hashintel · kostandinang · May 14, 2026 · May 14, 2026 · May 14, 2026 · May 14, 2026
diff --git a/HANDOFF.md b/HANDOFF.md
diff --git a/docs/design/UNIFIED_CHAT_UX.md b/docs/design/UNIFIED_CHAT_UX.md
diff --git a/drizzle/0020_thread_substrate.sql b/drizzle/0020_thread_substrate.sql
@@ -0,0 +1,64 @@
+-- 1. Create thread table
+CREATE TABLE `thread` (
+	`id` integer PRIMARY KEY AUTOINCREMENT NOT NULL,
+	`chat_id` integer NOT NULL,
+	`kind` text NOT NULL,
+	`target_item_id` integer,
+	`context_spec` text,
+	`kickoff_turn_id` integer,
+	`invoked_in_turn_id` integer,
+	`active_turn_id` integer,
+	`status` text DEFAULT 'open' NOT NULL,
+	`created_at` text DEFAULT (datetime('now')) NOT NULL,
+	FOREIGN KEY (`chat_id`) REFERENCES `chat`(`id`) ON UPDATE no action ON DELETE no action,
+	FOREIGN KEY (`target_item_id`) REFERENCES `knowledge_item`(`id`) ON UPDATE no action ON DELETE no action,
+	FOREIGN KEY (`kickoff_turn_id`) REFERENCES `turn`(`id`) ON UPDATE no action ON DELETE no action,
+	FOREIGN KEY (`invoked_in_turn_id`) REFERENCES `turn`(`id`) ON UPDATE no action ON DELETE no action,
+	FOREIGN KEY (`active_turn_id`) REFERENCES `turn`(`id`) ON UPDATE no action ON DELETE no action
+);--> statement-breakpoint
+
+-- 2. Partial unique index: exactly one interview thread per chat
+CREATE UNIQUE INDEX `thread_interview_unique` ON `thread` (`chat_id`) WHERE kind = 'interview';--> statement-breakpoint
+
+-- 3. Seed one interview thread per existing chat
+INSERT INTO `thread` (`chat_id`, `kind`, `active_turn_id`)
+SELECT `id`, 'interview', `active_turn_id` FROM `chat`;--> statement-breakpoint
+
+-- 4. Recreate turn with thread_id instead of chat_id
+CREATE TABLE `turn_new` (
+	`id` integer PRIMARY KEY AUTOINCREMENT NOT NULL,
+	`specification_id` integer NOT NULL,
+	`thread_id` integer NOT NULL,
+	`parent_turn_id` integer,
+	`phase` text NOT NULL,
+	`turn_kind` text DEFAULT 'question' NOT NULL,
+	`question` text DEFAULT '' NOT NULL,
+	`why` text,
+	`impact` text,
+	`answer` text,
+	`is_resolution` integer DEFAULT false NOT NULL,
+	`user_parts` text,
+	`assistant_parts` text,
+	`created_at` text DEFAULT (datetime('now')) NOT NULL,
+	FOREIGN KEY (`specification_id`) REFERENCES `specification`(`id`) ON UPDATE no action ON DELETE no action,
+	FOREIGN KEY (`thread_id`) REFERENCES `thread`(`id`) ON UPDATE no action ON DELETE no action,
+	FOREIGN KEY (`parent_turn_id`) REFERENCES `turn_new`(`id`) ON UPDATE no action ON DELETE no action
+);--> statement-breakpoint
+INSERT INTO `turn_new` (`id`, `specification_id`, `thread_id`, `parent_turn_id`, `phase`, `turn_kind`, `question`, `why`, `impact`, `answer`, `is_resolution`, `user_parts`, `assistant_parts`, `created_at`)
+SELECT t.`id`, t.`specification_id`, th.`id`, t.`parent_turn_id`, t.`phase`, t.`turn_kind`, t.`question`, t.`why`, t.`impact`, t.`answer`, t.`is_resolution`, t.`user_parts`, t.`assistant_parts`, t.`created_at`
+FROM `turn` t
+JOIN `thread` th ON th.`chat_id` = t.`chat_id` AND th.`kind` = 'interview';--> statement-breakpoint
