diff --git a/mini-test.sh b/mini-test.sh
index 9ac8c70d5..e4c26721c 100755
--- a/mini-test.sh
+++ b/mini-test.sh
@@ -23,7 +23,7 @@ for arg in "$@"; do
       cat <<'USAGE'
 Usage: ./mini-test.sh [--dist] [--fresh] [--stop] [mini args...]
 
-  --dist    run built output with plain node instead of tsx on sources
+  --dist    run built output instead of sources
   --fresh   stop the detached session server first, so it picks up your changes
   --stop    stop the detached session server and exit
 
@@ -43,4 +43,6 @@ if [[ "$USE_DIST" == "true" ]]; then
   exec node "$MINI_DIST" ${ARGS[@]+"${ARGS[@]}"}
 fi
 
-exec "$SCRIPT_DIR/node_modules/.bin/tsx" --tsconfig "$SCRIPT_DIR/tsconfig.json" "$MINI_SRC" ${ARGS[@]+"${ARGS[@]}"}
+# --import takes a module specifier, so pass the resolver as a file URL (raw paths break on #, ?, %).
+RESOLVER_URL="$(node -p 'require("node:url").pathToFileURL(process.argv[1]).href' "$SCRIPT_DIR/packages/coding-agent/src/experimental/source-resolver.ts")"
+exec node --import "$RESOLVER_URL" "$MINI_SRC" ${ARGS[@]+"${ARGS[@]}"}
diff --git a/package-lock.json b/package-lock.json
index a4b5de131..08d63a44a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -20,12 +20,10 @@
 				"@anthropic-ai/sandbox-runtime": "0.0.26",
 				"@biomejs/biome": "2.3.5",
 				"@types/node": "22.19.19",
-				"@typescript/native-preview": "7.0.0-dev.20260120.1",
 				"esbuild": "0.28.2",
 				"husky": "9.1.7",
 				"shx": "0.4.0",
-				"tsx": "4.22.1",
-				"typescript": "5.9.3"
+				"typescript": "7.0.2"
 			},
 			"engines": {
 				"node": ">=22.19.0"
@@ -1835,29 +1833,27 @@
 			"dev": true,
 			"license": "MIT"
 		},
-		"node_modules/@typescript/native-preview": {
-			"version": "7.0.0-dev.20260120.1",
-			"resolved": "https://registry.npmjs.org/@typescript/native-preview/-/native-preview-7.0.0-dev.20260120.1.tgz",
-			"integrity": "sha512-nnEf37C9ue7OBRnF2zmV/OCBmV5Y7T/K4mCHa+nxgiXcF/1w8sA0cgdFl+gHQ0mysqUJ+Bu5btAMeWgpLyjrgg==",
+		"node_modules/@typescript/typescript-aix-ppc64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-aix-ppc64/-/typescript-aix-ppc64-7.0.2.tgz",
+			"integrity": "sha512-MTKKkWB7p/0E9xi1d1tHtZ5PiLkGEMIq88pK2CubZjOsLtYTLqhgIgi6zepFa+9GHZ6h05NMCkQxGKiPXMxXtQ==",
+			"cpu": [
+				"ppc64"
+			],
 			"dev": true,
 			"license": "Apache-2.0",
-			"bin": {
-				"tsgo": "bin/tsgo.js"
-			},
-			"optionalDependencies": {
-				"@typescript/native-preview-darwin-arm64": "7.0.0-dev.20260120.1",
-				"@typescript/native-preview-darwin-x64": "7.0.0-dev.20260120.1",
-				"@typescript/native-preview-linux-arm": "7.0.0-dev.20260120.1",
-				"@typescript/native-preview-linux-arm64": "7.0.0-dev.20260120.1",
-				"@typescript/native-preview-linux-x64": "7.0.0-dev.20260120.1",
-				"@typescript/native-preview-win32-arm64": "7.0.0-dev.20260120.1",
-				"@typescript/native-preview-win32-x64": "7.0.0-dev.20260120.1"
+			"optional": true,
+			"os": [
+				"aix"
+			],
+			"engines": {
+				"node": ">=16.20.0"
 			}
 		},
-		"node_modules/@typescript/native-preview-darwin-arm64": {
-			"version": "7.0.0-dev.20260120.1",
-			"resolved": "https://registry.npmjs.org/@typescript/native-preview-darwin-arm64/-/native-preview-darwin-arm64-7.0.0-dev.20260120.1.tgz",
-			"integrity": "sha512-r3pWFuR2H7mn6ScwpH5jJljKQqKto0npVuJSk6pRwFwexpTyxOGmJTZJ1V0AWiisaNxU2+CNAqWFJSJYIE/QTg==",
+		"node_modules/@typescript/typescript-darwin-arm64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-darwin-arm64/-/typescript-darwin-arm64-7.0.2.tgz",
+			"integrity": "sha512-gowzar9MwS/aRWp6f3a4KUqzRjAZjOsmGNCM6LcTgXum+dBfgsBVMN+AgvOCCbguXyick6LJhpBszxMebJ8syA==",
 			"cpu": [
 				"arm64"
 			],
@@ -1866,12 +1862,15 @@
 			"optional": true,
 			"os": [
 				"darwin"
-			]
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
 		},
-		"node_modules/@typescript/native-preview-darwin-x64": {
-			"version": "7.0.0-dev.20260120.1",
-			"resolved": "https://registry.npmjs.org/@typescript/native-preview-darwin-x64/-/native-preview-darwin-x64-7.0.0-dev.20260120.1.tgz",
-			"integrity": "sha512-cuC1+wLbUP+Ip2UT94G134fqRdp5w3b3dhcCO6/FQ4yXxvRNyv/WK+upHBUFDaeSOeHgDTyO9/QFYUWwC4If1A==",
+		"node_modules/@typescript/typescript-darwin-x64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-darwin-x64/-/typescript-darwin-x64-7.0.2.tgz",
+			"integrity": "sha512-SZ9xZInqApNlNGc9s0W1VSsktYSOe9cFqNOIqmN1Gs8SmkjKZYFt017G4VwPxASInODuAdbTW7sXiFUf893RgA==",
 			"cpu": [
 				"x64"
 			],
@@ -1880,12 +1879,49 @@
 			"optional": true,
 			"os": [
 				"darwin"
-			]
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
 		},
-		"node_modules/@typescript/native-preview-linux-arm": {
-			"version": "7.0.0-dev.20260120.1",
-			"resolved": "https://registry.npmjs.org/@typescript/native-preview-linux-arm/-/native-preview-linux-arm-7.0.0-dev.20260120.1.tgz",
-			"integrity": "sha512-vN6OYVySol/kQZjJGmAzd6L30SyVlCgmCXS8WjUYtE5clN0YrzQHop16RK29fYZHMxpkOniVBtRPxUYQANZBlQ==",
+		"node_modules/@typescript/typescript-freebsd-arm64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-freebsd-arm64/-/typescript-freebsd-arm64-7.0.2.tgz",
+			"integrity": "sha512-W5NH4y/J0plIIS5b2xvTEkU7JFxyqdMAOgf+Ilhl0vHQXKO5dZoxd+C/jEtq56c4F3wk71RB4BMRQ2XdI+bwYQ==",
+			"cpu": [
+				"arm64"
+			],
+			"dev": true,
+			"license": "Apache-2.0",
+			"optional": true,
+			"os": [
+				"freebsd"
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
+		},
+		"node_modules/@typescript/typescript-freebsd-x64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-freebsd-x64/-/typescript-freebsd-x64-7.0.2.tgz",
+			"integrity": "sha512-UMGDx5sTpzNw3WiPebH7l90IWfJggEd+egHt/q6p7/Cm3zqoV7VxkGXt+3DxPIw8CcmvAB0j3sVVfbhX+M4Tpw==",
+			"cpu": [
+				"x64"
+			],
+			"dev": true,
+			"license": "Apache-2.0",
+			"optional": true,
+			"os": [
+				"freebsd"
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
+		},
+		"node_modules/@typescript/typescript-linux-arm": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-linux-arm/-/typescript-linux-arm-7.0.2.tgz",
+			"integrity": "sha512-gffT3xPz9sR7j/YJExkyPntrI0P2EP9XbOyWzth2/Gs0RstK+90RBcO0ncXoXy/beYll1SXw846Nf2zdnEz0QQ==",
 			"cpu": [
 				"arm"
 			],
@@ -1894,12 +1930,15 @@
 			"optional": true,
 			"os": [
 				"linux"
-			]
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
 		},
-		"node_modules/@typescript/native-preview-linux-arm64": {
-			"version": "7.0.0-dev.20260120.1",
-			"resolved": "https://registry.npmjs.org/@typescript/native-preview-linux-arm64/-/native-preview-linux-arm64-7.0.0-dev.20260120.1.tgz",
-			"integrity": "sha512-zZGvEGY7wcHYefMZ87KNmvjN3NLIhsCMHEpHZiGCS3khKf+8z6ZsanrzCjOTodvL01VPyBzHxV1EtkSxAcLiQg==",
+		"node_modules/@typescript/typescript-linux-arm64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-linux-arm64/-/typescript-linux-arm64-7.0.2.tgz",
+			"integrity": "sha512-Qh4eU4/y3yDjnfjjyPYihMj5/ODIlmt+Bzu17OI+fiSRDW57QmU5SiN63exPRNJPKUzcc1INa1NXdrJ+MqHjUQ==",
 			"cpu": [
 				"arm64"
 			],
@@ -1908,12 +1947,100 @@
 			"optional": true,
 			"os": [
 				"linux"
-			]
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
 		},
-		"node_modules/@typescript/native-preview-linux-x64": {
-			"version": "7.0.0-dev.20260120.1",
-			"resolved": "https://registry.npmjs.org/@typescript/native-preview-linux-x64/-/native-preview-linux-x64-7.0.0-dev.20260120.1.tgz",
-			"integrity": "sha512-JBfNhWd/asd5MDeS3VgRvE24pGKBkmvLub6tsux6ypr+Yhy+o0WaAEzVpmlRYZUqss2ai5tvOu4dzPBXzZAtFw==",
+		"node_modules/@typescript/typescript-linux-loong64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-linux-loong64/-/typescript-linux-loong64-7.0.2.tgz",
+			"integrity": "sha512-uEHck9i8hoAzXPiYRib1O7miOnz23SxIeVl6F4LXox+qov1K35jHcEW6VHKvZI+pyvl7fZEP4MCU5LYvIq1GuQ==",
+			"cpu": [
+				"loong64"
+			],
+			"dev": true,
+			"license": "Apache-2.0",
+			"optional": true,
+			"os": [
+				"linux"
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
+		},
+		"node_modules/@typescript/typescript-linux-mips64el": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-linux-mips64el/-/typescript-linux-mips64el-7.0.2.tgz",
+			"integrity": "sha512-R4KvAMnE43W5Qeqb0Ly56O3mWMWIAgsMyz36DCaycd5nbg/9kzm0liw3JocfRqyJY0KPmzFjbswozXyW0DnIYA==",
+			"cpu": [
+				"mips64el"
+			],
+			"dev": true,
+			"license": "Apache-2.0",
+			"optional": true,
+			"os": [
+				"linux"
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
+		},
+		"node_modules/@typescript/typescript-linux-ppc64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-linux-ppc64/-/typescript-linux-ppc64-7.0.2.tgz",
+			"integrity": "sha512-DORx5b3sd/4S7eayxm4FQv+A7CrkUIGRaHiwI8oiHTAI1fAPWhF4J0vAlkC8biAlHSVVwxMQ3tjZ2/DVbnQiiA==",
+			"cpu": [
+				"ppc64"
+			],
+			"dev": true,
+			"license": "Apache-2.0",
+			"optional": true,
+			"os": [
+				"linux"
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
+		},
+		"node_modules/@typescript/typescript-linux-riscv64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-linux-riscv64/-/typescript-linux-riscv64-7.0.2.tgz",
+			"integrity": "sha512-wf0jqEDOjrPRnKwYRyyJDRo11KMbvMFrU+q4zqKyChODBzvlkbhNQfKvLxQCcwTpdDaXSHZTVuh0JoCrKCUMHQ==",
+			"cpu": [
+				"riscv64"
+			],
+			"dev": true,
+			"license": "Apache-2.0",
+			"optional": true,
+			"os": [
+				"linux"
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
+		},
+		"node_modules/@typescript/typescript-linux-s390x": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-linux-s390x/-/typescript-linux-s390x-7.0.2.tgz",
+			"integrity": "sha512-IkwJc3L7yhytWd/ewjyxNDfOmswCm9GWMJT/ue/dU4aZNbwZeYAetq42VyLmsmSjvoX7z74X6ZaYCtzAr0EuGw==",
+			"cpu": [
+				"s390x"
+			],
+			"dev": true,
+			"license": "Apache-2.0",
+			"optional": true,
+			"os": [
+				"linux"
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
+		},
+		"node_modules/@typescript/typescript-linux-x64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-linux-x64/-/typescript-linux-x64-7.0.2.tgz",
