diff --git a/.changeset/brave-papayas-obey.md b/.changeset/brave-papayas-obey.md
new file mode 100644
index 00000000..0d74290d
--- /dev/null
+++ b/.changeset/brave-papayas-obey.md
@@ -0,0 +1,5 @@
+---
+"barnard59-formats": patch
+---
+
+Added type declarations
diff --git a/.changeset/eighty-melons-boil.md b/.changeset/eighty-melons-boil.md
new file mode 100644
index 00000000..97fc1f9a
--- /dev/null
+++ b/.changeset/eighty-melons-boil.md
@@ -0,0 +1,5 @@
+---
+"barnard59-env": patch
+---
+
+Update `@zazuko/env-node`
diff --git a/.changeset/young-turkeys-sit.md b/.changeset/young-turkeys-sit.md
new file mode 100644
index 00000000..a70304e5
--- /dev/null
+++ b/.changeset/young-turkeys-sit.md
@@ -0,0 +1,5 @@
+---
+"barnard59-formats": patch
+---
+
+Ensures that the RDF/JS environment is used with parser streams
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 22e6d670..26c94dd3 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -81,14 +81,20 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os:
-          - ubuntu-latest
-          - macos-latest
-          - windows-latest
-    runs-on: ${{ matrix.os }}
+        env:
+          - os: ubuntu-latest
+            node: 20
+          - os: macos-latest
+            node: 20
+          - os: windows-latest
+            node: 20.12.1 # Pinned, because of https://github.com/approvals/Approvals.NodeJS/issues/176
+    runs-on: ${{ matrix.env.os }}
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.env.node }}
+          cache: npm
       - run: npm ci
       - run: npx barnard59 run test/e2e/definitions/file-loader.ttl
       - run: npx barnard59 run test/e2e/definitions/foreach/with-handler.ttl
@@ -103,25 +109,31 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os:
-          - ubuntu-latest
-          - macos-latest
-          - windows-latest
-    runs-on: ${{ matrix.os }}
+        env:
+          - os: ubuntu-latest
+            node: 20
+          - os: macos-latest
+            node: 20
+          - os: windows-latest
+            node: 20.12.1 # Pinned, because of https://github.com/approvals/Approvals.NodeJS/issues/176
+    runs-on: ${{ matrix.env.os }}
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.env.node }}
+          cache: npm
       - run: npm ci
       - name: pack all
         run: npm pack -ws
       - run: npm install -g barnard59-*.tgz
-        if: matrix.os == 'ubuntu-latest' || matrix.os == 'macos-latest'
+        if: matrix.env.os == 'ubuntu-latest' || matrix.env.os == 'macos-latest'
       - run: cmd /c npm install -g (Get-ChildItem -Filter barnard59-*.tgz).FullName
-        if: matrix.os == 'windows-latest'
+        if: matrix.env.os == 'windows-latest'
       - run: which barnard59
       - run: barnard59 --help
       - run: barnard59 shacl validate --shapes test/support/pipeline-shapes.ttl < test/e2e/definitions/file-loader.ttl
-        if: matrix.os == 'ubuntu-latest' || matrix.os == 'macos-latest'
+        if: matrix.env.os == 'ubuntu-latest' || matrix.os == 'macos-latest'
       - run: barnard59 shacl validate --shapes test/support/pipeline-shapes.ttl < test/e2e/definitions/file-loader.ttl
-        if: matrix.os == 'windows-latest'
+        if: matrix.env.os == 'windows-latest'
         shell: cmd
diff --git a/package-lock.json b/package-lock.json
index d5c42df2..8e56163e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -26,8 +26,7 @@
         "mocha": "^10.2.0",
         "sinon-chai": "^3.7.0",
         "ts-node": "^10.9.2",
-        "tsm": "^2.3.0",
-        "typescript": "^5.3.2",
