diff --git a/.gitignore b/.gitignore
index 7ad9e674..f115d26b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,3 +7,5 @@ node_modules
 package-lock.json
 yarn.lock
 .vscode
+.tmp-compiled-docs
+tsconfig-doc-check.aegir.json
diff --git a/package.json b/package.json
index 4ffb609f..732bf850 100644
--- a/package.json
+++ b/package.json
@@ -48,132 +48,155 @@
   "exports": {
     ".": {
       "types": "./dist/src/index.d.ts",
-      "import": "./dist/src/index.js"
+      "import": "./dist/src/index.js",
+      "module-sync": "./dist/src/index.js"
     },
     "./bases/base10": {
       "types": "./dist/src/bases/base10.d.ts",
-      "import": "./dist/src/bases/base10.js"
+      "import": "./dist/src/bases/base10.js",
+      "module-sync": "./dist/src/bases/base10.js"
     },
     "./bases/base16": {
       "types": "./dist/src/bases/base16.d.ts",
-      "import": "./dist/src/bases/base16.js"
+      "import": "./dist/src/bases/base16.js",
+      "module-sync": "./dist/src/bases/base16.js"
     },
     "./bases/base2": {
       "types": "./dist/src/bases/base2.d.ts",
-      "import": "./dist/src/bases/base2.js"
+      "import": "./dist/src/bases/base2.js",
+      "module-sync": "./dist/src/bases/base2.js"
     },
     "./bases/base256emoji": {
       "types": "./dist/src/bases/base256emoji.d.ts",
-      "import": "./dist/src/bases/base256emoji.js"
+      "import": "./dist/src/bases/base256emoji.js",
+      "module-sync": "./dist/src/bases/base256emoji.js"
     },
     "./bases/base32": {
       "types": "./dist/src/bases/base32.d.ts",
-      "import": "./dist/src/bases/base32.js"
+      "import": "./dist/src/bases/base32.js",
+      "module-sync": "./dist/src/bases/base32.js"
     },
     "./bases/base36": {
       "types": "./dist/src/bases/base36.d.ts",
-      "import": "./dist/src/bases/base36.js"
+      "import": "./dist/src/bases/base36.js",
+      "module-sync": "./dist/src/bases/base36.js"
     },
     "./bases/base58": {
       "types": "./dist/src/bases/base58.d.ts",
-      "import": "./dist/src/bases/base58.js"
+      "import": "./dist/src/bases/base58.js",
+      "module-sync": "./dist/src/bases/base58.js"
     },
     "./bases/base64": {
       "types": "./dist/src/bases/base64.d.ts",
-      "import": "./dist/src/bases/base64.js"
+      "import": "./dist/src/bases/base64.js",
+      "module-sync": "./dist/src/bases/base64.js"
     },
     "./bases/base8": {
       "types": "./dist/src/bases/base8.d.ts",
-      "import": "./dist/src/bases/base8.js"
+      "import": "./dist/src/bases/base8.js",
+      "module-sync": "./dist/src/bases/base8.js"
     },
     "./bases/identity": {
       "types": "./dist/src/bases/identity.d.ts",
-      "import": "./dist/src/bases/identity.js"
+      "import": "./dist/src/bases/identity.js",
+      "module-sync": "./dist/src/bases/identity.js"
     },
     "./bases/interface": {
       "types": "./dist/src/bases/interface.d.ts",
-      "import": "./dist/src/bases/interface.js"
+      "import": "./dist/src/bases/interface.js",
+      "module-sync": "./dist/src/bases/interface.js"
     },
     "./basics": {
       "types": "./dist/src/basics.d.ts",
-      "import": "./dist/src/basics.js"
+      "import": "./dist/src/basics.js",
+      "module-sync": "./dist/src/basics.js"
     },
     "./block": {
       "types": "./dist/src/block.d.ts",
-      "import": "./dist/src/block.js"
+      "import": "./dist/src/block.js",
+      "module-sync": "./dist/src/block.js"
     },
     "./block/interface": {
       "types": "./dist/src/block/interface.d.ts",
-      "import": "./dist/src/block/interface.js"
+      "import": "./dist/src/block/interface.js",
+      "module-sync": "./dist/src/block/interface.js"
     },
     "./bytes": {
       "types": "./dist/src/bytes.d.ts",
-      "import": "./dist/src/bytes.js"
+      "import": "./dist/src/bytes.js",
+      "module-sync": "./dist/src/bytes.js"
     },
     "./cid": {
       "types": "./dist/src/cid.d.ts",
-      "import": "./dist/src/cid.js"
+      "import": "./dist/src/cid.js",
+      "module-sync": "./dist/src/cid.js"
     },
     "./codecs/interface": {
       "types": "./dist/src/codecs/interface.d.ts",
-      "import": "./dist/src/codecs/interface.js"
+      "import": "./dist/src/codecs/interface.js",
+      "module-sync": "./dist/src/codecs/interface.js"
     },
     "./codecs/json": {
       "types": "./dist/src/codecs/json.d.ts",
-      "import": "./dist/src/codecs/json.js"
+      "import": "./dist/src/codecs/json.js",
+      "module-sync": "./dist/src/codecs/json.js"
     },
     "./codecs/raw": {
       "types": "./dist/src/codecs/raw.d.ts",
-      "import": "./dist/src/codecs/raw.js"
+      "import": "./dist/src/codecs/raw.js",
+      "module-sync": "./dist/src/codecs/raw.js"
     },
     "./hashes/digest": {
       "types": "./dist/src/hashes/digest.d.ts",
-      "import": "./dist/src/hashes/digest.js"
+      "import": "./dist/src/hashes/digest.js",
+      "module-sync": "./dist/src/hashes/digest.js"
     },
     "./hashes/hasher": {
       "types": "./dist/src/hashes/hasher.d.ts",
-      "import": "./dist/src/hashes/hasher.js"
+      "import": "./dist/src/hashes/hasher.js",
+      "module-sync": "./dist/src/hashes/hasher.js"
     },
     "./hashes/identity": {
       "types": "./dist/src/hashes/identity.d.ts",
-      "import": "./dist/src/hashes/identity.js"
+      "import": "./dist/src/hashes/identity.js",
+      "module-sync": "./dist/src/hashes/identity.js"
     },
     "./hashes/interface": {
       "types": "./dist/src/hashes/interface.d.ts",
-      "import": "./dist/src/hashes/interface.js"
+      "import": "./dist/src/hashes/interface.js",
+      "module-sync": "./dist/src/hashes/interface.js"
     },
     "./hashes/sha1": {
       "types": "./dist/types/src/hashes/sha1.d.ts",
       "browser": "./dist/src/hashes/sha1-browser.js",
-      "import": "./dist/src/hashes/sha1.js"
+      "import": "./dist/src/hashes/sha1.js",
+      "module-sync": "./dist/src/hashes/sha1.js"
     },
     "./hashes/sha2": {
       "types": "./dist/src/hashes/sha2.d.ts",
       "browser": "./dist/src/hashes/sha2-browser.js",
-      "import": "./dist/src/hashes/sha2.js"
+      "import": "./dist/src/hashes/sha2.js",
+      "module-sync": "./dist/src/hashes/sha2.js"
     },
     "./interface": {
       "types": "./dist/src/interface.d.ts",
-      "import": "./dist/src/interface.js"
+      "import": "./dist/src/interface.js",
+      "module-sync": "./dist/src/interface.js"
     },
     "./link": {
       "types": "./dist/src/link.d.ts",
-      "import": "./dist/src/link.js"
+      "import": "./dist/src/link.js",
+      "module-sync": "./dist/src/link.js"
     },
     "./link/interface": {
       "types": "./dist/src/link/interface.d.ts",
-      "import": "./dist/src/link/interface.js"
+      "import": "./dist/src/link/interface.js",
+      "module-sync": "./dist/src/link/interface.js"
     },
     "./traversal": {
       "types": "./dist/src/traversal.d.ts",
-      "import": "./dist/src/traversal.js"
-    }
-  },
-  "eslintConfig": {
-    "extends": "ipfs",
-    "parserOptions": {
-      "project": true,
-      "sourceType": "module"
+      "import": "./dist/src/traversal.js",
+      "module-sync": "./dist/src/traversal.js"
     }
   },
   "release": {
@@ -286,20 +309,11 @@
   "devDependencies": {
     "@stablelib/sha256": "^2.0.0",
     "@stablelib/sha512": "^2.0.0",
-    "@types/node": "^25.0.0",
-    "aegir": "^47.0.7",
+    "aegir": "^48.0.1",
     "buffer": "^6.0.3",
     "cids": "^1.1.9",
     "crypto-hash": "^4.0.0"
   },
-  "aegir": {
-    "test": {
-      "target": [
-        "node",
-        "browser"
-      ]
-    }
-  },
   "browser": {
     "./hashes/sha1": "./dist/src/hashes/sha1-browser.js",
     "./dist/src/hashes/sha1.js": "./dist/src/hashes/sha1-browser.js",
diff --git a/src/bases/base.ts b/src/bases/base.ts
index 12bea63b..afe6425c 100644
--- a/src/bases/base.ts
+++ b/src/bases/base.ts
@@ -1,9 +1,9 @@
-import { coerce } from '../bytes.js'
+import { coerce } from '../bytes.ts'
 import basex from '../vendor/base-x.js'
-import type { BaseCodec, BaseDecoder, BaseEncoder, CombobaseDecoder, Multibase, MultibaseCodec, MultibaseDecoder, MultibaseEncoder, UnibaseDecoder } from './interface.js'
+import type { BaseCodec, BaseDecoder, BaseEncoder, CombobaseDecoder, Multibase, MultibaseCodec, MultibaseDecoder, MultibaseEncoder, UnibaseDecoder } from './interface.ts'
 