+DROP TABLE `turn`;--> statement-breakpoint
+ALTER TABLE `turn_new` RENAME TO `turn`;--> statement-breakpoint
+
+-- 5. Recreate chat without kind and active_turn_id
+CREATE TABLE `chat_new` (
+	`id` integer PRIMARY KEY AUTOINCREMENT NOT NULL,
+	`specification_id` integer NOT NULL,
+	`created_at` text DEFAULT (datetime('now')) NOT NULL,
+	FOREIGN KEY (`specification_id`) REFERENCES `specification`(`id`) ON UPDATE no action ON DELETE no action
+);--> statement-breakpoint
+INSERT INTO `chat_new` (`id`, `specification_id`, `created_at`)
+SELECT `id`, `specification_id`, `created_at` FROM `chat`;--> statement-breakpoint
+DROP TABLE `chat`;--> statement-breakpoint
+ALTER TABLE `chat_new` RENAME TO `chat`;
diff --git a/drizzle/0021_turn_phase_nullable.sql b/drizzle/0021_turn_phase_nullable.sql
@@ -0,0 +1,27 @@
+-- Make turn.phase nullable so non-interview thread kinds (side, reconciliation,
+-- qa, agent_run) can persist turns without an interview phase.
+
+CREATE TABLE `turn_new` (
+	`id` integer PRIMARY KEY AUTOINCREMENT NOT NULL,
+	`specification_id` integer NOT NULL,
+	`thread_id` integer NOT NULL,
+	`parent_turn_id` integer,
+	`phase` text,
+	`turn_kind` text DEFAULT 'question' NOT NULL,
+	`question` text DEFAULT '' NOT NULL,
+	`why` text,
+	`impact` text,
+	`answer` text,
+	`is_resolution` integer DEFAULT false NOT NULL,
+	`user_parts` text,
+	`assistant_parts` text,
+	`created_at` text DEFAULT (datetime('now')) NOT NULL,
+	FOREIGN KEY (`specification_id`) REFERENCES `specification`(`id`) ON UPDATE no action ON DELETE no action,
+	FOREIGN KEY (`thread_id`) REFERENCES `thread`(`id`) ON UPDATE no action ON DELETE no action,
+	FOREIGN KEY (`parent_turn_id`) REFERENCES `turn_new`(`id`) ON UPDATE no action ON DELETE no action
+);--> statement-breakpoint
+INSERT INTO `turn_new` (`id`, `specification_id`, `thread_id`, `parent_turn_id`, `phase`, `turn_kind`, `question`, `why`, `impact`, `answer`, `is_resolution`, `user_parts`, `assistant_parts`, `created_at`)
+SELECT `id`, `specification_id`, `thread_id`, `parent_turn_id`, `phase`, `turn_kind`, `question`, `why`, `impact`, `answer`, `is_resolution`, `user_parts`, `assistant_parts`, `created_at`
+FROM `turn`;--> statement-breakpoint
+DROP TABLE `turn`;--> statement-breakpoint
+ALTER TABLE `turn_new` RENAME TO `turn`;
diff --git a/drizzle/meta/_journal.json b/drizzle/meta/_journal.json
@@ -141,6 +141,20 @@
       "when": 1776360000000,
       "tag": "0019_reconciliation_need_agent_columns",
       "breakpoints": true
+    },
+    {
+      "idx": 20,
+      "version": "7",
+      "when": 1776370000000,
+      "tag": "0020_thread_substrate",
+      "breakpoints": true
+    },
+    {
+      "idx": 21,
+      "version": "7",
+      "when": 1776380000000,
+      "tag": "0021_turn_phase_nullable",
+      "breakpoints": true
     }
   ]
 }
diff --git a/memory/PLAN.md b/memory/PLAN.md
@@ -27,13 +27,12 @@ The May 2026 intent-spec, multi-chat, changeset-ledger, prompt/context, and agen
 
