diff --git a/eslint.config.mjs b/eslint.config.mjs
index 36a0948..bc826fb 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -4,7 +4,7 @@ import configs from 'rete-cli/configs/eslint.mjs';
 export default tseslint.config(
   ...configs,
   {
-    files: ['**/*.test.ts'],
+    files: ['**/*.test.ts', '**/*.test-d.ts'],
     rules: {
       'eslint-disable': 'off',
       'init-declarations': 'off',
diff --git a/package-lock.json b/package-lock.json
index f4c77bb..10378a9 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12,9 +12,10 @@
         "@babel/runtime": "^7.21.0"
       },
       "devDependencies": {
+        "@tsd/typescript": "^5.7.2",
+        "jest-tsd": "^0.2.2",
         "rete": "^2.0.1",
-        "rete-cli": "~2.0.1",
-        "typescript": "4.8.4"
+        "rete-cli": "~2.0.1"
       },
       "peerDependencies": {
         "rete": "^2.0.1"
@@ -2584,14 +2585,56 @@
       }
     },
     "node_modules/@shikijs/core": {
-      "version": "1.14.1",
-      "resolved": "https://registry.npmjs.org/@shikijs/core/-/core-1.14.1.tgz",
-      "integrity": "sha512-KyHIIpKNaT20FtFPFjCQB5WVSTpLR/n+jQXhWHWVUMm9MaOaG9BGOG0MSyt7yA4+Lm+4c9rTc03tt3nYzeYSfw==",
+      "version": "1.24.4",
+      "resolved": "https://registry.npmjs.org/@shikijs/core/-/core-1.24.4.tgz",
+      "integrity": "sha512-jjLsld+xEEGYlxAXDyGwWsKJ1sw5Pc1pnp4ai2ORpjx2UX08YYTC0NNqQYO1PaghYaR+PvgMOGuvzw2he9sk0Q==",
+      "dev": true,
+      "dependencies": {
+        "@shikijs/engine-javascript": "1.24.4",
+        "@shikijs/engine-oniguruma": "1.24.4",
+        "@shikijs/types": "1.24.4",
+        "@shikijs/vscode-textmate": "^9.3.1",
+        "@types/hast": "^3.0.4",
+        "hast-util-to-html": "^9.0.4"
+      }
+    },
+    "node_modules/@shikijs/engine-javascript": {
+      "version": "1.24.4",
+      "resolved": "https://registry.npmjs.org/@shikijs/engine-javascript/-/engine-javascript-1.24.4.tgz",
+      "integrity": "sha512-TClaQOLvo9WEMJv6GoUsykQ6QdynuKszuORFWCke8qvi6PeLm7FcD9+7y45UenysxEWYpDL5KJaVXTngTE+2BA==",
       "dev": true,
       "dependencies": {
+        "@shikijs/types": "1.24.4",
+        "@shikijs/vscode-textmate": "^9.3.1",
+        "oniguruma-to-es": "0.8.1"
+      }
+    },
+    "node_modules/@shikijs/engine-oniguruma": {
+      "version": "1.24.4",
+      "resolved": "https://registry.npmjs.org/@shikijs/engine-oniguruma/-/engine-oniguruma-1.24.4.tgz",
+      "integrity": "sha512-Do2ry6flp2HWdvpj2XOwwa0ljZBRy15HKZITzPcNIBOGSeprnA8gOooA/bLsSPuy8aJBa+Q/r34dMmC3KNL/zw==",
+      "dev": true,
+      "dependencies": {
+        "@shikijs/types": "1.24.4",
+        "@shikijs/vscode-textmate": "^9.3.1"
+      }
+    },
+    "node_modules/@shikijs/types": {
+      "version": "1.24.4",
+      "resolved": "https://registry.npmjs.org/@shikijs/types/-/types-1.24.4.tgz",
+      "integrity": "sha512-0r0XU7Eaow0PuDxuWC1bVqmWCgm3XqizIaT7SM42K03vc69LGooT0U8ccSR44xP/hGlNx4FKhtYpV+BU6aaKAA==",
+      "dev": true,
+      "dependencies": {
+        "@shikijs/vscode-textmate": "^9.3.1",
         "@types/hast": "^3.0.4"
       }
     },
+    "node_modules/@shikijs/vscode-textmate": {
+      "version": "9.3.1",
+      "resolved": "https://registry.npmjs.org/@shikijs/vscode-textmate/-/vscode-textmate-9.3.1.tgz",
+      "integrity": "sha512-79QfK1393x9Ho60QFyLti+QfdJzRQCVLFb97kOIV7Eo9vQU/roINgk7m24uv0a7AUvN//RDH36FLjjK48v0s9g==",
+      "dev": true
+    },
     "node_modules/@sinclair/typebox": {
       "version": "0.27.8",
       "resolved": "https://registry.npmjs.org/@sinclair/typebox/-/typebox-0.27.8.tgz",
@@ -2678,6 +2721,15 @@
         "path-browserify": "^1.0.1"
       }
     },
+    "node_modules/@tsd/typescript": {
+      "version": "5.7.2",
+      "resolved": "https://registry.npmjs.org/@tsd/typescript/-/typescript-5.7.2.tgz",
+      "integrity": "sha512-Xuhtk1h4T35XXJWWKmufMV1UMK1C5aMA+3AYDgkQgiaR4lLS+7lNXOEC0lDancspFO9SOZzASpfOvUoATm2cPA==",
+      "dev": true,
+      "engines": {
+        "node": ">=14.17"
+      }
+    },
     "node_modules/@types/babel__core": {
       "version": "7.20.5",
       "resolved": "https://registry.npmjs.org/@types/babel__core/-/babel__core-7.20.5.tgz",
@@ -2821,6 +2873,15 @@
       "integrity": "sha512-5+fP8P8MFNC+AyZCDxrB2pkZFPGzqQWUzpSeuuVLvm8VMcorNYavBqoFcxK8bQz4Qsbn4oUEEem4wDLfcysGHA==",
       "dev": true
     },
+    "node_modules/@types/mdast": {
+      "version": "4.0.4",
+      "resolved": "https://registry.npmjs.org/@types/mdast/-/mdast-4.0.4.tgz",
+      "integrity": "sha512-kGaNbPh1k7AFzgpud/gMdvIm5xuECykRR+JnWKQno9TAXVa6WIVCGTPvYGekIDL4uwCZQSYbUxNBSb1aUo79oA==",
+      "dev": true,
+      "dependencies": {
+        "@types/unist": "*"
+      }
+    },
     "node_modules/@types/minimatch": {
       "version": "5.1.2",
