fix(rivetkit): auto-spawn engine binary path on local endpoint

docker/build/darwin-arm64.Dockerfile

@@ -43,6 +43,12 @@ RUN if [ "$BUILD_TARGET" = "engine" ] && [ "$BUILD_FRONTEND" = "true" ]; then \
         export SKIP_WASM_BUILD=1 && \
         pnpm install --ignore-scripts && \
         VITE_APP_API_URL="${VITE_APP_API_URL}" VITE_FEATURE_FLAGS="${VITE_FEATURE_FLAGS}" npx turbo build:engine -F @rivetkit/engine-frontend; \
+    elif [ "$BUILD_TARGET" = "rivetkit-napi" ]; then \
+        export NODE_OPTIONS="--max-old-space-size=8192" && \
+        export SKIP_NAPI_BUILD=1 && \
+        export SKIP_WASM_BUILD=1 && \
+        pnpm install --ignore-scripts && \
+        npx turbo build:inspector-ui -F @rivetkit/engine-frontend; \
     fi
 
 RUN --mount=type=cache,id=cargo-registry-darwin-arm64,target=/usr/local/cargo/registry,sharing=locked \

docker/build/darwin-x64.Dockerfile

@@ -43,6 +43,12 @@ RUN if [ "$BUILD_TARGET" = "engine" ] && [ "$BUILD_FRONTEND" = "true" ]; then \
         export SKIP_WASM_BUILD=1 && \
         pnpm install --ignore-scripts && \
         VITE_APP_API_URL="${VITE_APP_API_URL}" VITE_FEATURE_FLAGS="${VITE_FEATURE_FLAGS}" npx turbo build:engine -F @rivetkit/engine-frontend; \
+    elif [ "$BUILD_TARGET" = "rivetkit-napi" ]; then \
+        export NODE_OPTIONS="--max-old-space-size=8192" && \
+        export SKIP_NAPI_BUILD=1 && \
+        export SKIP_WASM_BUILD=1 && \
+        pnpm install --ignore-scripts && \
+        npx turbo build:inspector-ui -F @rivetkit/engine-frontend; \
     fi
 
 RUN --mount=type=cache,id=cargo-registry-darwin-x64,target=/usr/local/cargo/registry,sharing=locked \

docker/build/linux-arm64-gnu.Dockerfile

@@ -30,6 +30,12 @@ RUN if [ "$BUILD_TARGET" = "engine" ] && [ "$BUILD_FRONTEND" = "true" ]; then \
         export SKIP_WASM_BUILD=1 && \
         pnpm install --ignore-scripts && \
         VITE_APP_API_URL="${VITE_APP_API_URL}" VITE_FEATURE_FLAGS="${VITE_FEATURE_FLAGS}" npx turbo build:engine -F @rivetkit/engine-frontend; \
+    elif [ "$BUILD_TARGET" = "rivetkit-napi" ]; then \
+        export NODE_OPTIONS="--max-old-space-size=8192" && \
+        export SKIP_NAPI_BUILD=1 && \
+        export SKIP_WASM_BUILD=1 && \
+        pnpm install --ignore-scripts && \
+        npx turbo build:inspector-ui -F @rivetkit/engine-frontend; \
     fi
 
 RUN --mount=type=cache,id=cargo-registry-linux-arm64-gnu,target=/usr/local/cargo/registry,sharing=locked \

docker/build/linux-arm64-musl.Dockerfile

@@ -36,6 +36,12 @@ RUN if [ "$BUILD_TARGET" = "engine" ] && [ "$BUILD_FRONTEND" = "true" ]; then \
         export SKIP_WASM_BUILD=1 && \
         pnpm install --ignore-scripts && \
         VITE_APP_API_URL="${VITE_APP_API_URL}" VITE_FEATURE_FLAGS="${VITE_FEATURE_FLAGS}" npx turbo build:engine -F @rivetkit/engine-frontend; \
+    elif [ "$BUILD_TARGET" = "rivetkit-napi" ]; then \
+        export NODE_OPTIONS="--max-old-space-size=8192" && \
+        export SKIP_NAPI_BUILD=1 && \
+        export SKIP_WASM_BUILD=1 && \
+        pnpm install --ignore-scripts && \
+        npx turbo build:inspector-ui -F @rivetkit/engine-frontend; \
     fi
 