 interface EncodeFn { (bytes: Uint8Array): string }
-interface DecodeFn { (text: string): Uint8Array }
+interface DecodeFn { (text: string): Uint8Array<ArrayBuffer> }
 
 /**
  * Class represents both BaseEncoder and MultibaseEncoder meaning it
@@ -53,7 +53,7 @@ class Decoder<Base extends string, Prefix extends string> implements MultibaseDe
     this.baseDecode = baseDecode
   }
 
-  decode (text: string): Uint8Array {
+  decode (text: string): Uint8Array<ArrayBuffer> {
     if (typeof text === 'string') {
       if (text.codePointAt(0) !== this.prefixCodePoint) {
         throw Error(`Unable to decode multibase string ${JSON.stringify(text)}, ${this.name} decoder only supports inputs prefixed with ${this.prefix}`)
@@ -82,7 +82,7 @@ class ComposedDecoder<Prefix extends string> implements MultibaseDecoder<Prefix>
     return or(this, decoder)
   }
 
-  decode (input: string): Uint8Array {
+  decode (input: string): Uint8Array<ArrayBuffer> {
     const prefix = input[0] as Prefix
     const decoder = this.decoders[prefix]
     if (decoder != null) {
@@ -121,7 +121,7 @@ export class Codec<Base extends string, Prefix extends string> implements Multib
     return this.encoder.encode(input)
   }
 
-  decode (input: string): Uint8Array {
+  decode (input: string): Uint8Array<ArrayBuffer> {
     return this.decoder.decode(input)
   }
 }
@@ -136,11 +136,11 @@ export function baseX <Base extends string, Prefix extends string> ({ name, pref
     prefix,
     name,
     encode,
-    decode: (text: string): Uint8Array => coerce(decode(text))
+    decode: (text: string): Uint8Array<ArrayBuffer> => coerce(decode(text))
   })
 }
 
