diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a02b8463c1..fe8214e3d3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -819,6 +819,11 @@ jobs:
         with:
           save: "true"
       - run: npm ci
+      - name: Typecheck with the official Windows compiler
+        env:
+          GOMAXPROCS: "2"
+          GOMEMLIMIT: "3GiB"
+        run: npm run typecheck -- --checkers 2
       - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         with:
           name: rea-build-cache
@@ -849,6 +854,7 @@ jobs:
           npx vitest run --coverage.enabled=false
           src/process/capture/FilesystemSnapshot.test.ts
           tests/process-global/filesystemSnapshotFallbackCancellation.test.ts
+          tests/boundary/filesystem/typescriptCompiler.test.ts
           tests/boundary/filesystem/binaryTarget.test.ts
           tests/boundary/filesystem/safeOutputTree.test.ts
           tests/boundary/providers/native/artifactProvider.archiveSafety.test.ts
diff --git a/docs/testing.md b/docs/testing.md
index 4152100bd3..43ba47cde5 100644
--- a/docs/testing.md
+++ b/docs/testing.md
@@ -46,6 +46,24 @@ without executing tests or building. A missing Git base reports how to fetch
 it or select another revision.
 
 Source typechecking needs no compiled runtime or generated test metadata.
+Typecheck, runtime compilation, and Frida binding verification share
+`scripts/run-typescript.mjs`. The pinned tsrs package supplies Linux x64/arm64
+(GNU and musl) and macOS arm64 compilers. Windows and other unsupported hosts
+retain the existing stable official TypeScript compiler. Its upstream version
+can differ from tsrs, so both compiler tasks hash the selected package and version
+through `scripts/run-turbo.mjs` before cache lookup. Outputs from different
+compilers occupy different cache entries. Repository npm scripts and focused-test
+preparation use that entrypoint; a raw Turbo compiler task without matching
+identity fails instead of publishing an ambiguous successful cache entry.
+A missing binary on a supported host also fails without silently falling back.
+
+The Rust compiler defaults to at most two checker threads. For `--noEmit` checks,
+`--maxMemory 3G` also sets a soft memory target; emit builds do not use that target.
+Explicit compiler arguments can override the defaults. These controls do not
+impose a process-family memory limit. Termux's explicit build, Stryker's compiler
+API dependency, and independent fixture compiler oracles keep their existing
+TypeScript versions.
+
 `npm run build:cached` compiles the CLI/MCP runtime and its packaged skill.
 Turbo's strict task environment preserves caller-selected `GOMAXPROCS`,
 `GOMEMLIMIT`, and `UV_THREADPOOL_SIZE` for resource-constrained builds and
@@ -233,6 +251,11 @@ and retain representative compiled CLI parity checks. Every distinct source
 scenario still runs through the public workflow; session-lifecycle scenarios
 need their own sessions and cleanup assertions.
 
+When a matrix already holds a named tool definition from live `tools/list`,
+pass that definition through the SDK's `toolDefinition` call option. This keeps
+the selected output-schema validation without eagerly compiling unrelated
+catalog schemas. Re-read definitions if the server advertises a changed list.
+
 Report unavailable authority as a named skip. Await owned cleanup before a
 verifier reports success. Native process inspectors are released at Vitest
 worker teardown; fork termination does not run Node exit hooks, and per-file
@@ -648,8 +671,11 @@ missing entries are omitted as whole entries, and consumers rebuild cache misses
 including when every entry is unavailable. Malformed plans, non-file entries,
 and I/O errors other than disappearance still fail publication. After a trusted
 static run, superseded cross-run Turbo snapshots for that OS and architecture
-are deleted down to the two newest generations. The Windows lane relies on the Linux static job for typechecking. They retain the normal build and prepack
-commands, which restore matching outputs or rebuild on a cache miss. Native
+are deleted down to the two newest generations. The Windows lane also runs the
+official compiler's complete source typecheck with two checker threads,
+independently of the accelerated Linux checker. Both lanes retain the normal
+build and prepack commands, which restore matching outputs or rebuild on a cache
+miss. Native
 artifacts, dependency installs, package archives, and runtime verification remain
 host-local. Keep platform-dependent outputs out of this shared cache.
 
diff --git a/licenses/npm-dependencies.txt b/licenses/npm-dependencies.txt
index 8225eedadf..03d4921e06 100644
--- a/licenses/npm-dependencies.txt
+++ b/licenses/npm-dependencies.txt
@@ -2,7 +2,7 @@ REA npm dependency inventory
 Prepared from the root package-lock.json; refresh this inventory when locked dependencies change.
 License identifiers are upstream lockfile declarations, not a legal assessment.
 Runtime includes transitive and optional platform packages; development includes build, test and website tooling.
-Locked package entries: 752; runtime: 180.
+Locked package entries: 758; runtime: 180.
 Full runtime copyright/license/NOTICE texts: npm-runtime-notices.txt.
 
 @algolia/abtesting@1.25.0 | development | MIT
@@ -1390,6 +1390,31 @@ commander@13.1.0 | runtime | MIT
   Package: https://www.npmjs.com/package/@toon-format/toon/v/2.3.1
   Archive: https://registry.npmjs.org/@toon-format/toon/-/toon-2.3.1.tgz
   Integrity: sha512-sWqEMeAJGMda9qRrfPKrX3C4c33CO9SJuvJzzrcBEn5sbDB+k6pSLkDsfN0rVnLQwR97MV3sDgVbcxQNsq8xVw==
+@tsrs/darwin-arm64@0.18.0-ts7.1.0-dev.20260929 | development, optional | Apache-2.0
+  Lockfile path: node_modules/@tsrs/darwin-arm64
+  Package: https://www.npmjs.com/package/@tsrs/darwin-arm64/v/0.18.0-ts7.1.0-dev.20260929
+  Archive: https://registry.npmjs.org/@tsrs/darwin-arm64/-/darwin-arm64-0.18.0-ts7.1.0-dev.20260929.tgz
+  Integrity: sha512-sAirMpaGA9uRQm2W+t4zC7PjnijNuFa4PCSIfLKKo0JyAUCRfnMeev0UGBQ9F3g+9Nz187tvikUs5Irh5+eajA==
+@tsrs/linux-arm64-gnu@0.18.0-ts7.1.0-dev.20260929 | development, optional | Apache-2.0
+  Lockfile path: node_modules/@tsrs/linux-arm64-gnu
+  Package: https://www.npmjs.com/package/@tsrs/linux-arm64-gnu/v/0.18.0-ts7.1.0-dev.20260929
+  Archive: https://registry.npmjs.org/@tsrs/linux-arm64-gnu/-/linux-arm64-gnu-0.18.0-ts7.1.0-dev.20260929.tgz
+  Integrity: sha512-zm9/z9yylig68JiZF4Aq0Cm26n09KEU8YoQRlG7tdDWTBNAIViYw8knxnWYsjMWVZ2XiU4mYq1xdrOKuOgABHg==
+@tsrs/linux-arm64-musl@0.18.0-ts7.1.0-dev.20260929 | development, optional | Apache-2.0
+  Lockfile path: node_modules/@tsrs/linux-arm64-musl
+  Package: https://www.npmjs.com/package/@tsrs/linux-arm64-musl/v/0.18.0-ts7.1.0-dev.20260929
+  Archive: https://registry.npmjs.org/@tsrs/linux-arm64-musl/-/linux-arm64-musl-0.18.0-ts7.1.0-dev.20260929.tgz
+  Integrity: sha512-Lw7VVU/YQ9JcarODICEiwzMLdFqZprqh5RGTgbS5Uc6I95P635/g5xA1pOC8RVs4efBvAR30J54iDG3l5JEYiw==
+@tsrs/linux-x64-gnu@0.18.0-ts7.1.0-dev.20260929 | development, optional | Apache-2.0
