functionalscript · sergey-shandar · Aug 9, 2026 · Aug 9, 2026 · Aug 9, 2026 · Aug 9, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -20,6 +20,10 @@ history.
 
 ## Unreleased
 
+- **BREAKING CHANGES:** `fjs/types/bit_vec` migrates from authored TypeScript
+  (`.f.ts`) to JSDoc-typed JavaScript (`.f.mjs`) under the stage-1
+  TypeScript-to-mjs migration — importers must use the `.f.mjs` specifier
+  [#1460](https://github.com/functionalscript/functionalscript/pull/1460)
 - **BREAKING CHANGES:** `fjs/types/list`, `fjs/types/result`,
   `fjs/common/monoid`, `fjs/types/bigint`, and `fjs/types/nominal` migrate from
   authored TypeScript (`.f.ts`) to JSDoc-typed JavaScript (`.f.mjs`) under the

diff --git a/fjs/asn.1/module.f.ts b/fjs/asn.1/module.f.ts
@@ -16,7 +16,7 @@ import {
     vec8,
     type Unpacked,
     type Vec
-} from "../types/bit_vec/module.f.ts"
+} from "../types/bit_vec/module.f.mjs"
 import { identity } from "../types/function/module.f.mjs"
 import { max } from "../types/function/compare/module.f.mjs"
 import { encode as b128encode, decode as b128decode } from "../basen/base128/module.f.ts"

diff --git a/fjs/asn.1/proof.f.ts b/fjs/asn.1/proof.f.ts
@@ -1,4 +1,4 @@
-import { empty, isVec, length, msb, uint, unpack, vec, vec8, type Vec } from "../types/bit_vec/module.f.ts"
+import { empty, isVec, length, msb, uint, unpack, vec, vec8, type Vec } from "../types/bit_vec/module.f.mjs"
 import { asBase } from "../types/nominal/module.f.mjs"
 import {
     decodeRaw,

diff --git a/fjs/base_n/module.f.ts b/fjs/base_n/module.f.ts
@@ -11,7 +11,7 @@
  *
  * @module
  */
-import { msb, lsb, type Vec, vec, chunkList, unpack } from '../types/bit_vec/module.f.ts'
+import { msb, lsb, type Vec, vec, chunkList, unpack } from '../types/bit_vec/module.f.mjs'
 import { fold, type List } from '../types/list/module.f.mjs'
 import { compose } from '../types/function/module.f.mjs'
 import type { Nullable } from '../types/nullable/module.f.mjs'

diff --git a/fjs/base_n/proof.f.ts b/fjs/base_n/proof.f.ts
@@ -1,5 +1,5 @@
 import { assertEq } from '../asserts/module.f.mjs'
-import { empty, maxLength, vec, length } from '../types/bit_vec/module.f.ts'
+import { empty, maxLength, vec, length } from '../types/bit_vec/module.f.mjs'
 import { baseN } from './module.f.ts'
 
 const hex = baseN(4n, '0123456789abcdef')

diff --git a/fjs/basen/base128/module.f.ts b/fjs/basen/base128/module.f.ts
@@ -3,7 +3,7 @@
  *
  * @module
  */
-import { vec8, type Vec, msb, empty } from '../../types/bit_vec/module.f.ts'
+import { vec8, type Vec, msb, empty } from '../../types/bit_vec/module.f.mjs'
 
 const { concat, popFront } = msb
 

diff --git a/fjs/basen/base128/proof.f.ts b/fjs/basen/base128/proof.f.ts
@@ -1,4 +1,4 @@
-import { empty, vec, vec8, type Vec } from '../../types/bit_vec/module.f.ts'
+import { empty, vec, vec8, type Vec } from '../../types/bit_vec/module.f.mjs'
 import { asBase } from '../../types/nominal/module.f.mjs'
 import { encode, decode } from './module.f.ts'
 

diff --git a/fjs/basen/base64/module.f.ts b/fjs/basen/base64/module.f.ts
@@ -3,7 +3,7 @@
  *
  * @module
  */
-import { msb, type Vec, length, vec, maxLength } from "../../types/bit_vec/module.f.ts"
+import { msb, type Vec, length, vec, maxLength } from "../../types/bit_vec/module.f.mjs"
 import type { Nullable } from "../../types/nullable/module.f.mjs"
 import { baseN } from "../../base_n/module.f.ts"
 