-function decode (string: string, alphabetIdx: Record<string, number>, bitsPerChar: number, name: string): Uint8Array {
+function decode (string: string, alphabetIdx: Record<string, number>, bitsPerChar: number, name: string): Uint8Array<ArrayBuffer> {
   // Count the padding bytes:
   let end = string.length
   while (string[end - 1] === '=') {
@@ -234,7 +234,7 @@ export function rfc4648 <Base extends string, Prefix extends string> ({ name, pr
     encode (input: Uint8Array): string {
       return encode(input, alphabet, bitsPerChar)
     },
-    decode (input: string): Uint8Array {
+    decode (input: string): Uint8Array<ArrayBuffer> {
       return decode(input, alphabetIdx, bitsPerChar, name)
     }
   })
diff --git a/src/bases/base10.ts b/src/bases/base10.ts
index fca32758..7b2941d1 100644
--- a/src/bases/base10.ts
+++ b/src/bases/base10.ts
@@ -1,4 +1,4 @@
-import { baseX } from './base.js'
+import { baseX } from './base.ts'
 
 export const base10 = baseX({
   prefix: '9',
diff --git a/src/bases/base16.ts b/src/bases/base16.ts
index 8e7b2380..4797518f 100644
--- a/src/bases/base16.ts
+++ b/src/bases/base16.ts
@@ -1,4 +1,4 @@
-import { rfc4648 } from './base.js'
+import { rfc4648 } from './base.ts'
 
 export const base16 = rfc4648({
   prefix: 'f',
diff --git a/src/bases/base2.ts b/src/bases/base2.ts
index 2ff4977d..427b2db2 100644
--- a/src/bases/base2.ts
+++ b/src/bases/base2.ts
@@ -1,4 +1,4 @@
-import { rfc4648 } from './base.js'
+import { rfc4648 } from './base.ts'
 
 export const base2 = rfc4648({
   prefix: '0',
diff --git a/src/bases/base256emoji.ts b/src/bases/base256emoji.ts
index 9950cb9d..962e3b64 100644
--- a/src/bases/base256emoji.ts
+++ b/src/bases/base256emoji.ts
@@ -1,4 +1,4 @@
-import { from } from './base.js'
+import { from } from './base.ts'
 
 const alphabet = Array.from('🚀🪐☄🛰🌌🌑🌒🌓🌔🌕🌖🌗🌘🌍🌏🌎🐉☀💻🖥💾💿😂❤😍🤣😊🙏💕😭😘👍😅👏😁🔥🥰💔💖💙😢🤔😆🙄💪😉☺👌🤗💜😔😎😇🌹🤦🎉💞✌✨🤷😱😌🌸🙌😋💗💚😏💛🙂💓🤩😄😀🖤😃💯🙈👇🎶😒🤭❣😜💋👀😪😑💥🙋😞😩😡🤪👊🥳😥🤤👉💃😳✋😚😝😴🌟😬🙃🍀🌷😻😓⭐✅🥺🌈😈🤘💦✔😣🏃💐☹🎊💘😠☝😕🌺🎂🌻😐🖕💝🙊😹🗣💫💀👑🎵🤞😛🔴😤🌼😫⚽🤙☕🏆🤫👈😮🙆🍻🍃🐶💁😲🌿🧡🎁⚡🌞🎈❌✊👋😰🤨😶🤝🚶💰🍓💢🤟🙁🚨💨🤬✈🎀🍺🤓😙💟🌱😖👶🥴▶➡❓💎💸⬇😨🌚🦋😷🕺⚠🙅😟😵👎🤲🤠🤧📌🔵💅🧐🐾🍒😗🤑🌊🤯🐷☎💧😯💆👆🎤🙇🍑❄🌴💣🐸💌📍🥀🤢👅💡💩👐📸👻🤐🤮🎼🥵🚩🍎🍊👼💍📣🥂')
 const alphabetBytesToChars: string[] = (alphabet.reduce<string[]>((p, c, i) => { p[i] = c; return p }, ([])))
@@ -18,7 +18,7 @@ function encode (data: Uint8Array): string {
   }, '')
 }
 
-function decode (str: string): Uint8Array {
+function decode (str: string): Uint8Array<ArrayBuffer> {
   const byts = []
   for (const char of str) {
     const codePoint = char.codePointAt(0)
diff --git a/src/bases/base32.ts b/src/bases/base32.ts
index c28f4f57..f3717d9b 100644
--- a/src/bases/base32.ts
+++ b/src/bases/base32.ts
@@ -1,4 +1,4 @@
-import { rfc4648 } from './base.js'
+import { rfc4648 } from './base.ts'
 
 export const base32 = rfc4648({
   prefix: 'b',
diff --git a/src/bases/base36.ts b/src/bases/base36.ts
index 12990af5..bb087871 100644
--- a/src/bases/base36.ts
+++ b/src/bases/base36.ts
@@ -1,4 +1,4 @@
-import { baseX } from './base.js'
+import { baseX } from './base.ts'
 
 export const base36 = baseX({
   prefix: 'k',
diff --git a/src/bases/base58.ts b/src/bases/base58.ts
index 15432731..3ea300d4 100644
--- a/src/bases/base58.ts
+++ b/src/bases/base58.ts
@@ -1,4 +1,4 @@
-import { baseX } from './base.js'
+import { baseX } from './base.ts'
 
 export const base58btc = baseX({
   name: 'base58btc',
diff --git a/src/bases/base64.ts b/src/bases/base64.ts
index 6e66d933..abd2f173 100644
--- a/src/bases/base64.ts
+++ b/src/bases/base64.ts
@@ -1,4 +1,4 @@
-import { rfc4648 } from './base.js'
+import { rfc4648 } from './base.ts'
 
 export const base64 = rfc4648({
   prefix: 'm',
diff --git a/src/bases/base8.ts b/src/bases/base8.ts
index 7c584a57..8e824b14 100644
--- a/src/bases/base8.ts
+++ b/src/bases/base8.ts
@@ -1,4 +1,4 @@
-import { rfc4648 } from './base.js'
+import { rfc4648 } from './base.ts'
 
 export const base8 = rfc4648({
   prefix: '7',
diff --git a/src/bases/identity.ts b/src/bases/identity.ts
index 301ac7a8..fd59db48 100644
--- a/src/bases/identity.ts
+++ b/src/bases/identity.ts
@@ -1,5 +1,5 @@
-import { fromString, toString } from '../bytes.js'
-import { from } from './base.js'
+import { fromString, toString } from '../bytes.ts'
+import { from } from './base.ts'
 
 export const identity = from({
   prefix: '\x00',
diff --git a/src/bases/interface.ts b/src/bases/interface.ts
index f0b63abe..315efedb 100644
--- a/src/bases/interface.ts
+++ b/src/bases/interface.ts
@@ -20,7 +20,7 @@ export interface BaseDecoder {
    * Decodes **plain** (and not a multibase) string. Unlike
    * decode
    */
-  baseDecode(text: string): Uint8Array
+  baseDecode(text: string): Uint8Array<ArrayBuffer>
 }
 