+  Lockfile path: node_modules/@tsrs/linux-x64-gnu
+  Package: https://www.npmjs.com/package/@tsrs/linux-x64-gnu/v/0.18.0-ts7.1.0-dev.20260929
+  Archive: https://registry.npmjs.org/@tsrs/linux-x64-gnu/-/linux-x64-gnu-0.18.0-ts7.1.0-dev.20260929.tgz
+  Integrity: sha512-EdBwBgNICGu1r1h23ixdcKwsMo6E9ll7ZsY3mNERNYqE1Pwdtcat99d5E7zB1J+oy/Xk6YqiizaB6nolIjpDTw==
+@tsrs/linux-x64-musl@0.18.0-ts7.1.0-dev.20260929 | development, optional | Apache-2.0
+  Lockfile path: node_modules/@tsrs/linux-x64-musl
+  Package: https://www.npmjs.com/package/@tsrs/linux-x64-musl/v/0.18.0-ts7.1.0-dev.20260929
+  Archive: https://registry.npmjs.org/@tsrs/linux-x64-musl/-/linux-x64-musl-0.18.0-ts7.1.0-dev.20260929.tgz
+  Integrity: sha512-LHk+AOAtXuTlhJhOJ2+elriEIX17ycXljojeNxrrzckOipTG1LksoVWuCSas2nu00EnWAzrdKpt9oqPylUKZfQ==
 @turbo/darwin-64@2.11.7 | development, optional | MIT
   Lockfile path: node_modules/@turbo/darwin-64
   Package: https://www.npmjs.com/package/@turbo/darwin-64/v/2.11.7
@@ -3400,6 +3425,11 @@ tslib@2.8.1 | development | 0BSD
   Package: https://www.npmjs.com/package/tslib/v/2.8.1
   Archive: https://registry.npmjs.org/tslib/-/tslib-2.8.1.tgz
   Integrity: sha512-oJFu94HQb+KVduSUQL7wnpmqnfmLsOA/nAh6b6EH0wCEoK0/mPeXU6c3wKDV83MkOuHPRHtSXKKU99IBazS/2w==
+tsrs@0.18.0-ts7.1.0-dev.20260929 | development | Apache-2.0
+  Lockfile path: node_modules/tsrs
+  Package: https://www.npmjs.com/package/tsrs/v/0.18.0-ts7.1.0-dev.20260929
+  Archive: https://registry.npmjs.org/tsrs/-/tsrs-0.18.0-ts7.1.0-dev.20260929.tgz
+  Integrity: sha512-9T0b4Uam/yMFIK16GUx0fUrJqYZnJ/gvSmV9JB8NTyDePvwCI45WFWxyEV/UMV3KfdNRJG/PBsm3fSIB9WmWsA==
 tsx@4.23.15 | development | MIT
   Lockfile path: node_modules/tsx
   Package: https://www.npmjs.com/package/tsx/v/4.23.15
diff --git a/package-lock.json b/package-lock.json
index a8d20bd23d..392b35cdbf 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -74,6 +74,7 @@
         "oxfmt": "0.72.0",
         "oxlint": "1.87.0",
         "rolldown": "1.2.12",
+        "tsrs": "0.18.0-ts7.1.0-dev.20260929",
         "tsx": "4.23.15",
         "turbo": "2.11.7",
         "typescript": "7.0.2",
@@ -4407,6 +4408,103 @@
       "integrity": "sha512-sWqEMeAJGMda9qRrfPKrX3C4c33CO9SJuvJzzrcBEn5sbDB+k6pSLkDsfN0rVnLQwR97MV3sDgVbcxQNsq8xVw==",
       "license": "MIT"
     },
+    "node_modules/@tsrs/darwin-arm64": {
+      "version": "0.18.0-ts7.1.0-dev.20260929",
+      "resolved": "https://registry.npmjs.org/@tsrs/darwin-arm64/-/darwin-arm64-0.18.0-ts7.1.0-dev.20260929.tgz",
+      "integrity": "sha512-sAirMpaGA9uRQm2W+t4zC7PjnijNuFa4PCSIfLKKo0JyAUCRfnMeev0UGBQ9F3g+9Nz187tvikUs5Irh5+eajA==",
+      "cpu": [
+        "arm64"
+      ],
+      "dev": true,
+      "license": "Apache-2.0",
+      "optional": true,
+      "os": [
+        "darwin"
+      ],
+      "engines": {
+        "node": ">=16.20.0"
+      }
+    },
+    "node_modules/@tsrs/linux-arm64-gnu": {
+      "version": "0.18.0-ts7.1.0-dev.20260929",
+      "resolved": "https://registry.npmjs.org/@tsrs/linux-arm64-gnu/-/linux-arm64-gnu-0.18.0-ts7.1.0-dev.20260929.tgz",
+      "integrity": "sha512-zm9/z9yylig68JiZF4Aq0Cm26n09KEU8YoQRlG7tdDWTBNAIViYw8knxnWYsjMWVZ2XiU4mYq1xdrOKuOgABHg==",
+      "cpu": [
+        "arm64"
+      ],
+      "dev": true,
+      "libc": [
+        "glibc"
+      ],
+      "license": "Apache-2.0",
+      "optional": true,
+      "os": [
+        "linux"
+      ],
+      "engines": {
+        "node": ">=16.20.0"
+      }
+    },
+    "node_modules/@tsrs/linux-arm64-musl": {
+      "version": "0.18.0-ts7.1.0-dev.20260929",
+      "resolved": "https://registry.npmjs.org/@tsrs/linux-arm64-musl/-/linux-arm64-musl-0.18.0-ts7.1.0-dev.20260929.tgz",
+      "integrity": "sha512-Lw7VVU/YQ9JcarODICEiwzMLdFqZprqh5RGTgbS5Uc6I95P635/g5xA1pOC8RVs4efBvAR30J54iDG3l5JEYiw==",
+      "cpu": [
+        "arm64"
+      ],
+      "dev": true,
+      "libc": [
+        "musl"
+      ],
+      "license": "Apache-2.0",
+      "optional": true,
+      "os": [
+        "linux"
+      ],
+      "engines": {
+        "node": ">=16.20.0"
+      }
+    },
+    "node_modules/@tsrs/linux-x64-gnu": {
+      "version": "0.18.0-ts7.1.0-dev.20260929",
+      "resolved": "https://registry.npmjs.org/@tsrs/linux-x64-gnu/-/linux-x64-gnu-0.18.0-ts7.1.0-dev.20260929.tgz",
+      "integrity": "sha512-EdBwBgNICGu1r1h23ixdcKwsMo6E9ll7ZsY3mNERNYqE1Pwdtcat99d5E7zB1J+oy/Xk6YqiizaB6nolIjpDTw==",
+      "cpu": [
+        "x64"
+      ],
+      "dev": true,
+      "libc": [
+        "glibc"
+      ],
+      "license": "Apache-2.0",
+      "optional": true,
+      "os": [
+        "linux"
+      ],
+      "engines": {
+        "node": ">=16.20.0"
+      }
+    },
+    "node_modules/@tsrs/linux-x64-musl": {
+      "version": "0.18.0-ts7.1.0-dev.20260929",
+      "resolved": "https://registry.npmjs.org/@tsrs/linux-x64-musl/-/linux-x64-musl-0.18.0-ts7.1.0-dev.20260929.tgz",
+      "integrity": "sha512-LHk+AOAtXuTlhJhOJ2+elriEIX17ycXljojeNxrrzckOipTG1LksoVWuCSas2nu00EnWAzrdKpt9oqPylUKZfQ==",
+      "cpu": [
+        "x64"
+      ],
+      "dev": true,
+      "libc": [
+        "musl"
+      ],
+      "license": "Apache-2.0",
+      "optional": true,
+      "os": [
+        "linux"
+      ],
+      "engines": {
+        "node": ">=16.20.0"
+      }
+    },
     "node_modules/@turbo/darwin-64": {
       "version": "2.11.7",
       "resolved": "https://registry.npmjs.org/@turbo/darwin-64/-/darwin-64-2.11.7.tgz",
@@ -9832,6 +9930,26 @@
       "dev": true,
       "license": "0BSD"
     },
+    "node_modules/tsrs": {
+      "version": "0.18.0-ts7.1.0-dev.20260929",
+      "resolved": "https://registry.npmjs.org/tsrs/-/tsrs-0.18.0-ts7.1.0-dev.20260929.tgz",
+      "integrity": "sha512-9T0b4Uam/yMFIK16GUx0fUrJqYZnJ/gvSmV9JB8NTyDePvwCI45WFWxyEV/UMV3KfdNRJG/PBsm3fSIB9WmWsA==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "tsrs": "bin/tsrs"
+      },
+      "engines": {
+        "node": ">=16.20.0"
+      },
+      "optionalDependencies": {
+        "@tsrs/darwin-arm64": "0.18.0-ts7.1.0-dev.20260929",
+        "@tsrs/linux-arm64-gnu": "0.18.0-ts7.1.0-dev.20260929",
+        "@tsrs/linux-arm64-musl": "0.18.0-ts7.1.0-dev.20260929",
+        "@tsrs/linux-x64-gnu": "0.18.0-ts7.1.0-dev.20260929",
+        "@tsrs/linux-x64-musl": "0.18.0-ts7.1.0-dev.20260929"
+      }
+    },
     "node_modules/tsx": {
       "version": "4.23.15",
       "resolved": "https://registry.npmjs.org/tsx/-/tsx-4.23.15.tgz",
diff --git a/package.json b/package.json
index 8aab2719b9..4b34fdb6e8 100644
--- a/package.json
+++ b/package.json
@@ -104,31 +104,31 @@
     "metadata:generate": "node scripts/run-exclusive.mjs artifacts node scripts/generate-package-metadata.mjs",
     "metadata:check": "node scripts/generate-package-metadata.mjs --check",
     "mcp-registry:check": "node scripts/verify-mcp-registry-metadata.mjs",
-    "mcp-catalog:generate": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts turbo run artifacts:mcp-catalog",
-    "mcp-catalog:check": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts turbo run mcp-catalog:check:built",