+			"integrity": "sha512-EYdf2cNg7rgCWJnxCdJ+F3V39O8ihb37eHAu1LK8oAFizgTQbPOK7zHHXbPt8rX24COqODXeI3sIf0fCXG7H/A==",
 			"cpu": [
 				"x64"
 			],
@@ -1922,12 +2049,100 @@
 			"optional": true,
 			"os": [
 				"linux"
-			]
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
 		},
-		"node_modules/@typescript/native-preview-win32-arm64": {
-			"version": "7.0.0-dev.20260120.1",
-			"resolved": "https://registry.npmjs.org/@typescript/native-preview-win32-arm64/-/native-preview-win32-arm64-7.0.0-dev.20260120.1.tgz",
-			"integrity": "sha512-tTndRtYCq2xwgE0VkTi9ACNiJaV43+PqvBqCxk8ceYi3X36Ve+CCnwlZfZJ4k9NxZthtrAwF/kUmpC9iIYbq1w==",
+		"node_modules/@typescript/typescript-netbsd-arm64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-netbsd-arm64/-/typescript-netbsd-arm64-7.0.2.tgz",
+			"integrity": "sha512-+polYF4MF04aPpO5FTkHran9yUQDSXqy5GiSDKpsll5jy3l3+g9QLhpf39T+ePtefhXLOGrLl0QIjkQP6VnelA==",
+			"cpu": [
+				"arm64"
+			],
+			"dev": true,
+			"license": "Apache-2.0",
+			"optional": true,
+			"os": [
+				"netbsd"
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
+		},
+		"node_modules/@typescript/typescript-netbsd-x64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-netbsd-x64/-/typescript-netbsd-x64-7.0.2.tgz",
+			"integrity": "sha512-8YIT0EHM/3dq10ZOVF/A7pc/YSMtbcecct4rWtexrnSCHOPcpC2KTLXfTCR6vDpnSiY12heNb1GiN/wu+T/FyA==",
+			"cpu": [
+				"x64"
+			],
+			"dev": true,
+			"license": "Apache-2.0",
+			"optional": true,
+			"os": [
+				"netbsd"
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
+		},
+		"node_modules/@typescript/typescript-openbsd-arm64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-openbsd-arm64/-/typescript-openbsd-arm64-7.0.2.tgz",
+			"integrity": "sha512-APT8+ClYnuYm1u9+kgGXoMj2VzWzcymwh2gNSQVySHfkRDGOTVkoWLjCmOQSaO+PoqQ57B0flRp9SA+7GnnkzQ==",
+			"cpu": [
+				"arm64"
+			],
+			"dev": true,
+			"license": "Apache-2.0",
+			"optional": true,
+			"os": [
+				"openbsd"
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
+		},
+		"node_modules/@typescript/typescript-openbsd-x64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-openbsd-x64/-/typescript-openbsd-x64-7.0.2.tgz",
+			"integrity": "sha512-yX7s+Q0Dln0Dt9tEzZsAjXXR/+ytBM7AlglaqyeMPxQszJ1JhlJdZ6jLA+IzldHtflX81em7lDao1xXu+aRRkg==",
+			"cpu": [
+				"x64"
+			],
+			"dev": true,
+			"license": "Apache-2.0",
+			"optional": true,
+			"os": [
+				"openbsd"
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
+		},
+		"node_modules/@typescript/typescript-sunos-x64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-sunos-x64/-/typescript-sunos-x64-7.0.2.tgz",
+			"integrity": "sha512-dLJDGaLZ1D4HPQn62u1n8mBDkJREwMsAkCdkwd4Ieqw+x3TUyTsqY0YiBCtE6H6OzzgGk3iuZ3vFWRS+E8/d1g==",
+			"cpu": [
+				"x64"
+			],
+			"dev": true,
+			"license": "Apache-2.0",
+			"optional": true,
+			"os": [
+				"sunos"
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
+		},
+		"node_modules/@typescript/typescript-win32-arm64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-win32-arm64/-/typescript-win32-arm64-7.0.2.tgz",
+			"integrity": "sha512-Gyl1Vy6OsWesLzmq+EP0Fb7b4Nid5232AvcA2SFcdYreldpNtYFFofPjnt62y9hQy7VTaZp65ICJjuAQRaVcIQ==",
 			"cpu": [
 				"arm64"
 			],
@@ -1936,12 +2151,15 @@
 			"optional": true,
 			"os": [
 				"win32"
-			]
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
 		},
-		"node_modules/@typescript/native-preview-win32-x64": {
-			"version": "7.0.0-dev.20260120.1",
-			"resolved": "https://registry.npmjs.org/@typescript/native-preview-win32-x64/-/native-preview-win32-x64-7.0.0-dev.20260120.1.tgz",
-			"integrity": "sha512-oZia7hFL6k9pVepfonuPI86Jmyz6WlJKR57tWCDwRNmpA7odxuTq1PbvcYgy1z4+wHF1nnKKJY0PMAiq6ac18w==",
+		"node_modules/@typescript/typescript-win32-x64": {
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/@typescript/typescript-win32-x64/-/typescript-win32-x64-7.0.2.tgz",
+			"integrity": "sha512-0BQ3HkAHHlKLSp1qRvf3SUhGpGsDuhB/jgFw75guyqbxJqEaS0Cw/VFO8i2nHglJUzQCRtMMR/IBAKE3ETMC4g==",
 			"cpu": [
 				"x64"
 			],
@@ -1950,7 +2168,10 @@
 			"optional": true,
 			"os": [
 				"win32"
-			]
+			],
+			"engines": {
+				"node": ">=16.20.0"
+			}
 		},
 		"node_modules/@vitest-evals/core": {
 			"version": "0.15.0",
@@ -4860,25 +5081,6 @@
 			"integrity": "sha512-oJFu94HQb+KVduSUQL7wnpmqnfmLsOA/nAh6b6EH0wCEoK0/mPeXU6c3wKDV83MkOuHPRHtSXKKU99IBazS/2w==",
 			"license": "0BSD"
 		},
-		"node_modules/tsx": {
-			"version": "4.22.1",
-			"resolved": "https://registry.npmjs.org/tsx/-/tsx-4.22.1.tgz",
-			"integrity": "sha512-TvncJykhxAzFCk0VQZKBTClall4Pm7qXDSodb6uxi8QFa8X8mT6ABjxxsQ2opDRYxG7AzcRWXaFtruz5HJKuWg==",
-			"dev": true,
-			"license": "MIT",
-			"dependencies": {
-				"esbuild": "~0.28.0"
-			},
-			"bin": {
-				"tsx": "dist/cli.mjs"
-			},
-			"engines": {
-				"node": ">=18.0.0"
-			},
-			"optionalDependencies": {
-				"fsevents": "~2.3.3"
-			}
-		},
 		"node_modules/tunnel-agent": {
 			"version": "0.6.0",
 			"resolved": "https://registry.npmjs.org/tunnel-agent/-/tunnel-agent-0.6.0.tgz",
@@ -4905,17 +5107,38 @@
 			"license": "MIT"
 		},
 		"node_modules/typescript": {
-			"version": "5.9.3",
-			"resolved": "https://registry.npmjs.org/typescript/-/typescript-5.9.3.tgz",
-			"integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
+			"version": "7.0.2",
+			"resolved": "https://registry.npmjs.org/typescript/-/typescript-7.0.2.tgz",
+			"integrity": "sha512-8FYau96o3NKOhbjKi/qNvG/W5jhzxkbdm5sj9AbZ/5T5sWqn3hJgLfGx27sRKZWTvyzCP8dLRBTf5tBTSRVUNA==",
 			"dev": true,
 			"license": "Apache-2.0",
 			"bin": {
-				"tsc": "bin/tsc",
-				"tsserver": "bin/tsserver"
+				"tsc": "bin/tsc"
 			},
 			"engines": {
-				"node": ">=14.17"
+				"node": ">=16.20.0"
+			},
+			"optionalDependencies": {
+				"@typescript/typescript-aix-ppc64": "7.0.2",
+				"@typescript/typescript-darwin-arm64": "7.0.2",
+				"@typescript/typescript-darwin-x64": "7.0.2",
+				"@typescript/typescript-freebsd-arm64": "7.0.2",
+				"@typescript/typescript-freebsd-x64": "7.0.2",
+				"@typescript/typescript-linux-arm": "7.0.2",
+				"@typescript/typescript-linux-arm64": "7.0.2",
+				"@typescript/typescript-linux-loong64": "7.0.2",
+				"@typescript/typescript-linux-mips64el": "7.0.2",
+				"@typescript/typescript-linux-ppc64": "7.0.2",
+				"@typescript/typescript-linux-riscv64": "7.0.2",
+				"@typescript/typescript-linux-s390x": "7.0.2",
+				"@typescript/typescript-linux-x64": "7.0.2",
+				"@typescript/typescript-netbsd-arm64": "7.0.2",
+				"@typescript/typescript-netbsd-x64": "7.0.2",
+				"@typescript/typescript-openbsd-arm64": "7.0.2",
+				"@typescript/typescript-openbsd-x64": "7.0.2",
+				"@typescript/typescript-sunos-x64": "7.0.2",
+				"@typescript/typescript-win32-arm64": "7.0.2",
+				"@typescript/typescript-win32-x64": "7.0.2"
 			}
 		},
 		"node_modules/undici": {
@@ -5294,7 +5517,6 @@
 			"devDependencies": {
 				"@types/node": "22.19.19",
 				"@vitest/coverage-v8": "4.1.9",
-				"typescript": "5.9.3",
 				"vitest": "4.1.9"
 			},
 			"engines": {
@@ -5429,7 +5651,6 @@
 				"@types/semver": "7.7.1",
 				"marked": "18.0.11",
 				"shx": "0.4.0",
-				"typescript": "5.9.3",
 				"vitest": "4.1.9"
 			},
 			"engines": {
@@ -5541,7 +5762,6 @@
 				"@vitest-evals/core": "0.15.0",
 				"autoevals": "0.3.0",
 				"shx": "0.4.0",
-				"typescript": "5.9.3",
 				"vitest": "4.1.9",
 				"vitest-evals": "0.15.0"
 			}
diff --git a/package.json b/package.json
index 47c163512..d9fe33331 100644
--- a/package.json
+++ b/package.json
@@ -18,7 +18,7 @@
 		"build:native:darwin": "npm --prefix packages/tui run build:native:darwin",
 		"build:native:linux": "npm --prefix packages/tui run build:native:linux",
 		"build:native:win32": "npm --prefix packages/tui run build:native:win32",
-		"check": "biome check --write --error-on-warnings . && npm run check:pinned-deps && npm run check:runtime-deps && npm run check:ts-imports && npm run check:entry-graphs && npm run check:shrinkwrap && npm run check:install-lock:coding-agent && tsgo --noEmit && npm run check:browser-smoke",
+		"check": "biome check --write --error-on-warnings . && npm run check:pinned-deps && npm run check:runtime-deps && npm run check:ts-imports && npm run check:entry-graphs && npm run check:shrinkwrap && npm run check:install-lock:coding-agent && tsc --noEmit && npm run check:browser-smoke",
 		"check:browser-smoke": "node scripts/check-browser-smoke.mjs",
 		"check:pinned-deps": "node scripts/check-pinned-deps.mjs",
 		"check:runtime-deps": "node scripts/check-runtime-deps.mjs",
@@ -58,12 +58,10 @@
 		"@anthropic-ai/sandbox-runtime": "0.0.26",
 		"@biomejs/biome": "2.3.5",
 		"@types/node": "22.19.19",
-		"@typescript/native-preview": "7.0.0-dev.20260120.1",
 		"esbuild": "0.28.2",
 		"husky": "9.1.7",
 		"shx": "0.4.0",
-		"tsx": "4.22.1",
-		"typescript": "5.9.3"
+		"typescript": "7.0.2"
 	},
 	"engines": {
 		"node": ">=22.19.0"
diff --git a/packages/agent/benchmark/session/allocation-profile.ts b/packages/agent/benchmark/session/allocation-profile.ts
index 435760613..b4f89260d 100644
--- a/packages/agent/benchmark/session/allocation-profile.ts
+++ b/packages/agent/benchmark/session/allocation-profile.ts
@@ -20,15 +20,16 @@ interface AllocationProfileResult {
 const execFileAsync = promisify(execFile);
 const packageRoot = fileURLToPath(new URL("../..", import.meta.url));
 const workerPath = fileURLToPath(new URL("./allocation-profile-worker.ts", import.meta.url));
-const tsconfigPath = fileURLToPath(new URL("../tsconfig.json", import.meta.url));
+// Resolve workspace packages to their sources, matching the root tsconfig paths.
+const sourceResolverUrl = new URL("../../../coding-agent/src/experimental/source-resolver.ts", import.meta.url).href;
 const results: AllocationProfileResult[] = [];
 
