diff --git a/pkgs/development/compilers/nim/default.nix b/pkgs/development/compilers/nim/default.nix
index 25b1c4873572..ed46b988d2c6 100644
--- a/pkgs/development/compilers/nim/default.nix
+++ b/pkgs/development/compilers/nim/default.nix
@@ -1,8 +1,9 @@
 # https://nim-lang.github.io/Nim/packaging.html
 # https://nim-lang.org/docs/nimc.html
 
-{ lib, buildPackages, stdenv, fetchurl, fetchgit, fetchFromGitHub, makeWrapper
-, openssl, pcre, readline, boehmgc, sqlite, nim-unwrapped }:
+{ lib, callPackage, buildPackages, stdenv, fetchurl, fetchgit, fetchFromGitHub
+, makeWrapper, openssl, pcre, readline, boehmgc, sqlite, nim-unwrapped
+, nimble-unwrapped }:
 
 let
   parseCpu = platform:
@@ -186,138 +187,141 @@ in {
     nim' = buildPackages.nim-unwrapped;
     nimble' = buildPackages.nimble-unwrapped;
     inherit (stdenv) targetPlatform;
-  in stdenv.mkDerivation {
-    name = "${targetPlatform.config}-nim-wrapper-${nim'.version}";
-    inherit (nim') version;
-    preferLocalBuild = true;
-    strictDeps = true;
+    self = stdenv.mkDerivation {
+      name = "${targetPlatform.config}-nim-wrapper-${nim'.version}";
+      inherit (nim') version;
+      preferLocalBuild = true;
+      strictDeps = true;
 
-    nativeBuildInputs = [ makeWrapper ];
+      nativeBuildInputs = [ makeWrapper ];
 
-    patches = [
-      ./nim.cfg.patch
-      # Remove configurations that clash with ours
-    ];
+      patches = [
+        ./nim.cfg.patch
+        # Remove configurations that clash with ours
+      ];
 
-    unpackPhase = ''
-      runHook preUnpack
-      tar xf ${nim'.src} nim-$version/config
-      cd nim-$version
-      runHook postUnpack
-    '';
-
-    dontConfigure = true;
-
-    buildPhase =
-      # Configure the Nim compiler to use $CC and $CXX as backends
-      # The compiler is configured by two configuration files, each with
-      # a different DSL. The order of evaluation matters and that order
-      # is not documented, so duplicate the configuration across both files.
-      ''
-        runHook preBuild
-        cat >> config/config.nims << WTF
-
-        switch("os", "${nimTarget.os}")
-        switch("cpu", "${nimTarget.cpu}")
-        switch("define", "nixbuild")
-
-        # Configure the compiler using the $CC set by Nix at build time
-        import strutils
-        let cc = getEnv"CC"
-        if cc.contains("gcc"):
-          switch("cc", "gcc")
-        elif cc.contains("clang"):
-          switch("cc", "clang")
-        WTF
-
-        mv config/nim.cfg config/nim.cfg.old
-        cat > config/nim.cfg << WTF
-        os = "${nimTarget.os}"
-        cpu =  "${nimTarget.cpu}"
-        define:"nixbuild"
-        WTF
-
-        cat >> config/nim.cfg < config/nim.cfg.old
-        rm config/nim.cfg.old
-
-        cat >> config/nim.cfg << WTF
-
-        clang.cpp.exe %= "\$CXX"
-        clang.cpp.linkerexe %= "\$CXX"
-        clang.exe %= "\$CC"
-        clang.linkerexe %= "\$CC"
-        gcc.cpp.exe %= "\$CXX"
-        gcc.cpp.linkerexe %= "\$CXX"
-        gcc.exe %= "\$CC"
-        gcc.linkerexe %= "\$CC"
-        WTF
-
-        runHook postBuild
+      unpackPhase = ''
+        runHook preUnpack
+        tar xf ${nim'.src} nim-$version/config
+        cd nim-$version
+        runHook postUnpack
       '';
 