+    "mcp-catalog:generate": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts node scripts/run-turbo.mjs run artifacts:mcp-catalog",
+    "mcp-catalog:check": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts node scripts/run-turbo.mjs run mcp-catalog:check:built",
     "prebuild": "npm run deps:check",
-    "build": "node scripts/run-exclusive.mjs artifacts turbo run artifacts:skills --force",
+    "build": "node scripts/run-exclusive.mjs artifacts node scripts/run-turbo.mjs run artifacts:skills --force",
     "precheck": "npm run deps:check",
-    "check": "node scripts/run-exclusive.mjs artifacts turbo run typecheck lint:built format:check knip metadata:check && npm run verify:architecture-guards",
+    "check": "node scripts/run-exclusive.mjs artifacts node scripts/run-turbo.mjs run typecheck lint:built format:check knip metadata:check && npm run verify:architecture-guards",
     "precheck:fast": "npm run deps:check",
-    "check:fast": "turbo run typecheck lint --output-logs=errors-only",
+    "check:fast": "node scripts/run-turbo.mjs run typecheck lint --output-logs=errors-only",
     "precheck:changed": "npm run deps:check",
     "check:changed": "npm run check:fast && npm run test:changed",
     "precheck:test": "npm run deps:check",
-    "check:test": "node scripts/run-exclusive.mjs artifacts turbo run typecheck lint:built format:check knip metadata:check test:run",
+    "check:test": "node scripts/run-exclusive.mjs artifacts node scripts/run-turbo.mjs run typecheck lint:built format:check knip metadata:check test:run",
     "precheck:pr": "npm run deps:check",
-    "check:pr": "node scripts/run-exclusive.mjs artifacts turbo run typecheck lint:built format:check knip metadata:check test:run && npm run test:python && npm run docs:check && npm run jscpd && npm run scan:todos",
+    "check:pr": "node scripts/run-exclusive.mjs artifacts node scripts/run-turbo.mjs run typecheck lint:built format:check knip metadata:check test:run && npm run test:python && npm run docs:check && npm run jscpd && npm run scan:todos",
     "precheck:ci": "npm run deps:check",
     "precheck:ci:fast": "npm run deps:check",
     "precheck:ci:deep": "npm run deps:check",
     "check:ci": "npm run check:ci:fast && npm run check:ci:deep",
     "check:ci:fast": "node scripts/run-exclusive.mjs artifacts npm run check:ci:fast:tasks",
-    "check:ci:fast:tasks": "turbo run typecheck lint:built format:check",
+    "check:ci:fast:tasks": "node scripts/run-turbo.mjs run typecheck lint:built format:check",
     "check:ci:deep": "node scripts/run-exclusive.mjs artifacts npm run check:ci:deep:tasks && npm run verify:architecture-guards && npm run verify:test-discovery && npm run test:python",
-    "check:ci:deep:tasks": "turbo run knip metadata:check jscpd scan:todos",
-    "check:ci:tasks": "turbo run typecheck lint:built format:check knip metadata:check jscpd scan:todos",
+    "check:ci:deep:tasks": "node scripts/run-turbo.mjs run knip metadata:check jscpd scan:todos",
+    "check:ci:tasks": "node scripts/run-turbo.mjs run typecheck lint:built format:check knip metadata:check jscpd scan:todos",
     "ci:static-context": "node scripts/ci/static-task-context.mjs",
-    "build:cached": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts turbo run artifacts:skills",
+    "build:cached": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts node scripts/run-turbo.mjs run artifacts:skills",
     "build:termux": "node scripts/run-exclusive.mjs artifacts npm run build:termux:run",
     "build:termux:run": "npm run compile:termux && npm run artifacts:skills",
     "format": "oxfmt .",
@@ -151,7 +151,7 @@
     "test:built": "node scripts/ci/test-group.mjs built",
     "pretest:boundary": "npm run test:prepare",
     "test:boundary": "vitest run --project boundary --project cli-boundary --project process-boundary --project mcp-boundary --project process-global",
-    "pretest:mcp": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts turbo run artifacts:skills artifacts:mcp-catalog",
+    "pretest:mcp": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts node scripts/run-turbo.mjs run artifacts:skills artifacts:mcp-catalog",
     "test:mcp": "vitest run --project mcp-boundary",
     "pretest:acceptance": "npm run build:cached",
     "test:acceptance": "vitest run --project acceptance",
@@ -174,7 +174,7 @@
     "test:watch": "vitest --project domain --project services --project adapters --project composition --project conformance --project evaluation --changed",
     "pretest:watch:all": "npm run test:prepare",
     "test:watch:all": "vitest --changed",
-    "typecheck": "tsc --noEmit",
+    "typecheck": "node scripts/run-typescript.mjs --noEmit",
     "verify:test-temp-hygiene": "npm run test:prepare && node scripts/verify-test-temp-hygiene.mjs",
     "verify:hopper": "npm run verify:fixtures && npm run build:cached && node scripts/verify-real-hopper.mjs",
     "verify:hopper:deadlines": "npm run verify:fixtures && npm run build:cached && node scripts/verify-real-hopper-deadlines.mjs",
@@ -213,7 +213,7 @@
     "verify:ghidra:windows": "npm run build:cached && npm run build:ghidra-windows-fixture && node scripts/verify-real-ghidra-windows.mjs",
     "verify:browser": "npm run build:cached && node scripts/verify-real-browser.mjs",
     "verify:frida": "npm run build:cached && node scripts/verify-frida.mjs",
-    "verify:frida:bindings": "tsc --noEmit -p tsconfig.frida-verification.json",
+    "verify:frida:bindings": "node scripts/run-typescript.mjs --noEmit -p tsconfig.frida-verification.json",
     "verify:browser:dom": "node scripts/verify-browser-dom-destinations.mjs",
     "verify:browser:network": "npm run build:cached && node scripts/verify-browser-network.mjs",
     "verify:electron": "npm run build:cached && node scripts/verify-real-electron.mjs",
@@ -256,17 +256,17 @@
     "probe:windows-capabilities": "npm run build:cached && node scripts/windows-capabilities.mjs",
     "verify:published": "node scripts/verify-published-package.mjs",
     "config:print": "node scripts/print-mcp-config.mjs",
-    "evidence:generate": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts turbo run artifacts:managed-evidence",
-    "evidence:check": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts turbo run evidence:check:built",
+    "evidence:generate": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts node scripts/run-turbo.mjs run artifacts:managed-evidence",
+    "evidence:check": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts node scripts/run-turbo.mjs run evidence:check:built",
     "predocs:dev": "npm run docs:generate",
     "docs:dev": "vitepress dev docs",
     "predocs:build": "npm run docs:generate",
     "docs:build": "vitepress build docs",
     "docs:preview": "vitepress preview docs",
     "docs:generate": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts npm run docs:prepare",
-    "docs:check": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts turbo run docs:check:built && npm run test:local -- tests/conformance/readmeConsistency.test.ts",