+        "typescript": "^5.4.5",
         "wsrun": "^5.2.4"
       },
       "engines": {
@@ -6457,6 +6456,24 @@
         "rdf-js": "^4.0.2"
       }
     },
+    "node_modules/@types/rdf-parser-csvw": {
+      "version": "0.15.0",
+      "resolved": "https://registry.npmjs.org/@types/rdf-parser-csvw/-/rdf-parser-csvw-0.15.0.tgz",
+      "integrity": "sha512-m8YYxA9KIpEUucOONwLPlCb/X4OFwociBBhkK280uqhDNowZhpnQpDx3OtE7qE9u+1uAzUSfnH5rhL17Rah7oA==",
+      "dev": true,
+      "dependencies": {
+        "@rdfjs/types": "*"
+      }
+    },
+    "node_modules/@types/rdf-parser-csvw-xlsx": {
+      "version": "0.1.0",
+      "resolved": "https://registry.npmjs.org/@types/rdf-parser-csvw-xlsx/-/rdf-parser-csvw-xlsx-0.1.0.tgz",
+      "integrity": "sha512-TrgN5yDVKKWD8Reks+RI/GsHrNvLgU+vFcXVmic+MeIRHKSNOGCbulCk3l+YzhKhUvCiHyDX+k8Pqr9PMuJw7Q==",
+      "dev": true,
+      "dependencies": {
+        "@rdfjs/types": "*"
+      }
+    },
     "node_modules/@types/rdf-transform-triple-to-quad": {
       "version": "2.0.5",
       "dev": true,
@@ -6616,18 +6633,20 @@
       }
     },
     "node_modules/@types/rdfjs__parser-jsonld": {
-      "version": "2.1.1",
-      "license": "MIT",
+      "version": "2.1.7",
+      "resolved": "https://registry.npmjs.org/@types/rdfjs__parser-jsonld/-/rdfjs__parser-jsonld-2.1.7.tgz",
+      "integrity": "sha512-n35K+c1Y95580N202Jxly6xjFE953FF+Y2mwxok6zLfMo4rgIfgMBElnNwpja0IeYXTuzGm1tEz7va3lItGrTg==",
       "dependencies": {
-        "@types/jsonld": "*",
-        "rdf-js": "^4.0.2"
+        "@rdfjs/types": ">=1.0.0",
+        "@types/jsonld": "*"
       }
     },
     "node_modules/@types/rdfjs__parser-n3": {
-      "version": "2.0.1",
-      "license": "MIT",
+      "version": "2.0.6",
+      "resolved": "https://registry.npmjs.org/@types/rdfjs__parser-n3/-/rdfjs__parser-n3-2.0.6.tgz",
+      "integrity": "sha512-VHfdq7BDV6iMCtHkzTFSOuUWnqGlMUmEF0UZyK4+g9SzLWvc6TMcU5TYwQPQIz/e0s7dZ+xomxx6mVtIzsRQ/A==",
       "dependencies": {
-        "rdf-js": "^4.0.2"
+        "@rdfjs/types": ">=1.0.0"
       }
     },
     "node_modules/@types/rdfjs__prefix-map": {
@@ -6679,6 +6698,16 @@
         "@rdfjs/types": "*"
       }
     },
+    "node_modules/@types/rdfjs__sink-to-duplex": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/@types/rdfjs__sink-to-duplex/-/rdfjs__sink-to-duplex-1.0.0.tgz",
+      "integrity": "sha512-hUqFFuTbFvNBcBL/gfHG2+RwvV9T6wEcDUOA1rBQLsq/y+CgPygzFRT8AOuS5MSy0nzR4igajYn0wfkEasVZRw==",
+      "dev": true,
+      "dependencies": {
+        "@rdfjs/types": "*",
+        "@types/duplexify": "^3.6.4"
+      }
+    },
     "node_modules/@types/rdfjs__term-map": {
       "version": "2.0.9",
       "license": "MIT",
@@ -6719,6 +6748,15 @@
         "@types/node": "*"
       }
     },
+    "node_modules/@types/sax": {
+      "version": "1.2.7",
+      "resolved": "https://registry.npmjs.org/@types/sax/-/sax-1.2.7.tgz",
+      "integrity": "sha512-rO73L89PJxeYM3s3pPPjiPgVVcymqU490g0YO5n5By0k2Erzj6tay/4lr1CHAAU4JyOWd1rpQ8bCf6cZfHU96A==",
+      "dev": true,
+      "dependencies": {
+        "@types/node": "*"
+      }
+    },
     "node_modules/@types/semver": {
       "version": "6.2.3",
       "dev": true,
@@ -12007,57 +12045,6 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
-    "node_modules/esbuild": {
-      "version": "0.15.18",
-      "dev": true,
-      "hasInstallScript": true,
-      "license": "MIT",
-      "bin": {
-        "esbuild": "bin/esbuild"
-      },
-      "engines": {
-        "node": ">=12"
