automations: the conversation can change one in place

PERF.md

@@ -1570,6 +1570,14 @@ measures **52,713** bytes and the lean **44,935**, and both waivers fall to sit
 exactly on the measurement: the full cap is **52,713** (4,713 over its target)
 and the lean cap **44,935** (13,435 over).
 
+**`automation` learns `change`, and pays for it (2026-10-14).** The op, the
+sentence in the tool's description that says when to use it and the page's
+"one that exists is CHANGED, never proposed again" were taken out of what the
+description already said twice — a watch's look and condition, which the schema
+says beside their own fields — and out of the `id` field's list of the ops that
+take one. Both arms come out **22** bytes lighter: the full cap is **52,691**
+(4,691 over) and the lean cap **44,913** (13,413 over).
+
 ## Following through on a completion claim
 
 A turn may decline handoff once per request when its own continuation says no

docs/changes/unreleased/1829-automation-change-op.md

@@ -0,0 +1,11 @@
+---
+kind: added
+title: the conversation can change an automation in place, on a save this change? card
+pr: 1829
+surface: [chat, engine, docs]
+invalidates:
+  - "The `automation` tool had no way to change an existing automation, so \"move my reminder to 5pm\" proposed a second one beside the first, often a finished one. It has a `change` op: an id and only what changes, saved through `Store.Update`, which wakes a finished one-time reminder given a new moment."
+  - "The manual said the chat had no verb that changes an automation in place, and that changing one was `e` or a new proposal that replaces it. Asking in the conversation changes it in place, and `e` on `/automations` still does."
+  - "`save this change?` was a card only a typed `/automations edit` raised. The model's `change` raises the same card; any card whose automation already has an id is a change, with only `1 Save` and `0 Don't save`."
+  - "The prefix waivers were 4,713 bytes on the fixed arm and 13,435 on the lean. They are 4,691 and 13,413: `change` was paid for out of the tool description's repeat of the watch fields."
+---

docs/design/automations/DESIGN.md

@@ -40,11 +40,15 @@ codeaf is open`), because the model judges every look; with no known price for
 the judging model it shows nothing.
 
 **Three ways in, one card.** Said in a conversation (the model calls the
-`automation` tool); typed with exact syntax (`/automations add …`, no model in
-between); or edited on the list (`e` puts the automation's own
-`/automations edit …` line in the box). All three end on a card, and nothing is
-saved before the person says yes on it. A typed line's card is the surface's
-own (`save this automation?`, `save this change?`), because no model asked.
+`automation` tool — `propose` for a new one, `change` with its id for one that
+exists); typed with exact syntax (`/automations add …`, no model in between); or
+edited on the list (`e` puts the automation's own `/automations edit …` line in
+the box). All three end on a card, and nothing is saved before the person says
+yes on it. A typed add's card is the surface's own (`save this automation?`),
+because no model asked. A change's card is `save this change?` from either door —
+the model's `change` or a typed `edit` — with only `1 Save` and `0 Don't save`:
+an automation with an id on a card is a change to it, and session's
+`AutomationHead` and `AutomationOptions` decide that once for both.
 
 **The typed grammar** is a word and one value per clause, a value with a space
 in it quoted (`internal/automation`'s `command.go`):

internal/automation/store.go

@@ -338,7 +338,7 @@ func (s *Store) Update(a Automation) (Automation, error) {
 		if lookChanged(current.Look, a.Look) {
 			a.Seen, a.Memo = "", ""
 		}
-		if scheduleChanged(current.Schedule, a.Schedule) {
+		if ScheduleChanged(current.Schedule, a.Schedule) {
 			if a.Schedule.Repeats() && a.Schedule.Interval() > 0 {
 				a.Schedule.Anchor = now
 			}
@@ -997,7 +997,12 @@ func lookChanged(a, b *Look) bool {
 	return a.Command != b.Command || a.Files != b.Files || a.Tool != b.Tool || string(a.Args) != string(b.Args) || a.Condition != b.Condition
 }
 