+    "docs:check": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts node scripts/run-turbo.mjs run docs:check:built && npm run test:local -- tests/conformance/readmeConsistency.test.ts",
     "docs:check:built": "node scripts/generate-package-metadata.mjs --check && node scripts/generate-skill-metadata.mjs --check && node scripts/generate-product-catalog.mjs --check && node scripts/generate-completion-ledger.mjs --check && node scripts/check-doc-facts.mjs && node scripts/generate-error-schema.mjs --check && npm run licenses:check",
-    "docs:error-schema": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts turbo run artifacts:error-schema",
+    "docs:error-schema": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts node scripts/run-turbo.mjs run artifacts:error-schema",
     "prepack": "node scripts/prepack.mjs",
     "prepare": "node scripts/prepare.mjs",
     "verify:asset-catalog": "npm run build:cached && node scripts/verify/apple/asset-catalog.mjs",
@@ -305,16 +305,16 @@
     "verify:solidity:metadata": "npm run build:cached && node scripts/verify-solidity-metadata.mjs",
     "verify:recorded:crash": "npm run build:cached && node scripts/verify-recorded-crash.mjs",
     "mcp-catalog:check:built": "node scripts/generate-mcp-tool-catalog.mjs --check",
-    "compile": "node scripts/clean-build-output.mjs && tsc -p tsconfig.build.json && node scripts/record-catalog-digests.mjs && node scripts/bundle-runtime.mjs",
+    "compile": "node scripts/clean-build-output.mjs && node scripts/run-typescript.mjs -p tsconfig.build.json && node scripts/record-catalog-digests.mjs && node scripts/bundle-runtime.mjs",
     "compile:termux": "node scripts/clean-build-output.mjs && node --max-old-space-size=3072 node_modules/typescript-termux/lib/tsc.js -p tsconfig.build.json && node scripts/record-catalog-digests.mjs && node scripts/bundle-runtime.mjs",
     "artifacts:mcp-catalog": "node scripts/generate-mcp-tool-catalog.mjs",
     "artifacts:skills": "node scripts/generate-skill-metadata.mjs",
     "artifacts:product-catalog": "node scripts/generate-product-catalog.mjs",
     "artifacts:managed-evidence": "node scripts/generate-completion-ledger.mjs",
     "artifacts:error-schema": "node scripts/generate-error-schema.mjs",
-    "test:prepare": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts turbo run artifacts:mcp-catalog artifacts:product-catalog artifacts:managed-evidence",
+    "test:prepare": "node scripts/check-dependency-install.mjs && node scripts/run-exclusive.mjs artifacts node scripts/run-turbo.mjs run artifacts:mcp-catalog artifacts:product-catalog artifacts:managed-evidence",
     "evidence:check:built": "node scripts/generate-completion-ledger.mjs --check",
-    "docs:prepare": "node scripts/generate-package-metadata.mjs && turbo run artifacts:product-catalog artifacts:managed-evidence artifacts:error-schema",
+    "docs:prepare": "node scripts/generate-package-metadata.mjs && node scripts/run-turbo.mjs run artifacts:product-catalog artifacts:managed-evidence artifacts:error-schema",
     "verify:web:qlog": "npm run build:cached && node scripts/verify-qlog-captures.mjs",
     "licenses:generate": "node scripts/generate-third-party-inventory.mjs",
     "licenses:check": "node scripts/generate-third-party-inventory.mjs --check"
@@ -396,6 +396,7 @@
     "oxfmt": "0.72.0",
     "oxlint": "1.87.0",
     "rolldown": "1.2.12",
+    "tsrs": "0.18.0-ts7.1.0-dev.20260929",
     "tsx": "4.23.15",
     "turbo": "2.11.7",
     "typescript": "7.0.2",
diff --git a/scripts/ci/plan.mjs b/scripts/ci/plan.mjs
index e7c3de8ddb..fb9260bde4 100644
--- a/scripts/ci/plan.mjs
+++ b/scripts/ci/plan.mjs
@@ -63,6 +63,31 @@ function classifyPackage(base, head) {
   const after = JSON.parse(git("show", `${head}:package.json`));
   const { scripts: beforeScripts, ...beforeRest } = before;
   const { scripts: afterScripts, ...afterRest } = after;
+  const compilerDependencies = (metadata) => ({
+    dependencies: {
+      typescript: metadata.dependencies?.typescript,
+      tsrs: metadata.dependencies?.tsrs,
+    },
+    devDependencies: {
+      typescript: metadata.devDependencies?.typescript,
+      tsrs: metadata.devDependencies?.tsrs,
+    },
+  });
+  const compilerScripts = [
+    "compile",
+    "typecheck",
+    "build",
+    "build:cached",
+    "test:prepare",
+    "docs:prepare",
+    "verify:frida:bindings",
+  ].flatMap((name) => [name, `pre${name}`, `post${name}`]);
+  selected.package ||=
+    JSON.stringify(compilerDependencies(before)) !==
+      JSON.stringify(compilerDependencies(after)) ||
+    compilerScripts.some(
+      (name) => beforeScripts?.[name] !== afterScripts?.[name],
+    );
   if (JSON.stringify(beforeRest) !== JSON.stringify(afterRest)) {
     full("Package metadata or dependencies changed");
     return;
diff --git a/scripts/ci/scopes.mjs b/scripts/ci/scopes.mjs
index 32a15faaa3..54ebaa7d17 100644
--- a/scripts/ci/scopes.mjs
+++ b/scripts/ci/scopes.mjs
@@ -92,6 +92,17 @@ export const SCOPES = {
   ],
   // Four-host installed-package matrix and the Windows curated lane.
   package: [
+    // Both host compilers must be exercised when their installation, options,
+    // or entrypoints change; Linux's accelerated checker cannot stand in for Go.
+    "scripts/run-typescript.*",
+    "scripts/run-turbo.mjs",
+    "turbo.json",
+    "tsconfig.json",
+    "tsconfig.build.json",
+    "tsconfig.frida-verification.json",
+    "package-lock.json",
+    ".nvmrc",
+    ".npmrc",
     ".github/actions/publish-mcp/**",
     ".github/actions/prepare-release-package/**",
     ".github/workflows/release-recovery.yml",
@@ -135,6 +146,7 @@ export const SCOPES = {
     "src/application/DshCordis*.ts",
     "src/cli/interactiveSetup.ts",
     "src/cli/setupCommands.ts",
+    "tests/boundary/filesystem/typescriptCompiler.test.ts",
     "tests/boundary/filesystem/binaryTarget.test.ts",
     "tests/boundary/filesystem/safeOutputTree.test.ts",
     "tests/boundary/providers/native/artifactProvider.archiveSafety.test.ts",
diff --git a/scripts/run-development-tests.mjs b/scripts/run-development-tests.mjs
index d53b59c847..8237f8ad58 100644
--- a/scripts/run-development-tests.mjs
+++ b/scripts/run-development-tests.mjs
@@ -59,7 +59,7 @@ try {
         "scripts/run-exclusive.mjs",
         "artifacts",
         process.execPath,
-        resolve("node_modules/turbo/bin/turbo"),
+        resolve("scripts/run-turbo.mjs"),
         "run",
         ...(plan.needsBuild ? ["artifacts:skills"] : []),
         ...plan.artifactTasks,
diff --git a/scripts/run-turbo.mjs b/scripts/run-turbo.mjs
new file mode 100644
index 0000000000..0c8404bcf1
--- /dev/null
+++ b/scripts/run-turbo.mjs
@@ -0,0 +1,11 @@
+#!/usr/bin/env node
+
+import { createRequire } from "node:module";
+import { pathToFileURL } from "node:url";
+
+import { resolveTypeScriptCompiler } from "./run-typescript.mjs";
+
+// Compute the actual host compiler before Turbo hashes or restores its tasks.