diff --git a/fjs/basen/base64/proof.f.ts b/fjs/basen/base64/proof.f.ts
@@ -1,5 +1,5 @@
 import { assertEq } from '../../asserts/module.f.mjs'
-import { empty, vec, repeat, vec8, maxLength, type Vec } from "../../types/bit_vec/module.f.ts"
+import { empty, vec, repeat, vec8, maxLength, type Vec } from "../../types/bit_vec/module.f.mjs"
 import { encode, decode } from "./module.f.ts"
 
 const check = (s: string, v: Vec) => {

diff --git a/fjs/basen/cbase32/module.f.ts b/fjs/basen/cbase32/module.f.ts
@@ -3,7 +3,7 @@
  *
  * @module
  */
-import { msb, lsb, type Vec, length, vec, empty } from "../../types/bit_vec/module.f.ts"
+import { msb, lsb, type Vec, length, vec, empty } from "../../types/bit_vec/module.f.mjs"
 import type { Nullable } from "../../types/nullable/module.f.mjs"
 import { baseN } from "../../base_n/module.f.ts"
 

diff --git a/fjs/basen/cbase32/proof.f.ts b/fjs/basen/cbase32/proof.f.ts
@@ -1,4 +1,4 @@
-import { empty, vec, type Vec } from "../../types/bit_vec/module.f.ts"
+import { empty, vec, type Vec } from "../../types/bit_vec/module.f.mjs"
 import { cBase32ToVec, cBase32ToVec5x, vec5xToCBase32, vecToCBase32 } from "./module.f.ts"
 import { assertEq } from '../../asserts/module.f.mjs'
 

diff --git a/fjs/cas/cli/proof.f.ts b/fjs/cas/cli/proof.f.ts
@@ -1,6 +1,6 @@
 import { commands } from './module.f.ts'
 import { computeSync, sha256 } from '../../crypto/sha2/module.f.ts'
-import { maxLength, vec, vec8 } from '../../types/bit_vec/module.f.ts'
+import { maxLength, vec, vec8 } from '../../types/bit_vec/module.f.mjs'
 import { defaultNodeProgramOptions, emptyState, virtual } from '../../effects/node/virtual/module.f.ts'
 import { type NodeProgramOptions } from '../../effects/node/module.f.ts'
 import { dispatch } from '../../cli/module.f.ts'

diff --git a/fjs/cas/evo/module.f.ts b/fjs/cas/evo/module.f.ts
@@ -54,7 +54,7 @@ import { ok, error, type Ok, type Result } from '../../types/result/module.f.mjs
 import { nonEmpty, empty as elEmpty } from '../../effects/list/module.f.ts'
 import { at, definedEntries, type StringMap } from '../../types/object/module.f.ts'
 import { unwrap } from '../../types/nullable/module.f.mjs'
-import type { Vec } from '../../types/bit_vec/module.f.ts'
+import type { Vec } from '../../types/bit_vec/module.f.mjs'
 import { isNotFound, type IoResult } from '../../effects/node/module.f.ts'
 
 /** A cBase32 content hash, as accepted/returned by `Cas<O>`. */

diff --git a/fjs/cas/evo/proof.f.ts b/fjs/cas/evo/proof.f.ts
@@ -3,7 +3,7 @@ import { pure } from '../../effects/module.f.ts'
 import { fileCas, type Cas } from '../module.f.ts'
 import { sha256 } from '../../crypto/sha2/module.f.ts'
 import { emptyState, virtual } from '../../effects/node/virtual/module.f.ts'
-import { vec, vec8, type Vec } from '../../types/bit_vec/module.f.ts'
+import { vec, vec8, type Vec } from '../../types/bit_vec/module.f.mjs'
 import { cBase32ToVec, vecToCBase32 } from '../../basen/cbase32/module.f.ts'
 import { unwrap } from '../../types/nullable/module.f.mjs'
 import { ok, error, type Ok } from '../../types/result/module.f.mjs'

