1 files changed, 37 insertions, 6 deletions
diff --git a/src/features/chat/ports.ts b/src/features/chat/ports.ts
index 07943c7..2fe10dc 100644
--- a/src/features/chat/ports.ts
+++ b/src/features/chat/ports.ts
@@ -1,12 +1,43 @@
-import type { ChatSendMessage, ConversationHistoryResponse } from "@dispatch/transport-contract";
+import type {
+  ChatQueueMessage,
+  ChatSendMessage,
+  ConversationHistoryResponse,
+  ConversationMetricsResponse,
+} from "@dispatch/transport-contract";
 
-/** Injected transport port — sends chat messages to the server. */
+/**
+ * Injected transport port — sends chat messages to the server. Accepts both
+ * `chat.send` (start a turn) and `chat.queue` (enqueue a steering message;
+ * auto-starts a turn if idle).
+ */
 export interface ChatTransport {
-	send(msg: ChatSendMessage): void;
+  send(msg: ChatSendMessage | ChatQueueMessage): void;
 }
 
-/** Injected history-sync port — fetches incremental history from the server. */
+/**
+ * Optional windowing for a history fetch ([email protected], CR-5).
+ * Both must be POSITIVE integers when present (the server 400s otherwise).
+ */
+export interface HistoryWindow {
+  /** Return only the NEWEST `limit` chunks of the selection (still ascending). */
+  readonly limit?: number;
+  /** Exclusive upper bound: only chunks with `seq < beforeSeq` (backfill paging). */
+  readonly beforeSeq?: number;
+}
+
+/**
+ * Injected history-sync port — fetches incremental history from the server
+ * (`GET /conversations/:id?sinceSeq=&beforeSeq=&limit=`). NOTE the contract
+ * caveat: on a windowed/backfill read the response's `latestSeq` describes the
+ * returned window, not the conversation's high-water mark — never regress a
+ * tail cursor from it (the FE's cursor comes from the cache's max seq, which
+ * satisfies this naturally).
+ */
 export type HistorySync = (
-	conversationId: string,
-	sinceSeq: number,
+  conversationId: string,
+  sinceSeq: number,
+  window?: HistoryWindow,
 ) => Promise<ConversationHistoryResponse>;
+
+/** Injected metrics-sync port — fetches persisted per-turn metrics from the server. */
+export type MetricsSync = (conversationId: string) => Promise<ConversationMetricsResponse>;