feat: add change_seq to transcripts for ingestion support (#868)

* feat: add change_seq to transcripts for ingestion support

Add a monotonically increasing change_seq column to the transcript table,
backed by a PostgreSQL sequence and BEFORE INSERT OR UPDATE trigger. Every
mutation gets a new sequence value, letting external ingesters checkpoint
and never miss an update.

* chore: regenerate frontend API types

server/migrations/versions/623af934249a_add_change_seq_to_transcript.py

@@ -0,0 +1,74 @@
+"""add_change_seq_to_transcript
+
+Revision ID: 623af934249a
+Revises: 3aa20b96d963
+Create Date: 2026-02-19 18:53:12.315440
+
+"""
+
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = "623af934249a"
+down_revision: Union[str, None] = "3aa20b96d963"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # Sequence
+    op.execute("CREATE SEQUENCE IF NOT EXISTS transcript_change_seq;")
+
+    # Column (nullable first for backfill)
+    op.add_column("transcript", sa.Column("change_seq", sa.BigInteger(), nullable=True))
+
+    # Backfill existing rows with sequential values (ordered by created_at for determinism)
+    op.execute("""
+        UPDATE transcript SET change_seq = sub.seq FROM (
+            SELECT id, nextval('transcript_change_seq') AS seq
+            FROM transcript ORDER BY created_at ASC
+        ) sub WHERE transcript.id = sub.id;
+    """)
+
+    # Now make NOT NULL
+    op.alter_column("transcript", "change_seq", nullable=False)
+
+    # Default for any inserts between now and trigger creation
+    op.alter_column(
+        "transcript",
+        "change_seq",
+        server_default=sa.text("nextval('transcript_change_seq')"),
+    )
+
+    # Trigger function
+    op.execute("""
+        CREATE OR REPLACE FUNCTION set_transcript_change_seq()
+        RETURNS TRIGGER AS $$
+        BEGIN
+            NEW.change_seq := nextval('transcript_change_seq');
+            RETURN NEW;
+        END;
+        $$ LANGUAGE plpgsql;
+    """)
+
+    # Trigger (fires on every INSERT or UPDATE)
+    op.execute("""
+        CREATE TRIGGER trigger_transcript_change_seq
+            BEFORE INSERT OR UPDATE ON transcript
+            FOR EACH ROW
+            EXECUTE FUNCTION set_transcript_change_seq();
+    """)
+
+    # Index for efficient polling
+    op.create_index("idx_transcript_change_seq", "transcript", ["change_seq"])
+
+
+def downgrade() -> None:
+    op.execute("DROP TRIGGER IF EXISTS trigger_transcript_change_seq ON transcript;")
+    op.execute("DROP FUNCTION IF EXISTS set_transcript_change_seq();")
+    op.drop_index("idx_transcript_change_seq", table_name="transcript")
+    op.drop_column("transcript", "change_seq")
+    op.execute("DROP SEQUENCE IF EXISTS transcript_change_seq;")

server/reflector/db/search.py

@@ -151,6 +151,7 @@ class SearchResultDB(BaseModel):
     title: str | None = None
     source_kind: SourceKind
     room_id: str | None = None
+    change_seq: int | None = None
     rank: float = Field(..., ge=0, le=1)
 
 
@@ -173,6 +174,7 @@ class SearchResult(BaseModel):
     total_match_count: NonNegativeInt = Field(
         default=0, description="Total number of matches found in the transcript"
     )
+    change_seq: int | None = None
 
     @field_serializer("created_at", when_used="json")
     def serialize_datetime(self, dt: datetime) -> str:
@@ -356,6 +358,7 @@ class SearchController:
             transcripts.c.user_id,
             transcripts.c.room_id,
             transcripts.c.source_kind,
+            transcripts.c.change_seq,
             transcripts.c.webvtt,
             transcripts.c.long_summary,
             sqlalchemy.case(

server/reflector/db/transcripts.py

@@ -35,6 +35,8 @@ class SourceKind(enum.StrEnum):
     FILE = enum.auto()
 