+process.env.REA_TYPESCRIPT_COMPILER = resolveTypeScriptCompiler().identity;
+const require = createRequire(import.meta.url);
+await import(pathToFileURL(require.resolve("turbo/bin/turbo")).href);
diff --git a/scripts/run-typescript.d.mts b/scripts/run-typescript.d.mts
new file mode 100644
index 0000000000..f5bafbab36
--- /dev/null
+++ b/scripts/run-typescript.d.mts
@@ -0,0 +1,11 @@
+export function selectTypeScriptCompiler(
+  platform: string,
+  arch: string,
+  optionalDependencies: Readonly<Record<string, string>>,
+): "tsrs" | "typescript";
+
+export function resolveTypeScriptCompiler(): {
+  readonly name: "tsrs" | "typescript";
+  readonly identity: string;
+  readonly launcher: string;
+};
diff --git a/scripts/run-typescript.mjs b/scripts/run-typescript.mjs
new file mode 100644
index 0000000000..1fc0c2351a
--- /dev/null
+++ b/scripts/run-typescript.mjs
@@ -0,0 +1,75 @@
+#!/usr/bin/env node
+
+import { readFileSync } from "node:fs";
+import { createRequire } from "node:module";
+import { availableParallelism } from "node:os";
+import { dirname, resolve } from "node:path";
+import { fileURLToPath, pathToFileURL } from "node:url";
+
+/** Use the pinned package's platform inventory; let its launcher select libc. */
+export const selectTypeScriptCompiler = (
+  platform,
+  arch,
+  optionalDependencies,
+) => {
+  if (platform === "win32") return "typescript";
+  const prefix = `@tsrs/${platform}-${arch}`;
+  return Object.keys(optionalDependencies).some(
+    (name) => name === prefix || name.startsWith(`${prefix}-`),
+  )
+    ? "tsrs"
+    : "typescript";
+};
+
+export const resolveTypeScriptCompiler = () => {
+  const require = createRequire(import.meta.url);
+  const rustPackagePath = require.resolve("tsrs/package.json");
+  const rustPackage = JSON.parse(readFileSync(rustPackagePath, "utf8"));
+  const compiler = selectTypeScriptCompiler(
+    process.platform,
+    process.arch,
+    rustPackage.optionalDependencies,
+  );
+  const packagePath =
+    compiler === "tsrs"
+      ? rustPackagePath
+      : require.resolve("typescript/package.json");
+  const metadata =
+    compiler === "tsrs"
+      ? rustPackage
+      : JSON.parse(readFileSync(packagePath, "utf8"));
+  const command = compiler === "tsrs" ? "tsrs" : "tsc";
+  return {
+    name: compiler,
+    identity: `${compiler}@${metadata.version}`,
+    launcher: resolve(dirname(packagePath), metadata.bin[command]),
+  };
+};
+
+const main = async () => {
+  const compiler = resolveTypeScriptCompiler();
+  if (
+    process.env.TURBO_HASH !== undefined &&
+    process.env.REA_TYPESCRIPT_COMPILER !== compiler.identity
+  )
+    throw new Error(
+      "Compiler identity is missing or stale. Run Turbo through scripts/run-turbo.mjs.",
+    );
+  if (compiler.name === "tsrs") {
+    const args = process.argv.slice(2);
+    // Rust consumes --maxMemory once; duplicating it becomes an unknown option.
+    // Preserve explicit resource choices rather than injecting another value.
+    const defaults = [
+      ["--checkers", String(Math.min(2, availableParallelism()))],
+      ["--maxMemory", "3G"],
+    ].flatMap(([option, value]) =>
+      args.includes(option) ? [] : [option, value],
+    );
+    process.argv.splice(2, 0, ...defaults);
+  }
+  // Delegate execution, diagnostics, status and signals to the package's launcher.
+  // An unavailable binary on a supported host must fail rather than hide drift.
+  await import(pathToFileURL(compiler.launcher).href);
+};
+
+if (process.argv[1] === fileURLToPath(import.meta.url)) await main();
diff --git a/scripts/verify-real-browser.mjs b/scripts/verify-real-browser.mjs
index 4ba8d1e964..ed5d8f8680 100644
--- a/scripts/verify-real-browser.mjs
+++ b/scripts/verify-real-browser.mjs
@@ -555,6 +555,12 @@ async function verifyPageScopedTransport(provider, proxy, origin) {
     throw new Error(
       "Page-scoped CDP disconnect must report transport loss without claiming a target crash",
     );
+  const remaining = await provider.listTargets(
+    listBrowserTargetsInputSchema.parse({ cdp_endpoint: proxy.endpoint }),
+  );
+  if (!remaining.ok) throw remaining.error;
+  if (!remaining.value.targets.some(({ target_id }) => target_id === target))
+    throw new Error("Page-scoped CDP disconnect removed its live target");
 }
 
 async function browserExecutable() {
diff --git a/src/application/binary/AnalysisProviderRegistry.test.ts b/src/application/binary/AnalysisProviderRegistry.test.ts
index bd258f3702..a09112ff2f 100644
--- a/src/application/binary/AnalysisProviderRegistry.test.ts
+++ b/src/application/binary/AnalysisProviderRegistry.test.ts
@@ -5,6 +5,7 @@ import {
   createAnalysisExecution,
   type AnalysisClient,
   type AnalysisProviderCandidate,
+  type AnalysisProviderInspectionOptions,
   type CapabilityDescriptor,
   type ProviderAvailability,
   type ProviderIdentity,
@@ -825,7 +826,9 @@ it("joins cancelled readiness finalization and shutdown before admitting another
   const registry = new AnalysisProviderRegistry([
     {
       ...base,
-      inspectAvailability: async ({ signal } = {}) => {
+      inspectAvailability: async ({
+        signal,
+      }: AnalysisProviderInspectionOptions = {}) => {
         calls++;
         if (calls === 1) {
           observed = signal;
@@ -982,7 +985,9 @@ it("registers selection before async readiness can race shutdown", async () => {
   const registry = new AnalysisProviderRegistry([
     {
       ...base,
-      inspectAvailability: async ({ signal } = {}) => {
+      inspectAvailability: async ({
+        signal,
+      }: AnalysisProviderInspectionOptions = {}) => {
         calls++;
         observed = signal;
         return base.inspectAvailability();
diff --git a/tests/acceptance/applications/peResources.test.ts b/tests/acceptance/applications/peResources.test.ts
index 202a19e9d4..8b606bc011 100644
--- a/tests/acceptance/applications/peResources.test.ts
+++ b/tests/acceptance/applications/peResources.test.ts
@@ -9,7 +9,11 @@ import { peResourcesSchema } from "../../../src/domain/native/peResources.js";
 import { peResourceFixture } from "../../../src/native/pe/PeResources.fixture.js";
 import { createTestTempDirectory } from "../../fixtures/temporaryDirectory.js";
 import { parseMcpToolError } from "../../fixtures/mcpToolError.js";
-import { cliTest, type TestCli } from "../../support/cli/cliFixture.js";
+import {
+  cliTest,
+  runFileCli,
+  type TestCli,
+} from "../../support/cli/cliFixture.js";
 
 type PeResourceCall = (
   arguments_: Record<string, unknown>,
@@ -22,7 +26,7 @@ const expectPeInputFailureAcrossAdapters = async (input: {
   readonly reason: "invalid_format" | "invalid_value";
 }) => {
   const { cli, call, path, reason } = input;
-  const result = await cli.run({
+  const result = await runFileCli(cli, {
     arguments: ["inspect-pe-resources", path, "--json"],
   });
   expect(result.exitCode).toBe(1);
@@ -105,7 +109,7 @@ const expectPeWordAlignedRecordsAcrossAdapters = async (input: {
       );
       const path = join(root, `word-aligned-${plus}-${index}.exe`);
       await writeFile(path, fixture.bytes);
-      const result = await cli.run({
+      const result = await runFileCli(cli, {
         arguments: ["inspect-pe-resources", path, "--json"],
       });
       expect(result.exitCode, result.stderr).toBe(0);
@@ -196,7 +200,7 @@ const expectPeMappingOwnershipAcrossAdapters = async (
       });
       continue;
     }
-    const result = await cli.run({
+    const result = await runFileCli(cli, {
       arguments: ["inspect-pe-resources", path, "--json"],
     });
     expect(result.exitCode, name).toBe(0);
@@ -249,9 +253,14 @@ const expectPeInventoriesAcrossAdapters = async (
       `resource${plus ? "64" : "32"}${empty ? "-empty" : ""}.exe`,
     );
     await writeFile(path, fixture.bytes);
-    const result = await cli.run({
+    const invocation = {
       arguments: ["inspect-pe-resources", path, "--json"],
-    });
+    };
+    // Keep an independent public-wrapper process for both PE32 and PE32+.
+    // The empty-payload variants reuse only compiled-command startup.