 /**
@@ -70,7 +70,7 @@ export interface MultibaseDecoder<Prefix extends string> {
    * Decodes **multibase** string (which must have a multibase prefix added).
    * If prefix does not match
    */
-  decode(multibase: Multibase<Prefix>): Uint8Array
+  decode(multibase: Multibase<Prefix>): Uint8Array<ArrayBuffer>
 }
 
 /**
diff --git a/src/basics.ts b/src/basics.ts
index 11b45ed1..d4c2a556 100644
--- a/src/basics.ts
+++ b/src/basics.ts
@@ -1,18 +1,18 @@
-import * as base10 from './bases/base10.js'
-import * as base16 from './bases/base16.js'
-import * as base2 from './bases/base2.js'
-import * as base256emoji from './bases/base256emoji.js'
-import * as base32 from './bases/base32.js'
-import * as base36 from './bases/base36.js'
-import * as base58 from './bases/base58.js'
-import * as base64 from './bases/base64.js'
-import * as base8 from './bases/base8.js'
-import * as identityBase from './bases/identity.js'
-import * as json from './codecs/json.js'
-import * as raw from './codecs/raw.js'
-import * as identity from './hashes/identity.js'
-import * as sha2 from './hashes/sha2.js'
-import { CID, hasher, digest, varint, bytes } from './index.js'
+import * as base10 from './bases/base10.ts'
+import * as base16 from './bases/base16.ts'
+import * as base2 from './bases/base2.ts'
+import * as base256emoji from './bases/base256emoji.ts'
+import * as base32 from './bases/base32.ts'
+import * as base36 from './bases/base36.ts'
+import * as base58 from './bases/base58.ts'
+import * as base64 from './bases/base64.ts'
+import * as base8 from './bases/base8.ts'
+import * as identityBase from './bases/identity.ts'
+import * as json from './codecs/json.ts'
+import * as raw from './codecs/raw.ts'
+import * as identity from './hashes/identity.ts'
+import * as sha2 from './hashes/sha2.ts'
+import { CID, hasher, digest, varint, bytes } from './index.ts'
 
 export const bases = { ...identityBase, ...base2, ...base8, ...base10, ...base16, ...base32, ...base36, ...base58, ...base64, ...base256emoji }
 export const hashes = { ...sha2, ...identity }
diff --git a/src/block.ts b/src/block.ts
index 55f625c2..0383f99f 100644
--- a/src/block.ts
+++ b/src/block.ts
@@ -1,5 +1,5 @@
-import { bytes as binary, CID } from './index.js'
-import type * as API from './interface.js'
+import { bytes as binary, CID } from './index.ts'
+import type * as API from './interface.ts'
 
 function readonly ({ enumerable = true, configurable = false } = {}): { enumerable: boolean, configurable: boolean, writable: false } {
   return { enumerable, configurable, writable: false }
diff --git a/src/block/interface.ts b/src/block/interface.ts
index d09c73c5..8c2c0823 100644
--- a/src/block/interface.ts
+++ b/src/block/interface.ts
@@ -1,5 +1,5 @@
-import type { CID } from '../cid.js'
-import type { Link, Version } from '../link/interface.js'
+import type { CID } from '../cid.ts'
+import type { Link, Version } from '../link/interface.ts'
 
 /**
  * A byte-encoded representation of some type of `Data`.
diff --git a/src/bytes.ts b/src/bytes.ts
index 72c5899f..8a6f9319 100644
--- a/src/bytes.ts
+++ b/src/bytes.ts
@@ -4,7 +4,7 @@ export function toHex (d: Uint8Array): string {
   return d.reduce((hex, byte) => hex + byte.toString(16).padStart(2, '0'), '')
 }
 
-export function fromHex (hex: string): Uint8Array {
+export function fromHex (hex: string): Uint8Array<ArrayBuffer> {
   const hexes = hex.match(/../g)
   return hexes != null ? new Uint8Array(hexes.map(b => parseInt(b, 16))) : empty
 }
@@ -24,11 +24,24 @@ export function equals (aa: Uint8Array, bb: Uint8Array): boolean {
   return true
 }
 
-export function coerce (o: ArrayBufferView | ArrayBuffer | Uint8Array): Uint8Array {
-  if (o instanceof Uint8Array && o.constructor.name === 'Uint8Array') { return o }
-  if (o instanceof ArrayBuffer) { return new Uint8Array(o) }
+/**
+ * Normalize binary input to a plain `Uint8Array` backed by an `ArrayBuffer`.
+ *
+ * Returns the input itself when it is already a plain `Uint8Array` over an
+ * `ArrayBuffer`, otherwise a fresh view (or, for `SharedArrayBuffer`-backed
+ * input, a copy) over the same bytes.
+ *
+ * Throws if input is not a recognised binary type.
+ */
+export function coerce (o: ArrayBufferView | ArrayBuffer | Uint8Array): Uint8Array<ArrayBuffer> {
+  if (o instanceof Uint8Array && o.constructor.name === 'Uint8Array') {
+    return toArrayBufferBackedArray(o)
+  }
+  if (o instanceof ArrayBuffer) {
+    return new Uint8Array(o)
+  }
   if (ArrayBuffer.isView(o)) {
-    return new Uint8Array(o.buffer, o.byteOffset, o.byteLength)
+    return toArrayBufferBackedArray(new Uint8Array(o.buffer, o.byteOffset, o.byteLength))
   }
   throw new Error('Unknown type, must be binary type')
 }
@@ -37,10 +50,26 @@ export function isBinary (o: unknown): o is ArrayBuffer | ArrayBufferView {
   return o instanceof ArrayBuffer || ArrayBuffer.isView(o)
 }
 
