feat(ai-chat): durable detached agent runs — phase 1 (#184/#234)

Squashed for a clean rebase onto develop (was 19 commits; the reviewer approved the net diff at fb246080). Detaches an agent run from the HTTP request/browser window: a run is a first-class lifecycle object (ai_chat_runs), a browser disconnect no longer kills it, a concurrent-run insert-gate prevents double runs, and a reopened chat live-follows a still-running run via a polled observer merge. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-07-04 23:20:21 +03:00
parent 5336f06d10
commit 68899a2c2e
37 changed files with 4535 additions and 605 deletions
@@ -0,0 +1,106 @@
+import { type Kysely, sql } from 'kysely';
+
+/**
+ * `ai_chat_runs` — the agent RUN as a first-class, server-side lifecycle object
+ * (#184 phase 1: autonomous agent runs detached from the browser window).
+ *
+ * Until now an agent turn lived ONLY as long as the HTTP request was open
+ * (`res.hijack()` in ai-chat.controller.ts); a browser disconnect aborted it.
+ * This table makes a turn a persistent object the server owns: it is created
+ * when a run starts (inserted directly as 'running' in phase 1 — 'pending' is
+ * only this column's default + a reserved value, never written by code yet) and
+ * advances to succeeded|failed|aborted, surviving the subscriber (browser) going
+ * away when it settles. The DB is the source of
+ * truth — a later client reconnects/sees the result by reading this row plus the
+ * assistant message it projects (`assistant_message_id`).
+ *
+ * The assistant message row (#183 step-granular durability) is the PROJECTION of
+ * a run's output; this row is the run's LIFECYCLE. They are linked by
+ * `assistant_message_id` (SET NULL if the message is later pruned).
+ *
+ * `status`  : 'pending' | 'running' | 'succeeded' | 'failed' | 'aborted'.
+ * `trigger` : 'user' | 'autostart' | 'schedule' | 'api' | 'continue' — only
+ *             'user' is produced in phase 1; the others are reserved for the
+ *             autonomy triggers deferred to phase 2 so they need no later
+ *             migration.
+ *
+ * ONE ACTIVE RUN PER CHAT is enforced by a partial unique index on `chat_id`
+ * WHERE status IN ('pending','running'): an autonomous run and a user run can
+ * never trample each other on the same chat. Settled runs (succeeded/failed/
+ * aborted) are excluded from the index so a chat can accumulate any number of
+ * historical runs.
+ */
+export async function up(db: Kysely<any>): Promise<void> {
+  await db.schema
+    .createTable('ai_chat_runs')
+    .ifNotExists()
+    .addColumn('id', 'uuid', (col) =>
+      col.primaryKey().defaultTo(sql`gen_uuid_v7()`),
+    )
+    .addColumn('chat_id', 'uuid', (col) =>
+      col.references('ai_chats.id').onDelete('cascade').notNull(),
+    )
+    .addColumn('workspace_id', 'uuid', (col) =>
+      col.references('workspaces.id').onDelete('cascade').notNull(),
+    )
+    // The human who triggered the run (audit). SET NULL on user deletion so the
+    // run history outlives its author; NULL is also the natural value for a
+    // future system/cron/api trigger with no human actor.
+    .addColumn('created_by', 'uuid', (col) =>
+      col.references('users.id').onDelete('set null'),
+    )
+    // The assistant message this run materializes (the #183 projection). SET NULL
+    // if that message row is later deleted; nullable because the run row is
+    // created a moment BEFORE the assistant row is seeded.
+    .addColumn('assistant_message_id', 'uuid', (col) =>
+      col.references('ai_chat_messages.id').onDelete('set null'),
+    )
+    .addColumn('trigger', 'varchar(20)', (col) =>
+      col.notNull().defaultTo('user'),
+    )
+    .addColumn('status', 'varchar(20)', (col) =>
+      col.notNull().defaultTo('pending'),
+    )
+    // Terminal error message for a failed run (provider/transport cause),
+    // mirroring the assistant message's metadata.error.
+    .addColumn('error', 'text', (col) => col)
+    // Number of agent steps finished so far (kept monotonic with the projection).
+    .addColumn('step_count', 'integer', (col) => col.notNull().defaultTo(0))
+    // Set when an EXPLICIT user stop is requested (distinct from a mere browser
+    // disconnect, which never stops a run). The runner aborts the turn and the
+    // run settles as 'aborted'.
+    .addColumn('stop_requested_at', 'timestamptz', (col) => col)
+    .addColumn('started_at', 'timestamptz', (col) => col)
+    .addColumn('finished_at', 'timestamptz', (col) => col)
+    .addColumn('created_at', 'timestamptz', (col) =>
+      col.notNull().defaultTo(sql`now()`),
+    )
+    .addColumn('updated_at', 'timestamptz', (col) =>
+      col.notNull().defaultTo(sql`now()`),
+    )
+    .execute();
+
+  // Reconnect / "latest run for this chat" reads hit chat_id first.
+  await db.schema
+    .createIndex('ai_chat_runs_chat_id_idx')
+    .ifNotExists()
+    .on('ai_chat_runs')
+    .column('chat_id')
+    .execute();
+
+  // One ACTIVE run per chat (advisory at the DB level): a second pending/running
+  // run on the same chat is rejected, so a user turn and an autonomous turn can
+  // never race on the same chat. Partial so settled runs do not collide.
+  await db.schema
+    .createIndex('ai_chat_runs_one_active_per_chat')
+    .ifNotExists()
+    .on('ai_chat_runs')
+    .column('chat_id')
+    .unique()
+    .where(sql.ref('status'), 'in', sql`('pending','running')`)
+    .execute();
+}
+
+export async function down(db: Kysely<any>): Promise<void> {
+  await db.schema.dropTable('ai_chat_runs').execute();
+}