 for (const target of storageBenchmarkTargets) {
 	for (const dataset of STORAGE_BENCHMARK_DATASETS) {
 		const { stdout } = await execFileAsync(
 			process.execPath,
-			["--import", "tsx", workerPath, target.name, dataset.name],
-			{ cwd: packageRoot, env: { ...process.env, TSX_TSCONFIG_PATH: tsconfigPath } },
+			["--import", sourceResolverUrl, workerPath, target.name, dataset.name],
+			{ cwd: packageRoot },
 		);
 		results.push(JSON.parse(stdout) as AllocationProfileResult);
 	}
diff --git a/packages/agent/benchmark/session/loaded-footprint.ts b/packages/agent/benchmark/session/loaded-footprint.ts
index 273422c1c..82a8a7eab 100644
--- a/packages/agent/benchmark/session/loaded-footprint.ts
+++ b/packages/agent/benchmark/session/loaded-footprint.ts
@@ -16,7 +16,8 @@ interface LoadedFootprintResult {
 const execFileAsync = promisify(execFile);
 const packageRoot = fileURLToPath(new URL("../..", import.meta.url));
 const workerPath = fileURLToPath(new URL("./loaded-footprint-worker.ts", import.meta.url));
-const tsconfigPath = fileURLToPath(new URL("../tsconfig.json", import.meta.url));
+// Resolve workspace packages to their sources, matching the root tsconfig paths.
+const sourceResolverUrl = new URL("../../../coding-agent/src/experimental/source-resolver.ts", import.meta.url).href;
 const results: LoadedFootprintResult[] = [];
 
 for (const target of storageBenchmarkTargets) {
@@ -26,12 +27,12 @@ for (const target of storageBenchmarkTargets) {
 			[
 				"--expose-gc",
 				"--import",
-				"tsx",
+				sourceResolverUrl,
 				workerPath,
 				target.name,
 				dataset.name,
 			],
-			{ cwd: packageRoot, env: { ...process.env, TSX_TSCONFIG_PATH: tsconfigPath } },
+			{ cwd: packageRoot },
 		);
 		results.push(JSON.parse(stdout) as LoadedFootprintResult);
 	}
diff --git a/packages/agent/benchmark/tsconfig.json b/packages/agent/benchmark/tsconfig.json
index 674e8c305..3e78650c6 100644
--- a/packages/agent/benchmark/tsconfig.json
+++ b/packages/agent/benchmark/tsconfig.json
@@ -1,11 +1,10 @@
 {
 	"extends": "../../../tsconfig.base.json",
 	"compilerOptions": {
-		"baseUrl": "../../..",
 		"noEmit": true,
 		"paths": {
-			"@earendil-works/pi-ai": ["packages/ai/src/index.ts"],
-			"@earendil-works/pi-ai/*": ["packages/ai/src/*"]
+			"@earendil-works/pi-ai": ["../../ai/src/index.ts"],
+			"@earendil-works/pi-ai/*": ["../../ai/src/*"]
 		}
 	},
 	"include": ["./**/*.ts", "../src/**/*.ts"]
diff --git a/packages/agent/package.json b/packages/agent/package.json
index b2732d5d9..fa8c6cd78 100644
--- a/packages/agent/package.json
+++ b/packages/agent/package.json
@@ -48,10 +48,10 @@
 		"clean": "shx rm -rf dist",
 		"generate-telemetry-docs": "node scripts/generate-telemetry-docs.ts",
 		"check:telemetry-docs": "node scripts/generate-telemetry-docs.ts --check",
-		"build": "tsgo -p tsconfig.build.json",
+		"build": "tsc -p tsconfig.build.json",
 		"bench:session:timing": "vitest bench --config vitest.benchmark.config.ts",
-		"bench:session:memory": "tsx --tsconfig benchmark/tsconfig.json benchmark/session/loaded-footprint.ts",
-		"bench:session:allocations": "tsx --tsconfig benchmark/tsconfig.json benchmark/session/allocation-profile.ts",
+		"bench:session:memory": "node --import ../coding-agent/src/experimental/source-resolver.ts benchmark/session/loaded-footprint.ts",
+		"bench:session:allocations": "node --import ../coding-agent/src/experimental/source-resolver.ts benchmark/session/allocation-profile.ts",
 		"test": "vitest --run",
 		"test:harness": "vitest --run --config vitest.harness.config.ts",
 		"test:session:conformance": "vitest --run --config vitest.harness.config.ts test/harness/memory-conformance.test.ts",
@@ -87,7 +87,6 @@
 	"devDependencies": {
 		"@types/node": "22.19.19",
 		"@vitest/coverage-v8": "4.1.9",
-		"typescript": "5.9.3",
 		"vitest": "4.1.9"
 	}
 }
diff --git a/packages/ai/package.json b/packages/ai/package.json
index eb4e39663..ebd7865f7 100644
--- a/packages/ai/package.json
+++ b/packages/ai/package.json
@@ -58,7 +58,7 @@
 		"generate-model-catalog": "node scripts/generate-models.ts --strict --json-only --json-output ../../.artifacts/model-catalog",
 		"check:model-data": "node scripts/check-model-data.ts",
 		"build": "npm run generate-models && npm run build:offline",
-		"build:offline": "npm run check:model-data && tsgo -p tsconfig.build.json && shx rm -rf dist/providers/data && shx cp -r src/providers/data dist/providers/data",
+		"build:offline": "npm run check:model-data && tsc -p tsconfig.build.json && shx rm -rf dist/providers/data && shx cp -r src/providers/data dist/providers/data",
 		"test": "vitest --run",
 		"prepublishOnly": "npm run clean && npm run build"
 	},
diff --git a/packages/chord/package.json b/packages/chord/package.json
index 10dd4270f..e1aacf0a6 100644
--- a/packages/chord/package.json
+++ b/packages/chord/package.json
@@ -41,7 +41,7 @@
 	],
 	"scripts": {
 		"clean": "shx rm -rf dist",
-		"build": "tsgo -p tsconfig.build.json",
+		"build": "tsc -p tsconfig.build.json",
 		"test": "vitest --run",
 		"prepublishOnly": "npm run clean && npm run build"
 	},
diff --git a/packages/client/package.json b/packages/client/package.json
index 9104494a9..9f6eb7088 100644
--- a/packages/client/package.json
+++ b/packages/client/package.json
@@ -24,9 +24,9 @@
 	],
 	"scripts": {
 		"clean": "shx rm -rf dist",
-		"build": "tsgo -p tsconfig.build.json",
+		"build": "tsc -p tsconfig.build.json",
 		"test": "vitest --run",
-		"typecheck": "tsgo -p tsconfig.test.json",
+		"typecheck": "tsc -p tsconfig.test.json",
 		"prepublishOnly": "npm run clean && npm run build"
 	},
 	"keywords": [
diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index 4ab640f42..ca85bcf72 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -10,6 +10,10 @@
 - Added the `provider_stream_event` extension event for observing parsed provider events before normalization, with an opt-in `/debug-provider` example viewer ([#9784](https://github.com/earendil-works/pi/issues/9784)).
 - Added a show/hide toggle (`H`) in HTML exports for custom messages marked `display: false`. Messages remain hidden by default and can also be revealed from the sidebar ([#8896](https://github.com/earendil-works/pi/issues/8896)).
 
