feat(db): track API endpoint dimension on usage_history

Add an `endpoint` column to `usage_history` (migration 103) so the proxy
records which API entry point a request came through — typically
`/v1/chat/completions`, `/v1/messages`, or `/v1/responses`. Every
`saveRequestUsage(...)` call site in `open-sse/handlers/chatCore.ts`
(success, stream, failure) and the codex-responses-ws route now plumbs
the endpoint through, and a new `getEndpointUsageRows(...)` analytics
query in `src/lib/db/usageAnalytics.ts` aggregates per
endpoint × provider × model with NULL → 'unknown' folding for backward
compatibility with rows from before the migration.

The aggregation reads directly from `usage_history` (matching the
`getAutoRoutingVariantBreakdown` pattern) so the existing unified-source
CTE — and the `daily_usage_summary` rollup it joins — stay untouched.

TDD: tests/unit/usage-endpoint-dimension.test.ts covers persistence
round-trip, NULL fallback, and the sinceIso filter (3/3 passing).

Co-authored-by: toanalien <toanalien@gmail.com>
Inspired-by: https://github.com/decolua/9router/pull/152

config/quality/file-size-baseline.json

@@ -199,7 +199,7 @@
     "src/lib/db/providers.ts": 1063,
     "src/lib/db/proxies.ts": 1057,
     "src/lib/db/settings.ts": 1149,
-    "src/lib/db/usageAnalytics.ts": 873,
+    "src/lib/db/usageAnalytics.ts": 925,
     "src/lib/evals/evalRunner.ts": 961,
     "src/lib/memory/retrieval.ts": 1171,
     "src/lib/modelsDevSync.ts": 934,

open-sse/handlers/chatCore.ts

@@ -433,6 +433,7 @@ export async function handleChatCore({
         statusCode,
         errorCode,
         latencyMs: Date.now() - startTime,
+        endpoint: endpointPath,
       })
     ).catch(() => {});
   };
@@ -3422,6 +3423,7 @@ export async function handleChatCore({
       effectiveServiceTier,
       isCombo,
       comboStrategy,
+      endpoint: endpointPath,
     });
 
     // Translate response to client's expected format (usually OpenAI)
@@ -3806,6 +3808,7 @@ export async function handleChatCore({
       effectiveServiceTier,
       isCombo,
       comboStrategy,
+      endpoint: endpointPath,
     });
 
     persistAttemptLogs({

open-sse/handlers/chatCore/failureUsage.ts

@@ -19,6 +19,7 @@ export function buildFailureUsageRecord(opts: {
   statusCode: number;
   errorCode: string | null | undefined;
   latencyMs: number;
+  endpoint?: string | null | undefined;
 }) {
   return {
     provider: opts.provider || "unknown",
@@ -35,5 +36,6 @@ export function buildFailureUsageRecord(opts: {
     apiKeyName: opts.apiKeyInfo?.name || undefined,
     serviceTier: opts.effectiveServiceTier,
     comboStrategy: opts.isCombo ? opts.comboStrategy || undefined : undefined,
+    endpoint: opts.endpoint || undefined,
   };
 }

open-sse/handlers/chatCore/nonStreamingUsageStats.ts

@@ -27,6 +27,7 @@ export type RecordNonStreamingUsageStatsContext = {
   effectiveServiceTier: EffectiveServiceTier;
   isCombo: boolean;
   comboStrategy: string | null | undefined;
+  endpoint?: string | null | undefined;
 };
 
 function logUsageTrace(
@@ -55,6 +56,7 @@ function persistUsageRow(usage: object, ctx: RecordNonStreamingUsageStatsContext
     apiKeyName: apiKeyInfo?.name || undefined,
     serviceTier: effectiveServiceTier,
     comboStrategy: ctx.isCombo ? ctx.comboStrategy || undefined : undefined,
+    endpoint: ctx.endpoint || undefined,
   }).catch((err) => {
     console.error("Failed to save usage stats:", err.message);
   });

open-sse/handlers/chatCore/streamingUsageStats.ts

@@ -27,6 +27,7 @@ export type RecordStreamingUsageStatsContext = {
   effectiveServiceTier: EffectiveServiceTier;
   isCombo: boolean;
   comboStrategy: string | null | undefined;
+  endpoint?: string | null | undefined;
 };
 
 function persistStreamingUsageRow(usage: object, ctx: RecordStreamingUsageStatsContext): void {
@@ -46,6 +47,7 @@ function persistStreamingUsageRow(usage: object, ctx: RecordStreamingUsageStatsC
     apiKeyName: ctx.apiKeyInfo?.name || undefined,
     serviceTier: ctx.effectiveServiceTier,
     comboStrategy: ctx.isCombo ? ctx.comboStrategy || undefined : undefined,
+    endpoint: ctx.endpoint || undefined,
   }).catch((err) => {
     console.error("Failed to save usage stats:", err.message);
   });