 RUN --mount=type=cache,id=cargo-registry-linux-arm64-musl,target=/usr/local/cargo/registry,sharing=locked \

docker/build/linux-x64-gnu.Dockerfile

@@ -39,6 +39,12 @@ RUN if [ "$BUILD_TARGET" = "engine" ] && [ "$BUILD_FRONTEND" = "true" ]; then \
         export SKIP_WASM_BUILD=1 && \
         pnpm install --ignore-scripts && \
         VITE_APP_API_URL="${VITE_APP_API_URL}" VITE_FEATURE_FLAGS="${VITE_FEATURE_FLAGS}" npx turbo build:engine -F @rivetkit/engine-frontend; \
+    elif [ "$BUILD_TARGET" = "rivetkit-napi" ]; then \
+        export NODE_OPTIONS="--max-old-space-size=8192" && \
+        export SKIP_NAPI_BUILD=1 && \
+        export SKIP_WASM_BUILD=1 && \
+        pnpm install --ignore-scripts && \
+        npx turbo build:inspector-ui -F @rivetkit/engine-frontend; \
     fi
 
 # Build binary.

docker/build/linux-x64-musl.Dockerfile

@@ -35,6 +35,12 @@ RUN if [ "$BUILD_TARGET" = "engine" ] && [ "$BUILD_FRONTEND" = "true" ]; then \
         export SKIP_WASM_BUILD=1 && \
         pnpm install --ignore-scripts && \
         VITE_APP_API_URL="${VITE_APP_API_URL}" VITE_FEATURE_FLAGS="${VITE_FEATURE_FLAGS}" npx turbo build:engine -F @rivetkit/engine-frontend; \
+    elif [ "$BUILD_TARGET" = "rivetkit-napi" ]; then \
+        export NODE_OPTIONS="--max-old-space-size=8192" && \
+        export SKIP_NAPI_BUILD=1 && \
+        export SKIP_WASM_BUILD=1 && \
+        pnpm install --ignore-scripts && \
+        npx turbo build:inspector-ui -F @rivetkit/engine-frontend; \
     fi
 
 RUN --mount=type=cache,id=cargo-registry-linux-x64-musl,target=/usr/local/cargo/registry,sharing=locked \

docker/build/windows-x64.Dockerfile

@@ -43,6 +43,12 @@ RUN if [ "$BUILD_TARGET" = "engine" ] && [ "$BUILD_FRONTEND" = "true" ]; then \
         export SKIP_WASM_BUILD=1 && \
         pnpm install --ignore-scripts && \
         VITE_APP_API_URL="${VITE_APP_API_URL}" VITE_FEATURE_FLAGS="${VITE_FEATURE_FLAGS}" npx turbo build:engine -F @rivetkit/engine-frontend; \
+    elif [ "$BUILD_TARGET" = "rivetkit-napi" ]; then \
+        export NODE_OPTIONS="--max-old-space-size=8192" && \
+        export SKIP_NAPI_BUILD=1 && \
+        export SKIP_WASM_BUILD=1 && \
+        pnpm install --ignore-scripts && \
+        npx turbo build:inspector-ui -F @rivetkit/engine-frontend; \
     fi
 
 RUN --mount=type=cache,id=cargo-registry-windows-x64,target=/usr/local/cargo/registry,sharing=locked \

rivetkit-typescript/packages/rivetkit-napi/scripts/build.mjs

@@ -16,6 +16,14 @@ if (process.env.SKIP_NAPI_BUILD === "1") {
 	process.exit(0);
 }
 