diff --git a/fjs/cas/module.f.ts b/fjs/cas/module.f.ts
@@ -5,7 +5,7 @@
  */
 import { sha256, type Sha2, type State as Sha2State } from '../crypto/sha2/module.f.ts'
 import { join, normalize, parse } from '../path/module.f.ts'
-import { empty, length, maxLength, maxLengthBytes, msb, vec, type Vec } from '../types/bit_vec/module.f.ts'
+import { empty, length, maxLength, maxLengthBytes, msb, vec, type Vec } from '../types/bit_vec/module.f.mjs'
 import { cBase32ToVec, vecToCBase32 } from '../basen/cbase32/module.f.ts'
 import { foldStep, forEachStep, history, historyStep, okStep, pure, step, type Effect, type Operation } from '../effects/module.f.ts'
 import { eff } from '../effects/eff/module.f.ts'

diff --git a/fjs/cas/proof.f.ts b/fjs/cas/proof.f.ts
@@ -1,4 +1,4 @@
-import { length, maxLength, msb, vec, vec8, type Vec } from '../types/bit_vec/module.f.ts'
+import { length, maxLength, msb, vec, vec8, type Vec } from '../types/bit_vec/module.f.mjs'
 import { cBase32ToVec, vecToCBase32 } from '../basen/cbase32/module.f.ts'
 import { computeSync, sha256 } from '../crypto/sha2/module.f.ts'
 import { fileCas, casAddFile, collectRead, type FileCasOperation, casUpload } from './module.f.ts'

diff --git a/fjs/ci/proof.f.ts b/fjs/ci/proof.f.ts
@@ -3,7 +3,7 @@ import { functionalscript, node } from './config/module.f.ts'
 import { nodeNixJobs } from './node/module.f.ts'
 import { coverageInclude } from './deno/module.f.ts'
 import { utf8, utf8ToString } from '../text/module.f.ts'
-import { empty as emptyVec, isVec } from '../types/bit_vec/module.f.ts'
+import { empty as emptyVec } from '../types/bit_vec/module.f.mjs'
 import { type MetaStep, type Os, test, ubuntu, type GitHubAction, parseGitHubAction } from './common/module.f.ts'
 import { assert, assertEq } from '../asserts/module.f.mjs'
 import type { State } from '../effects/node/virtual/module.f.ts'

