Prompt Rollback + Redo — JetBrains Parity

Bring the VS Code "rollback / redo" (CLI revert / unrevert) feature to the JetBrains plugin, and fix the misleading VS Code hint string. Implementation-capable agent required — this plan touches source and tests.

Context (verified)

• CLI already exposes everything needed; no CLI release or SDK regen required. Pinned CLI version is 7.4.1 (packages/kilo-jetbrains/package.json).
  • POST /session/{id}/revert body { messageID, partID? }, POST /session/{id}/unrevert.
  • Session.revert?: { messageID, partID?, snapshot?, diff? } — packages/sdk/js/src/gen/types.gen.ts:554. Pushed via session.updated SSE.
• VS Code entry points: RevertBanner.tsx, VscodeSessionTurn.tsx, session.tsx context. Per-user-message rollback restores reverted prompt text into the input; redo banner shows count + per-file diff stats + Redo / Redo All + hint; reverted messages/parts hidden (id >= revert.messageID, partID partial-turn boundary).
• JetBrains split-mode packages differ from AGENTS.md's stated ai.kilocode.jetbrains; actual source roots are:
  • shared → packages/kilo-jetbrains/shared/src/main/kotlin/ai/kilocode/rpc/
  • backend → packages/kilo-jetbrains/backend/src/main/kotlin/ai/kilocode/backend/
  • frontend → packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/
• All target files confirmed to exist: SessionDto.kt, KiloSessionRpcApi.kt, KiloBackendChatManager.kt, KiloSessionRpcApiImpl.kt, KiloSessionService.kt, SessionController.kt, SessionModel.kt, SessionModelEvent.kt, SessionView.kt, MessageView.kt, MessageToolbar.kt, PromptPanel.kt, PromptEditorTextField.kt, plus reuse targets DiffStatBadge.kt, HoverIcon.kt, PermissionDiffView.kt.

Decisions

• Reuse DiffStatBadge (already the shared per-file +/- renderer used by PermissionDiffView) for the banner's per-file diff rows. No new diff-stat component.
• Reuse the existing user-prompt hover toolbar (MessageToolbar) for the per-message rollback control.
• Reuse the existing session.updated → model.setSession(...) pipeline for the revert boundary; no new SSE handling.
• Stale non-English hint strings: reset all to the new English value and flag for re-translation (applies to VS Code locales; JetBrains base bundle only, others fall back).

Part A — VS Code string fix

File: packages/kilo-vscode/webview-ui/src/i18n/en.ts:138

• Change revert.banner.hint from "Send a new message to make this permanent" to "You can redo these changes until you send a new message".
• In the 19 non-English locale files under packages/kilo-vscode/webview-ui/src/i18n/ (ar, br, bs, da, de, es, fr, it, ja, ko, nl, no, pl, ru, th, tr, uk, zh, zht), overwrite revert.banner.hint with the identical new English string; leave a note that these need re-translation.
• Do not touch the other revert keys (revert.banner.count_one, revert.banner.count_other, revert.banner.redo, revert.banner.redo.all, revert.disabled.agentBusy) — only the hint changes meaning.

Part B — JetBrains implementation

1. Shared (DTO + RPC contract)

• shared/.../rpc/dto/SessionDto.kt: add val revert: SessionRevertDto? = null; add @Serializable data class SessionRevertDto(val messageID: String, val partID: String? = null, val snapshot: String? = null, val diff: String? = null). Field names must match CLI JSON for kotlinx auto-mapping through session.updated.
• shared/.../rpc/KiloSessionRpcApi.kt: add
  • suspend fun revert(id: String, directory: String, messageID: String, partID: String?)
  • suspend fun unrevert(id: String, directory: String)

2. Backend (RPC impl + HTTP)

• backend/.../app/KiloBackendChatManager.kt: add revert(id, dir, messageID, partID?) → POST /session/$id/revert?directory=… with {messageID, partID?} body, and unrevert(id, dir) → POST /session/$id/unrevert?directory=…. Mirror the existing compact() OkHttp pattern; add JSON body builders to KiloCliDataParser.
• backend/.../rpc/KiloSessionRpcApiImpl.kt: implement both, resolve worktree dir via sessions.getDirectory(id, directory), wrap in ready { } like compact/abort.

3. Frontend service

• frontend/.../app/KiloSessionService.kt: add suspend revert(...) / unrevert(...) wrappers over the RPC, using durable {} per split-mode rules.

4. Frontend controller (session/controller/SessionController.kt)

• Add EDT-entry actions dispatched to the coroutine scope:
  • revert(messageID, partID?)
  • unrevert()
  • redo() — mirror RevertBanner.handleRedo: find the next user message after the boundary and revert to it; unrevert() if none.
  • redoAll() → unrevert().
• Revert boundary already arrives via is ChatEventDto.SessionUpdated -> model.setSession(...) — no new SSE handling.
• On revert, restore the reverted user prompt text into the input (session/ui/prompt/PromptPanel.kt / PromptEditorTextField); on full redo (redoAll / final unrevert), clear it — matching VS Code and TUI.