+### Changed
+
+- Switched the build from the TypeScript native preview to TypeScript 7.0 with an ES2024 target, and replaced `tsx` with Node's built-in type stripping for running from source ([#9965](https://github.com/earendil-works/pi/issues/9965)).
+
 ### Fixed
 
 - Fixed X11 clipboard text being misidentified as an image when the clipboard owner accepts unadvertised image targets ([#9786](https://github.com/earendil-works/pi/issues/9786)).
diff --git a/packages/coding-agent/examples/README.md b/packages/coding-agent/examples/README.md
index 6783a02f3..80bc5e4e0 100644
--- a/packages/coding-agent/examples/README.md
+++ b/packages/coding-agent/examples/README.md
@@ -9,7 +9,7 @@ Example code for the pi-coding-agent SDK, process integration, and extensions.
 Build the coding-agent package before running it from a repository checkout:
 
 ```bash
-npx tsx examples/rpc-client.ts "Explain this repository"
+node examples/rpc-client.ts "Explain this repository"
 ```
 
 ## Directories
diff --git a/packages/coding-agent/examples/extensions/custom-provider-gitlab-duo/test.ts b/packages/coding-agent/examples/extensions/custom-provider-gitlab-duo/test.ts
index 79ba3d718..ce8a392b2 100644
--- a/packages/coding-agent/examples/extensions/custom-provider-gitlab-duo/test.ts
+++ b/packages/coding-agent/examples/extensions/custom-provider-gitlab-duo/test.ts
@@ -1,16 +1,16 @@
 /**
  * Test script for GitLab Duo extension
- * Run: npx tsx test.ts [model-id] [--thinking]
+ * Run: node test.ts [model-id] [--thinking]
  *
  * Examples:
- *   npx tsx test.ts                              # Test default (claude-sonnet-4-5-20250929)
- *   npx tsx test.ts gpt-5-codex                  # Test GPT-5 Codex
- *   npx tsx test.ts claude-sonnet-4-5-20250929 --thinking
+ *   node test.ts                              # Test default (claude-sonnet-4-5-20250929)
+ *   node test.ts gpt-5-codex                  # Test GPT-5 Codex
+ *   node test.ts claude-sonnet-4-5-20250929 --thinking
  */
 
 import { type Api, type Context, type Model, registerApiProvider, streamSimple } from "@earendil-works/pi-ai/compat";
+import { getAgentDir } from "@earendil-works/pi-coding-agent";
 import { readFileSync } from "fs";
-import { getAgentDir } from "packages/coding-agent/src/config.js";
 import { join } from "path";
 import { MODELS, streamGitLabDuo } from "./index.ts";
 
diff --git a/packages/coding-agent/examples/rpc-client.ts b/packages/coding-agent/examples/rpc-client.ts
index f31c67944..38eff524e 100644
--- a/packages/coding-agent/examples/rpc-client.ts
+++ b/packages/coding-agent/examples/rpc-client.ts
@@ -2,7 +2,7 @@
  * Run one prompt through a Pi RPC child process.
  *
  * Build the coding-agent package first, then run:
- * npx tsx examples/rpc-client.ts "Explain this repository"
+ * node examples/rpc-client.ts "Explain this repository"
  */
 
 import { dirname, join } from "node:path";
diff --git a/packages/coding-agent/examples/rpc-extension-ui.ts b/packages/coding-agent/examples/rpc-extension-ui.ts
index 401b7bb0f..0d2be07a5 100644
--- a/packages/coding-agent/examples/rpc-extension-ui.ts
+++ b/packages/coding-agent/examples/rpc-extension-ui.ts
@@ -5,7 +5,7 @@
  * Demonstrates how to build a custom UI on top of the RPC protocol,
  * including handling extension UI requests (select, confirm, input, editor).
  *
- * Usage: npx tsx examples/rpc-extension-ui.ts
+ * Usage: node examples/rpc-extension-ui.ts
  *
  * Slash commands:
  *   /select  - demo select dialog
diff --git a/packages/coding-agent/examples/sdk/README.md b/packages/coding-agent/examples/sdk/README.md
index 1f8e89f85..0adfff318 100644
--- a/packages/coding-agent/examples/sdk/README.md
+++ b/packages/coding-agent/examples/sdk/README.md
@@ -26,7 +26,7 @@ The runtime example shows how to build a recreate function that closes over proc
 
 ```bash
 cd packages/coding-agent
-npx tsx examples/sdk/01-minimal.ts
+node examples/sdk/01-minimal.ts
 ```
 
 ## Quick Reference
diff --git a/packages/coding-agent/package.json b/packages/coding-agent/package.json
index 62c01de66..c6c7a9d11 100644
--- a/packages/coding-agent/package.json
+++ b/packages/coding-agent/package.json
@@ -40,7 +40,7 @@
 	"scripts": {
 		"clean": "shx rm -rf dist",
 		"build": "npm run build:unbundled && node ../../scripts/build-coding-agent-bundle.mjs",
-		"build:unbundled": "tsgo -p tsconfig.build.json && shx chmod +x dist/cli.js dist/rpc-entry.js && npm run copy-assets",
+		"build:unbundled": "tsc -p tsconfig.build.json && shx chmod +x dist/cli.js dist/rpc-entry.js && npm run copy-assets",
 		"build:binary": "npm --prefix ../tui run build && npm --prefix ../telemetry run build && npm --prefix ../ai run build && npm --prefix ../agent run build && npm --prefix ../protocol run build && npm --prefix ../client run build && npm run build && bun build --compile --no-compile-autoload-bunfig ./src/bun/cli.ts ./src/utils/image-resize-worker.ts --outfile dist/pi && npm run copy-binary-assets",
 		"copy-assets": "shx mkdir -p dist/modes/interactive/theme && shx cp src/modes/interactive/theme/*.json dist/modes/interactive/theme/ && shx mkdir -p dist/modes/interactive/assets && shx cp src/modes/interactive/assets/*.png dist/modes/interactive/assets/ && shx mkdir -p dist/core/export-html/vendor && shx cp src/core/export-html/template.html src/core/export-html/template.css src/core/export-html/template.js dist/core/export-html/ && shx cp src/core/export-html/vendor/*.js dist/core/export-html/vendor/",
 		"copy-binary-assets": "shx cp package.json dist/ && shx cp README.md dist/ && shx cp CHANGELOG.md dist/ && shx mkdir -p dist/theme && shx cp src/modes/interactive/theme/*.json dist/theme/ && shx mkdir -p dist/assets && shx cp src/modes/interactive/assets/*.png dist/assets/ && shx mkdir -p dist/export-html/vendor && shx cp src/core/export-html/template.html dist/export-html/ && shx cp src/core/export-html/vendor/*.js dist/export-html/vendor/ && shx cp -r docs dist/ && shx cp -r examples dist/ && shx cp ../../node_modules/@silvia-odwyer/photon-node/photon_rs_bg.wasm dist/",
@@ -83,7 +83,6 @@
 		"@types/semver": "7.7.1",
 		"marked": "18.0.11",
 		"shx": "0.4.0",
-		"typescript": "5.9.3",
 		"vitest": "4.1.9"
 	},
 	"keywords": [
diff --git a/packages/coding-agent/src/config.ts b/packages/coding-agent/src/config.ts
index 98398db2a..c7fc15d0e 100644
--- a/packages/coding-agent/src/config.ts
+++ b/packages/coding-agent/src/config.ts
@@ -366,7 +366,7 @@ export function getUpdateInstruction(packageName: string): string {
 /**
  * Get the base directory for resolving package assets (themes, package.json, README.md, CHANGELOG.md).
  * - For Bun binary: returns the directory containing the executable
- * - For Node.js and tsx: returns the package root containing package.json
+ * - For Node.js: returns the package root containing package.json
  * - Ignores Bun binary metadata copied into dist/ when the package root is available
  */
 export function findNodePackageDir(startDir: string): string {
@@ -404,7 +404,7 @@ export function getPackageDir(): string {
  * Get path to built-in themes directory (shipped with package)
  * - For Bun binary: theme/ next to executable
  * - For Node.js (dist/): dist/modes/interactive/theme/
- * - For tsx (src/): src/modes/interactive/theme/
+ * - For source (src/): src/modes/interactive/theme/
  */
 export function getThemesDir(): string {
 	if (isBunBinary) {
@@ -420,7 +420,7 @@ export function getThemesDir(): string {
  * Get path to HTML export template directory (shipped with package)
  * - For Bun binary: export-html/ next to executable
  * - For Node.js (dist/): dist/core/export-html/
- * - For tsx (src/): src/core/export-html/
+ * - For source (src/): src/core/export-html/
  */
 export function getExportTemplateDir(): string {
 	if (isBunBinary) {
@@ -460,7 +460,7 @@ export function getChangelogPath(): string {
  * Get path to built-in interactive assets directory.
  * - For Bun binary: assets/ next to executable
  * - For Node.js (dist/): dist/modes/interactive/assets/
- * - For tsx (src/): src/modes/interactive/assets/
+ * - For source (src/): src/modes/interactive/assets/
  */
 export function getInteractiveAssetsDir(): string {
 	if (isBunBinary) {
diff --git a/packages/coding-agent/src/experimental/micro/README.md b/packages/coding-agent/src/experimental/micro/README.md
index 659f6dd7d..e1dc3a68b 100644
--- a/packages/coding-agent/src/experimental/micro/README.md
+++ b/packages/coding-agent/src/experimental/micro/README.md
@@ -10,8 +10,8 @@ storage. Command failures and Pico events are folded into the view, so rendering
 result side channel.
 
 ```bash
-./node_modules/.bin/tsx --tsconfig tsconfig.json packages/coding-agent/src/experimental/micro/main.ts
-./node_modules/.bin/tsx --tsconfig tsconfig.json packages/coding-agent/src/experimental/micro/main.ts --continue
+node --import ./packages/coding-agent/src/experimental/source-resolver.ts packages/coding-agent/src/experimental/micro/main.ts
+node --import ./packages/coding-agent/src/experimental/source-resolver.ts packages/coding-agent/src/experimental/micro/main.ts --continue
 ```
 