diff --git a/fjs/crypto/hmac/module.f.ts b/fjs/crypto/hmac/module.f.ts
@@ -18,7 +18,7 @@
  * ```
  */
 
-import { length, type Vec, msb, vec, vec8, type Reduce, repeat } from '../../types/bit_vec/module.f.ts'
+import { length, type Vec, msb, vec, vec8, type Reduce, repeat } from '../../types/bit_vec/module.f.mjs'
 import { computeSync, type Sha2 } from '../sha2/module.f.ts'
 
 const { concat, xor } = msb

diff --git a/fjs/crypto/hmac/proof.f.ts b/fjs/crypto/hmac/proof.f.ts
@@ -1,6 +1,6 @@
 import { assertEq } from '../../asserts/module.f.mjs'
 import { utf8 } from '../../text/module.f.ts'
-import { uint, vec } from '../../types/bit_vec/module.f.ts'
+import { uint, vec } from '../../types/bit_vec/module.f.mjs'
 import { sha256, sha384, sha512 } from '../sha2/module.f.ts'
 import { hmac } from './module.f.ts'
 

diff --git a/fjs/crypto/pow/module.f.ts b/fjs/crypto/pow/module.f.ts
@@ -5,7 +5,7 @@
  * @module
  */
 import { mask } from '../../types/bigint/module.f.mjs'
-import { type Vec, uint } from '../../types/bit_vec/module.f.ts'
+import { type Vec, uint } from '../../types/bit_vec/module.f.mjs'
 import type { Nullable } from '../../types/nullable/module.f.mjs'
 import { computeSync, sha256, type Sha2 } from '../sha2/module.f.ts'
 

diff --git a/fjs/crypto/pow/proof.f.ts b/fjs/crypto/pow/proof.f.ts
@@ -1,5 +1,5 @@
 import { utf8 } from '../../text/module.f.ts'
-import { empty, uint } from '../../types/bit_vec/module.f.ts'
+import { empty, uint } from '../../types/bit_vec/module.f.mjs'
 import { computeSync, sha224, sha256 } from '../sha2/module.f.ts'
 import { bitcoinPow, genesisNBits, genesisTarget, pow, sha256Pow, targetFromNBits } from './module.f.ts'
 import { assert, assertEq, assertNotNullish } from '../../asserts/module.f.mjs'

diff --git a/fjs/crypto/sha2/module.f.ts b/fjs/crypto/sha2/module.f.ts
@@ -13,7 +13,7 @@ import {
     chunkList,
     uint,
     type Vec
-} from '../../types/bit_vec/module.f.ts'
+} from '../../types/bit_vec/module.f.mjs'
 import type { Fold } from '../../types/function/operator/module.f.mjs'
 import { fold, type List } from '../../types/list/module.f.mjs'
 

diff --git a/fjs/crypto/sha2/proof.f.ts b/fjs/crypto/sha2/proof.f.ts
@@ -1,5 +1,5 @@
 import { utf8 } from '../../text/module.f.ts'
-import { repeat, uint, vec } from '../../types/bit_vec/module.f.ts'
+import { repeat, uint, vec } from '../../types/bit_vec/module.f.mjs'
 import { flip } from '../../types/function/module.f.mjs'
 import { assertEq } from '../../asserts/module.f.mjs'
 import { map } from '../../types/list/module.f.mjs'

diff --git a/fjs/crypto/sign/module.f.ts b/fjs/crypto/sign/module.f.ts
@@ -6,7 +6,7 @@
 import { assertNotNullish } from '../../asserts/module.f.mjs'
 import type { Tuple } from '../../types/array/module.f.mjs'
 import { bitLength, divUp8, roundUp8 } from '../../types/bigint/module.f.mjs'
-import { empty, length, msb, repeat, unpack, vec, vec8, type Vec } from '../../types/bit_vec/module.f.ts'
+import { empty, length, msb, repeat, unpack, vec, vec8, type Vec } from '../../types/bit_vec/module.f.mjs'
 import { hmac } from '../hmac/module.f.ts'
 import type { Curve } from '../secp/module.f.ts'
 import { computeSync, type Sha2 } from '../sha2/module.f.ts'

diff --git a/fjs/crypto/sign/proof.f.ts b/fjs/crypto/sign/proof.f.ts
@@ -1,6 +1,6 @@
 import { utf8 } from "../../text/module.f.ts"
 import type { Tuple } from "../../types/array/module.f.mjs"
-import { empty, msb, repeat, vec, vec8, type Vec } from "../../types/bit_vec/module.f.ts"
+import { empty, msb, repeat, vec, vec8, type Vec } from "../../types/bit_vec/module.f.mjs"
 import { hmac } from "../hmac/module.f.ts"
 import { secp192r1, secp256r1, secp384r1, secp521r1, type Curve } from "../secp/module.f.ts"