-      },
-      "optionalDependencies": {
-        "@esbuild/android-arm": "0.15.18",
-        "@esbuild/linux-loong64": "0.15.18",
-        "esbuild-android-64": "0.15.18",
-        "esbuild-android-arm64": "0.15.18",
-        "esbuild-darwin-64": "0.15.18",
-        "esbuild-darwin-arm64": "0.15.18",
-        "esbuild-freebsd-64": "0.15.18",
-        "esbuild-freebsd-arm64": "0.15.18",
-        "esbuild-linux-32": "0.15.18",
-        "esbuild-linux-64": "0.15.18",
-        "esbuild-linux-arm": "0.15.18",
-        "esbuild-linux-arm64": "0.15.18",
-        "esbuild-linux-mips64le": "0.15.18",
-        "esbuild-linux-ppc64le": "0.15.18",
-        "esbuild-linux-riscv64": "0.15.18",
-        "esbuild-linux-s390x": "0.15.18",
-        "esbuild-netbsd-64": "0.15.18",
-        "esbuild-openbsd-64": "0.15.18",
-        "esbuild-sunos-64": "0.15.18",
-        "esbuild-windows-32": "0.15.18",
-        "esbuild-windows-64": "0.15.18",
-        "esbuild-windows-arm64": "0.15.18"
-      }
-    },
-    "node_modules/esbuild-darwin-64": {
-      "version": "0.15.18",
-      "cpu": [
-        "x64"
-      ],
-      "dev": true,
-      "license": "MIT",
-      "optional": true,
-      "os": [
-        "darwin"
-      ],
-      "engines": {
-        "node": ">=12"
-      }
-    },
     "node_modules/escalade": {
       "version": "3.1.1",
       "license": "MIT",
@@ -25736,20 +25723,6 @@
       "version": "2.5.3",
       "license": "0BSD"
     },
-    "node_modules/tsm": {
-      "version": "2.3.0",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "esbuild": "^0.15.16"
-      },
-      "bin": {
-        "tsm": "bin.js"
-      },
-      "engines": {
-        "node": ">=12"
-      }
-    },
     "node_modules/tty-table": {
       "version": "4.2.1",
       "dev": true,
@@ -25968,9 +25941,10 @@
       }
     },
     "node_modules/typescript": {
-      "version": "5.3.3",
+      "version": "5.4.5",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.4.5.tgz",
+      "integrity": "sha512-vcI4UpRgg81oIRUFwR0WSIHKt11nJ7SAVlYNIu+QpqeyXP+gpQJy/Z4+F0aGxSE4MqwjyXvW/TzgkLAx2AGHwQ==",
       "dev": true,
-      "license": "Apache-2.0",
       "bin": {
         "tsc": "bin/tsc",
         "tsserver": "bin/tsserver"
@@ -27449,11 +27423,17 @@
         "@rdfjs/serializer-ntriples": "^2.0.0",
         "@rdfjs/sink-to-duplex": "^1.0.0",
         "barnard59-base": "^2.0.1",
+        "is-stream": "^3.0.0",
         "rdf-parser-csvw": "^0.15.0",
         "rdf-parser-csvw-xlsx": "^0.1.0",
         "rdfxml-streaming-parser": "^1.2.0"
       },
       "devDependencies": {
+        "@types/rdf-parser-csvw": "^0.15.0",
+        "@types/rdf-parser-csvw-xlsx": "^0.1.0",
+        "@types/rdfjs__parser-jsonld": "^2.1.7",
+        "@types/rdfjs__sink-to-duplex": "^1.0.0",
+        "@types/sax": "^1.2.7",
         "@zazuko/env-core": "^1.1.2",
         "barnard59-env": "^1.2.5",
         "chai": "^4.3.7"
diff --git a/package.json b/package.json
index aaee31de..048c2d70 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,7 @@
     "mocha": "^10.2.0",
     "sinon-chai": "^3.7.0",
     "ts-node": "^10.9.2",
-    "typescript": "^5.3.2",
+    "typescript": "^5.4.5",
     "wsrun": "^5.2.4"
   },
   "lint-staged": {
diff --git a/packages/formats/csvw.js b/packages/formats/csvw.js
index 330daacf..148ba105 100644
--- a/packages/formats/csvw.js
+++ b/packages/formats/csvw.js
@@ -3,13 +3,41 @@ import CsvwParser from 'rdf-parser-csvw'
 import tracer from './lib/tracer.js'
 import { toDataset } from './lib/stream.js'
 