       "resolved": "https://registry.npmjs.org/@types/minimatch/-/minimatch-5.1.2.tgz",
@@ -3075,6 +3136,12 @@
         "url": "https://opencollective.com/eslint"
       }
     },
+    "node_modules/@ungap/structured-clone": {
+      "version": "1.2.1",
+      "resolved": "https://registry.npmjs.org/@ungap/structured-clone/-/structured-clone-1.2.1.tgz",
+      "integrity": "sha512-fEzPV3hSkSMltkw152tJKNARhOupqbH96MZWyRjNaYZOMIzbrTeQDG+MTc6Mr2pgzFQzFxAfmhGDNP5QK++2ZA==",
+      "dev": true
+    },
     "node_modules/acorn": {
       "version": "8.12.1",
       "resolved": "https://registry.npmjs.org/acorn/-/acorn-8.12.1.tgz",
@@ -3485,6 +3552,16 @@
         "node": ">= 0.8.0"
       }
     },
+    "node_modules/ccount": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/ccount/-/ccount-2.0.1.tgz",
+      "integrity": "sha512-eyrF0jiFpY+3drT6383f1qhkbGsLSifNAjA61IUjZjmLCWjItY6LB9ft9YhoDgwfmclB2zhu51Lc7+95b8NRAg==",
+      "dev": true,
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
+    },
     "node_modules/chalk": {
       "version": "4.1.2",
       "resolved": "https://registry.npmjs.org/chalk/-/chalk-4.1.2.tgz",
@@ -3510,6 +3587,26 @@
         "node": ">=10"
       }
     },
+    "node_modules/character-entities-html4": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/character-entities-html4/-/character-entities-html4-2.1.0.tgz",
+      "integrity": "sha512-1v7fgQRj6hnSwFpq1Eu0ynr/CDEw0rXo2B61qXrLNdHZmPKgb7fqS1a2JwF0rISo9q77jDI8VMEHoApn8qDoZA==",
+      "dev": true,
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
+    },
+    "node_modules/character-entities-legacy": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/character-entities-legacy/-/character-entities-legacy-3.0.0.tgz",
+      "integrity": "sha512-RpPp0asT/6ufRm//AJVwpViZbGM/MkjQFxJccQRHmISF/22NBtsHqAWmL+/pmkPWoIUJdWyeVleTl1wydHATVQ==",
+      "dev": true,
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
+    },
     "node_modules/ci-info": {
       "version": "3.9.0",
       "resolved": "https://registry.npmjs.org/ci-info/-/ci-info-3.9.0.tgz",
@@ -3605,6 +3702,16 @@
       "integrity": "sha512-Y2oEozpomLn7Q3HFP7dpww7AtMJplbM9lGZP6RDfHqmbeRjiwRg4n6VM6j4KLmRke85uWEI7JqF17f3pqdRA0g==",
       "dev": true
     },
+    "node_modules/comma-separated-tokens": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/comma-separated-tokens/-/comma-separated-tokens-2.0.3.tgz",
+      "integrity": "sha512-Fu4hJdvzeylCfQPp9SGWidpzrMs7tTrlu6Vb8XGaRGck8QSNZJJp538Wrb60Lax4fPwR64ViY468OIUTbRlGZg==",
+      "dev": true,
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
+    },
     "node_modules/commander": {
       "version": "9.4.1",
       "resolved": "https://registry.npmjs.org/commander/-/commander-9.4.1.tgz",
@@ -3748,6 +3855,15 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/dequal": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/dequal/-/dequal-2.0.3.tgz",
+      "integrity": "sha512-0je+qPKHEMohvfRTCEo3CrPG6cAzAYgmzKyxRiYSSDkS6eGJdyVJm7WaYA5ECaAD9wLB2T4EEeymA5aFVcYXCA==",
+      "dev": true,
+      "engines": {
+        "node": ">=6"
+      }
+    },
     "node_modules/detect-newline": {
       "version": "3.1.0",
       "resolved": "https://registry.npmjs.org/detect-newline/-/detect-newline-3.1.0.tgz",
@@ -3757,6 +3873,19 @@
         "node": ">=8"
       }
     },
+    "node_modules/devlop": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/devlop/-/devlop-1.1.0.tgz",
+      "integrity": "sha512-RWmIqhcFf1lRYBvNmr7qTNuyCt/7/ns2jbpp1+PalgE/rDQcBT0fioSMUpJ93irlUhC5hrg4cYqe6U+0ImW0rA==",
+      "dev": true,
+      "dependencies": {
+        "dequal": "^2.0.0"
+      },
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
+    },
     "node_modules/diff-sequences": {
       "version": "29.6.3",
       "resolved": "https://registry.npmjs.org/diff-sequences/-/diff-sequences-29.6.3.tgz",
@@ -3817,6 +3946,12 @@
       "integrity": "sha512-MSjYzcWNOA0ewAHpz0MxpYFvwg6yjy1NG3xteoqz644VCo/RPgnr1/GGt+ic3iJTzQ8Eu3TdM14SawnVUmGE6A==",
       "dev": true
     },
+    "node_modules/emoji-regex-xs": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/emoji-regex-xs/-/emoji-regex-xs-1.0.0.tgz",
+      "integrity": "sha512-LRlerrMYoIDrT6jgpeZ2YYl/L8EulRTt5hQcYjy5AInh7HWXKimpqx68aknBFpGL2+/IcogTcaydJEgaTmOpDg==",
+      "dev": true
+    },
     "node_modules/entities": {
       "version": "4.5.0",
       "resolved": "https://registry.npmjs.org/entities/-/entities-4.5.0.tgz",
@@ -4468,12 +4603,58 @@
         "node": ">= 0.4"
       }
     },
+    "node_modules/hast-util-to-html": {
+      "version": "9.0.4",
+      "resolved": "https://registry.npmjs.org/hast-util-to-html/-/hast-util-to-html-9.0.4.tgz",
+      "integrity": "sha512-wxQzXtdbhiwGAUKrnQJXlOPmHnEehzphwkK7aluUPQ+lEc1xefC8pblMgpp2w5ldBTEfveRIrADcrhGIWrlTDA==",