+    const result = await (empty
+      ? runFileCli(cli, invocation)
+      : cli.run(invocation));
     expect(result.exitCode).toBe(0);
     const evidence = contract.outputSchema.parse(result.json);
     const report = peResourcesSchema.parse(evidence.normalized_result);
diff --git a/tests/boundary/filesystem/ciChangeScope.test.ts b/tests/boundary/filesystem/ciChangeScope.test.ts
index d68af5ab0c..44b8044502 100644
--- a/tests/boundary/filesystem/ciChangeScope.test.ts
+++ b/tests/boundary/filesystem/ciChangeScope.test.ts
@@ -660,7 +660,7 @@ it.each([
     {
       code: true,
       runtime: true,
-      package: false,
+      package: true,
       evm: false,
       browser: false,
     },
@@ -1155,7 +1155,7 @@ it.each([
     {
       code: true,
       runtime: true,
-      package: false,
+      package: true,
       browser: false,
       evm: false,
       sqlite: false,
@@ -1166,7 +1166,7 @@ it.each([
     {
       code: true,
       runtime: true,
-      package: false,
+      package: true,
       browser: false,
       evm: false,
     },
@@ -1496,3 +1496,89 @@ it("never runs a manual-only verifier from an automatic workflow", async () => {
     ),
   ).toEqual([]);
 });
+
+it.each([
+  "scripts/run-typescript.mjs",
+  "scripts/run-typescript.d.mts",
+  "scripts/run-turbo.mjs",
+  "turbo.json",
+  "tsconfig.json",
+  "tsconfig.build.json",
+  "tsconfig.frida-verification.json",
+  "package-lock.json",
+  ".nvmrc",
+  ".npmrc",
+])("selects package hosts for compiler input %s", async (path) => {
+  const { directory, base } = await fixture();
+  const head = await change(directory, [path]);
+  const plan = await classify(directory, base, head);
+  expect(plan).toMatchObject({
+    tier: "fast",
+    code: true,
+    runtime: true,
+    package: true,
+  });
+  expect(plan.matrix).toEqual({
+    include: [
+      { os: "ubuntu-latest", platform: "linux", architecture: "x64" },
+      { os: "ubuntu-24.04-arm", platform: "linux", architecture: "arm64" },
+      { os: "macos-15", platform: "darwin", architecture: "arm64" },
+    ],
+  });
+});
+
+it.each(["typescript", "tsrs"])(
+  "selects fallback host checks when compiler dependency %s changes",
+  async (name) => {
+    const { directory } = await fixture();
+    const before = { name: "fixture", devDependencies: { [name]: "1.0.0" } };
+    const base = await change(
+      directory,
+      ["package.json"],
+      JSON.stringify(before),
+    );
+    const head = await change(
+      directory,
+      ["package.json"],
+      JSON.stringify({ ...before, devDependencies: { [name]: "2.0.0" } }),
+    );
+    expect(await classify(directory, base, head)).toMatchObject({
+      code: true,
+      runtime: true,
+      package: true,
+    });
+  },
+);
+
+it.each([
+  "compile",
+  "typecheck",
+  "build",
+  "build:cached",
+  "test:prepare",
+  "docs:prepare",
+  "verify:frida:bindings",
+  "prebuild:cached",
+  "postcompile",
+  "pretypecheck",
+])(
+  "selects fallback host checks when compiler command %s changes",
+  async (name) => {
+    const { directory } = await fixture();
+    const base = await change(
+      directory,
+      ["package.json"],
+      JSON.stringify({ scripts: { [name]: "node scripts/old.mjs" } }),
+    );
+    const head = await change(
+      directory,
+      ["package.json"],
+      JSON.stringify({ scripts: { [name]: "node scripts/new.mjs" } }),
+    );
+    expect(await classify(directory, base, head)).toMatchObject({
+      code: true,
+      runtime: true,
+      package: true,
+    });
+  },
+);
diff --git a/tests/boundary/filesystem/ciTestReports.test.ts b/tests/boundary/filesystem/ciTestReports.test.ts
index 582b8b77fb..815f736a50 100644
--- a/tests/boundary/filesystem/ciTestReports.test.ts
+++ b/tests/boundary/filesystem/ciTestReports.test.ts
@@ -364,7 +364,7 @@ it("runs the existing onboarding and Python producer guards from their selected
     "node scripts/run-exclusive.mjs artifacts npm run check:ci:fast:tasks",
   );
   expect(scripts["check:ci:fast:tasks"]).toBe(
-    "turbo run typecheck lint:built format:check",
+    "node scripts/run-turbo.mjs run typecheck lint:built format:check",
   );
   expect(scripts["test:python"]).toContain(
     "bridge/native/test_rea_lldb_tracer.py",
diff --git a/tests/boundary/filesystem/dependencyInstall.test.ts b/tests/boundary/filesystem/dependencyInstall.test.ts
index 1eef778637..34609de849 100644
--- a/tests/boundary/filesystem/dependencyInstall.test.ts
+++ b/tests/boundary/filesystem/dependencyInstall.test.ts
@@ -196,6 +196,8 @@ const createBuildCacheFixture = async (): Promise<string> => {
     "tsconfig.json",
     "tsconfig.build.json",
     "scripts/check-dependency-install.mjs",
+    "scripts/run-turbo.mjs",
+    "scripts/run-typescript.mjs",
     "scripts/run-exclusive.mjs",
     "scripts/run-exclusive-command.mjs",
     "scripts/lib/windows-owned-command.mjs",
@@ -277,7 +279,7 @@ const runTurbo = (cwd: string, environment: NodeJS.ProcessEnv = process.env) =>
   run(
     process.execPath,
     [
-      join(cwd, "node_modules", "turbo", "bin", "turbo"),
+      join(cwd, "scripts", "run-turbo.mjs"),
       "run",
       "artifacts:skills",
       "--output-logs=full",
diff --git a/tests/boundary/filesystem/staticTaskCache.test.ts b/tests/boundary/filesystem/staticTaskCache.test.ts
index fed6cf8e9c..823dc0a7cd 100644
--- a/tests/boundary/filesystem/staticTaskCache.test.ts
+++ b/tests/boundary/filesystem/staticTaskCache.test.ts
@@ -1,6 +1,7 @@
 import { spawnSync } from "node:child_process";
+import { createRequire } from "node:module";
 import { mkdir, readFile, rm, symlink, writeFile } from "node:fs/promises";
-import { join } from "node:path";
+import { dirname, join, resolve } from "node:path";
 import { fileURLToPath } from "node:url";
 
 import { expect, it } from "vitest";
@@ -8,9 +9,10 @@ import { z } from "zod";
 
 import { createTestTempDirectory } from "../../fixtures/temporaryDirectory.js";
 import { workflowGit } from "../../support/workflowGit.js";
+import { resolveTypeScriptCompiler } from "../../../scripts/run-typescript.mjs";
 
 const repository = fileURLToPath(new URL("../../../", import.meta.url));
-const turbo = join(repository, "node_modules/turbo/bin/turbo");
+const turbo = join(repository, "scripts/run-turbo.mjs");
 const reportScript = join(repository, "scripts/ci/static-check-report.mjs");
 const rootConfigSchema = z.object({
   globalDependencies: z.array(z.string()).optional(),
@@ -349,6 +351,13 @@ it.each([
     diagnostic: "TS2322",
     invalidatesCompile: false,
   },
+  {
+    label: "compiler launcher",
+    path: "scripts/run-typescript.mjs",
+    content: 'throw new Error("compiler launcher changed");\n',
+    diagnostic: "compiler launcher changed",
+    invalidatesCompile: true,
+  },
   {
     label: "source declaration",
     path: "src/types.d.mts",
@@ -410,11 +419,15 @@ it.each([
       ["compile", "typecheck"],
       {
         // Exercise the real compiler phase with the production task inputs.