-    wrapperArgs = [
-      "--prefix PATH : ${lib.makeBinPath [ buildPackages.gdb ]}:${
-        placeholder "out"
-      }/bin"
-      # Used by nim-gdb
+      dontConfigure = true;
 
-      "--prefix LD_LIBRARY_PATH : ${lib.makeLibraryPath [ openssl pcre ]}"
-      # These libraries may be referred to by the standard library.
-      # This is broken for cross-compilation because the package
-      # set will be shifted back by nativeBuildInputs.
+      buildPhase =
+        # Configure the Nim compiler to use $CC and $CXX as backends
+        # The compiler is configured by two configuration files, each with
+        # a different DSL. The order of evaluation matters and that order
+        # is not documented, so duplicate the configuration across both files.
+        ''
+          runHook preBuild
+          cat >> config/config.nims << WTF
 
-      "--set NIM_CONFIG_PATH ${placeholder "out"}/etc/nim"
-      # Use the custom configuration
+          switch("os", "${nimTarget.os}")
+          switch("cpu", "${nimTarget.cpu}")
+          switch("define", "nixbuild")
 
-      ''--set NIX_HARDENING_ENABLE "''${NIX_HARDENING_ENABLE/fortify}"''
-      # Fortify hardening appends -O2 to gcc flags which is unwanted for unoptimized nim builds.
-    ];
+          # Configure the compiler using the $CC set by Nix at build time
+          import strutils
+          let cc = getEnv"CC"
+          if cc.contains("gcc"):
+            switch("cc", "gcc")
+          elif cc.contains("clang"):
+            switch("cc", "clang")
+          WTF
 
-    installPhase = ''
-      runHook preInstall
+          mv config/nim.cfg config/nim.cfg.old
+          cat > config/nim.cfg << WTF
+          os = "${nimTarget.os}"
+          cpu =  "${nimTarget.cpu}"
+          define:"nixbuild"
+          WTF
 
-      mkdir -p $out/bin $out/etc
+          cat >> config/nim.cfg < config/nim.cfg.old
+          rm config/nim.cfg.old
 
-      cp -r config $out/etc/nim
+          cat >> config/nim.cfg << WTF
+
+          clang.cpp.exe %= "\$CXX"
+          clang.cpp.linkerexe %= "\$CXX"
+          clang.exe %= "\$CC"
+          clang.linkerexe %= "\$CC"
+          gcc.cpp.exe %= "\$CXX"
+          gcc.cpp.linkerexe %= "\$CXX"
+          gcc.exe %= "\$CC"
+          gcc.linkerexe %= "\$CC"
+          WTF
+
+          runHook postBuild
+        '';
+
+      wrapperArgs = [
+        "--prefix PATH : ${lib.makeBinPath [ buildPackages.gdb ]}:${
+          placeholder "out"
+        }/bin"
+        # Used by nim-gdb
+
+        "--prefix LD_LIBRARY_PATH : ${lib.makeLibraryPath [ openssl pcre ]}"
+        # These libraries may be referred to by the standard library.
+        # This is broken for cross-compilation because the package
+        # set will be shifted back by nativeBuildInputs.
+
+        "--set NIM_CONFIG_PATH ${placeholder "out"}/etc/nim"
+        # Use the custom configuration
+
+        ''--set NIX_HARDENING_ENABLE "''${NIX_HARDENING_ENABLE/fortify}"''
+        # Fortify hardening appends -O2 to gcc flags which is unwanted for unoptimized nim builds.
+      ];
+
+      installPhase = ''
+        runHook preInstall
+
+        mkdir -p $out/bin $out/etc
+
+        cp -r config $out/etc/nim
+
+        for binpath in ${nim'}/bin/nim?*; do
+          local binname=`basename $binpath`
+          makeWrapper \
+            $binpath $out/bin/${targetPlatform.config}-$binname \
+            $wrapperArgs
+          ln -s $out/bin/${targetPlatform.config}-$binname $out/bin/$binname
+        done
 