+      "dev": true,
+      "dependencies": {
+        "@types/hast": "^3.0.0",
+        "@types/unist": "^3.0.0",
+        "ccount": "^2.0.0",
+        "comma-separated-tokens": "^2.0.0",
+        "hast-util-whitespace": "^3.0.0",
+        "html-void-elements": "^3.0.0",
+        "mdast-util-to-hast": "^13.0.0",
+        "property-information": "^6.0.0",
+        "space-separated-tokens": "^2.0.0",
+        "stringify-entities": "^4.0.0",
+        "zwitch": "^2.0.4"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/hast-util-whitespace": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/hast-util-whitespace/-/hast-util-whitespace-3.0.0.tgz",
+      "integrity": "sha512-88JUN06ipLwsnv+dVn+OIYOvAuvBMy/Qoi6O7mQHxdPXpjy+Cd6xRkWwux7DKO+4sYILtLBRIKgsdpS2gQc7qw==",
+      "dev": true,
+      "dependencies": {
+        "@types/hast": "^3.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/html-escaper": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/html-escaper/-/html-escaper-2.0.2.tgz",
       "integrity": "sha512-H2iMtd0I4Mt5eYiapRdIDjp+XzelXQ0tFE4JS7YFwFevXXMmOp9myNrUvCg0D6ws8iqkRPBfKHgbwig1SmlLfg==",
       "dev": true
     },
+    "node_modules/html-void-elements": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/html-void-elements/-/html-void-elements-3.0.0.tgz",
+      "integrity": "sha512-bEqo66MRXsUGxWHV5IP0PUiAWwoEjba4VCzg0LjFJBpchPaTfyfCKTG6bc5F8ucKec3q5y6qOdGyYTSBEvhCrg==",
+      "dev": true,
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
+    },
     "node_modules/human-signals": {
       "version": "2.1.0",
       "resolved": "https://registry.npmjs.org/human-signals/-/human-signals-2.1.0.tgz",
@@ -5382,6 +5563,20 @@
         "node": ">=10"
       }
     },
+    "node_modules/jest-tsd": {
+      "version": "0.2.2",
+      "resolved": "https://registry.npmjs.org/jest-tsd/-/jest-tsd-0.2.2.tgz",
+      "integrity": "sha512-Nzgo5E9F1RON3GDkAHxVOf1dqSSRMnhJ5txULHhhK+qs2xSLmLWBbtYjKSlAYNpW/fOXSrGPOs6uE0YyWAchhA==",
+      "dev": true,
+      "dependencies": {
+        "@babel/code-frame": "^7.21.4",
+        "chalk": "^4.1.2",
+        "tsd-lite": "^0.7.0"
+      },
+      "peerDependencies": {
+        "@tsd/typescript": "4.x || 5.x"
+      }
+    },
     "node_modules/jest-util": {
       "version": "29.7.0",
       "resolved": "https://registry.npmjs.org/jest-util/-/jest-util-29.7.0.tgz",
@@ -5718,6 +5913,27 @@
         "markdown-it": "bin/markdown-it.mjs"
       }
     },
+    "node_modules/mdast-util-to-hast": {
+      "version": "13.2.0",
+      "resolved": "https://registry.npmjs.org/mdast-util-to-hast/-/mdast-util-to-hast-13.2.0.tgz",
+      "integrity": "sha512-QGYKEuUsYT9ykKBCMOEDLsU5JRObWQusAolFMeko/tYPufNkRffBAQjIE+99jbA87xv6FgmjLtwjh9wBWajwAA==",
+      "dev": true,
+      "dependencies": {
+        "@types/hast": "^3.0.0",
+        "@types/mdast": "^4.0.0",
+        "@ungap/structured-clone": "^1.0.0",
+        "devlop": "^1.0.0",
+        "micromark-util-sanitize-uri": "^2.0.0",
+        "trim-lines": "^3.0.0",
+        "unist-util-position": "^5.0.0",
+        "unist-util-visit": "^5.0.0",
+        "vfile": "^6.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/mdurl": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/mdurl/-/mdurl-2.0.0.tgz",
@@ -5739,6 +5955,95 @@
         "node": ">= 8"
       }
     },
+    "node_modules/micromark-util-character": {
+      "version": "2.1.1",
+      "resolved": "https://registry.npmjs.org/micromark-util-character/-/micromark-util-character-2.1.1.tgz",
+      "integrity": "sha512-wv8tdUTJ3thSFFFJKtpYKOYiGP2+v96Hvk4Tu8KpCAsTMs6yi+nVmGh1syvSCsaxz45J6Jbw+9DD6g97+NV67Q==",
+      "dev": true,
+      "funding": [
+        {
+          "type": "GitHub Sponsors",
+          "url": "https://github.com/sponsors/unifiedjs"
+        },
+        {
+          "type": "OpenCollective",
+          "url": "https://opencollective.com/unified"
+        }
+      ],
+      "dependencies": {
+        "micromark-util-symbol": "^2.0.0",
+        "micromark-util-types": "^2.0.0"
+      }
+    },
+    "node_modules/micromark-util-encode": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/micromark-util-encode/-/micromark-util-encode-2.0.1.tgz",
+      "integrity": "sha512-c3cVx2y4KqUnwopcO9b/SCdo2O67LwJJ/UyqGfbigahfegL9myoEFoDYZgkT7f36T0bLrM9hZTAaAyH+PCAXjw==",
+      "dev": true,
+      "funding": [
+        {
+          "type": "GitHub Sponsors",
+          "url": "https://github.com/sponsors/unifiedjs"
+        },
+        {
+          "type": "OpenCollective",
+          "url": "https://opencollective.com/unified"
+        }
+      ]
+    },
+    "node_modules/micromark-util-sanitize-uri": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/micromark-util-sanitize-uri/-/micromark-util-sanitize-uri-2.0.1.tgz",