-        compile: "tsc -p tsconfig.build.json",
-        typecheck: "tsc --noEmit",
+        compile: "node scripts/run-typescript.mjs -p tsconfig.build.json",
+        typecheck: "node scripts/run-typescript.mjs --noEmit",
       },
       { "#compiler-scope": "./scripts/root-types.d.mts" },
     );
+    await writeFile(
+      join(root, "scripts/run-typescript.mjs"),
+      await readFile(join(repository, "scripts/run-typescript.mjs")),
+    );
     for (const name of [
       "tsconfig.json",
       "tsconfig.build.json",
@@ -612,3 +625,125 @@ it("invalidates checker task hashes for Node, ignore, and VitePress config chang
       `${task} must ignore vitest.config.ts`,
     ).toBe(initial.get(task));
 });
+
+it.skipIf(resolveTypeScriptCompiler().name !== "tsrs")(
+  "does not replay an official compiler success for a Rust compiler error",
+  async () => {
+    const root = await createTestTempDirectory("rea-cross-compiler-cache-");
+    const cache = await createTestTempDirectory("rea-cross-compiler-store-");
+    const require = createRequire(import.meta.url);
+    await mkdir(join(root, "scripts"));
+    await mkdir(join(root, "src"));
+    await mkdir(join(root, "node_modules/tsrs"), { recursive: true });
+    for (const name of ["typescript", "turbo"])
+      await symlink(
+        dirname(require.resolve(`${name}/package.json`)),
+        join(root, "node_modules", name),
+        "junction",
+      );
+    for (const name of ["run-typescript.mjs", "run-turbo.mjs"])
+      await writeFile(
+        join(root, "scripts", name),
+        await readFile(join(repository, "scripts", name)),
+      );
+    await writeTaskFixture(root, ["compile", "typecheck"], {
+      compile: "node scripts/run-typescript.mjs -p tsconfig.build.json",
+      typecheck: "node scripts/run-typescript.mjs --noEmit",
+    });
+    const rustPath = require.resolve("tsrs/package.json");
+    const rust = z
+      .object({ version: z.string(), bin: z.object({ tsrs: z.string() }) })
+      .parse(JSON.parse(await readFile(rustPath, "utf8")));
+    const writeInventory = (supported: boolean) =>
+      writeFile(
+        join(root, "node_modules/tsrs/package.json"),
+        JSON.stringify({
+          name: "tsrs",
+          version: rust.version,
+          bin: { tsrs: resolve(dirname(rustPath), rust.bin.tsrs) },
+          optionalDependencies: supported
+            ? { [`@tsrs/${process.platform}-${process.arch}`]: rust.version }
+            : {},
+        }),
+      );
+    await writeInventory(false);
+    await writeFile(
+      join(root, "tsconfig.json"),
+      JSON.stringify({
+        compilerOptions: {
+          strict: true,
+          rootDir: "src",
+          types: [],
+          lib: ["ES2023", "DOM"],
+          target: "ES2023",
+          module: "NodeNext",
+          outDir: "dist",
+        },
+        include: ["src/**/*.ts"],
+      }),
+    );
+    await writeFile(
+      join(root, "tsconfig.build.json"),
+      '{"extends":"./tsconfig.json"}\n',
+    );
+    await writeFile(
+      join(root, ".gitignore"),
+      "node_modules/\ndist/\n.cache/\n.turbo/\n",
+    );
+    // TS 7.0 accepts this contextual callback; TS 7.1 reports TS7031.
+    // The source stays identical while only the selected compiler changes.
+    await writeFile(
+      join(root, "src/repro.ts"),
+      [
+        "interface Options { signal?: AbortSignal }",
+        "interface Provider { inspect(options?: Options): Promise<void> }",
+        "declare const base: Provider;",
+        "const providers: Provider[] = [{ ...base, inspect: async ({ signal } = {}) => {",
+        "  if (signal?.aborted) throw signal.reason;",
+        "} }];",
+      ].join("\n"),
+    );
+    await workflowGit(root, ["init", "--initial-branch=main"]);
+    await workflowGit(root, ["add", "."]);
+    await workflowGit(root, ["commit", "-m", "test: seed compiler isolation"]);
+    const run = (task: string, dryRun = false) =>
+      execute(
+        join(root, "scripts/run-turbo.mjs"),
+        [
+          "run",
+          task,
+          ...(dryRun ? ["--dry=json"] : ["--output-logs=errors-only"]),
+          "--cache=local:rw",
+          "--cache-dir",
+          cache,
+        ],
+        root,
+      );
+    const hash = (task: string) => {
+      const result = run(task, true);
+      expect(result.status, result.stdout + result.stderr).toBe(0);
+      const entry = dryRunSchema
+        .parse(JSON.parse(result.stdout))
+        .tasks.find((value) => value.taskId === task);
+      if (entry === undefined) throw new Error(`Missing compiler task ${task}`);
+      return entry.hash;
+    };
+    const hashes = new Map<string, string>();
+    for (const task of ["compile", "typecheck"]) {
+      const cold = run(task);
+      expect(cold.status, cold.stdout + cold.stderr).toBe(0);
+      hashes.set(task, hash(task));
+      const warm = run(task);
+      expect(warm.status, warm.stdout + warm.stderr).toBe(0);
+      expect(warm.stdout).toMatch(/Cached:\s+1 cached/u);
+    }
+    await writeInventory(true);
+    for (const task of ["compile", "typecheck"]) {
+      const result = run(task);
+      expect(result.status, result.stdout + result.stderr).toBeGreaterThan(0);
+      expect(result.stdout + result.stderr).toContain("TS7031");
+      expect(result.stdout).toMatch(/Cached:\s+0 cached/u);
+      expect(hash(task)).not.toBe(hashes.get(task));
+    }
+  },
+);
diff --git a/tests/boundary/filesystem/typescriptCompiler.test.ts b/tests/boundary/filesystem/typescriptCompiler.test.ts
new file mode 100644
index 0000000000..d49f5b6089
--- /dev/null
+++ b/tests/boundary/filesystem/typescriptCompiler.test.ts
@@ -0,0 +1,206 @@
+import { spawnSync } from "node:child_process";
+import { copyFile, mkdir, readFile, writeFile } from "node:fs/promises";
+import { createRequire } from "node:module";
+import { join } from "node:path";
+import { fileURLToPath } from "node:url";
+
+import { expect, it } from "vitest";
+import { z } from "zod";
+
+import {
+  resolveTypeScriptCompiler,
+  selectTypeScriptCompiler,
+} from "../../../scripts/run-typescript.mjs";
+import { createTestTempDirectory } from "../../fixtures/temporaryDirectory.js";
+
+const repository = fileURLToPath(new URL("../../../", import.meta.url));
+const launcher = join(repository, "scripts/run-typescript.mjs");
+const require = createRequire(import.meta.url);
+const rustPackage = z
+  .object({
+    version: z.string(),
+    optionalDependencies: z.record(z.string(), z.string()),
+  })
+  .parse(
+    JSON.parse(await readFile(require.resolve("tsrs/package.json"), "utf8")),
+  );
+const officialPackage = z
+  .object({ version: z.string() })
+  .parse(
+    JSON.parse(
+      await readFile(require.resolve("typescript/package.json"), "utf8"),
+    ),
+  );
+const execute = (script: string, args: string[]) =>
+  spawnSync(process.execPath, [script, ...args], {
+    encoding: "utf8",
+    timeout: 15_000,
+    env: { ...process.env, TURBO_HASH: undefined },
+  });
+
+it.each([
+  ["linux", "x64", "tsrs"],
+  ["linux", "arm64", "tsrs"],
+  ["darwin", "arm64", "tsrs"],
+  ["win32", "x64", "typescript"],
+  ["win32", "arm64", "typescript"],
+  ["darwin", "x64", "typescript"],
+  ["android", "arm64", "typescript"],
+  ["linux", "riscv64", "typescript"],
+])(
+  "selects %s/%s compiler %s from the pinned inventory",
+  (platform, arch, compiler) => {
+    expect(
+      selectTypeScriptCompiler(
+        platform,
+        arch,
+        rustPackage.optionalDependencies,
+      ),
+    ).toBe(compiler);
+  },
+);
+
+it("always retains the official compiler on Windows", () => {
+  expect(
+    selectTypeScriptCompiler("win32", "x64", { "@tsrs/win32-x64": "future" }),
+  ).toBe("typescript");
+});
+
+it("runs the selected installed compiler", () => {
+  const result = execute(launcher, ["--version"]);
+  expect(result.error).toBeUndefined();
+  expect(result.status, result.stderr).toBe(0);
+  const compiler = selectTypeScriptCompiler(
+    process.platform,
+    process.arch,
+    rustPackage.optionalDependencies,
+  );
+  expect(result.stdout).toContain(