-      for binpath in ${nim'}/bin/nim?*; do
-        local binname=`basename $binpath`
         makeWrapper \
-          $binpath $out/bin/${targetPlatform.config}-$binname \
+          ${nim'}/nim/bin/nim $out/bin/${targetPlatform.config}-nim \
+          --set-default CC $(command -v $CC) \
+          --set-default CXX $(command -v $CXX) \
           $wrapperArgs
-        ln -s $out/bin/${targetPlatform.config}-$binname $out/bin/$binname
-      done
+        ln -s $out/bin/${targetPlatform.config}-nim $out/bin/nim
 
-      makeWrapper \
-        ${nim'}/nim/bin/nim $out/bin/${targetPlatform.config}-nim \
-        --set-default CC $(command -v $CC) \
-        --set-default CXX $(command -v $CXX) \
-        $wrapperArgs
-      ln -s $out/bin/${targetPlatform.config}-nim $out/bin/nim
+        makeWrapper \
+          ${nim'}/bin/testament $out/bin/${targetPlatform.config}-testament \
+          $wrapperArgs
+        ln -s $out/bin/${targetPlatform.config}-testament $out/bin/testament
 
-      makeWrapper \
-        ${nim'}/bin/testament $out/bin/${targetPlatform.config}-testament \
-        $wrapperArgs
-      ln -s $out/bin/${targetPlatform.config}-testament $out/bin/testament
+        makeWrapper \
+          ${nimble'}/bin/nimble $out/bin/${targetPlatform.config}-nimble \
+          --suffix PATH : $out/bin
+        ln -s $out/bin/${targetPlatform.config}-nimble $out/bin/nimble
 
-      makeWrapper \
-        ${nimble'}/bin/nimble $out/bin/${targetPlatform.config}-nimble \
-        --suffix PATH : $out/bin
-      ln -s $out/bin/${targetPlatform.config}-nimble $out/bin/nimble
+        runHook postInstall
+      '';
 
-      runHook postInstall
-    '';
+      passthru = {
+        nim = nim';
+        nimble = nimble';
+      };
 
-    passthru = {
-      nim = nim';
-      nimble = nimble';
-    };
-
-    meta = nim'.meta // {
-      description = nim'.meta.description
-        + " (${targetPlatform.config} wrapper)";
-      platforms = with lib.platforms; unix ++ genode;
+      meta = nim'.meta // {
+        description = nim'.meta.description
+          + " (${targetPlatform.config} wrapper)";
+        platforms = with lib.platforms; unix ++ genode;
+      };
     };
+  in self // {
+    pkgs = callPackage ../../../top-level/nim-packages.nix { nim = self; };
   };
 