-func scheduleChanged(a, b Schedule) bool {
+// ScheduleChanged reports whether b is a different schedule from a: another
+// moment, another rhythm or another zone. It is the ONE reading of that, which
+// [Store.Update] reschedules on and a change's card works its next run out by
+// (internal/session's automation_tool.go), so the card cannot promise a next run
+// the save does not give.
+func ScheduleChanged(a, b Schedule) bool {
 	return !a.At.Equal(b.At) || strings.TrimSpace(a.Every) != strings.TrimSpace(b.Every) || a.Zone != b.Zone
 }
 

internal/manual/chat/automations.md

@@ -252,28 +252,37 @@ catches up for the paused time; a one-time reminder resumed after its moment run
 late. A finished one offers no pause. The foot names the row's verbs:
 `enter its history · → verbs: run now, pause, edit, delete, open where it was asked · tab next place · esc`.
 
-## Change an automation — edit its time, what it does or where it runs
-
-Press `→` then `e` on its row in `/automations`, and the automation's own line lands in the
+## Change an automation — move my reminder to 5pm, reschedule it, edit its time, what it does or where it runs
+
+**Ask me.** "Move my water reminder to 5pm", "make the weekly update Tuesdays", "have the
+CI watch look every 30 minutes": I find it with the `automation` tool's `list` and change
+it in place with its `change` op, sending only what changes. Its card is headed
+`save this change?` and shows the automation as it would be, with `next run` where a new
+one says `first run`: `1 Save` says
+`The automation runs this way from its next time.`, `0 Don't save` says `Nothing is saved.`,
+and a correction typed under it goes back to me. Saved, it leaves one dim line —
+`drink water · changed` — and it keeps its id, its history, where it runs and the
+conversation its news arrives in. No second automation is left beside the old one.
+
+**Or press `→` then `e`** on its row in `/automations`, and its own line lands in the
 message box, exactly as it would have to be typed:
 
 ```
 /automations edit 3f2a9c1e5b7d4a60 title "weekly update" zone America/Toronto every "0 9 * * 1" do "draft the weekly update from the git log" folder /home/you/code/app
 ```
 
-Change what you want and press enter. Nothing is saved yet: a card headed
-`save this change?` shows the automation as it would be, and `1 Save` saves it —
-`saved weekly update · next Mon 12 Oct at 09:00`. Any clause you leave out stays as it
-was. A new schedule is worked out again from now, and a finished one-time automation given
-a new moment wakes again. A watch whose look or condition changed forgets what it had
-seen, so its next yes speaks.
+Change what you want and press enter: the same `save this change?` card, and `1 Save` says
+`saved weekly update · next Mon 12 Oct at 09:00`. Any clause you leave out stays as it was.
 
-A watch that looks through a tool is written without its look — a tool's arguments are not
-something anybody types on one line — and the edit leaves that look as it was.
+Either way, a new schedule is worked out again from now, and **a finished one-time reminder
+given a new moment wakes again**. A new rhythm keeps the zone the old one was read in. A
+watch whose look or condition changed forgets what it had seen, so its next yes speaks. A
+paused automation stays paused until it is resumed. A change cannot turn a watch back into
+a plain reminder: delete it and ask for the reminder.
 
-**I have no verb that changes an existing automation in place.** In a conversation I can
-pause, resume, run, delete, list it and read its history; changing one is `e`, or a new
-proposal that replaces it.
+A watch that looks through a tool is written without its look in the typed line — a
+tool's arguments are not something anybody types on one line — and the edit leaves that
+look as it was.
 
 ## History — every run, read a run's whole result, why did I get this reminder, and open where it was asked
 
@@ -598,11 +607,13 @@ along, and switching one off.
 
 You never name a tool. When what you say is a reminder, scheduled work or a watch, I call
 the **`automation`** tool to propose it, and its card is what you see. The same tool
+**changes** one that exists — "move my reminder to 5pm" — on a `save this change?` card,
 **lists** the automations with their ids, **pauses**, **resumes**, **deletes** and **runs**
 one now, and reads one's **history** — so "pause the CI watch", "delete the weekly update"
-and "what did the nightly bump do on Tuesday" work in any conversation. A change made that
-way needs no card and leaves one dim line in the conversation — `ci on main · paused`,
-`weekly update · deleted` — while making a new one always goes through its card.
+and "what did the nightly bump do on Tuesday" work in any conversation. A pause, resume,
+delete or run made that way needs no card and leaves one dim line in the conversation —
+`ci on main · paused`, `weekly update · deleted` — while making a new one or changing one
+always goes through its card.
 
