall back to full-scan ingest.

Large indexed replays now bootstrap lazily for both local files and URL auto-loads. File loads use File.slice; URL loads use HTTP byte ranges when the host supports them.

The replay panel also includes a DSL editor for bt_def.dsl. Use apply to replace the rendered tree immediately, revert to restore the runtime definition, and save to export the edited DSL.

Replay mode now includes a first-class run summary panel for versions, tree identity, timings, warning counts, planner/scheduler activity, and deterministic digests.

Replay mode also includes an in-app diagnostics panel for large-log replay mode, recent seek latency, and rough replay memory use.

Replay mode also includes a first-class presentation flow in the right rail. Use it to open clean overview, summary, node, diff, or DSL layouts, then export PNG, SVG, or a zipped publication bundle.

The demo launcher uses URL query auto-load:

• demo_fixture=/demo/<fixture>/events.jsonl
• optional demo_sidecar=/demo/<fixture>/events.sidecar.tick-index.v1.json
• optional demo_tick=<n> and demo_node=<id> for deterministic screenshot or demo state selection
• optional demo_capture=hero|summary|node|diff|dsl for deterministic README and panel capture views

live monitoring

cmake --preset default -S apps/inspector
cmake --build apps/inspector/build --config Release
apps/inspector/build/mbt_inspector --attach mock --ws :8765 --run-loop '{"max_ticks":200}' --tick-hz 20 --log /tmp/live.jsonl
pnpm inspector:test

Then connect studio to ws://localhost:8765/events.

replay package entrypoints

• browser or UI consumption: @muesli/replay
• Node tooling consumption: @muesli/replay/node

muesli-bt pinning

Inspector pin metadata lives in apps/inspector/cmake/MuesliBtVersion.cmake.

• default CI and local fallback builds use that pinned URL and commit
• current pinned commit: 050c5e8793052d2a1a5d307897960d8b78e2afbc (tagged v0.3.1)
• scheduled CI builds inspector against muesli-bt main as an advisory check
• canonical contract reference: muesli-bt studio integration contract

local install vs fetchcontent

Inspector resolution order:

1. find_package(muesli_bt CONFIG QUIET)
2. if not found, FetchContent using the pinned URL and commit

No manual include or library path overrides are needed.

repository layout

schema/                # canonical event schema copy used by studio tooling
contracts/             # canonical integration contract copy
apps/studio/           # replay-first React + Vite UI
apps/inspector/        # C++ runtime bridge (muesli-bt + ixwebsocket)
docs/studio/           # studio-facing contract and workflow docs
packages/protocol/     # generated types, zod validation, protocol helpers
packages/replay/       # parser, index, and query API for append-only event ingestion
packages/ui/           # shared UI bits
tests/fixtures/        # bundle fixtures + golden summaries for regression checks
tests/benchmarks/      # sidecar benchmark baselines
tools/gen_types/       # schema-to-types generation scripts
tools/bench/           # sidecar benchmark tooling
tools/fixtures/        # canonical fixture logs
tools/studio           # studio CLI wrapper (`studio inspect`)
tools/sync_schema.sh   # sync schema from resolved muesli-bt source
tools/sync_contract.sh # sync contract from resolved muesli-bt source

current scope

The current release focuses on replay-first inspection and live monitoring. The studio also includes a lightweight DSL editor for swapping rendered tree definitions during inspection, while deeper authoring workflows remain out of scope for now.