+/**
+ * @typedef {{
+ *   metadata: import('@rdfjs/types').DatasetCore
+ *   timezone?: string
+ *   relaxColumnCount?: boolean
+ *   skipLinesWithError?: boolean
+ * }} Options
+ */
+
+/**
+ * @overload
+ * @param {Options} args
+ * @return {import('duplexify').Duplexify}
+ */
+
+/**
+ * @overload
+ * @param {import('@rdfjs/types').DatasetCore} metadata
+ * @return {import('duplexify').Duplexify}
+ */
+
+/**
+ * @this {import('barnard59-core').Context}
+ * @param {Options | import('@rdfjs/types').DatasetCore} args
+ */
 function parse(args) {
+  /**
+   * @type {import('@rdfjs/types').DatasetCore}
+   */
   let metadata
   let relaxColumnCount = false
   let skipLinesWithError = false
   let timezone = 'local'
 
-  if (args.metadata) {
+  if ('metadata' in args) {
     metadata = args.metadata
 
     if (typeof args.relaxColumnCount !== 'undefined') {
diff --git a/packages/formats/jsonld.js b/packages/formats/jsonld.js
index 3f308490..97d92d87 100644
--- a/packages/formats/jsonld.js
+++ b/packages/formats/jsonld.js
@@ -6,20 +6,28 @@ import sinkToDuplex from '@rdfjs/sink-to-duplex'
 import { combine, jsonStringify } from 'barnard59-base'
 import tracer from './lib/tracer.js'
 
+/**
+ * @this {import('barnard59-core').Context}
+ * @param {Object} [options]
+ * @param {string | Record<string, string>} [options.localContext]
+ */
 function parse({ localContext } = {}) {
-  let documentLoader = null
+  /**
+   * @type {import('@rdfjs/parser-jsonld').DocumentLoader | undefined}
+   */
+  let documentLoader
 
   if (localContext) {
     if (typeof localContext === 'string') {
-      localContext = JSON.parse(localContext)
+      documentLoader = new FsDocumentLoader(JSON.parse(localContext))
+    } else {
+      documentLoader = new FsDocumentLoader(localContext)
     }
-
-    documentLoader = new FsDocumentLoader(localContext)
   }
 
   return tracer.startActiveSpan('jsonld:parse', span => {
     const stream = sinkToDuplex(new Parser({ factory: this.env, documentLoader }), { objectMode: true })
-    stream.on('error', err => {
+    stream.on('error', /** @type {any} */ err => {
       span.recordException(err)
       span.setStatus({ code: SpanStatusCode.ERROR, message: err.message })
       span.end()
@@ -29,10 +37,13 @@ function parse({ localContext } = {}) {
   })
 }
 
+/**
+ * @this {import('barnard59-core').Context}
+ */
 const parseObject = function () {
   return tracer.startActiveSpan('jsonld:parse.object', span => {
     const stream = combine([jsonStringify(), parse.call(this)], { objectMode: true })
-    stream.on('error', err => {
+    stream.on('error', (/** @type Error */ err) => {
       span.recordException(err)
       span.setStatus({ code: SpanStatusCode.ERROR, message: err.message })
       span.end()
diff --git a/packages/formats/lib/stream.js b/packages/formats/lib/stream.js
index 094793e6..a74d915d 100644
--- a/packages/formats/lib/stream.js
+++ b/packages/formats/lib/stream.js
@@ -1,5 +1,12 @@
+import { isReadableStream } from 'is-stream'
+
+/**
+ * @param {import('@rdfjs/environment/Environment.js').Environment<ReturnType<import('@zazuko/env/lib/DatasetFactory.js').default>>} rdf
+ * @param {(import('@rdfjs/types').Stream & import('stream').Readable) | import('@rdfjs/types').DatasetCore} streamOrDataset
+ * @return {Promise<import('@rdfjs/types').DatasetCore>}
+ */
 export function toDataset(rdf, streamOrDataset) {
-  if (!streamOrDataset.readable) {
+  if (!isReadableStream(streamOrDataset)) {
     return Promise.resolve(streamOrDataset)
   }
 
diff --git a/packages/formats/n3.js b/packages/formats/n3.js
index 031cfb1f..6bc72d30 100644
--- a/packages/formats/n3.js
+++ b/packages/formats/n3.js
@@ -1,6 +1,10 @@
 import Parser from '@rdfjs/parser-n3'
 import sinkToDuplex from '@rdfjs/sink-to-duplex'
 