+      "integrity": "sha512-9N9IomZ/YuGGZZmQec1MbgxtlgougxTodVwDzzEouPKo3qFWvymFHWcnDi2vzV1ff6kas9ucW+o3yzJK9YB1AQ==",
+      "dev": true,
+      "funding": [
+        {
+          "type": "GitHub Sponsors",
+          "url": "https://github.com/sponsors/unifiedjs"
+        },
+        {
+          "type": "OpenCollective",
+          "url": "https://opencollective.com/unified"
+        }
+      ],
+      "dependencies": {
+        "micromark-util-character": "^2.0.0",
+        "micromark-util-encode": "^2.0.0",
+        "micromark-util-symbol": "^2.0.0"
+      }
+    },
+    "node_modules/micromark-util-symbol": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/micromark-util-symbol/-/micromark-util-symbol-2.0.1.tgz",
+      "integrity": "sha512-vs5t8Apaud9N28kgCrRUdEed4UJ+wWNvicHLPxCa9ENlYuAY31M0ETy5y1vA33YoNPDFTghEbnh6efaE8h4x0Q==",
+      "dev": true,
+      "funding": [
+        {
+          "type": "GitHub Sponsors",
+          "url": "https://github.com/sponsors/unifiedjs"
+        },
+        {
+          "type": "OpenCollective",
+          "url": "https://opencollective.com/unified"
+        }
+      ]
+    },
+    "node_modules/micromark-util-types": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/micromark-util-types/-/micromark-util-types-2.0.1.tgz",
+      "integrity": "sha512-534m2WhVTddrcKVepwmVEVnUAmtrx9bfIjNoQHRqfnvdaHQiFytEhJoTgpWJvDEXCO5gLTQh3wYC1PgOJA4NSQ==",
+      "dev": true,
+      "funding": [
+        {
+          "type": "GitHub Sponsors",
+          "url": "https://github.com/sponsors/unifiedjs"
+        },
+        {
+          "type": "OpenCollective",
+          "url": "https://opencollective.com/unified"
+        }
+      ]
+    },
     "node_modules/micromatch": {
       "version": "4.0.8",
       "resolved": "https://registry.npmjs.org/micromatch/-/micromatch-4.0.8.tgz",
@@ -5869,6 +6174,17 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/oniguruma-to-es": {
+      "version": "0.8.1",
+      "resolved": "https://registry.npmjs.org/oniguruma-to-es/-/oniguruma-to-es-0.8.1.tgz",
+      "integrity": "sha512-dekySTEvCxCj0IgKcA2uUCO/e4ArsqpucDPcX26w9ajx+DvMWLc5eZeJaRQkd7oC/+rwif5gnT900tA34uN9Zw==",
+      "dev": true,
+      "dependencies": {
+        "emoji-regex-xs": "^1.0.0",
+        "regex": "^5.0.2",
+        "regex-recursion": "^5.0.0"
+      }
+    },
     "node_modules/optionator": {
       "version": "0.9.4",
       "resolved": "https://registry.npmjs.org/optionator/-/optionator-0.9.4.tgz",
@@ -6184,6 +6500,16 @@
         "node": ">= 6"
       }
     },
+    "node_modules/property-information": {
+      "version": "6.5.0",
+      "resolved": "https://registry.npmjs.org/property-information/-/property-information-6.5.0.tgz",
+      "integrity": "sha512-PgTgs/BlvHxOu8QuEN7wi5A0OmXaBcHpmCSTehcs6Uuu9IkDIEo13Hy7n898RHfrQ49vKCoGeWZSaAK01nwVig==",
+      "dev": true,
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
+    },
     "node_modules/punycode": {
       "version": "2.3.1",
       "resolved": "https://registry.npmjs.org/punycode/-/punycode-2.3.1.tgz",
@@ -6285,6 +6611,31 @@
         "@babel/runtime": "^7.8.4"
       }
     },
+    "node_modules/regex": {
+      "version": "5.1.1",
+      "resolved": "https://registry.npmjs.org/regex/-/regex-5.1.1.tgz",
+      "integrity": "sha512-dN5I359AVGPnwzJm2jN1k0W9LPZ+ePvoOeVMMfqIMFz53sSwXkxaJoxr50ptnsC771lK95BnTrVSZxq0b9yCGw==",
+      "dev": true,
+      "dependencies": {
+        "regex-utilities": "^2.3.0"
+      }
+    },
+    "node_modules/regex-recursion": {
+      "version": "5.1.1",
+      "resolved": "https://registry.npmjs.org/regex-recursion/-/regex-recursion-5.1.1.tgz",
+      "integrity": "sha512-ae7SBCbzVNrIjgSbh7wMznPcQel1DNlDtzensnFxpiNpXt1U2ju/bHugH422r+4LAVS1FpW1YCwilmnNsjum9w==",
+      "dev": true,
+      "dependencies": {
+        "regex": "^5.1.1",
+        "regex-utilities": "^2.3.0"
+      }
+    },
+    "node_modules/regex-utilities": {
+      "version": "2.3.0",
+      "resolved": "https://registry.npmjs.org/regex-utilities/-/regex-utilities-2.3.0.tgz",
+      "integrity": "sha512-8VhliFJAWRaUiVvREIiW2NXXTmHs4vMNnSzuJVhscgmGav3g9VDxLrQndI3dZZVVdp0ZO/5v0xmX516/7M9cng==",
+      "dev": true
+    },
     "node_modules/regexpu-core": {
       "version": "5.3.2",
       "resolved": "https://registry.npmjs.org/regexpu-core/-/regexpu-core-5.3.2.tgz",
@@ -6452,10 +6803,32 @@
         "rete": "bin/index.js"
       }
     },
+    "node_modules/rete-cli/node_modules/typedoc": {
+      "version": "0.26.11",
+      "resolved": "https://registry.npmjs.org/typedoc/-/typedoc-0.26.11.tgz",
+      "integrity": "sha512-sFEgRRtrcDl2FxVP58Ze++ZK2UQAEvtvvH8rRlig1Ja3o7dDaMHmaBfvJmdGnNEFaLTpQsN8dpvZaTqJSu/Ugw==",