 New sessions default to `openai-codex/gpt-5.6-sol`. `--continue` keeps the session's stored model and
diff --git a/packages/coding-agent/src/experimental/mini/README.md b/packages/coding-agent/src/experimental/mini/README.md
index 7552e7b51..d327dd170 100644
--- a/packages/coding-agent/src/experimental/mini/README.md
+++ b/packages/coding-agent/src/experimental/mini/README.md
@@ -8,7 +8,7 @@ an RPC-shaped presentation actually needs from it.
 node packages/coding-agent/src/experimental/mini/main.ts [--continue]
 
 # while the harness is changing under us, run from source instead of built dist:
-./node_modules/.bin/tsx --tsconfig tsconfig.json packages/coding-agent/src/experimental/mini/main.ts
+node --import ./packages/coding-agent/src/experimental/source-resolver.ts packages/coding-agent/src/experimental/mini/main.ts
 ```
 
 `--continue` attaches to the newest session for the current directory. Starting `mini` twice attaches
diff --git a/packages/coding-agent/src/experimental/process.ts b/packages/coding-agent/src/experimental/process.ts
index 90c4b9eae..cea91b0e7 100644
--- a/packages/coding-agent/src/experimental/process.ts
+++ b/packages/coding-agent/src/experimental/process.ts
@@ -47,8 +47,9 @@ export function spawnInternalProcess(
 		throw new Error("A compiled Bun executable cannot launch an external internal-process entrypoint");
 	}
 	const entryUrl = defaultEntryUrl(role, options.entryUrl);
+	// --import takes a module specifier; a raw path breaks on Windows drives and on `#`, `?`, or `%` in the path.
 	const sourceRuntimeArgs = import.meta.url.endsWith(".ts")
-		? ["--import", fileURLToPath(new URL("source-resolver.ts", import.meta.url))]
+		? ["--import", new URL("source-resolver.ts", import.meta.url).href]
 		: [];
 	const child = spawn(
 		process.execPath,
diff --git a/packages/coding-agent/src/modes/interactive/theme/theme.ts b/packages/coding-agent/src/modes/interactive/theme/theme.ts
index 384126ffb..a9070f311 100644
--- a/packages/coding-agent/src/modes/interactive/theme/theme.ts
+++ b/packages/coding-agent/src/modes/interactive/theme/theme.ts
@@ -740,12 +740,12 @@ export function getDefaultTheme(): string {
 // Global Theme Instance
 // ============================================================================
 
-// Use globalThis to share theme across module loaders (tsx + jiti in dev mode)
+// Use globalThis to share theme across module loaders (node + jiti in dev mode)
 const THEME_KEY = Symbol.for("@earendil-works/pi-coding-agent:theme");
 const THEME_KEY_OLD = Symbol.for("@mariozechner/pi-coding-agent:theme");
 
 // Export theme as a getter that reads from globalThis
-// This ensures all module instances (tsx, jiti) see the same theme
+// This ensures all module instances (node, jiti) see the same theme
 export const theme: Theme = new Proxy({} as Theme, {
 	get(_target, prop) {
 		const t = (globalThis as Record<symbol, Theme>)[THEME_KEY];
diff --git a/packages/coding-agent/test/experimental-cli-entry.test.ts b/packages/coding-agent/test/experimental-cli-entry.test.ts
index c2277e45d..ae3b53906 100644
--- a/packages/coding-agent/test/experimental-cli-entry.test.ts
+++ b/packages/coding-agent/test/experimental-cli-entry.test.ts
@@ -2,10 +2,12 @@ import { spawnSync } from "node:child_process";
 import { mkdtempSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join, resolve } from "node:path";
+import { pathToFileURL } from "node:url";
 import { afterEach, describe, expect, it } from "vitest";
 import { VERSION } from "../src/config.ts";
 
-const sourceResolverPath = resolve(__dirname, "../src/experimental/source-resolver.ts");
+// --import takes a module specifier, not a filesystem path.
+const sourceResolverUrl = pathToFileURL(resolve(__dirname, "../src/experimental/source-resolver.ts")).href;
 const tempDirs: string[] = [];
 
 afterEach(() => {
@@ -19,7 +21,7 @@ function runEntry(entry: string, experimental: boolean) {
 		process.execPath,
 		[
 			"--import",
-			sourceResolverPath,
+			sourceResolverUrl,
 			resolve(__dirname, "../src", entry),
 			"server",
 			"--server-id",
diff --git a/packages/coding-agent/test/rpc-example.ts b/packages/coding-agent/test/rpc-example.ts
index aaa24fb1f..3be21ca55 100644
--- a/packages/coding-agent/test/rpc-example.ts
+++ b/packages/coding-agent/test/rpc-example.ts
@@ -7,7 +7,7 @@ const __dirname = dirname(fileURLToPath(import.meta.url));
 
 /**
  * Interactive example of using coding-agent via RpcClient.
- * Usage: npx tsx test/rpc-example.ts
+ * Usage: node test/rpc-example.ts
  */
 
 async function main() {
diff --git a/packages/coding-agent/test/session-file-invalid.test.ts b/packages/coding-agent/test/session-file-invalid.test.ts
index e2eb7015c..915936562 100644
--- a/packages/coding-agent/test/session-file-invalid.test.ts
+++ b/packages/coding-agent/test/session-file-invalid.test.ts
@@ -2,11 +2,13 @@ import { spawn } from "node:child_process";
 import { mkdirSync, mkdtempSync, readFileSync, realpathSync, rmSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join, resolve } from "node:path";
+import { pathToFileURL } from "node:url";
 import { afterEach, describe, expect, it } from "vitest";
 import { ENV_AGENT_DIR } from "../src/config.ts";
 
 const cliPath = resolve(__dirname, "../src/cli.ts");
-const sourceResolverPath = resolve(__dirname, "../src/experimental/source-resolver.ts");
+// --import takes a module specifier, not a filesystem path.
+const sourceResolverUrl = pathToFileURL(resolve(__dirname, "../src/experimental/source-resolver.ts")).href;
 const tempDirs: string[] = [];
 
 afterEach(() => {
@@ -24,7 +26,7 @@ function createTempDir(): string {
 async function runCli(args: string[], cwd: string, agentDir: string): Promise<{ code: number | null; stderr: string }> {
 	let stderr = "";
 	const code = await new Promise<number | null>((resolvePromise, reject) => {
-		const child = spawn(process.execPath, ["--import", sourceResolverPath, cliPath, ...args], {
+		const child = spawn(process.execPath, ["--import", sourceResolverUrl, cliPath, ...args], {
 			cwd,
 			env: {
 				...process.env,
diff --git a/packages/coding-agent/test/session-id-readonly.test.ts b/packages/coding-agent/test/session-id-readonly.test.ts
index 15916c6da..a867db789 100644
--- a/packages/coding-agent/test/session-id-readonly.test.ts
+++ b/packages/coding-agent/test/session-id-readonly.test.ts
@@ -11,6 +11,7 @@ import {
 } from "node:fs";
 import { tmpdir } from "node:os";
 import { join, resolve } from "node:path";
+import { pathToFileURL } from "node:url";
 import { afterEach, describe, expect, it, vi } from "vitest";
 import type { Args } from "../src/cli/args.ts";
 import { ENV_AGENT_DIR } from "../src/config.ts";
@@ -19,7 +20,8 @@ import { SettingsManager } from "../src/core/settings-manager.ts";
 import { createSessionManager } from "../src/main.ts";
 
 const cliPath = resolve(__dirname, "../src/cli.ts");
-const sourceResolverPath = resolve(__dirname, "../src/experimental/source-resolver.ts");
+// --import takes a module specifier, not a filesystem path.
+const sourceResolverUrl = pathToFileURL(resolve(__dirname, "../src/experimental/source-resolver.ts")).href;
 const tempDirs: string[] = [];
 
 afterEach(() => {
@@ -64,7 +66,7 @@ async function runCli(args: string[]): Promise<{ code: number | null; agentDir:
 	mkdirSync(projectDir, { recursive: true });
 
 	const code = await new Promise<number | null>((resolvePromise, reject) => {
-		const child = spawn(process.execPath, ["--import", sourceResolverPath, cliPath, ...args], {
+		const child = spawn(process.execPath, ["--import", sourceResolverUrl, cliPath, ...args], {
 			cwd: projectDir,
 			env: {
 				...process.env,
diff --git a/packages/coding-agent/test/startup-session-name.test.ts b/packages/coding-agent/test/startup-session-name.test.ts
index c953cd1ae..fbb0b1472 100644
--- a/packages/coding-agent/test/startup-session-name.test.ts
+++ b/packages/coding-agent/test/startup-session-name.test.ts
