Take the tour
This is what working in Mantis actually looks like: open a space, find a region worth attention, pull it out of the map, read what is inside it, and leave a mark for next time. Four short recordings carry the tour, and each one is a real capture of the shipped tool.
About the recordings
These clips were captured over several releases. The gestures, tool behavior, and results are current; some of the surrounding chrome has since been restyled, so panels and buttons may sit in different places than they do in your build.
1. Read the map first
Before selecting anything, look. Points that sit together were close in embedding space, cluster labels name what a region is about, and the Tree panel gives you that same structure as a hierarchy you can walk instead of a picture you have to squint at. The map controls let you dial how many labels are drawn and whether cluster boundaries are shown, which is worth doing before you decide a region is interesting.
Nothing on the map is selected yet, so most panels are empty. That is the normal starting state, not a fault: the Inspector says Select points / clusters to inspect until you give it something.
2. Take a region with the lasso
The lasso is the workhorse. Press Q, hold, and draw a closed shape around the points you want. Everything inside the boundary becomes the selection when you release.
Use the lasso when the shape you want is not a cluster: a spur off the edge of one, the overlap between two, a handful of outliers. It selects exactly what you enclose and nothing else.
A single commit is capped at 25,000 points. Past that, the extra points are silently dropped rather than dragging the map to a halt, so a lasso thrown around half a million-point space will not give you half a million points.
3. Let the magic lasso find the cluster
When the shape you want is a cluster, drawing it precisely is wasted effort. Press M, sketch roughly over the region, and Mantis compares your stroke against every cluster and returns the one that overlaps it best.
This means the magic lasso can hand you points you did not draw over, and can leave out points you did. That is the intent: it returns a cluster, not a region. If you want literally what you enclosed, use the plain lasso.
The 25,000-point cap applies here too, after the cluster expansion.
4. Read what you selected
With a selection live, the Inspector fills. Each selected point gets a tab across the top, up to twenty of them, and the panel below shows that point’s title, its coordinates, its keywords, and its metadata fields.
Two things appear only with multiple points selected: a cosine similarity readout comparing them against the current reference point, and a batch toolbar with Add to Active Bag, New Bag, and Clear. Selected clusters show at the top of the panel, above the point tabs, and can be removed one at a time.
5. Save it as a bag
A selection is transient. The next click replaces it. To keep a set of points, turn it into a bag: click New bag in the Bags panel, which is disabled until something is selected and shows the count when it is not.
Bags are the currency between panels. Once a set of points is a bag it can be highlighted on the map, combined with other bags, fed to analysis panels, referenced by name in the Composer, and reached from the CLI and extensions. Bags travel with the space state, so they are still there when you come back.
6. Leave a landmark
Selections and bags describe which points. A landmark describes why. Press N and click a spot on the map to drop a note there, anchored near the closest point.
Landmarks carry replies, so a region can accumulate a thread rather than a single label. They are shared: notes created by collaborators and by agent tools stream in over the same channel and appear on your map as they are made.
7. Bring in the Composer
Everything above also works the other way around. The Composer sits in the top-left of the default layout, sees your current selection, and drives the same tools you just used. Ask it about the region you lassoed, have it summarize a bag, or switch it to visual tour mode and let it walk the map in steps while you watch.
Keep it in ask mode when you want answers without anything changing underneath you: that mode is restricted to read-only tools and cannot mutate your space.