-export function fromString (str: string): Uint8Array {
+export function fromString (str: string): Uint8Array<ArrayBuffer> {
   return new TextEncoder().encode(str)
 }
 
 export function toString (b: Uint8Array): string {
   return new TextDecoder().decode(b)
 }
+
+function isByteArrayWithArrayBuffer (b?: Uint8Array): b is Uint8Array<ArrayBuffer> {
+  return b?.buffer instanceof ArrayBuffer
+}
+
+/**
+ * Ensures `b` is backed by an ArrayBuffer - if not a new Uint8Array will be
+ * created and the contents of `b` copied into it.
+ */
+export function toArrayBufferBackedArray (b: Uint8Array): Uint8Array<ArrayBuffer> {
+  if (isByteArrayWithArrayBuffer(b)) {
+    return b
+  }
+
+  return b.slice()
+}
diff --git a/src/cid.ts b/src/cid.ts
index d8b626b6..594162c2 100644
--- a/src/cid.ts
+++ b/src/cid.ts
@@ -1,13 +1,13 @@
-import { base32 } from './bases/base32.js'
-import { base36 } from './bases/base36.js'
-import { base58btc } from './bases/base58.js'
-import { coerce } from './bytes.js'
-import * as Digest from './hashes/digest.js'
-import * as varint from './varint.js'
-import type * as API from './link/interface.js'
+import { base32 } from './bases/base32.ts'
+import { base36 } from './bases/base36.ts'
+import { base58btc } from './bases/base58.ts'
+import { coerce, toArrayBufferBackedArray } from './bytes.ts'
+import * as Digest from './hashes/digest.ts'
+import * as varint from './varint.ts'
+import type * as API from './link/interface.ts'
 
 // This way TS will also expose all the types from module
-export * from './link/interface.js'
+export * from './link/interface.ts'
 
 export function format <T extends API.Link<unknown, number, number, API.Version>, Prefix extends string> (link: T, base?: API.MultibaseEncoder<Prefix>): API.ToString<T, Prefix> {
   const { bytes, version } = link
@@ -53,8 +53,8 @@ export class CID<Data = unknown, Format extends number = number, Alg extends num
   readonly code: Format
   readonly version: Version
   readonly multihash: API.MultihashDigest<Alg>
-  readonly bytes: Uint8Array
-  readonly '/': Uint8Array
+  readonly bytes: Uint8Array<ArrayBuffer>
+  readonly '/': Uint8Array<ArrayBuffer>
 
   /**
    * @param version - Version of the CID
@@ -65,11 +65,11 @@ export class CID<Data = unknown, Format extends number = number, Alg extends num
     this.code = code
     this.version = version
     this.multihash = multihash
-    this.bytes = bytes
+    this.bytes = toArrayBufferBackedArray(bytes)
 
     // flag to serializers that this is a CID and
     // should be treated specially
-    this['/'] = bytes
+    this['/'] = this.bytes
   }
 
   /**
diff --git a/src/codecs/interface.ts b/src/codecs/interface.ts
index 8e5d9d1a..d4e7e6ee 100644
--- a/src/codecs/interface.ts
+++ b/src/codecs/interface.ts
@@ -1,4 +1,4 @@
-import type { ArrayBufferView, ByteView } from '../block/interface.js'
+import type { ArrayBufferView, ByteView } from '../block/interface.ts'
 
 /**
  * IPLD encoder part of the codec.
diff --git a/src/codecs/json.ts b/src/codecs/json.ts
index e7d3dc39..e5f3329b 100644
--- a/src/codecs/json.ts
+++ b/src/codecs/json.ts
@@ -1,4 +1,4 @@
-import type { ArrayBufferView, ByteView } from './interface.js'
+import type { ArrayBufferView, ByteView } from './interface.ts'
 
 const textEncoder = new TextEncoder()
 const textDecoder = new TextDecoder()
diff --git a/src/codecs/raw.ts b/src/codecs/raw.ts
index 03ba4ae2..e39a85b3 100644
--- a/src/codecs/raw.ts
+++ b/src/codecs/raw.ts
@@ -1,5 +1,5 @@
-import { coerce } from '../bytes.js'
-import type { ArrayBufferView, ByteView } from './interface.js'
+import { coerce } from '../bytes.ts'
+import type { ArrayBufferView, ByteView } from './interface.ts'
 
 export const name = 'raw'
 export const code = 0x55
diff --git a/src/hashes/digest.ts b/src/hashes/digest.ts
index 93a7709a..271c7e03 100644
--- a/src/hashes/digest.ts
+++ b/src/hashes/digest.ts
@@ -1,6 +1,6 @@
-import { coerce, equals as equalBytes } from '../bytes.js'
-import * as varint from '../varint.js'
-import type { MultihashDigest } from './interface.js'
+import { coerce, equals as equalBytes, toArrayBufferBackedArray } from '../bytes.ts'
+import * as varint from '../varint.ts'
+import type { MultihashDigest } from './interface.ts'
 
 /**
  * Creates a multihash digest.
@@ -56,8 +56,8 @@ export function equals (a: MultihashDigest, b: unknown): b is MultihashDigest {
 export class Digest<Code extends number, Size extends number> implements MultihashDigest {
   readonly code: Code
   readonly size: Size
-  readonly digest: Uint8Array
-  readonly bytes: Uint8Array
+  readonly digest: Uint8Array<ArrayBuffer>
+  readonly bytes: Uint8Array<ArrayBuffer>
 
   /**
    * Creates a multihash digest.
@@ -65,8 +65,8 @@ export class Digest<Code extends number, Size extends number> implements Multiha
   constructor (code: Code, size: Size, digest: Uint8Array, bytes: Uint8Array) {
     this.code = code
     this.size = size
-    this.digest = digest
-    this.bytes = bytes
+    this.digest = toArrayBufferBackedArray(digest)
+    this.bytes = toArrayBufferBackedArray(bytes)
   }
 }
 
diff --git a/src/hashes/hasher.ts b/src/hashes/hasher.ts
index b711da2b..b4715f01 100644
--- a/src/hashes/hasher.ts
+++ b/src/hashes/hasher.ts
@@ -1,5 +1,5 @@
-import * as Digest from './digest.js'
-import type { MultihashHasher } from './interface.js'
+import * as Digest from './digest.ts'
+import type { MultihashHasher } from './interface.ts'
 
 type Await<T> = Promise<T> | T
 
diff --git a/src/hashes/identity.ts b/src/hashes/identity.ts
index d13d575b..4657707b 100644
--- a/src/hashes/identity.ts
+++ b/src/hashes/identity.ts
@@ -1,6 +1,6 @@
-import { coerce } from '../bytes.js'
-import * as Digest from './digest.js'
-import type { DigestOptions } from './hasher.js'
+import { coerce } from '../bytes.ts'
+import * as Digest from './digest.ts'
+import type { DigestOptions } from './hasher.ts'
 
 const code: 0x0 = 0x0
 const name = 'identity'
diff --git a/src/hashes/interface.ts b/src/hashes/interface.ts
index 92c4be09..5a6c944e 100644
--- a/src/hashes/interface.ts
+++ b/src/hashes/interface.ts
@@ -1,6 +1,6 @@
 // # Multihash
 