+    compiler === "tsrs"
+      ? `tsrs ${rustPackage.version}`
+      : `Version ${officialPackage.version}`,
+  );
+});
+
+it("forwards build arguments and preserves real type errors and exit status", async () => {
+  const root = await createTestTempDirectory("rea-typescript-compiler-");
+  const input = join(root, "input.ts");
+  await writeFile(
+    join(root, "tsconfig.json"),
+    JSON.stringify({
+      compilerOptions: {
+        strict: true,
+        target: "ES2023",
+        types: [],
+        outDir: "output",
+      },
+      files: ["input.ts"],
+    }),
+  );
+  await writeFile(input, "export const value: number = 1;\n");
+  const valid = execute(launcher, ["-p", root, "--pretty", "false"]);
+  expect(valid.error).toBeUndefined();
+  expect(valid.status, valid.stdout + valid.stderr).toBe(0);
+  expect(await readFile(join(root, "output/input.js"), "utf8")).toContain(
+    "value = 1",
+  );
+  const resourceArgs =
+    resolveTypeScriptCompiler().name === "tsrs"
+      ? ["--checkers", "1", "--maxMemory", "1G"]
+      : ["--checkers", "1"];
+  const checked = execute(launcher, ["-p", root, "--noEmit", ...resourceArgs]);
+  expect(checked.error).toBeUndefined();
+  expect(checked.status, checked.stdout + checked.stderr).toBe(0);
+  await writeFile(input, 'export const value: number = "invalid";\n');
+  const invalid = execute(launcher, [
+    "-p",
+    root,
+    "--noEmit",
+    "--pretty",
+    "false",
+  ]);
+  const direct = execute(resolveTypeScriptCompiler().launcher, [
+    "-p",
+    root,
+    "--noEmit",
+    "--pretty",
+    "false",
+  ]);
+  expect(direct.error).toBeUndefined();
+  expect(direct.status, direct.stdout + direct.stderr).toBeGreaterThan(0);
+  expect(direct.stdout + direct.stderr).toContain("TS2322");
+  expect(invalid.error).toBeUndefined();
+  expect(invalid.status, invalid.stdout + invalid.stderr).toBe(direct.status);
+  expect(invalid.stdout + invalid.stderr).toContain("TS2322");
+  expect(await readFile(join(root, "output/input.js"), "utf8")).toContain(
+    "value = 1",
+  );
+});
+
+it.skipIf(process.platform === "win32")(
+  "does not retry failed supported compilers with the official compiler",
+  async () => {
+    const root = await createTestTempDirectory("rea-typescript-failure-");
+    const script = join(root, "run-typescript.mjs");
+    await copyFile(launcher, script);
+    for (const name of ["tsrs", "typescript"]) {
+      const directory = join(root, "node_modules", name);
+      await mkdir(directory, { recursive: true });
+      await writeFile(
+        join(directory, "package.json"),
+        JSON.stringify({
+          name,
+          type: "module",
+          bin: { [name === "tsrs" ? "tsrs" : "tsc"]: "cli.mjs" },
+          optionalDependencies: {
+            [`@tsrs/${process.platform}-${process.arch}`]: "fixture",
+          },
+        }),
+      );
+      await writeFile(
+        join(directory, "cli.mjs"),
+        name === "tsrs"
+          ? 'console.error("supported compiler failed"); process.exitCode = 42;\n'
+          : 'console.log("unexpected fallback");\n',
+      );
+    }
+    const result = execute(script, ["--noEmit"]);
+    expect(result.error).toBeUndefined();
+    expect(result.status, result.stdout + result.stderr).toBe(42);
+    expect(result.stderr).toContain("supported compiler failed");
+    expect(result.stdout).not.toContain("unexpected fallback");
+    // The same selection must expose a missing installed launcher as a failure.
+    await writeFile(
+      join(root, "node_modules/tsrs/package.json"),
+      JSON.stringify({
+        name: "tsrs",
+        bin: { tsrs: "missing.mjs" },
+        optionalDependencies: {
+          [`@tsrs/${process.platform}-${process.arch}`]: "fixture",
+        },
+      }),
+    );
+    const missing = execute(script, ["--noEmit"]);
+    expect(missing.status, missing.stdout + missing.stderr).toBe(1);
+    expect(missing.stderr).toContain("ERR_MODULE_NOT_FOUND");
+    expect(missing.stdout).not.toContain("unexpected fallback");
+  },
+);
+
+it.each([undefined, "typescript@stale"])(
+  "rejects missing or stale compiler identity %s inside a Turbo task",
+  (identity) => {
+    const result = spawnSync(process.execPath, [launcher, "--version"], {
+      encoding: "utf8",
+      timeout: 15_000,
+      env: {
+        ...process.env,
+        TURBO_HASH: "compiler-task",
+        REA_TYPESCRIPT_COMPILER: identity,
+      },
+    });
+    expect(result.error).toBeUndefined();
+    expect(result.status, result.stdout + result.stderr).toBe(1);
+    expect(result.stderr).toContain("Compiler identity is missing or stale");
+  },
+);
diff --git a/tests/boundary/mcp/providerSelectionMcp.test.ts b/tests/boundary/mcp/providerSelectionMcp.test.ts
index df484959d2..66d49eec6b 100644
--- a/tests/boundary/mcp/providerSelectionMcp.test.ts
+++ b/tests/boundary/mcp/providerSelectionMcp.test.ts
@@ -12,6 +12,7 @@ import { createTestTempDirectory } from "../../fixtures/temporaryDirectory.js";
 import {
   createAnalysisExecution,
   type AnalysisProviderCandidate,
+  type AnalysisProviderInspectionOptions,
   type CapabilityDescriptor,
   type ProviderIdentity,
 } from "../../../src/application/AnalysisProvider.js";
@@ -411,7 +412,9 @@ it.each(["ready", "cancelled", "physical"] as const)(
       new AnalysisProviderRegistry([
         {
           ...base,
-          inspectAvailability: async ({ signal } = {}) => {
+          inspectAvailability: async ({
+            signal,
+          }: AnalysisProviderInspectionOptions = {}) => {
             enter();
             await gate;
             if (mode === "physical")
diff --git a/tests/process-global/curatedWindowsLane.test.ts b/tests/process-global/curatedWindowsLane.test.ts
index 637ca8d23a..48a1edda6b 100644
--- a/tests/process-global/curatedWindowsLane.test.ts
+++ b/tests/process-global/curatedWindowsLane.test.ts
@@ -136,3 +136,16 @@ it("keeps every explicit focused CI test path executable after file moves", asyn
   );
   expect(missing.filter((path) => path !== undefined)).toEqual([]);
 }, 10_000);
+
+it("checks the complete source with the fallback compiler before Windows build reuse", async () => {
+  const workflow = workflowSchema.parse(
+    parse(await readFile(WORKFLOW, "utf8")),
+  );
+  const steps = workflow.jobs["windows-curated"]?.steps ?? [];
+  const checked = steps.findIndex(
+    (step) => step.run === "npm run typecheck -- --checkers 2",
+  );
+  const built = steps.findIndex((step) => step.run === "npm run build:cached");
+  expect(checked).toBeGreaterThan(-1);
+  expect(built).toBeGreaterThan(checked);
+});
diff --git a/turbo.json b/turbo.json
index 37783a4afd..e3be6d9d9d 100644
--- a/turbo.json
+++ b/turbo.json
@@ -3,13 +3,20 @@
   "cacheMaxAge": "7d",
   "cacheMaxSize": "500MB",
   "globalDependencies": [".nvmrc", ".npmrc"],
-  "globalPassThroughEnv": ["GOMAXPROCS", "GOMEMLIMIT", "UV_THREADPOOL_SIZE"],
+  "globalPassThroughEnv": [
+    "GOMAXPROCS",
+    "GOMEMLIMIT",
+    "UV_THREADPOOL_SIZE",
+    "REA_TYPESCRIPT_COMPILER"
+  ],
   "tasks": {
     "compile": {
       "dependsOn": ["metadata:check"],
       "inputs": [
         "package.json",
         "package-lock.json",
+        "scripts/run-turbo.mjs",
+        "scripts/run-typescript.mjs",
         "scripts/check-dependency-install.mjs",
         "scripts/clean-build-output.mjs",
         "scripts/bundle-runtime.mjs",
@@ -22,12 +29,15 @@
         "tsconfig.json",
         "tsconfig.build.json"
       ],
-      "outputs": ["dist/**"]
+      "outputs": ["dist/**"],
+      "env": ["REA_TYPESCRIPT_COMPILER"]
     },
     "typecheck": {
       "inputs": [
         "package.json",
         "package-lock.json",
+        "scripts/run-turbo.mjs",
+        "scripts/run-typescript.mjs",
         "src/**/*.{cts,mts,ts,tsx}",
         "src/**/package.json",
         "tests/**/*.{cts,mts,ts,tsx}",
@@ -44,7 +54,8 @@
         "!docs/.vitepress/cache/**",
         "!docs/.vitepress/dist/**"
       ],
-      "outputs": []
+      "outputs": [],
+      "env": ["REA_TYPESCRIPT_COMPILER"]
     },
     "metadata:check": {
       "inputs": [