@@ -2,11 +2,13 @@ import { spawn } from "node:child_process";
 import { mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join, resolve } from "node:path";
+import { pathToFileURL } from "node:url";
 import { afterEach, describe, expect, it } from "vitest";
 import { ENV_AGENT_DIR } from "../src/config.ts";
 
 const cliPath = resolve(__dirname, "../src/cli.ts");
-const sourceResolverPath = resolve(__dirname, "../src/experimental/source-resolver.ts");
+// --import takes a module specifier, not a filesystem path.
+const sourceResolverUrl = pathToFileURL(resolve(__dirname, "../src/experimental/source-resolver.ts")).href;
 const tempDirs: string[] = [];
 
 afterEach(() => {
@@ -66,7 +68,7 @@ function readSessionInfoNames(sessionFile: string): string[] {
 
 async function runCli(args: string[], dirs: CliDirs): Promise<CliResult> {
 	let stderr = "";
-	const child = spawn(process.execPath, ["--import", sourceResolverPath, cliPath, ...args], {
+	const child = spawn(process.execPath, ["--import", sourceResolverUrl, cliPath, ...args], {
 		cwd: dirs.projectDir,
 		env: {
 			...process.env,
diff --git a/packages/coding-agent/test/stdout-cleanliness.test.ts b/packages/coding-agent/test/stdout-cleanliness.test.ts
index baaf296a5..c66b21f16 100644
--- a/packages/coding-agent/test/stdout-cleanliness.test.ts
+++ b/packages/coding-agent/test/stdout-cleanliness.test.ts
@@ -2,12 +2,14 @@ import { spawn } from "node:child_process";
 import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join, resolve } from "node:path";
+import { pathToFileURL } from "node:url";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { ENV_AGENT_DIR } from "../src/config.ts";
 import { allowNetwork } from "./test-network-env.ts";
 
 const cliPath = resolve(__dirname, "../src/cli.ts");
-const sourceResolverPath = resolve(__dirname, "../src/experimental/source-resolver.ts");
+// --import takes a module specifier, not a filesystem path.
+const sourceResolverUrl = pathToFileURL(resolve(__dirname, "../src/experimental/source-resolver.ts")).href;
 
 const tempDirs: string[] = [];
 
@@ -60,7 +62,7 @@ async function runCli(args: string[]): Promise<{ stdout: string; stderr: string;
 	);
 
 	return await new Promise((resolvePromise, reject) => {
-		const child = spawn(process.execPath, ["--import", sourceResolverPath, cliPath, ...args], {
+		const child = spawn(process.execPath, ["--import", sourceResolverUrl, cliPath, ...args], {
 			cwd: projectDir,
 			env: {
 				...process.env,
diff --git a/packages/coding-agent/test/streaming-render-debug.ts b/packages/coding-agent/test/streaming-render-debug.ts
index 934782380..2a1e4638b 100644
--- a/packages/coding-agent/test/streaming-render-debug.ts
+++ b/packages/coding-agent/test/streaming-render-debug.ts
@@ -1,7 +1,7 @@
 /**
  * Debug script to reproduce streaming rendering issues.
  * Uses real fixture data that caused the bug.
- * Run with: npx tsx test/streaming-render-debug.ts
+ * Run with: node --import ./src/experimental/source-resolver.ts test/streaming-render-debug.ts
  */
 
 import type { AssistantMessage } from "@earendil-works/pi-ai";
diff --git a/packages/coding-agent/test/test-theme-colors.ts b/packages/coding-agent/test/test-theme-colors.ts
index 4e7181f35..3c61a660e 100644
--- a/packages/coding-agent/test/test-theme-colors.ts
+++ b/packages/coding-agent/test/test-theme-colors.ts
@@ -242,8 +242,11 @@ if (cmd === "contrast") {
 } else if (cmd === "light" || cmd === "dark") {
 	cmdTheme(cmd);
 } else {
-	console.log("Usage:");
-	console.log("  npx tsx test-theme-colors.ts light|dark     Test built-in theme");
-	console.log("  npx tsx test-theme-colors.ts contrast 4.5   Compute colors at ratio");
-	console.log("  npx tsx test-theme-colors.ts test file.json Test any JSON file");
+	console.log("Usage (from packages/coding-agent):");
+	console.log("  node --import ./src/experimental/source-resolver.ts test/test-theme-colors.ts <command>");
+	console.log("");
+	console.log("Commands:");
+	console.log("  light|dark     Test built-in theme");
+	console.log("  contrast 4.5   Compute colors at ratio");
+	console.log("  test file.json Test any JSON file");
 }
diff --git a/packages/durable/package.json b/packages/durable/package.json
index 7e439987f..e7ffc9046 100644
--- a/packages/durable/package.json
+++ b/packages/durable/package.json
@@ -61,7 +61,7 @@
 	],
 	"scripts": {
 		"clean": "shx rm -rf dist",
-		"build": "tsgo -p tsconfig.build.json",
+		"build": "tsc -p tsconfig.build.json",
 		"test": "vitest --run",
 		"bench:storage": "vitest bench --config vitest.benchmark.config.ts",
 		"bench:storage:memory": "node --conditions=source --experimental-strip-types test/storage-memory.ts",
diff --git a/packages/evals/package.json b/packages/evals/package.json
index f7056cbc7..7609c388b 100644
--- a/packages/evals/package.json
+++ b/packages/evals/package.json
@@ -11,14 +11,13 @@
 		"test": "vitest run --config vitest.test.config.ts"
 	},
 	"devDependencies": {
-		"autoevals": "0.3.0",
 		"@earendil-works/pi-ai": "^0.87.1",
 		"@earendil-works/pi-coding-agent": "^0.87.1",
 		"@types/node": "22.19.19",
 		"@vitest-evals/core": "0.15.0",
+		"autoevals": "0.3.0",
 		"shx": "0.4.0",
-		"typescript": "5.9.3",
-		"vitest-evals": "0.15.0",
-		"vitest": "4.1.9"
+		"vitest": "4.1.9",
+		"vitest-evals": "0.15.0"
 	}
 }
diff --git a/packages/protocol/package.json b/packages/protocol/package.json
index 605655f2c..ef7f7a208 100644
--- a/packages/protocol/package.json
+++ b/packages/protocol/package.json
@@ -17,7 +17,7 @@
 	],
 	"scripts": {
 		"clean": "shx rm -rf dist",
-		"build": "tsgo -p tsconfig.build.json",
+		"build": "tsc -p tsconfig.build.json",
 		"test": "vitest --run",
 		"prepublishOnly": "npm run clean && npm run build"
 	},
diff --git a/packages/server/package.json b/packages/server/package.json
index 36cae1657..131d5240e 100644
--- a/packages/server/package.json
+++ b/packages/server/package.json
@@ -26,10 +26,10 @@
 	],
 	"scripts": {
 		"clean": "shx rm -rf dist",
-		"dev": "tsgo -p tsconfig.build.json --watch --preserveWatchOutput",
-		"build": "tsgo -p tsconfig.build.json",
+		"dev": "tsc -p tsconfig.build.json --watch --preserveWatchOutput",
+		"build": "tsc -p tsconfig.build.json",
 		"test": "vitest --run",
-		"typecheck": "tsgo -p tsconfig.test.json",
+		"typecheck": "tsc -p tsconfig.test.json",
 		"prepublishOnly": "npm run clean && npm run build"
 	},
 	"keywords": [
diff --git a/packages/session-backends/sqlite-node/package.json b/packages/session-backends/sqlite-node/package.json
index dbc91b15e..0e1215a1a 100644
--- a/packages/session-backends/sqlite-node/package.json
+++ b/packages/session-backends/sqlite-node/package.json
@@ -18,7 +18,7 @@
 	],
 	"scripts": {
 		"clean": "node -e \"import('node:fs/promises').then(fs=>fs.rm('dist',{recursive:true,force:true}))\"",
-		"build": "tsgo -p tsconfig.build.json && node scripts/copy-migrations.mjs",
+		"build": "tsc -p tsconfig.build.json && node scripts/copy-migrations.mjs",
 		"bench:session:timing": "vitest bench --config vitest.benchmark.config.ts",
 		"test": "vitest --run",
 		"coverage": "vitest --run --coverage",
diff --git a/packages/telemetry/package.json b/packages/telemetry/package.json
index 753286462..9eb8eaf57 100644
--- a/packages/telemetry/package.json
+++ b/packages/telemetry/package.json
@@ -21,7 +21,7 @@
 	],
 	"scripts": {
 		"clean": "shx rm -rf dist",
-		"build": "tsgo -p tsconfig.build.json",
+		"build": "tsc -p tsconfig.build.json",
 		"test": "vitest --run",
 		"prepublishOnly": "npm run clean && npm run build"
 	},
diff --git a/packages/tui/README.md b/packages/tui/README.md
index 6a3c6427b..20992f87a 100644
--- a/packages/tui/README.md
+++ b/packages/tui/README.md
@@ -920,7 +920,7 @@ See `test/chat-simple.ts` for a complete chat interface example with:
 
 Run it:
 ```bash
-npx tsx test/chat-simple.ts
+node test/chat-simple.ts
 ```
 
 ## Development
@@ -933,7 +933,7 @@ npm install
 npm run check
 
 # Run the demo
-npx tsx test/chat-simple.ts
+node test/chat-simple.ts
 ```
 