 import { computeSync, sha224, sha256, sha384, sha512, type Sha2 } from "../sha2/module.f.ts"

diff --git a/fjs/djs/proof.f.ts b/fjs/djs/proof.f.ts
@@ -1,7 +1,7 @@
 import { compile } from './module.f.ts'
 import { virtual, emptyState } from '../effects/node/virtual/module.f.ts'
 import { utf8, utf8ToString } from '../text/module.f.ts'
-import type { Vec } from '../types/bit_vec/module.f.ts'
+import type { Vec } from '../types/bit_vec/module.f.mjs'
 import { assert, assertEq } from '../asserts/module.f.mjs'
 
 const readOutput = (root: typeof emptyState.root, path: string): string => {

diff --git a/fjs/effects/node/module.f.ts b/fjs/effects/node/module.f.ts
@@ -12,7 +12,7 @@ import { utf8, utf8ToString } from '../../text/module.f.ts'
 import { toCodePointList } from '../../text/utf8/module.f.ts'
 import { codePointListToString } from '../../text/utf16/module.f.ts'
 import { reverse, type List as EffectList } from '../../types/list/module.f.mjs'
-import { length, type Vec } from '../../types/bit_vec/module.f.ts'
+import { length, type Vec } from '../../types/bit_vec/module.f.mjs'
 import type { MemOp } from '../memory/module.f.ts'
 import type { Nominal } from '../../types/nominal/module.f.mjs'
 import { ok, error as resultError, mapOk, type Result } from '../../types/result/module.f.mjs'

diff --git a/fjs/effects/node/module.ts b/fjs/effects/node/module.ts
@@ -43,7 +43,7 @@ import { error, ok, type Result } from '../../types/result/module.f.mjs'
 import { asyncTryCatch } from '../../types/result/module.ts'
 import { fromVec, listToVec, toVec } from '../../types/uint8array/module.f.ts'
 import type { StringMap } from '../../types/object/module.f.ts'
-import { maxLengthBytes } from '../../types/bit_vec/module.f.ts'
+import { maxLengthBytes } from '../../types/bit_vec/module.f.mjs'
 
 type Server = {
     readonly listen: (port: number) => void

diff --git a/fjs/effects/node/proof.f.ts b/fjs/effects/node/proof.f.ts
@@ -1,4 +1,4 @@
-import { empty, isVec, uint, vec, vec8, type Vec } from "../../types/bit_vec/module.f.ts"
+import { empty, isVec, uint, vec, vec8, type Vec } from "../../types/bit_vec/module.f.mjs"
 import { utf8, utf8ToString } from "../../text/module.f.ts"
 import { match, pure, step } from "../module.f.ts"
 import { both, fetch, mkdir, now, readdir, readFile, readUtf8File, rm, sandbox, writeFile, writeUtf8File, rename, readBytes, randomInt, writeFromStream, usesInlineTestContext, versionLessThan, type IoResult, type ReadFile } from "./module.f.ts"

diff --git a/fjs/effects/node/virtual/module.f.ts b/fjs/effects/node/virtual/module.f.ts
@@ -6,7 +6,7 @@
 import { todo } from '../../../asserts/module.f.mjs'
 import { isProperPrefix, join, parse } from '../../../path/module.f.ts'
 import { utf8ToString } from '../../../text/module.f.ts'
-import { empty, length, maxLengthBytes, msb, vec, type Vec } from '../../../types/bit_vec/module.f.ts'
+import { empty, length, maxLengthBytes, msb, vec, type Vec } from '../../../types/bit_vec/module.f.mjs'
 import { error, ok } from '../../../types/result/module.f.mjs'
 import { run, type MemOperationMap, type RunInstance } from '../../mock/module.f.ts'
 import { asBase, asNominal, type Key } from '../../memory/module.f.ts'

diff --git a/fjs/effects/node/virtual/proof.f.ts b/fjs/effects/node/virtual/proof.f.ts
@@ -1,6 +1,6 @@
 import { assert, assertEq } from '../../../asserts/module.f.mjs'
 import { access, awaitIfPromise, fetch, rm, writeFile, readFile, readdir, import_, rename, readBytes, writeBytes } from '../module.f.ts'
-import { maxLengthBytes, vec, vec8 } from '../../../types/bit_vec/module.f.ts'
+import { maxLengthBytes, vec, vec8 } from '../../../types/bit_vec/module.f.mjs'
 import { emptyState, virtual, type Dir, type JsModule } from './module.f.ts'
 
 export const proof = {