src/app/api/internal/codex-responses-ws/route.ts

@@ -513,6 +513,7 @@ async function persistResponsesWsCallHistory(body: JsonRecord) {
     latencyMs: durationMs,
     timeToFirstTokenMs: durationMs,
     errorCode,
+    endpoint: "/v1/responses",
   });
 
   logProxyEvent({

src/lib/db/migrations/105_usage_history_endpoint.sql

@@ -0,0 +1,6 @@
+-- Migration 105: Add endpoint column to usage_history
+-- Tracks the API endpoint path (e.g. /v1/chat/completions, /v1/messages, /v1/responses)
+-- so usage analytics can break down activity per endpoint dimension.
+-- Backward compatible: existing rows default to NULL; aggregation queries fold NULL into 'unknown'.
+ALTER TABLE usage_history ADD COLUMN endpoint TEXT;
+CREATE INDEX IF NOT EXISTS idx_uh_endpoint ON usage_history(endpoint);

src/lib/db/usageAnalytics.ts

@@ -821,6 +821,79 @@ export function getPresetCostModelRows(
     .all(params) as PresetCostModelRow[];
 }
 
+// ---------------------------------------------------------------------------
+// Endpoint dimension — ported from decolua/9router#152 (thanks @toanalien).
+// Reads directly from usage_history (raw rows) so the unified CTE stays
+// untouched; matches the pattern used by getAutoRoutingVariantBreakdown.
+// ---------------------------------------------------------------------------
+
+export interface EndpointUsageRow {
+  endpoint: string;
+  provider: string;
+  model: string;
+  requests: number;
+  promptTokens: number;
+  completionTokens: number;
+  cacheReadTokens: number;
+  cacheCreationTokens: number;
+  reasoningTokens: number;
+  totalTokens: number;
+  avgLatencyMs: number;
+  successfulRequests: number;
+  lastUsed: string;
+}
+
+export interface EndpointUsageParams {
+  sinceIso?: string | null;
+  untilIso?: string | null;
+}
+
+/**
+ * Per-endpoint × provider × model usage aggregates from `usage_history`.
+ * NULL endpoints fold into the 'unknown' bucket so legacy rows stay visible.
+ *
+ * Inspired by decolua/9router#152 (byEndpoint aggregation), reshaped for the
+ * OmniRoute SQLite schema + analytics conventions.
+ */
+export function getEndpointUsageRows(params: EndpointUsageParams = {}): EndpointUsageRow[] {
+  const db = getDbInstance();
+  const conditions: string[] = [];
+  const bind: Record<string, unknown> = {};
+  if (params.sinceIso) {
+    conditions.push("timestamp >= @since");
+    bind.since = params.sinceIso;
+  }
+  if (params.untilIso) {
+    conditions.push("timestamp <= @until");
+    bind.until = params.untilIso;
+  }
+  const whereSql = conditions.length > 0 ? `WHERE ${conditions.join(" AND ")}` : "";
+  return db
+    .prepare(
+      `
+      SELECT
+        COALESCE(NULLIF(endpoint, ''), 'unknown') as endpoint,
+        LOWER(COALESCE(provider, 'unknown')) as provider,
+        LOWER(COALESCE(model, 'unknown')) as model,
+        COUNT(*) as requests,
+        COALESCE(SUM(tokens_input), 0) as promptTokens,
+        COALESCE(SUM(tokens_output), 0) as completionTokens,
+        COALESCE(SUM(tokens_cache_read), 0) as cacheReadTokens,
+        COALESCE(SUM(tokens_cache_creation), 0) as cacheCreationTokens,
+        COALESCE(SUM(tokens_reasoning), 0) as reasoningTokens,
+        COALESCE(SUM(tokens_input + tokens_output), 0) as totalTokens,
+        COALESCE(AVG(latency_ms), 0) as avgLatencyMs,
+        COALESCE(SUM(CASE WHEN success = 1 THEN 1 ELSE 0 END), 0) as successfulRequests,
+        COALESCE(MAX(timestamp), '') as lastUsed
+      FROM usage_history
+      ${whereSql}
+      GROUP BY endpoint, LOWER(COALESCE(provider, 'unknown')), LOWER(COALESCE(model, 'unknown'))
+      ORDER BY requests DESC
+    `
+    )
+    .all(bind) as EndpointUsageRow[];
+}
+
 // ---------------------------------------------------------------------------
 // Export-JSON backup — /api/settings/export-json
 // ---------------------------------------------------------------------------

src/lib/usage/usageHistory.ts

@@ -641,8 +641,8 @@ export async function saveRequestUsage(entry: any) {
       `
       INSERT INTO usage_history (provider, model, connection_id, api_key_id, api_key_name,
         tokens_input, tokens_output, tokens_cache_read, tokens_cache_creation, tokens_reasoning,
-        service_tier, status, success, latency_ms, ttft_ms, error_code, combo_strategy, timestamp)
-      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+        service_tier, status, success, latency_ms, ttft_ms, error_code, combo_strategy, endpoint, timestamp)
+      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
     `
     ).run(
       entry.provider || null,
@@ -666,6 +666,7 @@ export async function saveRequestUsage(entry: any) {
           : 0,
       entry.errorCode || null,
       entry.comboStrategy || entry.combo_strategy || null,
+      entry.endpoint || null,
       timestamp
     );
 