 ### Debug logging
@@ -941,5 +941,5 @@ npx tsx test/chat-simple.ts
 Set `PI_TUI_WRITE_LOG` to capture the raw ANSI stream written to stdout.
 
 ```bash
-PI_TUI_WRITE_LOG=/tmp/tui-ansi.log npx tsx test/chat-simple.ts
+PI_TUI_WRITE_LOG=/tmp/tui-ansi.log node test/chat-simple.ts
 ```
diff --git a/packages/tui/package.json b/packages/tui/package.json
index 90e79d4e5..209f4e6fe 100644
--- a/packages/tui/package.json
+++ b/packages/tui/package.json
@@ -6,7 +6,7 @@
 	"main": "dist/index.js",
 	"scripts": {
 		"clean": "shx rm -rf dist",
-		"build": "tsgo -p tsconfig.build.json",
+		"build": "tsc -p tsconfig.build.json",
 		"build:native:darwin": "native/darwin/build.sh",
 		"build:native:linux": "native/linux/build.sh",
 		"build:native:win32": "node native/win32/build.mjs",
diff --git a/packages/tui/test/image-test.ts b/packages/tui/test/image-test.ts
index 73a26862d..05fb32ac5 100644
--- a/packages/tui/test/image-test.ts
+++ b/packages/tui/test/image-test.ts
@@ -17,7 +17,7 @@ try {
 	imageBuffer = readFileSync(testImagePath);
 } catch (_e) {
 	console.error(`Failed to load image: ${testImagePath}`);
-	console.error("Usage: npx tsx test/image-test.ts [path-to-image.png]");
+	console.error("Usage: node test/image-test.ts [path-to-image.png]");
 	process.exit(1);
 }
 
diff --git a/packages/tui/test/viewport-overwrite-repro.ts b/packages/tui/test/viewport-overwrite-repro.ts
index 1826af068..f4541d5bf 100644
--- a/packages/tui/test/viewport-overwrite-repro.ts
+++ b/packages/tui/test/viewport-overwrite-repro.ts
@@ -2,11 +2,11 @@
  * TUI viewport overwrite repro
  *
  * Place this file at: packages/tui/test/viewport-overwrite-repro.ts
- * Run from repo root: npx tsx packages/tui/test/viewport-overwrite-repro.ts
+ * Run from repo root: node packages/tui/test/viewport-overwrite-repro.ts
  *
  * For reliable repro, run in a small terminal (8-12 rows) or a tmux session:
  *   tmux new-session -d -s tui-bug -x 80 -y 12
- *   tmux send-keys -t tui-bug "npx tsx packages/tui/test/viewport-overwrite-repro.ts" Enter
+ *   tmux send-keys -t tui-bug "node packages/tui/test/viewport-overwrite-repro.ts" Enter
  *   tmux attach -t tui-bug
  *
  * Expected behavior:
diff --git a/pi-test.ps1 b/pi-test.ps1
index 610aeaeb2..dc3625a57 100644
--- a/pi-test.ps1
+++ b/pi-test.ps1
@@ -58,13 +58,10 @@ if ($noEnv) {
 	Write-Host "Running without API keys..."
 }
 
-$tsxBin = Join-Path $scriptDir "node_modules/.bin/tsx.cmd"
-if (-not (Test-Path -LiteralPath $tsxBin)) {
-	throw "tsx not found at $tsxBin. Run npm install from the repo root first."
-}
-
+# --import takes a module specifier, so pass the resolver as a file URL (Windows paths are not specifiers).
+$resolverUrl = ([System.Uri](Join-Path $scriptDir "packages/coding-agent/src/experimental/source-resolver.ts")).AbsoluteUri
 $cliPath = Join-Path $scriptDir "packages/coding-agent/src/cli.ts"
-& $tsxBin $cliPath @forwardArgs
+& node --import $resolverUrl $cliPath @forwardArgs
 $exitCode = $LASTEXITCODE
 if ($exitCode -ne 0) {
 	exit $exitCode
diff --git a/pi-test.sh b/pi-test.sh
index 3f40112bd..29a2510ce 100755
--- a/pi-test.sh
+++ b/pi-test.sh
@@ -54,4 +54,6 @@ if [[ "$NO_ENV" == "true" ]]; then
   echo "Running without API keys..."
 fi
 
-"$SCRIPT_DIR/node_modules/.bin/tsx" --tsconfig "$SCRIPT_DIR/tsconfig.json" "$SCRIPT_DIR/packages/coding-agent/src/experimental/cli.ts" ${ARGS[@]+"${ARGS[@]}"}
+# --import takes a module specifier, so pass the resolver as a file URL (raw paths break on #, ?, %).
+RESOLVER_URL="$(node -p 'require("node:url").pathToFileURL(process.argv[1]).href' "$SCRIPT_DIR/packages/coding-agent/src/experimental/source-resolver.ts")"
+node --import "$RESOLVER_URL" "$SCRIPT_DIR/packages/coding-agent/src/experimental/cli.ts" ${ARGS[@]+"${ARGS[@]}"}
diff --git a/scripts/check-runtime-deps.mjs b/scripts/check-runtime-deps.mjs
index 7d3850772..e24627be2 100644
--- a/scripts/check-runtime-deps.mjs
+++ b/scripts/check-runtime-deps.mjs
@@ -3,9 +3,24 @@
 import { existsSync, readFileSync } from "node:fs";
 import { isBuiltin } from "node:module";
 import { isAbsolute, join, relative, resolve } from "node:path";
-import ts from "typescript";
+import { SyntaxKind } from "typescript/unstable/ast";
+import {
+	isCallExpression,
+	isExportDeclaration,
+	isIdentifier,
+	isImportDeclaration,
+	isNamedExports,
+	isNamedImports,
+	isNoSubstitutionTemplateLiteral,
+	isPropertyAccessExpression,
+	isStringLiteral,
+} from "typescript/unstable/ast/is";
+import { API } from "typescript/unstable/sync";
 import { getPublicWorkspacePackages } from "./release-packages.mjs";
 
+// Packages without tsconfig.build.json are checked against a synthetic config.
+const fallbackConfigName = "tsconfig.runtime-deps-fallback.json";
+const fallbackConfig = JSON.stringify({ include: ["src/**/*"] });
 const failures = [];
 
 function checkSource(source, manifest) {
@@ -18,7 +33,7 @@ function checkSource(source, manifest) {
 	]);
 
 	function checkSpecifier(node) {
-		if (!node || !ts.isStringLiteralLike(node)) return;
+		if (!node || !(isStringLiteral(node) || isNoSubstitutionTemplateLiteral(node))) return;
 		const specifier = node.text;
 		if (specifier.startsWith(".") || specifier.startsWith("/") || isBuiltin(specifier)) return;
 		const name = specifier.split("/").slice(0, specifier.startsWith("@") ? 2 : 1).join("/");
@@ -28,61 +43,86 @@ function checkSource(source, manifest) {
 	}
 
 	function visit(node) {
-		if (ts.isImportDeclaration(node)) {
+		if (isImportDeclaration(node)) {
 			const clause = node.importClause;
 			const bindings = clause?.namedBindings;
 			if (
 				!clause ||
-				(!clause.isTypeOnly &&
-					(clause.name || !bindings || !ts.isNamedImports(bindings) ||
-						bindings.elements.length === 0 || bindings.elements.some((element) => !element.isTypeOnly)))
+				(clause.phaseModifier !== SyntaxKind.TypeKeyword &&
+					(clause.name ||
+						!bindings ||
+						!isNamedImports(bindings) ||
+						bindings.elements.length === 0 ||
+						bindings.elements.some((element) => !element.isTypeOnly)))
 			) {
 				checkSpecifier(node.moduleSpecifier);
 			}
-		} else if (ts.isExportDeclaration(node) && !node.isTypeOnly) {
+		} else if (isExportDeclaration(node) && !node.isTypeOnly) {
 			const clause = node.exportClause;
-			if (!clause || !ts.isNamedExports(clause) || clause.elements.length === 0 || clause.elements.some((element) => !element.isTypeOnly)) {
+			if (
+				!clause ||
+				!isNamedExports(clause) ||
+				clause.elements.length === 0 ||
+				clause.elements.some((element) => !element.isTypeOnly)
+			) {
 				checkSpecifier(node.moduleSpecifier);
 			}
 		} else if (
-			ts.isCallExpression(node) &&
-			(node.expression.kind === ts.SyntaxKind.ImportKeyword ||
-				(ts.isIdentifier(node.expression) && node.expression.text === "require") ||
-				(ts.isPropertyAccessExpression(node.expression) && node.expression.getText(source) === "require.resolve"))
+			isCallExpression(node) &&
+			(node.expression.kind === SyntaxKind.ImportKeyword ||
+				(isIdentifier(node.expression) && node.expression.text === "require") ||
+				(isPropertyAccessExpression(node.expression) && node.expression.getText(source) === "require.resolve"))
 		) {
 			checkSpecifier(node.arguments[0]);
 		}
-		ts.forEachChild(node, visit);
+		node.forEachChild(visit);
 	}
 	visit(source);
 }
 