 A run of scheduled work ends by calling **`automation_report`** with `done` or `incomplete`
 and a short summary: that summary is the line you read, and a run that never calls it is

internal/manual/chat/keys.md

@@ -2621,17 +2621,16 @@ verbs, and their letters work only while that strip is drawn:
 A verb that cannot work on the row is not drawn: `s` only while a run is in hand and `r`
 only while none is, no `pause` on a finished one, no `o` with no conversation behind it. A
 click on a row opens it; the wheel walks. Home's `automations` panel has none of these
-keys — its rows open this place, and `ctrl+e`, `ctrl+x` and `alt+e` do nothing to an
-automation.
+keys — its rows open this place — and `ctrl+e`, `ctrl+x` and `alt+e` do nothing to one.
 
 **On an automation's card** — `wants to remind you`, `wants to schedule work`,
 `wants to watch for something` — `1` Save · `2` Save and run it now (`2` Save and check it
 now on a watch; no `2` on a reminder or on work kept in a separate worktree) · `0` Don't
 save · `o` Change…, which asks for your correction in words · `esc` later, which puts the
 card off until `alt+y` raises it. A card raised by a typed `/automations add` or `edit` —
-`save this automation?`, `save this change?` — has only `1` and `0`. In home's `ask here`
-pane the same keys answer it while the pane has the keyboard, and `esc` there hands the
-keyboard back to the list instead.
+`save this automation?`, `save this change?` — has only `1` and `0`; a change I raise
+has `1`, `0` and `o`. In home's `ask here` pane the same keys answer it while the pane has
+the keyboard, and `esc` there hands it back to the list.
 
 *Automations* says what each verb and each answer does.
 

internal/manual/chat/questions.md

@@ -1307,7 +1307,8 @@ card — the title, when it first runs, what it says or does, where work runs an
 for anything but a reminder, what one run may take and spend (*Automations*,
 *The card*) — and its question goes on the block above your box. The first line
 says the kind: `wants to remind you`, `wants to schedule work` or
-`wants to watch for something`. The line under it is
+`wants to watch for something` — or `save this change?` when I change one that exists,
+with only `1 Save` and `0 Don't save`. The line under it is
 `nothing is saved until you say so`.
 
 The answers are `1 Save`; `2 Save and run it now`, or `2 Save and check it now` on
@@ -1439,8 +1440,8 @@ It depends on what was proposed, and the card says which beside `1 Save`:
 (on a watch, `Saves it, then takes one look now, here, while you watch.`), and
 `0 Don't save` says `Nothing is saved and nothing runs.` On the card a typed
 `/automations add` raises, `1 Save` says
-`It runs on this schedule while codeaf is open.`; on an edit's,
-`The automation runs this way from its next time.`
+`It runs on this schedule while codeaf is open.`; on a change's — typed with `edit`, or
+asked of me in a conversation — `The automation runs this way from its next time.`
 
 Saving is not forever: pausing or deleting one later is `/automations`, or asking me
 (*Automations*). A rule such as "always use tabs" is not an automation — it has no

internal/manual/chat_test.go

@@ -2585,6 +2585,12 @@ func TestTheChatManualAnswersTheQuestionsPeopleAsk(t *testing.T) {
 		{"I pressed esc on a reminder card and it did not say no", "automations"},
 		{"where did 2 change when or where go on the standing card", "automations"},
 		{"how do I change the time on a standing card", "automations"},
+		// The wave that gave `automation` its `change` op. Before it the chat
+		// could only propose a second automation beside the first, and the page
+		// said so; these are the sentences a person says to the one they have.
+		{"move my reminder to 5pm", "automations"},
+		{"can you reschedule my water reminder", "automations"},
+		{"why is my old reminder still there after I asked you to change it", "automations"},
 		// The wave that gave the engine on the far machine its own ambient
 		// side. This is what a person asks before they rely on it — and what an
 		// attached window keeps running there now is that machine's automations.