From Slima 4.0, the AI edits structured files field by field. Ask it to add a scene, move a city south, or slot another beat into act two, and it changes only the field it addressed; nothing else is even writable in that turn. The edits stop being a JSON blob in the chat panel, too: new items appear as dashed cards exactly where they belong, edits and deletions are marked on the existing card, and Accept and Skip sit right next to them. All five structured file types are covered: screenplays, beat boards, relationship maps, world maps and story-structure timelines.
That is the whole conclusion. The rest of this post is why it was hard and what you actually see.
The old problem was not a dumb model
In 3.x the AI had exactly one way to write to a structured file: read the whole thing, generate a new whole thing, overwrite.
You said “change the location of scene three to the harbour pub”. It did that, then handed back a rewritten copy of the entire screenplay. Most of the time it looked fine. The damage was in the parts it had not been thinking about: the silent character you added by hand yesterday because he is in the room but never speaks, the scene order you spent an evening on, the reminder you left in the notes field of scene seven. Anything you did not mention had no special protection, so the rewrite quietly took it with it.
That was not a reasoning failure. We had handed the model a single blunt instrument and called it editing.
The worst part was how quiet it is. The file is still there, the format still parses, the word count looks about right. You find out three days later, and by then you have no idea which conversation did it.
The same screenplay file, after the AI touched it
Before: whole-file overwrite
You mentioned scene three; it rewrote all of it
Hatched rows went along for the ride.
Now: field-level editing
It touches the one field it addressed
Everything else is untouched.
What field-level actually means
4.0 breaks each structured file into fields that can be addressed on their own, and the AI’s tools are broken up the same way.
“Add a scene” resolves to “insert one entry in this screenplay’s scene sequence”. “Move that city south” resolves to “change this location’s coordinates”. “Change scene three’s location” resolves to “write scene three’s location field”. No tool has the whole file as its scope.
So your work survives, and not because the model remembered to be careful. It could not reach anywhere else that turn.
All five structured types are editable:
.scriptscreenplay: scenes, synopsis, location, time of day, cast.beatsbeat board: acts, beat cards, the chapter a card points to.maprelationship map: nodes, relationships, groups, coordinates.geomapworld map: terrain, places, routes, name tiers.timelinestory-structure timeline: events, timing, lanes, calendar
The timeline was the last piece to land. It used to be read-only to the AI; now it can add events, change when they happen, rename them, delete them, and set up a calendar for your world.
In practice the asks sound like this: “split those three beats that are crammed together in act two and put a turn between them”, “reroute the road outside the wall through the valley”, “change the protagonist’s link to his mentor from teacher to creditor”. Each one lands on specific fields. When you go back, everything else is where you left it.
Changes appear where they belong
Once the tools got finer, the review surface had to change with them. A JSON diff in the chat panel asks you to reassemble the file in your head and then approve it on faith.
Now the changes show up on the file itself:
- New items appear as dashed cards in position. If a scene goes in after scene five, that dashed card sits between five and six.
- Edits and pending deletions are marked on the original card, so you can see which field moved.
- Accept and Skip sit next to that card. One card, one decision.
- Happy with the lot? Accept all in this file, once.
- Anything that no longer applies because you edited in the meantime is listed separately, instead of getting stranded in a queue with no way in.
On phones, that row of buttons used to hide behind the floating review pill. It does not any more.
What this really changes is a habit. Letting the AI touch a file you care about used to mean planning your recovery first. Now the worst case is that you press Skip three times. Trusting it enough to let it try and it being right are two separate problems, and the first one is usually what stops people.
A batch lands whole or not at all
One batch of edits
One sentence is rarely one action. “Add an antagonist and put him on the old-town storyline” is two steps, and the second one needs the result of the first.
When the AI does several things at once they arrive as a single batch, and later steps can refer to what earlier steps just created, so it can build the character and wire up the relationship in one go. If any step fails, none of it is applied. You never end up with an orphan node that has no relationships, or a relationship pointing at a character that does not exist.
Three things fixed alongside it
The AI can see coordinates on relationship maps. It used to know only which nodes existed, so every edit came with a helpful re-layout that flattened the arrangement you spent half an hour on. Now it reads positions, so “put him below her” is something it can actually do, and “below” means below.
You can ask it to start a blank one. “Make me a timeline”, “open a relationship map”. What it creates is identical to what you get from right-clicking in the file tree: no half-formed format, just a file you can open.
Failures speak. If a reply starts repeating itself the AI stops on its own instead of running the loop until it fills the panel. When a tool call fails it explains why, rather than leaving a bare red cross for you to interpret.
Why this had to wait for 4.0
Because the file format comes first, and the AI second.
You need a screenplay file where a scene is genuinely one record before you can change just that record. In 3.x the screenplay lived in a different studio, the relationship map was a picture, and timelines and beat boards did not exist at all. This release pulled them into one file tree and gave each of them a format, which is what gave field-level editing something to address.
The order is not negotiable. Format, then addressing; addressing, then single-field edits; single-field edits, then in-place review. Drop any link and the whole chain falls back to overwriting the file.
So what actually changed in this release is how the AI works: from producing a new file to editing the one in front of you. The shape of the product moved first, and the AI’s abilities followed. That is why this one is 4.0 and not 3.9.
Next
- What each of the five file types is for: Writing Studio
- If you also write in your own editor, MCP is another door into the same manuscripts