tests/unit/usage-endpoint-dimension.test.ts

@@ -0,0 +1,125 @@
+/**
+ * Ported feature regression — decolua/9router#152 (thanks @toanalien).
+ *
+ * Covers the new `endpoint` column on usage_history + getEndpointUsageRows()
+ * aggregation. Asserts: persistence round-trip, NULL → 'unknown' folding,
+ * per-endpoint grouping, sinceIso filter.
+ */
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-usage-endpoint-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+const core = await import("../../src/lib/db/core.ts");
+const usageHistory = await import("../../src/lib/usage/usageHistory.ts");
+const usageAnalytics = await import("../../src/lib/db/usageAnalytics.ts");
+
+async function resetStorage() {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+  fs.mkdirSync(TEST_DATA_DIR, { recursive: true });
+  usageHistory.clearPendingRequests();
+}
+
+test.beforeEach(async () => {
+  await resetStorage();
+});
+
+test.after(() => {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+test("saveRequestUsage persists endpoint and getEndpointUsageRows groups by endpoint", async () => {
+  await usageHistory.saveRequestUsage({
+    provider: "openai",
+    model: "gpt-4o-mini",
+    tokens: { input: 10, output: 5 },
+    success: true,
+    latencyMs: 100,
+    timestamp: new Date().toISOString(),
+    endpoint: "/v1/chat/completions",
+  });
+  await usageHistory.saveRequestUsage({
+    provider: "openai",
+    model: "gpt-4o-mini",
+    tokens: { input: 20, output: 8 },
+    success: true,
+    latencyMs: 200,
+    timestamp: new Date().toISOString(),
+    endpoint: "/v1/chat/completions",
+  });
+  await usageHistory.saveRequestUsage({
+    provider: "anthropic",
+    model: "claude-sonnet-4",
+    tokens: { input: 30, output: 12 },
+    success: true,
+    latencyMs: 300,
+    timestamp: new Date().toISOString(),
+    endpoint: "/v1/messages",
+  });
+
+  const rows = usageAnalytics.getEndpointUsageRows();
+  const byKey = new Map(rows.map((r) => [`${r.endpoint}|${r.provider}|${r.model}`, r]));
+
+  const chat = byKey.get("/v1/chat/completions|openai|gpt-4o-mini");
+  assert.ok(chat, "expected /v1/chat/completions row");
+  assert.equal(chat.requests, 2);
+  assert.equal(chat.promptTokens, 30);
+  assert.equal(chat.completionTokens, 13);
+
+  const messages = byKey.get("/v1/messages|anthropic|claude-sonnet-4");
+  assert.ok(messages, "expected /v1/messages row");
+  assert.equal(messages.requests, 1);
+  assert.equal(messages.promptTokens, 30);
+});
+
+test("getEndpointUsageRows folds NULL endpoint into 'unknown' bucket (backward compat)", async () => {
+  // Legacy entry: no endpoint field set → stored as NULL.
+  await usageHistory.saveRequestUsage({
+    provider: "openai",
+    model: "gpt-4o-mini",
+    tokens: { input: 5, output: 5 },
+    success: true,
+    latencyMs: 50,
+    timestamp: new Date().toISOString(),
+  });
+
+  const rows = usageAnalytics.getEndpointUsageRows();
+  const unknown = rows.find((r) => r.endpoint === "unknown");
+  assert.ok(unknown, "NULL endpoint should fold into 'unknown'");
+  assert.equal(unknown.requests, 1);
+});
+
+test("getEndpointUsageRows honors sinceIso filter", async () => {
+  const old = new Date(Date.now() - 24 * 60 * 60 * 1000).toISOString();
+  const recent = new Date().toISOString();
+  await usageHistory.saveRequestUsage({
+    provider: "openai",
+    model: "gpt-4o-mini",
+    tokens: { input: 5, output: 5 },
+    success: true,
+    latencyMs: 50,
+    timestamp: old,
+    endpoint: "/v1/chat/completions",
+  });
+  await usageHistory.saveRequestUsage({
+    provider: "openai",
+    model: "gpt-4o-mini",
+    tokens: { input: 5, output: 5 },
+    success: true,
+    latencyMs: 50,
+    timestamp: recent,
+    endpoint: "/v1/chat/completions",
+  });
+
+  const sinceIso = new Date(Date.now() - 60 * 60 * 1000).toISOString();
+  const rows = usageAnalytics.getEndpointUsageRows({ sinceIso });
+  const chat = rows.find((r) => r.endpoint === "/v1/chat/completions");
+  assert.ok(chat);
+  assert.equal(chat.requests, 1, "only the recent row should be counted");
+});