 ### Next
 
-1. `chat-runtime-threads` — Track 2 of the runtime umbrella; immediate successor to continuous-workspace, unblocker for Tracks 3 and 5. First slice should be a sub-RFC on the thread substrate shape (p / q / r).
-2. `intent-graph-semantics` — highest-coordination semantic substrate after FE-705 reconciliation.
-3. `changeset-ledger` — Track 4 of the runtime umbrella; parallel with Track 2; semantic history spine needed before canonical proposal acceptance, direct-edit atomicity, and productized scenario options.
-4. `thread-context-provision` — Track 5 of the runtime umbrella; after Track 2 lands the thread substrate.
-5. `reconciliation-runtime` — Track 3 of the runtime umbrella; after Track 2 + Track 4 provide thread substrate and durable attribution.
-6. `graph-review-scenario-options` — artifact-only critique/probe lane; can advance in parallel with FE-700 if it does not commit canonical graph truth.
-7. `productized-scenario-options` — user-facing acceleration surface after FE-700 semantics, FE-701 changesets, and graph-review probes.
+1. `intent-graph-semantics` — highest-coordination semantic substrate after FE-705 reconciliation.
+2. `changeset-ledger` — Track 4 of the runtime umbrella; parallel with Track 2; semantic history spine needed before canonical proposal acceptance, direct-edit atomicity, and productized scenario options.
+3. `thread-context-provision` — Track 5 of the runtime umbrella; after Track 2 lands the thread substrate.
+4. `reconciliation-runtime` — Track 3 of the runtime umbrella; after Track 2 + Track 4 provide thread substrate and durable attribution.
+5. `graph-review-scenario-options` — artifact-only critique/probe lane; can advance in parallel with FE-700 if it does not commit canonical graph truth.
+6. `productized-scenario-options` — user-facing acceleration surface after FE-700 semantics, FE-701 changesets, and graph-review probes.
 
 ### Parallel / Low-conflict
 
@@ -74,15 +73,16 @@ The May 2026 intent-spec, multi-chat, changeset-ledger, prompt/context, and agen
 ### chat-runtime-threads
 
 - **Name:** Chat runtime — thread substrate + in-stream rendering (Conversational Workspace Runtime — Track 2)
-- **Linear:** unassigned in this plan snapshot
+- **Linear:** FE-710
 - **Kind:** structural
-- **Status:** not-started
-- **Objective:** Add a thread primitive to the chat substrate, render threads inline as collapsibles in the main chat surface (Cursor-style), and retire the SideChatPopover and transient staged-patches strip. Decide the thread substrate shape via a sub-RFC: (p) `parent_chat_id` on `chat`, (q) new `thread` table, or (r) UI-only rendering.
-- **Why now / unlocks:** Track 1 (workspace shell) ships, providing the stable host. Threads are the critical unblocker for reconciliation absorption into the chat surface (Track 3), `#` mention / turn-zero / context provision (Track 5), and the retirement of the V3.1 popover and staged-patches surfaces. Supersedes the prior side-chat V4a persistence horizon — persistent side-chat history becomes the main chat stream where threads stay collapsed.
-- **Acceptance:** Thread kinds (`interview`, `side`, `reconciliation`, `qa`) are representable in the substrate; threads render inline as collapsibles in the unified chat surface; SideChatPopover retires as cutover; transient staged-patches strip retires (replaced by in-thread mutation state); turn-zero (`turn_kind='kickoff'`) becomes the universal thread entry.
+- **Status:** done
+- **Objective:** Add a `thread` primitive between chat and turn, render threads inline as collapsibles in the main chat surface (Cursor-style), and retire `SideChatPopover`. Substrate sub-RFC settled: option (q) new `thread` table; chat collapses to a pure container; flat threads with `thread.invoked_in_turn_id` for inline agent runs (no nested threads in V1).
+- **Why now / unlocks:** Track 1 (workspace shell) shipped, providing the stable host. Threads are the critical unblocker for reconciliation absorption into the chat surface (Track 3), `#` mention / turn-zero / context provision (Track 5), changeset attribution (Track 4), and the retirement of the V3.1 popover and staged-patches surfaces. Supersedes the prior side-chat V4a persistence horizon — persistent side-chat history becomes the main chat stream where threads stay collapsed.
+- **Acceptance:** `thread` table exists with kinds (`interview`, `side`, `reconciliation`, `qa`, `agent_run`); `turn.thread_id` replaces `turn.chat_id`; `chat.kind` and `chat.active_turn_id` retire; threads render inline as collapsibles in the unified chat surface; `SideChatPopover` retires as cutover; each thread carries its own in-thread mutation state (edit mode + patch staging via ThreadCollapsible) — the global `PatchListOverlay` strip remains as a deliberate cross-thread summary surface; turn-zero (`turn_kind='kickoff'`) becomes the universal thread entry; agent runs render inline via `thread.invoked_in_turn_id`. `PendingReviewSection` retirement deferred to `reconciliation-runtime` (Track 3).
 - **Verification:** Thread substrate schema/migration tests, in-stream collapsible rendering tests, manual walkthroughs for thread creation/display/collapse per kind, regression on existing interview flow.
-- **Traceability:** A82, A83, A88; D86, D87, D110, D114, D138, D146; I111, I113.
+- **Traceability:** Requirements 39 (updated), 45; A88, A94; D86, D87, D110, D114, D138, D146, D153, D154; I111 (extended), I113.
 - **Design docs:** `docs/design/CONVERSATIONAL_WORKSPACE_RUNTIME.md` §3.2 + §5 Track 2; `docs/design/MULTI_CHAT.md`; `docs/design/SIDE_CHAT.md`.
+- **Current execution pointer:** all acceptance criteria met (slices 1–11). Thread substrate, inline streaming + edit mode, popover retirement + dead-code deletion (-3200 LOC), turn-zero kickoff, agent runs inline. Frontier ready to close.
 
