feat(sse): allow disabling conversation tracking

.env.example

@@ -621,6 +621,15 @@ ALLOW_API_KEY_REVEAL=false
 # Validated to >= 1, clamped to <= 32.  |  Default: 3
 # COMBO_CONCURRENCY_PER_MODEL=3
 
+# Disable conversation-history tracking (#13150).
+# Used by: open-sse/services/conversationTracker.ts. resolveConversationId()
+# returns an untracked result before it reads SQLite or parses message history,
+# and the switch also covers client-supplied session IDs. Routing sessions are
+# unaffected and existing records are not deleted. Use it when the dashboard's
+# conversation view is unused and the turn table has grown large.
+# Set to 1 to disable.  |  Default: unset (tracking enabled)
+# OMNIROUTE_DISABLE_CONVERSATION_TRACKING=1
+
 # ═══════════════════════════════════════════════════════════════════════════════
 # 7. URLS & CLOUD SYNC
 # ═══════════════════════════════════════════════════════════════════════════════

changelog.d/features/13150-disable-conversation-tracking.md

@@ -0,0 +1 @@
+- **feat(sse):** `OMNIROUTE_DISABLE_CONVERSATION_TRACKING=1` turns off conversation-history collection for operators who do not use the dashboard's conversation view. `resolveConversationId()` returns an untracked result before it reads SQLite or parses message history, and the switch also covers client-supplied session IDs. Routing-session handling is unchanged, tracking stays on by default, and existing records are not deleted. One reporting install held 5.97 million turn records at about 4.26 GB ([#13150](https://github.com/diegosouzapw/OmniRoute/pull/13150))

docs/reference/ENVIRONMENT.md

@@ -309,6 +309,7 @@ OmniRoute provides a two-layer defense: request-side injection scanning and resp
 | `OMNIROUTE_PREFER_CLAUDE_CODE_FOR_UNPREFIXED_CLAUDE_MODELS` | `false`                      | `open-sse/services/model.ts`        | Opt-in: route bare `claude-*` model IDs from Claude Code clients through the Claude Code OAuth account instead of requiring a provider prefix. Explicit provider prefixes still win. Also configurable via a dashboard toggle on the Claude provider page. |
 | `COMBO_CONCURRENCY_PER_MODEL`                               | `3`                          | `open-sse/services/comboConfig.ts`  | Per-model concurrency cap for round-robin combos (#9100). The round-robin combo semaphore was hard-capped at 3 concurrent requests per model with no override, serializing higher-concurrency traffic behind that cap. Validated to `>= 1`, clamped to `<= 32`.                                          |
 | `DISABLE_CONTEXT_WINDOW_CHECKS`                             | `false`                      | `open-sse/handlers/chatCore.ts`     | Dangerous opt-in that skips OmniRoute's local context-window / max-input-token check for direct single-model requests. Upstream providers still enforce their actual limits; prompt compression and the model's own output-token cap remain active. Effective precedence is Feature Flags DB override > environment variable > default; no restart is required.                                          |
+| `OMNIROUTE_DISABLE_CONVERSATION_TRACKING`                   | _(unset)_                    | `open-sse/services/conversationTracker.ts` | Set `1` to stop collecting conversation history. `resolveConversationId()` returns an untracked result before it reads SQLite or parses message history, and client-supplied session IDs are covered too. Routing-session handling is unchanged and existing records are not deleted. For deployments that do not use the dashboard's conversation view and want the turn table to stop growing. |
 
 ---
 

open-sse/services/conversationTracker.ts

@@ -77,7 +77,7 @@ export interface ResolveConversationIdInput {
 }
 
 export interface ResolveConversationIdResult {
-  conversationId: string;
+  conversationId: string | null;
   isNewConversation: boolean;
 }
 
@@ -459,6 +459,10 @@ const MAX_STORED_ID_LENGTH = 128;
 export async function resolveConversationId(
   input: ResolveConversationIdInput
 ): Promise<ResolveConversationIdResult> {
+  if (process.env.OMNIROUTE_DISABLE_CONVERSATION_TRACKING === "1") {
+    return { conversationId: null, isNewConversation: false };
+  }
+
   // Client override wins outright — deterministic, zero heuristic risk.
   // Same header feature #8249 already reads (chatCore.ts); we don't invent a
   // new prefix so the existing header's contract/format stays unchanged.

tests/unit/conversationTracker.test.ts

@@ -144,6 +144,37 @@ test("computeFingerprintHash: identical apiKeyId/model/toolNames produce the sam
   assert.equal(a, b);
 });
 
+test("resolveConversationId: disabled tracking skips database access and message parsing", async () => {
+  const { getDbInstance } = await import("../../src/lib/db/core.ts");
+  const db = getDbInstance();
+  const previous = process.env.OMNIROUTE_DISABLE_CONVERSATION_TRACKING;
+  const prepare = test.mock.method(db, "prepare", () => {
+    throw new Error("disabled tracking must not access SQLite");
+  });
+  process.env.OMNIROUTE_DISABLE_CONVERSATION_TRACKING = "1";
+  try {
+    for (const clientSessionIdHeader of [null, "explicit-session"]) {
+      const result = await resolveConversationId({
+        body: {
+          get messages() {
+            throw new Error("disabled tracking must not parse messages");
+          },
+        },
+        model: "test-model",
+        apiKeyId: "test-key",
+        clientSessionIdHeader,
+        correlationId: "disabled-tracking",
+      });
+      assert.deepEqual(result, { conversationId: null, isNewConversation: false });
+    }
+    assert.equal(prepare.mock.callCount(), 0);
+  } finally {
+    prepare.mock.restore();
+    if (previous === undefined) delete process.env.OMNIROUTE_DISABLE_CONVERSATION_TRACKING;
+    else process.env.OMNIROUTE_DISABLE_CONVERSATION_TRACKING = previous;
+  }
+});
+
 test("resolveConversationId: exact-match continuation reuses the same id", async () => {
   const apiKeyId = "key-exact";
   const turn1 = await resolveConversationId({