+      "dev": true,
+      "dependencies": {
+        "lunr": "^2.3.9",
+        "markdown-it": "^14.1.0",
+        "minimatch": "^9.0.5",
+        "shiki": "^1.16.2",
+        "yaml": "^2.5.1"
+      },
+      "bin": {
+        "typedoc": "bin/typedoc"
+      },
+      "engines": {
+        "node": ">= 18"
+      },
+      "peerDependencies": {
+        "typescript": "4.6.x || 4.7.x || 4.8.x || 4.9.x || 5.0.x || 5.1.x || 5.2.x || 5.3.x || 5.4.x || 5.5.x || 5.6.x"
+      }
+    },
     "node_modules/rete-cli/node_modules/typescript": {
-      "version": "5.5.4",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.5.4.tgz",
-      "integrity": "sha512-Mtq29sKDAEYP7aljRgtPOpTvOfbwRWlS6dPRzwjdE+C0R4brX/GUyhHSecbHMFLNBLcJIPt9nl9yG5TZ1weH+Q==",
+      "version": "5.6.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.6.3.tgz",
+      "integrity": "sha512-hjcS1mhfuyi4WW8IWtjP7brDrG2cuDZukyrYrSauoXGNgx0S7zceP07adYkJycEr56BOUTNPzbInooiN3fn1qw==",
       "dev": true,
       "bin": {
         "tsc": "bin/tsc",
@@ -6640,12 +7013,16 @@
       }
     },
     "node_modules/shiki": {
-      "version": "1.14.1",
-      "resolved": "https://registry.npmjs.org/shiki/-/shiki-1.14.1.tgz",
-      "integrity": "sha512-FujAN40NEejeXdzPt+3sZ3F2dx1U24BY2XTY01+MG8mbxCiA2XukXdcbyMyLAHJ/1AUUnQd1tZlvIjefWWEJeA==",
+      "version": "1.24.4",
+      "resolved": "https://registry.npmjs.org/shiki/-/shiki-1.24.4.tgz",
+      "integrity": "sha512-aVGSFAOAr1v26Hh/+GBIsRVDWJ583XYV7CuNURKRWh9gpGv4OdbisZGq96B9arMYTZhTQkmRF5BrShOSTvNqhw==",
       "dev": true,
       "dependencies": {
-        "@shikijs/core": "1.14.1",
+        "@shikijs/core": "1.24.4",
+        "@shikijs/engine-javascript": "1.24.4",
+        "@shikijs/engine-oniguruma": "1.24.4",
+        "@shikijs/types": "1.24.4",
+        "@shikijs/vscode-textmate": "^9.3.1",
         "@types/hast": "^3.0.4"
       }
     },
@@ -6689,6 +7066,16 @@
         "source-map": "^0.6.0"
       }
     },
+    "node_modules/space-separated-tokens": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/space-separated-tokens/-/space-separated-tokens-2.0.2.tgz",
+      "integrity": "sha512-PEGlAwrG8yXGXRjW32fGbg66JAlOAwbObuqVoJpv/mRgoWDQfgH1wDPvtzWyUSNAXBGSk8h755YDbbcEy3SH2Q==",
+      "dev": true,
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
+    },
     "node_modules/sprintf-js": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/sprintf-js/-/sprintf-js-1.0.3.tgz",
@@ -6743,6 +7130,20 @@
         "node": ">=8"
       }
     },
+    "node_modules/stringify-entities": {
+      "version": "4.0.4",
+      "resolved": "https://registry.npmjs.org/stringify-entities/-/stringify-entities-4.0.4.tgz",
+      "integrity": "sha512-IwfBptatlO+QCJUo19AqvrPNqlVMpW9YEL2LIVY+Rpv2qsjCGxaDLNRgeGsQWJhfItebuJhsGSLjaBbNSQ+ieg==",
+      "dev": true,
+      "dependencies": {
+        "character-entities-html4": "^2.0.0",
+        "character-entities-legacy": "^3.0.0"
+      },
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
+    },
     "node_modules/strip-ansi": {
       "version": "6.0.1",
       "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-6.0.1.tgz",
@@ -6902,6 +7303,16 @@
         "node": ">=8.0"
       }
     },
+    "node_modules/trim-lines": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/trim-lines/-/trim-lines-3.0.1.tgz",
+      "integrity": "sha512-kRj8B+YHZCc9kQYdWfJB2/oUl9rA99qbowYYBtr4ui4mZyAQ2JpvVBd/6U2YloATfqBhBTSMhTpgBHtU0Mf3Rg==",
+      "dev": true,
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
+    },
     "node_modules/ts-api-utils": {
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/ts-api-utils/-/ts-api-utils-1.3.0.tgz",
@@ -6997,6 +7408,19 @@
         "typescript": "2 || 3 || 4 || 5"
       }
     },
+    "node_modules/tsd-lite": {
+      "version": "0.7.0",
+      "resolved": "https://registry.npmjs.org/tsd-lite/-/tsd-lite-0.7.0.tgz",
+      "integrity": "sha512-XhQ7w/RPzfjSb98LIQB1qx7yAvRV6+h5JFP4dCvd79Hbp23X8CCx4EdRAQm6faTkRdprKYvZE8kxlK6LpJp8vg==",
+      "deprecated": "'tsd-lite' is deprecated. For details, see the deprecation notice: https://github.com/mrazauskas/tsd-lite/issues/364",
+      "dev": true,
+      "engines": {
+        "node": ">=14"
+      },
+      "peerDependencies": {
+        "@tsd/typescript": "4.x || 5.x"
+      }
+    },
     "node_modules/tslib": {
       "version": "2.4.0",
       "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.4.0.tgz",
@@ -7087,39 +7511,18 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
-    "node_modules/typedoc": {
-      "version": "0.26.6",
-      "resolved": "https://registry.npmjs.org/typedoc/-/typedoc-0.26.6.tgz",
-      "integrity": "sha512-SfEU3SH3wHNaxhFPjaZE2kNl/NFtLNW5c1oHsg7mti7GjmUj1Roq6osBQeMd+F4kL0BoRBBr8gQAuqBlfFu8LA==",