+/**
+ * @this {import('barnard59-core').Context}
+ * @param {import('@rdfjs/parser-n3').ParserOptions} args
+ */
 function parse(args) {
   return sinkToDuplex(new Parser({ factory: this.env, ...args }), {
     readableObjectMode: true,
diff --git a/packages/formats/package.json b/packages/formats/package.json
index d6fa4612..d48d7f43 100644
--- a/packages/formats/package.json
+++ b/packages/formats/package.json
@@ -5,7 +5,10 @@
   "main": "index.js",
   "type": "module",
   "scripts": {
-    "test": "mocha"
+    "test": "mocha",
+    "prebuild": "rimraf -g *.d.ts lib/*.d.ts",
+    "build": "tsc",
+    "prepack": "npm run build"
   },
   "repository": {
     "type": "git",
@@ -27,11 +30,17 @@
     "@rdfjs/serializer-ntriples": "^2.0.0",
     "@rdfjs/sink-to-duplex": "^1.0.0",
     "barnard59-base": "^2.0.1",
+    "is-stream": "^3.0.0",
     "rdf-parser-csvw": "^0.15.0",
     "rdf-parser-csvw-xlsx": "^0.1.0",
     "rdfxml-streaming-parser": "^1.2.0"
   },
   "devDependencies": {
+    "@types/rdfjs__sink-to-duplex": "^1.0.0",
+    "@types/rdf-parser-csvw": "^0.15.0",
+    "@types/rdf-parser-csvw-xlsx": "^0.1.0",
+    "@types/rdfjs__parser-jsonld": "^2.1.7",
+    "@types/sax": "^1.2.7",
     "@zazuko/env-core": "^1.1.2",
     "barnard59-env": "^1.2.5",
     "chai": "^4.3.7"
@@ -40,6 +49,6 @@
     "node": ">= 14.0.0"
   },
   "mocha": {
-    "loader": "ts-node/esm"
+    "loader": "ts-node/esm/transpile-only"
   }
 }
diff --git a/packages/formats/rdf-xml.js b/packages/formats/rdf-xml.js
index 361b5b12..aac02a7e 100644
--- a/packages/formats/rdf-xml.js
+++ b/packages/formats/rdf-xml.js
@@ -1,6 +1,9 @@
 import sinkToDuplex from '@rdfjs/sink-to-duplex'
 import { RdfXmlParser } from 'rdfxml-streaming-parser'
 
+/**
+ * @this {import('barnard59-core').Context}
+ */
 function parse() {
   return sinkToDuplex(new RdfXmlParser({
     dataFactory: this.env,
diff --git a/packages/formats/tsconfig.json b/packages/formats/tsconfig.json
new file mode 100644
index 00000000..2f57222f
--- /dev/null
+++ b/packages/formats/tsconfig.json
@@ -0,0 +1,11 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "allowJs": true,
+    "checkJs": true,
+    "emitDeclarationOnly": true
+  },
+  "files": [
+    "./index.js"
+  ]
+}
diff --git a/packages/formats/xlsx.js b/packages/formats/xlsx.js
index 2518b3f9..d69031b8 100644
--- a/packages/formats/xlsx.js
+++ b/packages/formats/xlsx.js
@@ -3,11 +3,37 @@ import CsvwXlsxParser from 'rdf-parser-csvw-xlsx'
 import tracer from './lib/tracer.js'
 import { toDataset } from './lib/stream.js'
 
+/**
+ * @typedef {{
+ *  metadata: import('@rdfjs/types').DatasetCore
+ *  timezone?: string
+ * }} Options
+ */
+
+/**
+ * @overload
+ * @param {Options} args
+ * @return {import('duplexify').Duplexify}
+ */
+
+/**
+ * @overload
+ * @param {import('@rdfjs/types').DatasetCore} metadata
+ * @return {import('duplexify').Duplexify}
+ */
+
+/**
+ * @this {import('barnard59-core').Context}
+ * @param {Options | import('@rdfjs/types').DatasetCore} args
+ */
 function parse(args) {
+  /**
+   * @type {import('rdf-js').DatasetCore}
+   */
   let metadata
   let timezone = 'local'
 
-  if (args.metadata) {
+  if ('metadata' in args) {
     metadata = args.metadata
 
     if (typeof args.timezone !== 'undefined') {