-import type { DigestOptions } from './hasher.js'
+import type { DigestOptions } from './hasher.ts'
 
 /**
  * Represents a multihash digest which carries information about the
@@ -20,7 +20,7 @@ export interface MultihashDigest<Code extends number = number> {
   /**
    * Raw digest (without a hashing algorithm info)
    */
-  digest: Uint8Array
+  digest: Uint8Array<ArrayBuffer>
 
   /**
    * byte length of the `this.digest`
@@ -30,7 +30,7 @@ export interface MultihashDigest<Code extends number = number> {
   /**
    * Binary representation of this multihash digest.
    */
-  bytes: Uint8Array
+  bytes: Uint8Array<ArrayBuffer>
 }
 
 /**
diff --git a/src/hashes/sha1-browser.ts b/src/hashes/sha1-browser.ts
index 6764ba8e..a4c81ffe 100644
--- a/src/hashes/sha1-browser.ts
+++ b/src/hashes/sha1-browser.ts
@@ -1,9 +1,9 @@
 /* global crypto */
 
-import { from } from './hasher.js'
+import { from } from './hasher.ts'
 
 const sha = (name: AlgorithmIdentifier) =>
-  async (data: Uint8Array) => new Uint8Array(await crypto.subtle.digest(name, data))
+  async (data: Uint8Array<ArrayBuffer>) => new Uint8Array(await crypto.subtle.digest(name, data))
 
 export const sha1 = from({
   name: 'sha-1',
diff --git a/src/hashes/sha1.ts b/src/hashes/sha1.ts
index f8480519..fbd9dd5f 100644
--- a/src/hashes/sha1.ts
+++ b/src/hashes/sha1.ts
@@ -1,6 +1,6 @@
-import crypto from 'crypto'
-import { coerce } from '../bytes.js'
-import { from } from './hasher.js'
+import crypto from 'node:crypto'
+import { coerce } from '../bytes.ts'
+import { from } from './hasher.ts'
 
 export const sha1 = from({
   name: 'sha-1',
diff --git a/src/hashes/sha2-browser.ts b/src/hashes/sha2-browser.ts
index cbf0b7b8..b8c424c8 100644
--- a/src/hashes/sha2-browser.ts
+++ b/src/hashes/sha2-browser.ts
@@ -1,8 +1,8 @@
 /* global crypto */
 
-import { from } from './hasher.js'
+import { from } from './hasher.ts'
 
-function sha (name: AlgorithmIdentifier): (data: Uint8Array) => Promise<Uint8Array> {
+function sha (name: AlgorithmIdentifier): (data: Uint8Array<ArrayBuffer>) => Promise<Uint8Array> {
   return async data => new Uint8Array(await crypto.subtle.digest(name, data))
 }
 
diff --git a/src/hashes/sha2.ts b/src/hashes/sha2.ts
index 37d6f2bd..c2a5ade3 100644
--- a/src/hashes/sha2.ts
+++ b/src/hashes/sha2.ts
@@ -1,6 +1,6 @@
-import crypto from 'crypto'
-import { coerce } from '../bytes.js'
-import { from } from './hasher.js'
+import crypto from 'node:crypto'
+import { coerce } from '../bytes.ts'
+import { from } from './hasher.ts'
 
 export const sha256 = from({
   name: 'sha2-256',
diff --git a/src/index.ts b/src/index.ts
index 677ef877..494f6a12 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -200,13 +200,13 @@
  * | `dag-jose` | `dag-jose`                 | [ceramicnetwork/js-dag-jose](https://github.com/ceramicnetwork/js-dag-jose)                            |
  */
 
-import * as bytes from './bytes.js'
-import { CID } from './cid.js'
-import * as digest from './hashes/digest.js'
-import * as hasher from './hashes/hasher.js'
-import * as varint from './varint.js'
+import * as bytes from './bytes.ts'
+import { CID } from './cid.ts'
+import * as digest from './hashes/digest.ts'
+import * as hasher from './hashes/hasher.ts'
+import * as varint from './varint.ts'
 
 // This way TS will also expose all the types from module
-export * from './interface.js'
+export * from './interface.ts'
 
 export { CID, hasher, digest, varint, bytes }
diff --git a/src/interface.ts b/src/interface.ts
index e2a56c67..e6632051 100644
--- a/src/interface.ts
+++ b/src/interface.ts
@@ -1,5 +1,5 @@
-export * from './bases/interface.js'
-export * from './hashes/interface.js'
-export * from './codecs/interface.js'
-export * from './link/interface.js'
-export * from './block/interface.js'
+export * from './bases/interface.ts'
+export * from './hashes/interface.ts'
+export * from './codecs/interface.ts'
+export * from './link/interface.ts'
+export * from './block/interface.ts'
diff --git a/src/link.ts b/src/link.ts
index c39052bd..2b09fa48 100644
--- a/src/link.ts
+++ b/src/link.ts
@@ -1,7 +1,7 @@
-import { CID, format, toJSON, fromJSON } from './cid.js'
-import type * as API from './link/interface.js'
+import { CID, format, toJSON, fromJSON } from './cid.ts'
+import type * as API from './link/interface.ts'
 // This way TS will also expose all the types from module
-export * from './link/interface.js'
+export * from './link/interface.ts'
 
 const DAG_PB_CODE = 0x70
 // eslint-disable-next-line
diff --git a/src/link/interface.ts b/src/link/interface.ts
index 31a8c366..0fd3fcd7 100644
--- a/src/link/interface.ts
+++ b/src/link/interface.ts
@@ -1,6 +1,6 @@
-import type { MultibaseEncoder, MultibaseDecoder, Multibase } from '../bases/interface.js'
-import type { Phantom, ByteView } from '../block/interface.js'
-import type { MultihashDigest } from '../hashes/interface.js'
+import type { MultibaseEncoder, MultibaseDecoder, Multibase } from '../bases/interface.ts'
+import type { Phantom, ByteView } from '../block/interface.ts'
+import type { MultihashDigest } from '../hashes/interface.ts'
 