5. Frontend model (session/model/SessionModel.kt, SessionModelEvent.kt)

• Add SessionModelEvent.RevertChanged(revert: SessionRevertDto?) with a stable toString(), fired from setSession() when the revert value changes. Reset in loadHistory() and clear().
• Add derived helpers: revert(): SessionRevertDto? and revertedCount() (count of user messages with id >= boundary, mirroring session.tsx).
• Transcript hiding: expose whether a message id is hidden by the boundary (id >= revert.messageID, with partID partial-turn handling), applied both to newly-arriving messages and on RevertChanged.
• Follow the AGENTS.md "Adding a New Event" checklist (event subclass → model field + mutation + resets → controller handling → -> Unit stubs in exhaustive when blocks).

6. Frontend views

• New session/ui/RevertBanner.kt Swing view, built once and mutated via update() per retained-Swing rules. Listens to RevertChanged + DiffUpdated. Contents:
  • arrow-left icon + count label (localized count.one/other),
  • per-file diff rows reusing ai.kilocode.client.ui.DiffStatBadge fed from model.diff (DiffFileDto.additions/deletions),
  • Redo button → controller.redo(), Redo All (only when count > 1) → controller.redoAll(),
  • hint label (same new wording as Part A).
  • Placed in session/ui/SessionView.kt at the bottom of the transcript, above the prompt input; shown only when revert != null.
• Per-user-message rollback control in session/views/MessageView.kt: user prompt bubbles already carry a hover promptToolbar (MessageToolbar with copy) + promptHover state. Add a rollback HoverIcon (arrow-left) alongside copy for user messages, wired through SessionView → controller.revert(msgId). Disable/hide while the agent is busy or when there are no assistant messages after it, with the revert.disabled.agentBusy tooltip — mirroring VscodeSessionTurn onRevert + data-revert-disabled. Extend MessageToolbar.kt to host the extra action (or add a sibling control).
• Apply transcript hiding: SessionView/TurnView toggle MessageView visibility on RevertChanged (prefer visibility toggle over rebuild, per Swing lifecycle guidance).

7. i18n (frontend/src/main/resources/messages/KiloBundle*.properties)

• Add to base KiloBundle.properties: revert.banner.count.one, revert.banner.count.other, revert.banner.redo, revert.banner.redo.all, revert.banner.hint (new wording), revert.disabled.agentBusy.
• Other locale bundles fall back to base until translated; do not add stale translations.

8. Tests

• Backend: extend KiloSessionRpcApiImplTest / a KiloBackendChatManager test against MockCliServer asserting the exact HTTP path + JSON body for revert/unrevert, and that a session carrying revert deserializes into SessionRevertDto.
• Frontend controller (SessionControllerTestBase + FakeSessionRpcApi, add revert/unrevert call tracking): revert()/unrevert()/redo()/redoAll() hit the right RPC; RevertChanged fires; count logic; reverted messages hidden and restored; prompt-text restore on revert / clear on full redo.
• Frontend views (BasePlatformTestCase): RevertBanner renders count + per-file DiffStatBadge + redo buttons (Redo All only when count > 1); MessageView shows the rollback control on user messages and disables it while busy; retained-component assertions (assertSame, bounded count) per Swing lifecycle rules.

Deliverables

Area	Files
VS Code string	webview-ui/src/i18n/en.ts + 19 non-English locale hints reset
Shared	SessionDto.kt (+SessionRevertDto), KiloSessionRpcApi.kt
Backend	KiloBackendChatManager.kt, KiloCliDataParser, KiloSessionRpcApiImpl.kt
Frontend service/controller/model	KiloSessionService.kt, SessionController.kt, SessionModel.kt, SessionModelEvent.kt
Frontend views	new RevertBanner.kt (reusing DiffStatBadge), MessageView.kt, MessageToolbar.kt, SessionView.kt, PromptPanel.kt
i18n	KiloBundle.properties
Tests	backend RPC/chat-manager, frontend controller + view tests, FakeSessionRpcApi

Validation

• VS Code string change: bun run typecheck from repo root (or from packages/kilo-vscode/).
• JetBrains: ./gradlew typecheck and ./gradlew test from packages/kilo-jetbrains/ (Java 21).
• Manual: ./gradlew runIde (or split mode) to exercise rollback → redo → redo-all and reverted-transcript hiding.

Risks / Notes

• Confirm no kilocode_change markers are needed for the VS Code i18n edits (Kilo-owned webview path — none required).
• Reset (not delete) is chosen for VS Code locale hints, so the fallback path is not relied upon; flag the 19 files for re-translation.
• Keep new Kotlin identifiers single-word per repo style; annotate EDT/model-touching methods with @RequiresEdt; wrap frontend RPC in durable {}.