-      "dev": true,
-      "dependencies": {
-        "lunr": "^2.3.9",
-        "markdown-it": "^14.1.0",
-        "minimatch": "^9.0.5",
-        "shiki": "^1.9.1",
-        "yaml": "^2.4.5"
-      },
-      "bin": {
-        "typedoc": "bin/typedoc"
-      },
-      "engines": {
-        "node": ">= 18"
-      },
-      "peerDependencies": {
-        "typescript": "4.6.x || 4.7.x || 4.8.x || 4.9.x || 5.0.x || 5.1.x || 5.2.x || 5.3.x || 5.4.x || 5.5.x"
-      }
-    },
     "node_modules/typescript": {
-      "version": "4.8.4",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-4.8.4.tgz",
-      "integrity": "sha512-QCh+85mCy+h0IGff8r5XWzOVSbBO+KfeYrMQh7NJ58QujwcE22u+NUSmUxqF+un70P9GXKxa2HCNiTTMJknyjQ==",
+      "version": "5.7.2",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.7.2.tgz",
+      "integrity": "sha512-i5t66RHxDvVN40HfDd1PsEThGNnlMCMT3jMUuoh9/0TaqWevNontacunWyN02LA9/fIbEWlcHZcgTKb9QoaLfg==",
       "dev": true,
+      "peer": true,
       "bin": {
         "tsc": "bin/tsc",
         "tsserver": "bin/tsserver"
       },
       "engines": {
-        "node": ">=4.2.0"
+        "node": ">=14.17"
       }
     },
     "node_modules/typescript-eslint": {
@@ -7191,6 +7594,74 @@
         "node": ">=4"
       }
     },
+    "node_modules/unist-util-is": {
+      "version": "6.0.0",
+      "resolved": "https://registry.npmjs.org/unist-util-is/-/unist-util-is-6.0.0.tgz",
+      "integrity": "sha512-2qCTHimwdxLfz+YzdGfkqNlH0tLi9xjTnHddPmJwtIG9MGsdbutfTc4P+haPD7l7Cjxf/WZj+we5qfVPvvxfYw==",
+      "dev": true,
+      "dependencies": {
+        "@types/unist": "^3.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/unist-util-position": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/unist-util-position/-/unist-util-position-5.0.0.tgz",
+      "integrity": "sha512-fucsC7HjXvkB5R3kTCO7kUjRdrS0BJt3M/FPxmHMBOm8JQi2BsHAHFsy27E0EolP8rp0NzXsJ+jNPyDWvOJZPA==",
+      "dev": true,
+      "dependencies": {
+        "@types/unist": "^3.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/unist-util-stringify-position": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/unist-util-stringify-position/-/unist-util-stringify-position-4.0.0.tgz",
+      "integrity": "sha512-0ASV06AAoKCDkS2+xw5RXJywruurpbC4JZSm7nr7MOt1ojAzvyyaO+UxZf18j8FCF6kmzCZKcAgN/yu2gm2XgQ==",
+      "dev": true,
+      "dependencies": {
+        "@types/unist": "^3.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/unist-util-visit": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/unist-util-visit/-/unist-util-visit-5.0.0.tgz",
+      "integrity": "sha512-MR04uvD+07cwl/yhVuVWAtw+3GOR/knlL55Nd/wAdblk27GCVt3lqpTivy/tkJcZoNPzTwS1Y+KMojlLDhoTzg==",
+      "dev": true,
+      "dependencies": {
+        "@types/unist": "^3.0.0",
+        "unist-util-is": "^6.0.0",
+        "unist-util-visit-parents": "^6.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/unist-util-visit-parents": {
+      "version": "6.0.1",
+      "resolved": "https://registry.npmjs.org/unist-util-visit-parents/-/unist-util-visit-parents-6.0.1.tgz",
+      "integrity": "sha512-L/PqWzfTP9lzzEa6CKs0k2nARxTdZduw3zyh8d2NVBnsyvHjSX4TWse388YrrQKbvI8w20fGjGlhgT96WwKykw==",
+      "dev": true,
+      "dependencies": {
+        "@types/unist": "^3.0.0",
+        "unist-util-is": "^6.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/universalify": {
       "version": "0.1.2",
       "resolved": "https://registry.npmjs.org/universalify/-/universalify-0.1.2.tgz",
@@ -7253,6 +7724,34 @@
         "node": ">=10.12.0"
       }
     },
+    "node_modules/vfile": {
+      "version": "6.0.3",
+      "resolved": "https://registry.npmjs.org/vfile/-/vfile-6.0.3.tgz",
+      "integrity": "sha512-KzIbH/9tXat2u30jf+smMwFCsno4wHVdNmzFyL+T/L3UGqqk6JKfVqOFOZEpZSHADH1k40ab6NUIXZq422ov3Q==",
+      "dev": true,
+      "dependencies": {
+        "@types/unist": "^3.0.0",
+        "vfile-message": "^4.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
+    "node_modules/vfile-message": {
+      "version": "4.0.2",
+      "resolved": "https://registry.npmjs.org/vfile-message/-/vfile-message-4.0.2.tgz",
+      "integrity": "sha512-jRDZ1IMLttGj41KcZvlrYAaI3CfqpLpfpf+Mfig13viT6NKvRzWZ+lXz0Y5D60w6uJIBAOGq9mSHf0gktF0duw==",
+      "dev": true,
+      "dependencies": {
+        "@types/unist": "^3.0.0",
+        "unist-util-stringify-position": "^4.0.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/unified"
+      }
+    },
     "node_modules/walker": {
       "version": "1.0.8",
       "resolved": "https://registry.npmjs.org/walker/-/walker-1.0.8.tgz",
@@ -7338,9 +7837,9 @@
       "dev": true
     },
     "node_modules/yaml": {
-      "version": "2.5.0",
-      "resolved": "https://registry.npmjs.org/yaml/-/yaml-2.5.0.tgz",
