diff --git a/package.json b/package.json
index 821019d..ee9c521 100644
--- a/package.json
+++ b/package.json
@@ -9,6 +9,7 @@
     "db:generate": "dotenv -- drizzle-kit generate",
     "db:migrate": "dotenv -- drizzle-kit migrate",
     "db:sync-prod": "bash scripts/sync-prod-db.sh",
+    "backfill:canonical": "dotenv -- tsx scripts/backfill-cli.ts",
     "dev": "NODE_OPTIONS='--import ./instrument.server.mjs' dotenv -- tsx watch server.ts",
     "start": "NODE_ENV=production NODE_OPTIONS='--import ./instrument.server.mjs' node dist/server.js",
     "start:production": "NODE_ENV=production NODE_OPTIONS='--import ./instrument.server.mjs' node dist/server.js",
diff --git a/scripts/backfill-cli.ts b/scripts/backfill-cli.ts
new file mode 100644
index 0000000..4a6d3d0
--- /dev/null
+++ b/scripts/backfill-cli.ts
@@ -0,0 +1,78 @@
+/**
+ * CLI entry point for the Phase 2 canonical backfill.
+ *
+ * Usage:
+ *   npm run backfill:canonical -- [--dry-run | --apply] [--sport=<uuid>]
+ *
+ * Defaults to --dry-run for safety. No writes will be issued unless
+ * --apply is passed explicitly.
+ */
+
+import { runBackfill } from "./backfill-canonical-layer";
+import type { BackfillOptions } from "./backfill-canonical-layer";
+
+function printHelp(): void {
+  console.log(
+    [
+      "Usage: backfill-cli [options]",
+      "",
+      "Options:",
+      "  --dry-run         Run without writing (default).",
+      "  --apply           Actually write to the database.",
+      "  --sport=<uuid>    Only backfill for the given sport id.",
+      "  --help            Show this message.",
+    ].join("\n"),
+  );
+}
+
+function parseArgs(): BackfillOptions {
+  const args = process.argv.slice(2);
+  const opts: BackfillOptions = { dryRun: true }; // dry-run by default for safety
+  for (const a of args) {
+    if (a === "--apply") {
+      opts.dryRun = false;
+    } else if (a === "--dry-run") {
+      opts.dryRun = true;
+    } else if (a.startsWith("--sport=")) {
+      opts.sportId = a.slice("--sport=".length);
+    } else if (a === "--help" || a === "-h") {
+      printHelp();
+      process.exit(0);
+    } else {
+      console.error(`unknown arg: ${a}`);
+      process.exit(1);
+    }
+  }
+  return opts;
+}
+
+async function main() {
+  const opts = parseArgs();
+  console.log(
+    `Running backfill (dryRun=${opts.dryRun}, sportId=${opts.sportId ?? "all"})`,
+  );
+  const report = await runBackfill(opts);
+
+  console.log("---");
+  console.log(`tournamentsCreated:        ${report.tournamentsCreated}`);
+  console.log(`tournamentsLinked:         ${report.tournamentsLinked}`);
+  console.log(`participantsCreated:       ${report.participantsCreated}`);
+  console.log(`participantsLinked:        ${report.participantsLinked}`);
+  console.log(`tournamentResultsCreated:  ${report.tournamentResultsCreated}`);
+  console.log(`surfaceElosCreated:        ${report.surfaceElosCreated}`);
+
+  if (report.warnings.length) {
+    console.log("\nWARNINGS:");
+    for (const w of report.warnings) console.log(`  ${w}`);
+  }
+  if (report.errors.length) {
+    console.log("\nERRORS:");
+    for (const e of report.errors) console.log(`  ${e}`);
+    process.exit(2);
+  }
+}
+
+main().catch((e) => {
+  console.error(e);
+  process.exit(1);
+});