-for (const { directory } of getPublicWorkspacePackages()) {
-	const sourceDirectory = resolve(directory, "src");
-	if (!existsSync(sourceDirectory)) continue;
-	const manifest = JSON.parse(readFileSync(join(directory, "package.json"), "utf8"));
-	const configPath = join(directory, "tsconfig.build.json");
-	const config = existsSync(configPath)
-		? ts.readConfigFile(configPath, ts.sys.readFile)
-		: { config: { include: ["src/**/*"] } };
-	if (config.error) throw new Error(ts.flattenDiagnosticMessageText(config.error.messageText, "\n"));
-	const parsed = ts.parseJsonConfigFileContent(config.config, ts.sys, resolve(directory));
-	if (parsed.errors.length > 0) {
-		throw new Error(parsed.errors.map((error) => ts.flattenDiagnosticMessageText(error.messageText, "\n")).join("\n"));
-	}
-	const roots = new Set(parsed.fileNames.map((file) => resolve(file)));
-	const program = ts.createProgram(parsed.fileNames, parsed.options);
-	for (const source of program.getSourceFiles()) {
-		if (source.isDeclarationFile || source.fileName.endsWith(".json")) continue;
-		const path = relative(sourceDirectory, resolve(source.fileName));
-		if (path.startsWith("..") || isAbsolute(path)) continue;
-		// TypeScript's exclude only filters roots: imports can pull excluded files
-		// back into the build. Reject that too, including type-only imports.
-		if (!roots.has(resolve(source.fileName))) {
-			failures.push(`${source.fileName} is excluded from ${manifest.name}'s build but imported by it`);
+const packages = getPublicWorkspacePackages()
+	.map(({ directory }) => ({ directory, sourceDirectory: resolve(directory, "src") }))
+	.filter(({ sourceDirectory }) => existsSync(sourceDirectory))
+	.map(({ directory, sourceDirectory }) => {
+		const configPath = resolve(directory, "tsconfig.build.json");
+		return {
+			sourceDirectory,
+			manifest: JSON.parse(readFileSync(join(directory, "package.json"), "utf8")),
+			configPath: existsSync(configPath) ? configPath : resolve(directory, fallbackConfigName),
+		};
+	});
+
+const fallbackConfigs = new Set(
+	packages.map(({ configPath }) => configPath).filter((path) => path.endsWith(fallbackConfigName)),
+);
+const api = new API({
+	cwd: process.cwd(),
+	fs: {
+		fileExists: (fileName) => (fallbackConfigs.has(resolve(fileName)) ? true : undefined),
+		readFile: (fileName) => (fallbackConfigs.has(resolve(fileName)) ? fallbackConfig : undefined),
+	},
+});
+try {
+	const snapshot = api.updateSnapshot({ openProjects: packages.map(({ configPath }) => configPath) });
+	for (const { sourceDirectory, manifest, configPath } of packages) {
+		const project = snapshot.getProject(configPath);
+		const diagnostics = project.program.getConfigFileParsingDiagnostics();
+		if (diagnostics.length > 0) throw new Error(diagnostics.map((diagnostic) => diagnostic.text).join("\n"));
+		const roots = new Set(project.rootFiles.map((file) => resolve(file)));
+		for (const fileName of project.program.getSourceFileNames()) {
+			if (fileName.endsWith(".d.ts") || fileName.endsWith(".json")) continue;
+			const path = relative(sourceDirectory, resolve(fileName));
+			if (path.startsWith("..") || isAbsolute(path)) continue;
+			// TypeScript's exclude only filters roots: imports can pull excluded files
+			// back into the build. Reject that too, including type-only imports.
+			if (!roots.has(resolve(fileName))) {
+				failures.push(`${fileName} is excluded from ${manifest.name}'s build but imported by it`);
+			}
+			checkSource(project.program.getSourceFile(fileName), manifest);
 		}
-		checkSource(source, manifest);
 	}
+} finally {
+	api.close();
 }
 
 if (failures.length > 0) {
diff --git a/scripts/check-ts-relative-imports.mjs b/scripts/check-ts-relative-imports.mjs
index bf21a5d0a..26ff0a791 100644
--- a/scripts/check-ts-relative-imports.mjs
+++ b/scripts/check-ts-relative-imports.mjs
@@ -1,6 +1,16 @@
-import { readdirSync, readFileSync } from "node:fs";
-import { join } from "node:path";
-import ts from "typescript";
+import { readdirSync } from "node:fs";
+import { join, relative, resolve } from "node:path";
+import { SyntaxKind } from "typescript/unstable/ast";
+import {
+	isCallExpression,
+	isExportDeclaration,
+	isImportDeclaration,
+	isImportTypeNode,
+	isLiteralTypeNode,
+	isNoSubstitutionTemplateLiteral,
+	isStringLiteral,
+} from "typescript/unstable/ast/is";
+import { API } from "typescript/unstable/sync";
 
 const ignoredDirectories = new Set([".git", "coverage", "dist", "node_modules"]);
 const files = [];
@@ -20,13 +30,17 @@ function collectTypescriptFiles(directory) {
 	}
 }
 
+function isStringLiteralLike(node) {
+	return node !== undefined && (isStringLiteral(node) || isNoSubstitutionTemplateLiteral(node));
+}
+
 function isRelativeJavaScriptSpecifier(specifier) {
 	return /^\.\.?\//.test(specifier) && /\.js(?:[?#].*)?$/.test(specifier);
 }
 
 function getImportTypeSpecifier(node) {
-	if (!ts.isLiteralTypeNode(node.argument)) return undefined;
-	if (!ts.isStringLiteralLike(node.argument.literal)) return undefined;
+	if (!isLiteralTypeNode(node.argument)) return undefined;
+	if (!isStringLiteralLike(node.argument.literal)) return undefined;
 	return node.argument.literal;
 }
 
@@ -34,37 +48,54 @@ const failures = [];
 
 collectTypescriptFiles(".");
 
-for (const file of files.sort()) {
-	const sourceText = readFileSync(file, "utf8");
-	const sourceFile = ts.createSourceFile(file, sourceText, ts.ScriptTarget.Latest, true);
+// Parse every file through one synthetic project. noResolve keeps the program to exactly these files.
+const configPath = resolve("tsconfig.check-ts-relative-imports.json");
+const config = JSON.stringify({
+	compilerOptions: { noResolve: true, noLib: true, types: [] },
+	files: files.map((file) => resolve(file)),
+});
+const api = new API({
+	cwd: process.cwd(),
+	fs: {
+		fileExists: (fileName) => (resolve(fileName) === configPath ? true : undefined),
+		readFile: (fileName) => (resolve(fileName) === configPath ? config : undefined),
+	},
+});
 
-	function checkSpecifier(node) {
-		if (!isRelativeJavaScriptSpecifier(node.text)) return;
-		const { line, character } = sourceFile.getLineAndCharacterOfPosition(node.getStart(sourceFile));
-		failures.push(`${file}:${line + 1}:${character + 1}: ${node.text}`);
-	}
+try {
+	const program = api.updateSnapshot({ openProjects: [configPath] }).getProject(configPath).program;
+	for (const file of files.sort()) {
+		const sourceFile = program.getSourceFile(resolve(file));
 
-	function visit(node) {
-		if (ts.isImportDeclaration(node) && ts.isStringLiteralLike(node.moduleSpecifier)) {
-			checkSpecifier(node.moduleSpecifier);
-		} else if (ts.isExportDeclaration(node) && node.moduleSpecifier && ts.isStringLiteralLike(node.moduleSpecifier)) {
-			checkSpecifier(node.moduleSpecifier);
-		} else if (
-			ts.isCallExpression(node) &&
-			node.expression.kind === ts.SyntaxKind.ImportKeyword &&
-			node.arguments[0] &&
-			ts.isStringLiteralLike(node.arguments[0])
-		) {
-			checkSpecifier(node.arguments[0]);
-		} else if (ts.isImportTypeNode(node)) {
-			const specifier = getImportTypeSpecifier(node);
-			if (specifier) checkSpecifier(specifier);
+		function checkSpecifier(node) {
+			if (!isRelativeJavaScriptSpecifier(node.text)) return;
+			const { line, character } = sourceFile.getLineAndCharacterOfPosition(node.getStart(sourceFile));
+			failures.push(`${relative(".", file)}:${line + 1}:${character + 1}: ${node.text}`);
 		}
 
-		ts.forEachChild(node, visit);
-	}
+		function visit(node) {
+			if (isImportDeclaration(node) && isStringLiteralLike(node.moduleSpecifier)) {
+				checkSpecifier(node.moduleSpecifier);
+			} else if (isExportDeclaration(node) && isStringLiteralLike(node.moduleSpecifier)) {
+				checkSpecifier(node.moduleSpecifier);
+			} else if (
+				isCallExpression(node) &&
+				node.expression.kind === SyntaxKind.ImportKeyword &&
+				isStringLiteralLike(node.arguments[0])
+			) {
+				checkSpecifier(node.arguments[0]);
+			} else if (isImportTypeNode(node)) {
+				const specifier = getImportTypeSpecifier(node);
+				if (specifier) checkSpecifier(specifier);
+			}
 
-	visit(sourceFile);
+			node.forEachChild(visit);
+		}
+
+		visit(sourceFile);
+	}
+} finally {
+	api.close();
 }
 
 if (failures.length > 0) {
diff --git a/tsconfig.base.json b/tsconfig.base.json
index 57e97d6e3..4449172b2 100644
--- a/tsconfig.base.json
+++ b/tsconfig.base.json
@@ -1,10 +1,11 @@
 {
 	"compilerOptions": {
-		"target": "ES2022",
+		"target": "ES2024",
 		"module": "Node16",
-		"lib": ["ES2022"],
+		"lib": ["ES2024"],
 		"strict": true,
 		"erasableSyntaxOnly": true,
+		"verbatimModuleSyntax": true,
 		"esModuleInterop": true,
 		"skipLibCheck": true,
 		"forceConsistentCasingInFileNames": true,
@@ -17,9 +18,6 @@
 		"resolveJsonModule": true,
 		"allowImportingTsExtensions": true,
 		"rewriteRelativeImportExtensions": true,
-		"experimentalDecorators": true,
-		"emitDecoratorMetadata": true,
-		"useDefineForClassFields": false,
 		"types": ["node"]
 	}
 }
diff --git a/tsconfig.json b/tsconfig.json
index 31d343d92..2dd9e0ccf 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -5,7 +5,6 @@
 		"module": "NodeNext",
 		"moduleResolution": "NodeNext",
 		"paths": {
-			"*": ["./*"],
 			"@earendil-works/chord": ["./packages/chord/src/index.ts"],
 			"@earendil-works/chord/bundler": ["./packages/chord/src/bundler.ts"],
 			"@earendil-works/chord/context": ["./packages/chord/src/context/index.ts"],