 export type { MultihashDigest, MultibaseEncoder, MultibaseDecoder }
 export type Version = 0 | 1
diff --git a/src/traversal.ts b/src/traversal.ts
index abb07663..ef7d834c 100644
--- a/src/traversal.ts
+++ b/src/traversal.ts
@@ -1,6 +1,6 @@
-import { base58btc } from './bases/base58.js'
-import type { BlockView as _BlockView } from './block/interface.js'
-import type { CID, Version } from './cid.js'
+import { base58btc } from './bases/base58.ts'
+import type { BlockView as _BlockView } from './block/interface.ts'
+import type { CID, Version } from './cid.ts'
 
 type BlockView<T=unknown, C extends number = number, A extends number = number, V extends Version = Version> = _BlockView<T, C, A, V>
 
diff --git a/test/test-block.spec.ts b/test/test-block.spec.ts
index 2d131cd8..c2cac932 100644
--- a/test/test-block.spec.ts
+++ b/test/test-block.spec.ts
@@ -1,10 +1,10 @@
 /* globals describe, it */
 
 import { assert } from 'aegir/chai'
-import * as main from '../src/block.js'
-import * as codec from '../src/codecs/json.js'
-import { sha256 as hasher } from '../src/hashes/sha2.js'
-import { CID, bytes } from '../src/index.js'
+import * as main from '../src/block.ts'
+import * as codec from '../src/codecs/json.ts'
+import { sha256 as hasher } from '../src/hashes/sha2.ts'
+import { CID, bytes } from '../src/index.ts'
 
 const fixture = { hello: 'world' }
 const link = CID.parse('bafyreidykglsfhoixmivffc5uwhcgshx4j465xwqntbmu43nb2dzqwfvae')
diff --git a/test/test-bytes.spec.ts b/test/test-bytes.spec.ts
index aac7f531..205f8780 100644
--- a/test/test-bytes.spec.ts
+++ b/test/test-bytes.spec.ts
@@ -1,7 +1,7 @@
 /* globals describe, it */
 
 import { assert } from 'aegir/chai'
-import * as bytes from '../src/bytes.js'
+import * as bytes from '../src/bytes.ts'
 
 describe('bytes', () => {
   it('isBinary', () => {
@@ -11,7 +11,6 @@ describe('bytes', () => {
 
   it('coerce', () => {
     const fixture = bytes.fromString('test')
-    // @ts-expect-error
     assert.deepStrictEqual(bytes.coerce(fixture.buffer), fixture)
     assert.deepStrictEqual(bytes.coerce(new DataView(fixture.buffer)), fixture)
   })
@@ -25,4 +24,18 @@ describe('bytes', () => {
     const fixture = 'hello world'
     assert.deepStrictEqual(bytes.toString(bytes.fromString(fixture)), fixture)
   })
+
+  it('toArrayBufferBackedArray()', function () {
+    if (globalThis.SharedArrayBuffer == null) {
+      return this.skip()
+    }
+
+    const b = new Uint8Array(10)
+    assert.equal(b, bytes.toArrayBufferBackedArray(b))
+
+    const s = new SharedArrayBuffer(10)
+    const b2 = new Uint8Array(s, 0, s.byteLength)
+    assert.notEqual(b2, bytes.toArrayBufferBackedArray(b2) as any)
+    assert.deepEqual(b, bytes.toArrayBufferBackedArray(b2))
+  })
 })
diff --git a/test/test-cid.spec.ts b/test/test-cid.spec.ts
index 7b84183a..4d34b3d6 100644
--- a/test/test-cid.spec.ts
+++ b/test/test-cid.spec.ts
@@ -2,15 +2,15 @@
 
 import { assert } from 'aegir/chai'
 import OLDCID from 'cids'
-import { base32 } from '../src/bases/base32.js'
-import { base36 } from '../src/bases/base36.js'
-import { base58btc } from '../src/bases/base58.js'
-import { base64 } from '../src/bases/base64.js'
-import { fromHex, toHex, equals } from '../src/bytes.js'
-import { sha256, sha512 } from '../src/hashes/sha2.js'
-import { varint, CID } from '../src/index.js'
-import invalidMultihash from './fixtures/invalid-multihash.js'
-import type { MultihashDigest } from '../src/index.js'
+import { base32 } from '../src/bases/base32.ts'
+import { base36 } from '../src/bases/base36.ts'
+import { base58btc } from '../src/bases/base58.ts'
+import { base64 } from '../src/bases/base64.ts'
+import { fromHex, toHex, equals } from '../src/bytes.ts'
+import { sha256, sha512 } from '../src/hashes/sha2.ts'
+import { varint, CID } from '../src/index.ts'
+import invalidMultihash from './fixtures/invalid-multihash.ts'
+import type { MultihashDigest } from '../src/index.ts'
 
 const textEncoder = new TextEncoder()
 
diff --git a/test/test-link.spec.ts b/test/test-link.spec.ts
index 1165e8a4..27bb4a77 100644
--- a/test/test-link.spec.ts
+++ b/test/test-link.spec.ts
@@ -1,8 +1,8 @@
 /* globals describe, it */
 
 import { assert } from 'aegir/chai'
-import { sha256 } from '../src/hashes/sha2.js'
-import * as Link from '../src/link.js'
+import { sha256 } from '../src/hashes/sha2.ts'
+import * as Link from '../src/link.ts'
 
 const utf8 = new TextEncoder()
 
diff --git a/test/test-multibase-spec.spec.ts b/test/test-multibase-spec.spec.ts
index 1f7f2523..63d5acf5 100644
--- a/test/test-multibase-spec.spec.ts
+++ b/test/test-multibase-spec.spec.ts
@@ -1,8 +1,6 @@
-/* eslint-env mocha */
-
 import { assert } from 'aegir/chai'
-import { bases } from '../src/basics.js'
-import { fromString } from '../src/bytes.js'
+import { bases } from '../src/basics.ts'
+import { fromString } from '../src/bytes.ts'
 