+// The per-actor inspector UI (frontend/dist/inspector-ui, embedded into
+// rivetkit-core by its build.rs) must be built before this napi build runs.
+// It is NOT built here: rivetkit-core's embed needs rivetkit/inspector-tab,
+// which is downstream of this package in the build graph, so building it from
+// the napi build would invert the dependency order. CI builds it via
+// `turbo build:inspector-ui` in docker/build/*.Dockerfile before `napi build`;
+// for local builds run `pnpm -F @rivetkit/engine-frontend build:inspector-ui`
+// (or `turbo build:inspector-ui`) first.
 const cmd = ["build", "--platform", ...extraFlags];
 console.log(`[rivetkit-napi/build] running: napi ${cmd.join(" ")}`);
 execFileSync("napi", cmd, { stdio: "inherit" });

rivetkit-typescript/packages/rivetkit/src/registry/native.ts

@@ -4756,12 +4756,29 @@ export async function buildServeConfig(
 		serverlessMaxStartPayloadBytes: config.serverless.maxStartPayloadBytes,
 	};
 
-	if (config.startEngine) {
+	// Always best-effort resolve the npm-installed engine binary and hand its
+	// path to the core. The core alone decides whether to actually spawn a local
+	// engine (its `should_manage_engine`, based on the endpoint + spawn mode), so
+	// JS must not duplicate that decision here. Only JS knows the npm
+	// `node_modules` layout, so it resolves the path; if no binary is available
+	// (remote-only install, unsupported platform, optional deps skipped), leave
+	// it unset and let the core report `engine.binary_unavailable` if it actually
+	// needs one.
+	try {
 		const { getEnginePath } = await loadEngineCli();
 		serveConfig.engineBinaryPath = getEnginePath();
-		serveConfig.engineHost = config.engineHost;
-		serveConfig.enginePort = config.enginePort;
+	} catch (error) {
+		// The npm-installed engine binary could not be resolved. The core still
+		// decides whether it needs to spawn a local engine; if it does, it will
+		// fail with engine.binary_unavailable (auto-download is off in the napi
+		// runtime). Warn so the cause is actionable.
+		logger().warn({
+			msg: "could not resolve a local engine binary; if a local engine must be spawned it will fail with engine.binary_unavailable — set RIVET_ENGINE_BINARY_PATH or install the @rivetkit/engine-cli platform package",
+			error: stringifyError(error),
+		});
 	}
+	serveConfig.engineHost = config.engineHost;
+	serveConfig.enginePort = config.enginePort;
 	if (config.test?.enabled) {
 		serveConfig.inspectorTestToken =
 			getEnvUniversal("_RIVET_TEST_INSPECTOR_TOKEN") ?? "token";

rivetkit-typescript/packages/rivetkit/src/registry/runtime.ts

@@ -1,5 +1,7 @@
+import { stringifyError } from "@/common/utils";
 import type { SqliteNativeMetrics } from "@/common/database/config";
 import type { RegistryConfig } from "./config";
+import { logger } from "./log";
 
 declare const handleBrand: unique symbol;
 
@@ -599,11 +601,25 @@ export async function buildServeConfig(
 		serverlessMaxStartPayloadBytes: config.serverless.maxStartPayloadBytes,
 	};
 
-	if (config.startEngine) {
+	// Always best-effort resolve the engine binary path and hand it to the core.
+	// The core alone decides whether to actually spawn a local engine, so JS must
+	// not duplicate that decision here. `loadEnginePath` throws when no binary is
+	// available (remote-only install, unsupported platform, optional deps
+	// skipped); in that case leave it unset and let the core report
+	// `engine.binary_unavailable` only if it actually needs one.
+	try {
 		serveConfig.engineBinaryPath = await loadEnginePath();
-		serveConfig.engineHost = config.engineHost;
-		serveConfig.enginePort = config.enginePort;
+	} catch (error) {
+		// The engine binary could not be resolved. The core still decides whether
+		// it needs to spawn a local engine; if it does, it will fail with
+		// engine.binary_unavailable (auto-download is off in the napi runtime).
+		logger().warn({
+			msg: "could not resolve a local engine binary; if a local engine must be spawned it will fail with engine.binary_unavailable — set RIVET_ENGINE_BINARY_PATH or install the @rivetkit/engine-cli platform package",
+			error: stringifyError(error),
+		});
 	}
+	serveConfig.engineHost = config.engineHost;
+	serveConfig.enginePort = config.enginePort;
 	if (config.test?.enabled) {
 		serveConfig.inspectorTestToken =
 			process.env._RIVET_TEST_INSPECTOR_TOKEN ?? "token";