 ### reconciliation-runtime
 
@@ -387,6 +387,7 @@ The May 2026 intent-spec, multi-chat, changeset-ledger, prompt/context, and agen
 
 ## Recently Completed
 
+- [2026-05-15] `chat-runtime-threads` — Done: FE-710 / PR #138. Thread substrate (new `thread` table, `turn.thread_id`, chat simplified to pure container), inline ThreadCollapsible with streaming + edit mode + patch staging, SideChatPopover fully retired and deleted (-3200 LOC), turn-zero kickoff, agent runs inline via `invoked_in_turn_id`. Global `PatchListOverlay` strip remains as deliberate cross-thread summary. `PendingReviewSection` retirement deferred to `reconciliation-runtime` (Track 3). Verified: `npm run verify` 1157 pass / 15 skipped (retirement debt). Watch: 15 skipped tests cover retired popover bridge/undo modules and annotate auto-apply — delete when replacement coverage exists.
 - [2026-05-13] `continuous-workspace` — Done: FE-709 / PR #134. Replaced per-phase InterviewView with ContinuousWorkspaceView (cumulative center pane), extracted `useContinuousWorkspaceController`, added sidebar scroll-spy via WorkspaceFocusContext, extracted shared controller helpers to core, retired route-first test assumptions. Verified: `npm run verify` 1213 / 1214 pass (1 pre-existing flake). Watch: Step 5 route-collapse decision deferred — hybrid works as intended.
 - [2026-05-11] `side-chat-v3-1-agent-grouped-reconciliation` — Done: FE-674 / PR #124 + downstack closed the V3.x arc end-to-end with spec-level classifier route, per-row reset route, agent classification lifecycle, chips, per-class actions, and bulk Confirm-all / Apply-all-suggested. Verified: `npm run verify` 1178 / 1179 pass with one unrelated `side-chat-route` flake. Watch: A88 outer-loop walkthrough on a dense spec remains open to assess legibility vs V3.0's flat list.
 - [2026-05-11] `fe-698-reconciliation-context-pack` — Done: added proposal-only reconciliation prompt/context scenario rendering open reconciliation needs with source/target anchors, reason/status, prompt/context fingerprints, and read-only capability metadata. Verified: `npm run verify`. Watch: next FE-698 work can broaden read-only/proposal-only probes and Pi adapter spike without treating this pack as a resolution agent.