 const encoded = [
   {
diff --git a/test/test-multibase.spec.ts b/test/test-multibase.spec.ts
index 93b446b5..0e000595 100644
--- a/test/test-multibase.spec.ts
+++ b/test/test-multibase.spec.ts
@@ -1,15 +1,15 @@
 /* globals describe, it */
 
 import { assert } from 'aegir/chai'
-import * as b10 from '../src/bases/base10.js'
-import * as b16 from '../src/bases/base16.js'
-import * as b2 from '../src/bases/base2.js'
-import * as b32 from '../src/bases/base32.js'
-import * as b36 from '../src/bases/base36.js'
-import * as b58 from '../src/bases/base58.js'
-import * as b64 from '../src/bases/base64.js'
-import * as b8 from '../src/bases/base8.js'
-import * as bytes from '../src/bytes.js'
+import * as b10 from '../src/bases/base10.ts'
+import * as b16 from '../src/bases/base16.ts'
+import * as b2 from '../src/bases/base2.ts'
+import * as b32 from '../src/bases/base32.ts'
+import * as b36 from '../src/bases/base36.ts'
+import * as b58 from '../src/bases/base58.ts'
+import * as b64 from '../src/bases/base64.ts'
+import * as b8 from '../src/bases/base8.ts'
+import * as bytes from '../src/bytes.ts'
 
 const { base16, base32, base58btc, base64 } = { ...b16, ...b32, ...b58, ...b64 }
 
diff --git a/test/test-multicodec.spec.ts b/test/test-multicodec.spec.ts
index f2493bae..4de8148c 100644
--- a/test/test-multicodec.spec.ts
+++ b/test/test-multicodec.spec.ts
@@ -1,9 +1,9 @@
 /* globals describe, it */
 
 import { assert } from 'aegir/chai'
-import * as bytes from '../src/bytes.js'
-import * as json from '../src/codecs/json.js'
-import * as raw from '../src/codecs/raw.js'
+import * as bytes from '../src/bytes.ts'
+import * as json from '../src/codecs/json.ts'
+import * as raw from '../src/codecs/raw.ts'
 
 describe('multicodec', () => {
   it('encode/decode raw', () => {
diff --git a/test/test-multihash.spec.ts b/test/test-multihash.spec.ts
index 31a57bcd..5d7e229c 100644
--- a/test/test-multihash.spec.ts
+++ b/test/test-multihash.spec.ts
@@ -4,14 +4,14 @@ import { hash as slSha256 } from '@stablelib/sha256'
 import { hash as slSha512 } from '@stablelib/sha512'
 import { assert } from 'aegir/chai'
 import { sha1 as chSha1 } from 'crypto-hash'
-import { fromHex, fromString } from '../src/bytes.js'
-import { decode as decodeDigest, create as createDigest, hasCode as digestHasCode } from '../src/hashes/digest.js'
-import { identity } from '../src/hashes/identity.js'
-import { sha1 } from '../src/hashes/sha1.js'
-import { sha256, sha512 } from '../src/hashes/sha2.js'
-import invalid from './fixtures/invalid-multihash.js'
-import valid from './fixtures/valid-multihash.js'
-import type { MultihashDigest } from '../src/cid.js'
+import { fromHex, fromString } from '../src/bytes.ts'
+import { decode as decodeDigest, create as createDigest, hasCode as digestHasCode } from '../src/hashes/digest.ts'
+import { identity } from '../src/hashes/identity.ts'
+import { sha1 } from '../src/hashes/sha1.ts'
+import { sha256, sha512 } from '../src/hashes/sha2.ts'
+import invalid from './fixtures/invalid-multihash.ts'
+import valid from './fixtures/valid-multihash.ts'
+import type { MultihashDigest } from '../src/cid.ts'
 
 const sample = (code: number | string, size: number, hex: string): Uint8Array => {
   const toHex = (i: number | string): string => {
@@ -197,6 +197,19 @@ describe('multihash', () => {
         })
       }, /Invalid truncate option/)
     })
+
+    it('hash identity with non-ArrayBuffer backing buffer', function () {
+      if (globalThis.SharedArrayBuffer == null) {
+        return this.skip()
+      }
+
+      const s = new SharedArrayBuffer(10)
+      const b = new Uint8Array(s, 0, s.byteLength)
+      const hash = identity.digest(b)
+
+      assert.notEqual(b.buffer.constructor.name, hash.digest.buffer.constructor.name)
+      assert.deepStrictEqual(b.slice(), hash.digest)
+    })
   })
   describe('decode', () => {
     for (const { encoding, hex, size } of valid) {
diff --git a/test/test-traversal.spec.ts b/test/test-traversal.spec.ts
index 57c59cd4..87b922a3 100644
--- a/test/test-traversal.spec.ts
+++ b/test/test-traversal.spec.ts
@@ -1,13 +1,13 @@
 /* globals describe, it */
 
 import { assert } from 'aegir/chai'
-import * as main from '../src/block.js'
-import { fromString } from '../src/bytes.js'
-import * as codec from '../src/codecs/json.js'
-import { sha256 as hasher } from '../src/hashes/sha2.js'
-import { walk } from '../src/traversal.js'
-import type { BlockView } from '../src/block/interface.js'
-import type { CID } from '../src/cid.js'
+import * as main from '../src/block.ts'
+import { fromString } from '../src/bytes.ts'
+import * as codec from '../src/codecs/json.ts'
+import { sha256 as hasher } from '../src/hashes/sha2.ts'
+import { walk } from '../src/traversal.ts'
+import type { BlockView } from '../src/block/interface.ts'
+import type { CID } from '../src/cid.ts'
 
 // from dag-pb, simplified
 function createNode (data: Uint8Array, links: Array<{ Hash: CID, Name: string, Tsize: number }>): { Data: Uint8Array, Links: Array<{ Hash: CID, Name: string, Tsize: number }> } {
diff --git a/test/test-varint.spec.ts b/test/test-varint.spec.ts
index 137c9fbb..1177219a 100644
--- a/test/test-varint.spec.ts
+++ b/test/test-varint.spec.ts
@@ -1,7 +1,7 @@
 /* globals describe, it */
 
 import { assert } from 'aegir/chai'
-import { varint } from '../src/index.js'
+import { varint } from '../src/index.ts'
 
 const UTF8 = new TextEncoder()