-      "integrity": "sha512-2wWLbGbYDiSqqIKoPjar3MPgB94ErzCtrNE1FdqGuaO0pi2JGjmE8aW8TDZwzU7vuxcGRdL/4gPQwQ7hD5AMSw==",
+      "version": "2.6.1",
+      "resolved": "https://registry.npmjs.org/yaml/-/yaml-2.6.1.tgz",
+      "integrity": "sha512-7r0XPzioN/Q9kXBro/XPnA6kznR73DHq+GXh5ON7ZozRO6aMjbmiBuKste2wslTFkC5d1dw0GooOCepZXJ2SAg==",
       "dev": true,
       "bin": {
         "yaml": "bin.mjs"
@@ -7387,6 +7886,16 @@
       "funding": {
         "url": "https://github.com/sponsors/sindresorhus"
       }
+    },
+    "node_modules/zwitch": {
+      "version": "2.0.4",
+      "resolved": "https://registry.npmjs.org/zwitch/-/zwitch-2.0.4.tgz",
+      "integrity": "sha512-bXE4cR/kVZhKZX/RjPEflHaKVhUVl85noU3v6b8apfQEc1x4A+zBxjZ4lN8LqGd6WZ3dl98pY4o717VFmoPp+A==",
+      "dev": true,
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
     }
   }
 }
diff --git a/package.json b/package.json
index 47d0a10..1de39c4 100644
--- a/package.json
+++ b/package.json
@@ -29,9 +29,10 @@
     "rete": "^2.0.1"
   },
   "devDependencies": {
+    "@tsd/typescript": "^5.7.2",
+    "jest-tsd": "^0.2.2",
     "rete": "^2.0.1",
-    "rete-cli": "~2.0.1",
-    "typescript": "4.8.4"
+    "rete-cli": "~2.0.1"
   },
   "dependencies": {
     "@babel/runtime": "^7.21.0"
diff --git a/src/dataflow-engine.ts b/src/dataflow-engine.ts
index 823fc1b..f8ba61a 100644
--- a/src/dataflow-engine.ts
+++ b/src/dataflow-engine.ts
@@ -6,8 +6,9 @@ import { Cache } from './utils/cache'
 import { Cancellable, createCancellblePromise } from './utils/cancellable'
 
 export type DataflowNode = { data(inputs: Record<string, any>): Promise<Record<string, any>> | Record<string, any> }
+type Node = ClassicScheme['Node'] & DataflowNode
 export type DataflowEngineScheme = GetSchemes<
-  ClassicScheme['Node'] & DataflowNode,
+  Node,
   ClassicScheme['Connection']
 >
 
@@ -111,8 +112,12 @@ export class DataflowEngine<Schemes extends DataflowEngineScheme> extends Scope<
    * @param nodeId Node id to fetch input data for
    * @throws `Cancelled when `reset` is called while fetching data
    */
-  public async fetchInputs(nodeId: NodeId) {
-    return this.getDataflow().fetchInputs(nodeId)
+  public async fetchInputs<N extends Node>(node: NodeId | N): Promise<Parameters<N['data']>[0]> {
+    const id = typeof node === 'object'
+      ? node.id
+      : node
+
+    return this.getDataflow().fetchInputs<Parameters<N['data']>[0]>(id)
   }
 
   /**
@@ -120,7 +125,11 @@ export class DataflowEngine<Schemes extends DataflowEngineScheme> extends Scope<
    * @param nodeId Node id to fetch data from
    * @throws `Cancelled` when `reset` is called while fetching data
    */
-  public async fetch(nodeId: NodeId) {
-    return this.getDataflow().fetch(nodeId)
+  public async fetch<N extends Node>(node: NodeId | N): Promise<ReturnType<N['data']>> {
+    const id = typeof node === 'object'
+      ? node.id
+      : node
+
+    return this.getDataflow().fetch<ReturnType<N['data']>>(id)
   }
 }
diff --git a/src/dataflow.ts b/src/dataflow.ts
index e57866e..28b9070 100644
--- a/src/dataflow.ts
+++ b/src/dataflow.ts
@@ -12,9 +12,13 @@ export type DataflowNodeSetup<
 > = {
   inputs: () => (keyof I)[]
   outputs: () => (keyof O)[]
-  data(fetchInputs: () => Promise<{ [key in keyof I]: I[key][] }>): Promise<O> | O
+  data(fetchInputs: () => Promise<Partial<{ [key in keyof I]: I[key][] }>>): Promise<O> | O
 }
 
+type DefaultInputs = null
+type Inputs = Partial<Record<string, any[]>> | DefaultInputs
+type FetchInputs<T> = T extends DefaultInputs ? Record<string, any> : Partial<T>
+
 /**
  * Dataflow is a class that allows to process nodes in a graph using Dataflow approach.
  * @priority 8
@@ -55,7 +59,7 @@ export class Dataflow<Schemes extends ClassicScheme> {
    * @param nodeId Node id
    * @returns Object with inputs
    */
-  public async fetchInputs(nodeId: NodeId) {
+  public async fetchInputs<T extends Inputs = DefaultInputs>(nodeId: NodeId): Promise<FetchInputs<T>> {
     const result = this.setups.get(nodeId)
 
     if (!result) throw new Error('node is not initialized')
@@ -66,7 +70,7 @@ export class Dataflow<Schemes extends ClassicScheme> {
       return c.target === nodeId && inputKeys.includes(c.targetInput)
     })
 
-    const inputs: Record<string, any> = {}
+    const inputs = {} as FetchInputs<T>
     const consWithSourceData = await Promise.all(cons.map(async c => {
       return {
         c,
@@ -75,11 +79,12 @@ export class Dataflow<Schemes extends ClassicScheme> {
     }))
 
     for (const { c, sourceData } of consWithSourceData) {
-      const previous = inputs[c.targetInput]
+      const previous = (inputs[c.targetInput]
         ? inputs[c.targetInput]
-        : []
+        : [])!