 
+transcript_change_seq = sqlalchemy.Sequence("transcript_change_seq", metadata=metadata)
+
 transcripts = sqlalchemy.Table(
     "transcript",
     metadata,
@@ -89,6 +91,12 @@ transcripts = sqlalchemy.Table(
     sqlalchemy.Column("webvtt", sqlalchemy.Text),
     # Hatchet workflow run ID for resumption of failed workflows
     sqlalchemy.Column("workflow_run_id", sqlalchemy.String),
+    sqlalchemy.Column(
+        "change_seq",
+        sqlalchemy.BigInteger,
+        transcript_change_seq,
+        server_default=transcript_change_seq.next_value(),
+    ),
     sqlalchemy.Index("idx_transcript_recording_id", "recording_id"),
     sqlalchemy.Index("idx_transcript_user_id", "user_id"),
     sqlalchemy.Index("idx_transcript_created_at", "created_at"),
@@ -229,6 +237,7 @@ class Transcript(BaseModel):
     audio_deleted: bool | None = None
     webvtt: str | None = None
     workflow_run_id: str | None = None  # Hatchet workflow run ID for resumption
+    change_seq: int | None = None
 
     @field_serializer("created_at", when_used="json")
     def serialize_datetime(self, dt: datetime) -> str:
@@ -381,6 +390,7 @@ class TranscriptController:
         source_kind: SourceKind | None = None,
         room_id: str | None = None,
         search_term: str | None = None,
+        change_seq_from: int | None = None,
         return_query: bool = False,
         exclude_columns: list[str] = [
             "topics",
@@ -401,6 +411,7 @@ class TranscriptController:
         - `filter_recording`: filter out transcripts that are currently recording
         - `room_id`: filter transcripts by room ID
         - `search_term`: filter transcripts by search term
+        - `change_seq_from`: filter transcripts with change_seq > this value
         """
 
         query = transcripts.select().join(
@@ -423,6 +434,9 @@ class TranscriptController:
         if search_term:
             query = query.where(transcripts.c.title.ilike(f"%{search_term}%"))
 
+        if change_seq_from is not None:
+            query = query.where(transcripts.c.change_seq > change_seq_from)
+
         # Exclude heavy JSON columns from list queries
         transcript_columns = [
             col for col in transcripts.c if col.name not in exclude_columns
@@ -436,9 +450,10 @@ class TranscriptController:
         )
 
         if order_by is not None:
-            field = getattr(transcripts.c, order_by[1:])
             if order_by.startswith("-"):
-                field = field.desc()
+                field = getattr(transcripts.c, order_by[1:]).desc()
+            else:
+                field = getattr(transcripts.c, order_by)
             query = query.order_by(field)
 
         if filter_empty:

server/reflector/views/transcripts.py

@@ -111,6 +111,7 @@ class GetTranscriptMinimal(BaseModel):
     room_id: str | None = None
     room_name: str | None = None
     audio_deleted: bool | None = None
+    change_seq: int | None = None
 
 
 class TranscriptParticipantWithEmail(TranscriptParticipant):
@@ -266,12 +267,22 @@ async def transcripts_list(
     source_kind: SourceKind | None = None,
     room_id: str | None = None,
     search_term: str | None = None,
+    change_seq_from: int | None = None,
+    sort_by: Literal["created_at", "change_seq"] | None = None,
 ):
     if not user and not settings.PUBLIC_MODE:
         raise HTTPException(status_code=401, detail="Not authenticated")
 
     user_id = user["sub"] if user else None
 
+    # Default behavior preserved: sort_by=None → "-created_at"
+    if sort_by == "change_seq":
+        order_by = "change_seq"  # ASC (ascending for checkpoint-based polling)
+    elif sort_by == "created_at":
+        order_by = "-created_at"  # DESC (newest first, same as current default)
+    else:
+        order_by = "-created_at"  # default, backward compatible
+
     return await apaginate(
         get_database(),
         await transcripts_controller.get_all(
@@ -279,7 +290,8 @@ async def transcripts_list(
             source_kind=SourceKind(source_kind) if source_kind else None,
             room_id=room_id,
             search_term=search_term,
-            order_by="-created_at",
+            order_by=order_by,
+            change_seq_from=change_seq_from,
             return_query=True,
         ),
     )
@@ -512,6 +524,7 @@ async def transcript_get(
         "room_id": transcript.room_id,
         "room_name": room_name,
         "audio_deleted": transcript.audio_deleted,
+        "change_seq": transcript.change_seq,
         "participants": participants,
     }