diff --git a/fjs/mcp/cas/module.f.ts b/fjs/mcp/cas/module.f.ts
@@ -111,7 +111,7 @@ import { tryUtf8 } from '../../text/module.f.ts'
 import { detectStream } from '../../media/type/module.f.ts'
 import { detect } from '../../media/module.f.ts'
 import { revisionDialect } from '../../media/revision/module.f.ts'
-import { maxLengthBytes, type Vec } from '../../types/bit_vec/module.f.ts'
+import { maxLengthBytes, type Vec } from '../../types/bit_vec/module.f.mjs'
 import { ok, type Ok } from '../../types/result/module.f.mjs'
 import {
     toolEntry, errorResult, okResult,

diff --git a/fjs/mcp/evo/proof.f.ts b/fjs/mcp/evo/proof.f.ts
@@ -2,7 +2,7 @@ import { assert, assertEq } from '../../asserts/module.f.mjs'
 import { fileCas } from '../../cas/module.f.ts'
 import { sha256 } from '../../crypto/sha2/module.f.ts'
 import { emptyState, virtual } from '../../effects/node/virtual/module.f.ts'
-import { vec8 } from '../../types/bit_vec/module.f.ts'
+import { vec8 } from '../../types/bit_vec/module.f.mjs'
 import { vecToCBase32 } from '../../basen/cbase32/module.f.ts'
 import { initEvo, evo, type Evo } from '../../cas/evo/module.f.ts'
 import { evoToolRegistry } from './module.f.ts'

diff --git a/fjs/mcp/proof.f.ts b/fjs/mcp/proof.f.ts
@@ -5,7 +5,7 @@ import { parse as parseJson, type Unknown } from '../media/json/module.f.ts'
 import { number as rttiNumber, option, string as rttiString } from '../types/rtti/module.f.ts'
 import { parse as rttiParse } from '../types/rtti/parse/module.f.ts'
 import type { Response } from '../protocol/json_rpc/module.f.ts'
-import { msb, u8ListToVec, vec8, repeat, length, type Vec, maxLengthBytes } from '../types/bit_vec/module.f.ts'
+import { msb, u8ListToVec, vec8, repeat, length, type Vec, maxLengthBytes } from '../types/bit_vec/module.f.mjs'
 import { vecToCBase32 } from '../basen/cbase32/module.f.ts'
 import { encode as base64Encode } from '../basen/base64/module.f.ts'
 import { utf8 } from '../text/module.f.ts'

diff --git a/fjs/media/html/module.f.ts b/fjs/media/html/module.f.ts
@@ -10,7 +10,7 @@ import { definedEntries, type Entry, type StringMap } from '../../types/object/m
 import { compose } from '../../types/function/module.f.mjs'
 import { stringToList } from '../../text/utf16/module.f.ts'
 import { includes } from '../../types/array/module.f.mjs'
-import { type Vec } from '../../types/bit_vec/module.f.ts'
+import { type Vec } from '../../types/bit_vec/module.f.mjs'
 import { utf8 } from '../../text/module.f.ts'
 import { quotationMark, ampersand, lessThanSign, greaterThanSign } from '../../text/ascii/module.f.ts'
 

diff --git a/fjs/media/module.f.ts b/fjs/media/module.f.ts
@@ -41,7 +41,7 @@
  *
  * @module
  */
-import type { Vec } from '../types/bit_vec/module.f.ts'
+import type { Vec } from '../types/bit_vec/module.f.mjs'
 import { fromVec } from '../text/utf8/module.f.ts'
 import { detectVec, type DetectMeta } from './type/module.f.ts'
 import { parse } from './json/module.f.ts'

diff --git a/fjs/media/proof.f.ts b/fjs/media/proof.f.ts
@@ -1,5 +1,5 @@
 import { assertEq } from '../asserts/module.f.mjs'
-import { msb, u8ListToVec, repeat, vec8, type Vec } from '../types/bit_vec/module.f.ts'
+import { msb, u8ListToVec, repeat, vec8, type Vec } from '../types/bit_vec/module.f.mjs'
 import { detect, dialectEntry, type DialectEntry } from './module.f.ts'
 import { dialect, revisionDialect } from './revision/module.f.ts'
 import { number, string } from '../types/rtti/module.f.ts'

diff --git a/fjs/media/type/module.f.ts b/fjs/media/type/module.f.ts
@@ -32,7 +32,7 @@
  *
  * @module
  */
-import { msb, fromSentinel, length, u8List, type Vec } from '../../types/bit_vec/module.f.ts'
+import { msb, fromSentinel, length, u8List, type Vec } from '../../types/bit_vec/module.f.mjs'