+      const inputsMutation = inputs as Record<string, any[]>
 
-      inputs[c.targetInput] = [...previous, sourceData[c.sourceOutput]]
+      inputsMutation[c.targetInput] = [...previous, sourceData[c.sourceOutput]]
     }
 
     return inputs
@@ -91,7 +96,7 @@ export class Dataflow<Schemes extends ClassicScheme> {
    * @param nodeId Node id
    * @returns Object with outputs
    */
-  public async fetch(nodeId: NodeId): Promise<Record<string, any>> {
+  public async fetch<T extends Record<string, any>>(nodeId: NodeId): Promise<T> {
     const result = this.setups.get(nodeId)
 
     if (!result) throw new Error('node is not initialized')
diff --git a/src/utils/cancellable.ts b/src/utils/cancellable.ts
index 945050a..3200935 100644
--- a/src/utils/cancellable.ts
+++ b/src/utils/cancellable.ts
@@ -34,7 +34,7 @@ function createCancellblePromise(...sequence: S<any, any>[]): Cancellable<any> {
     const t = p.then(item as any).then(commit)
 
     return t
-  }, promise)
+  }, promise) as Cancellable<any>
 
   n.cancel = () => {
     if (!cancelled) reject(new Cancelled())
diff --git a/test/types.test-d.ts b/test/types.test-d.ts
new file mode 100644
index 0000000..437ccee
--- /dev/null
+++ b/test/types.test-d.ts
@@ -0,0 +1,110 @@
+import { describe, it } from '@jest/globals'
+import { expectType } from 'jest-tsd'
+import { ClassicPreset, NodeEditor } from 'rete'
+
+import { Dataflow } from '../src/dataflow'
+import { DataflowEngine, DataflowEngineScheme, DataflowNode } from '../src/dataflow-engine'
+import { ClassicScheme } from '../src/types'
+
+describe('Dataflow types', () => {
+  let editor!: NodeEditor<ClassicScheme>
+  let dataflow: Dataflow<ClassicScheme>
+
+  beforeEach(() => {
+    editor = new NodeEditor<ClassicScheme>()
+    dataflow = new Dataflow(editor)
+  })
+
+  it('returns default Record type for node data', () => {
+    const node = new ClassicPreset.Node('label')
+
+    expectType<Promise<Record<string, any>>>(dataflow.fetch(node.id))
+  })
+
+  it('returns default Record type for node inputs', () => {
+    const node = new ClassicPreset.Node('label')
+
+    expectType<Promise<Record<string, any>>>(dataflow.fetchInputs(node.id))
+  })
+
+  it('accepts fetch data type as generic parameter', () => {
+    const node = new ClassicPreset.Node('label')
+
+    expectType<Promise<{ a: string }>>(dataflow.fetch<{ a: string }>(node.id))
+  })
+
+  it('accepts inputs data type as generic parameter', () => {
+    const node = new ClassicPreset.Node('label')
+
+    expectType<Promise<{ a?: string[] }>>(dataflow.fetchInputs<{ a: string[] }>(node.id))
+  })
+})
+
+class Node extends ClassicPreset.Node implements DataflowNode {
+  data(inputs: { a?: number[], b?: boolean[] }) {
+    return {
+      a: inputs.a?.join('') ?? '',
+      b: inputs.b?.join('') ?? ''
+    }
+  }
+}
+
+describe('DataflowEngine types', () => {
+  let editor!: NodeEditor<DataflowEngineScheme>
+  let dataflow: DataflowEngine<DataflowEngineScheme>
+
+  beforeEach(() => {
+    editor = new NodeEditor<DataflowEngineScheme>()
+    dataflow = new DataflowEngine()
+
+    editor.use(dataflow)
+  })
+
+  it('returns default Record type for node data', async () => {
+    const node1 = new Node('label1')
+
+    const data = await dataflow.fetch(node1.id)
+
+    expectType<Record<string, any>>(data)
+  })
+
+  it('returns default Record type fetch inputs', async () => {
+    const node1 = new Node('label1')
+
+    const data = await dataflow.fetchInputs(node1.id)
+
+    expectType<Record<string, any>>(data)
+  })
+
+  it('returns custom type for node instance', async () => {
+    const node1 = new Node('label1')
+
+    const data = await dataflow.fetch(node1)
+
+    expectType<{ a: string, b: string }>(data)
+  })
+
+  it('returns custom type for genetic parameter', async () => {
+    const node1 = new Node('label1')
+
+    const data = await dataflow.fetch<Node>(node1)
+
+    expectType<{ a: string, b: string }>(data)
+  })
+
+  it('returns custom type for fetch inputs', async () => {
+    const node1 = new Node('label1')
+
+    const data = await dataflow.fetchInputs(node1)
+
+    expectType<{ a?: number[], b?: boolean[] }>(data)
+  })
+
+  it('returns custom type for fetch inputs generic parameter', async () => {
+    const node1 = new Node('label1')
+
+    const data = await dataflow.fetchInputs<Node>(node1)
+
+    expectType<{ a?: number[], b?: boolean[] }>(data)
+  })
+})
diff --git a/test/types.test.ts b/test/types.test.ts
new file mode 100644
index 0000000..0b1655b
--- /dev/null
+++ b/test/types.test.ts
@@ -0,0 +1,6 @@
+import { it } from '@jest/globals'
+import { expectTypeTestsToPassAsync } from 'jest-tsd'
+
+it('should not produce static type errors', async () => {
+  await expectTypeTestsToPassAsync(__filename)
+})