scripts/publish/src/ci/bin.ts

@@ -47,15 +47,21 @@ const RUST_CRATES = [
 	"rivet-error",
 	"rivet-metrics",
 	"rivet-util-serde",
+	// rivet-envoy-protocol must precede rivet-depot-client, which pins it as an
+	// exact dependency. Publishing depot-client first makes cargo fail to
+	// resolve rivet-envoy-protocol because it is not yet on crates.io.
+	"rivet-envoy-protocol",
 	"rivet-depot-client-types",
 	"rivet-depot-client",
-	"rivet-envoy-protocol",
 	"rivetkit-shared-types",
 	"rivet-envoy-client",
 	"rivetkit-actor-persist",
 	"rivetkit-client-protocol",
 	"rivetkit-inspector-protocol",
 	"rivetkit-client",
+	// rivetkit-core has an optional dependency on rivetkit-engine-process, which
+	// cargo still requires to be resolvable on crates.io at publish time.
+	"rivetkit-engine-process",
 	"rivetkit-core",
 	"rivetkit",
 ] as const;

scripts/publish/src/lib/npm.ts

@@ -385,8 +385,12 @@ export async function publishAll(
 		counts.failed === 0 &&
 		counts.alreadyExists === packages.length
 	) {
-		throw new Error(
-			`release mode: all ${packages.length} packages already published at this version. Did you forget to bump the version?`,
+		// This usually means a forgotten version bump, but it also happens on a
+		// legitimate re-run after npm fully published and a later pipeline step
+		// (crates.io, git tag, GitHub release) failed. Warn instead of failing so
+		// the re-run can reach those downstream steps; they are idempotent.
+		log.warn(
+			`release mode: all ${packages.length} packages already published at this version. Continuing (assuming a re-run); ensure the version was bumped.`,
 		);
 	}
 

scripts/publish/src/lib/version.ts

@@ -60,6 +60,7 @@ const PUBLISHED_RUST_WORKSPACE_DEPS = new Set([
 	"rivetkit-inspector-protocol",
 	"rivetkit-client",
 	"rivetkit-core",
+	"rivetkit-engine-process",
 ]);
 
 export interface BumpOptions {

scripts/publish/src/local/cut-release.ts

@@ -24,6 +24,7 @@ import { Command } from "commander";
 import { $ } from "execa";
 import { scoped } from "../lib/logger.js";
 import {
+	bumpCargoVersions,
 	bumpPackageJsons,
 	getLatestGitVersion,
 	listRecentVersions,
@@ -137,6 +138,14 @@ async function main() {
 	log.info("updating source files (Cargo.toml, examples)");
 	await updateSourceFiles(repoRoot, version);
 
+	// Bump the Cargo.toml workspace dependency pins (the `version = "=X"`
+	// exact pins on internal crates). updateSourceFiles only rewrites the
+	// [workspace.package] version, so without this the internal crate pins
+	// stay on the previous version and the Rust/wasm build fails to resolve.
+	// Always writes (like updateSourceFiles); dry-run still mutates source
+	// files and only skips the commit/push/trigger tail.
+	await bumpCargoVersions(repoRoot, version);
+
 	// 6. Rewrite package.json version fields via discovery. Uses versionOnly
 	// mode so `workspace:*` dep specs are preserved — the lockfile depends on
 	// them. CI runs the full publish-time bump (with dep rewriting +

turbo.json

@@ -25,6 +25,18 @@
 			"outputs": ["dist/**"],
 			"env": ["BASE_URL", "VITE_APP_*", "VITE_FEATURE_FLAGS"]
 		},
+		"build:inspector-ui": {
+			"dependsOn": ["^build"],
+			"inputs": [
+				"src/**",
+				"apps/inspector-ui/**",
+				"scripts/**",
+				"vite.inspector-ui.config.ts",
+				"tsconfig.json",
+				"package.json"
+			],
+			"outputs": ["dist/inspector-ui/**", "dist/inspector-tab/**"]
+		},
 		"build:ladle": {
 			"dependsOn": ["^build"],
 			"inputs": [