 import { iterable } from '../../types/list/module.f.mjs'
 import type { Nullable } from '../../types/nullable/module.f.mjs'
 import { pure, step, type Effect, type Operation } from '../../effects/module.f.ts'

diff --git a/fjs/media/type/proof.f.ts b/fjs/media/type/proof.f.ts
@@ -1,5 +1,5 @@
 import { assert, assertEq } from '../../asserts/module.f.mjs'
-import { msb, u8ListToVec, vec8, repeat, empty, type Vec } from '../../types/bit_vec/module.f.ts'
+import { msb, u8ListToVec, vec8, repeat, empty, type Vec } from '../../types/bit_vec/module.f.mjs'
 import { runPure } from '../../effects/module.f.ts'
 import { nonEmpty, empty as emptyList, type List } from '../../effects/list/module.f.ts'
 import { ok, type Result } from '../../types/result/module.f.mjs'

diff --git a/fjs/protocol/mcp/stdio/proof.f.ts b/fjs/protocol/mcp/stdio/proof.f.ts
@@ -5,7 +5,7 @@ import type { Unknown } from '../../../media/json/module.f.ts'
 import { stringify } from '../../../media/json/module.f.ts'
 import { utf8 } from '../../../text/module.f.ts'
 import { fromVec } from '../../../types/uint8array/module.f.ts'
-import { maxLengthBytes } from '../../../types/bit_vec/module.f.ts'
+import { maxLengthBytes } from '../../../types/bit_vec/module.f.mjs'
 import { sort } from '../../../types/object/module.f.ts'
 import { internalError, jsonrpc, parseError, type Id, type Response } from '../../json_rpc/module.f.ts'
 import { stdioTransport, type Step } from './module.f.ts'

diff --git a/fjs/sul/id/module.f.ts b/fjs/sul/id/module.f.ts
@@ -15,7 +15,7 @@ import {
     unpack,
     vec,
     type Vec
-} from '../../types/bit_vec/module.f.ts'
+} from '../../types/bit_vec/module.f.mjs'
 import { assertEq } from '../../asserts/module.f.mjs'
 import { utf8 } from '../../text/module.f.ts'
 import { secp256r1, type Point2D } from '../../crypto/secp/module.f.ts'

diff --git a/fjs/sul/id/proof.f.ts b/fjs/sul/id/proof.f.ts
@@ -1,6 +1,6 @@
 import { assert, assertEq } from '../../asserts/module.f.mjs'
 import { mask } from '../../types/bigint/module.f.mjs'
-import { vec } from '../../types/bit_vec/module.f.ts'
+import { vec } from '../../types/bit_vec/module.f.mjs'
 import { compress, hashId, isHash, isRaw, level3Id, rawId } from './module.f.ts'
 import { asBase } from '../../types/nominal/module.f.mjs'
 

diff --git a/fjs/sul/level/literal/module.f.ts b/fjs/sul/level/literal/module.f.ts
@@ -6,7 +6,7 @@
  */
 
 import { log2 } from '../../../types/bigint/module.f.mjs'
-import { msb, vec, type Vec } from '../../../types/bit_vec/module.f.ts'
+import { msb, vec, type Vec } from '../../../types/bit_vec/module.f.mjs'
 import type { Func } from '../../../types/function/module.f.mjs'
 import { strictEqual, type Equal, type StateScan } from '../../../types/function/operator/module.f.mjs'
 import { equal, map, type List } from '../../../types/list/module.f.mjs'

diff --git a/fjs/sul/level/literal/proof.f.ts b/fjs/sul/level/literal/proof.f.ts
@@ -1,4 +1,4 @@
-import { chunkList, msb, vec, type Vec } from '../../../types/bit_vec/module.f.ts'
+import { chunkList, msb, vec, type Vec } from '../../../types/bit_vec/module.f.mjs'
 import { assert, assertEq } from '../../../asserts/module.f.mjs'
 import { map, stateScan, toArray } from '../../../types/list/module.f.mjs'
 import {

diff --git a/fjs/text/module.f.ts b/fjs/text/module.f.ts
@@ -5,7 +5,7 @@
  *
  * @module
  */
-import { msb, tryU8ListToVec, u8List, type Vec } from '../types/bit_vec/module.f.ts'
+import { msb, tryU8ListToVec, u8List, type Vec } from '../types/bit_vec/module.f.mjs'
 import { flatMap, type List } from '../types/list/module.f.mjs'
 import { fromCodePointList, toCodePointList } from './utf8/module.f.ts'
 import { stringToCodePointList, codePointListToString } from './utf16/module.f.ts'