 }
diff --git a/pkgs/development/nim-packages/build-nim-package/default.nix b/pkgs/development/nim-packages/build-nim-package/default.nix
new file mode 100644
index 000000000000..6c7aafd22c81
--- /dev/null
+++ b/pkgs/development/nim-packages/build-nim-package/default.nix
@@ -0,0 +1,43 @@
+{ lib, stdenv, nim, nim_builder }:
+
+{ strictDeps ? true, nativeBuildInputs ? [ ], configurePhase ? null
+, buildPhase ? null, checkPhase ? null, installPhase ? null, meta ? { }, ...
+}@attrs:
+
+stdenv.mkDerivation (attrs // {
+  inherit strictDeps;
+  nativeBuildInputs = [ nim nim_builder ] ++ nativeBuildInputs;
+
+  configurePhase = if isNull configurePhase then ''
+    runHook preConfigure
+    find $NIX_BUILD_TOP -name .attrs.json
+    nim_builder --phase:configure
+    runHook postConfigure
+  '' else
+    buildPhase;
+
+  buildPhase = if isNull buildPhase then ''
+    runHook preBuild
+    nim_builder --phase:build
+    runHook postBuild
+  '' else
+    buildPhase;
+
+  checkPhase = if isNull checkPhase then ''
+    runHook preCheck
+    nim_builder --phase:check
+    runHook postCheck
+  '' else
+    checkPhase;
+
+  installPhase = if isNull installPhase then ''
+    runHook preInstall
+    nim_builder --phase:install
+    runHook postInstall
+  '' else
+    installPhase;
+
+  meta = meta // {
+    maintainers = (meta.maintainers or [ ]) ++ [ lib.maintainers.ehmry ];
+  };
+})
diff --git a/pkgs/development/nim-packages/fetch-nimble/builder.sh b/pkgs/development/nim-packages/fetch-nimble/builder.sh
new file mode 100644
index 000000000000..693ab339408e
--- /dev/null
+++ b/pkgs/development/nim-packages/fetch-nimble/builder.sh
@@ -0,0 +1,12 @@
+source $stdenv/setup
+export HOME=$NIX_BUILD_TOP
+
+nimble --accept --noSSLCheck develop "${pkgname}@${version}"
+# TODO: bring in the certificates for Nimble to verify the fetch of
+# the package list.
+
+pkgdir=${NIX_BUILD_TOP}/${pkgname}
+
+find "$pkgdir" -name .git -print0 | xargs -0 rm -rf
+
+cp -a "$pkgdir" "$out"
diff --git a/pkgs/development/nim-packages/fetch-nimble/default.nix b/pkgs/development/nim-packages/fetch-nimble/default.nix
new file mode 100644
index 000000000000..ccdacc8e27b9
--- /dev/null
+++ b/pkgs/development/nim-packages/fetch-nimble/default.nix
@@ -0,0 +1,20 @@
+{ lib, makeOverridable, stdenv, gitMinimal, nim, cacert }:
+
+makeOverridable (
+
+  { pname, version, hash ? lib.fakeHash,
+
+  meta ? { }, passthru ? { }, preferLocalBuild ? true }:
+  stdenv.mkDerivation {
+    inherit version meta passthru preferLocalBuild;
+    pname = pname + "-src";
+    pkgname = pname;
+    builder = ./builder.sh;
+    nativeBuildInputs = [ gitMinimal nim ];
+    outputHash = hash;
+    outputHashAlgo = null;
+    outputHashMode = "recursive";
+    impureEnvVars = lib.fetchers.proxyImpureEnvVars
+      ++ [ "GIT_PROXY_COMMAND" "SOCKS_SERVER" ];
+    GIT_SSL_CAINFO = "${cacert}/etc/ssl/certs/ca-bundle.crt";
+  })
diff --git a/pkgs/development/nim-packages/nim_builder/default.nix b/pkgs/development/nim-packages/nim_builder/default.nix
new file mode 100644
index 000000000000..34da4dfa61a0
--- /dev/null
+++ b/pkgs/development/nim-packages/nim_builder/default.nix
@@ -0,0 +1,19 @@
+{ lib, stdenv, nim }:
+
+stdenv.mkDerivation {
+  pname = "nim_builder";
+  inherit (nim) version;
+  dontUnpack = true;
+  nativeBuildInputs = [ nim ];
+  buildPhase = ''
+    cp ${./nim_builder.nim} nim_builder.nim
+    nim c --nimcache:$TMPDIR nim_builder
+  '';
+  installPhase = ''
+    install -Dt $out/bin nim_builder
+  '';
+  meta = {
+    description = "Internal Nixpkgs utility for buildNimPackage.";
+    maintainers = [ lib.maintainers.ehmry ];
+  };
+}
diff --git a/pkgs/development/nim-packages/nim_builder/nim_builder.nim b/pkgs/development/nim-packages/nim_builder/nim_builder.nim
new file mode 100644
index 000000000000..b8881b700047
--- /dev/null
+++ b/pkgs/development/nim-packages/nim_builder/nim_builder.nim
@@ -0,0 +1,166 @@
+# SPDX-FileCopyrightText: 2021 Nixpkgs/NixOS contributors
+## Custom Nim builder for Nixpkgs.
+
+import std/[os, osproc, parseutils, sequtils, streams, strutils]
+
+proc findNimbleFile(): string =
+  ## Copied from Nimble.
+  ## Copyright (c) 2015, Dominik Picheta
+  ## BSD3
+  let dir = getCurrentDir()
+  result = ""
+  var hits = 0
+  for kind, path in walkDir(dir):
+    if kind in {pcFile, pcLinkToFile}:
+      let ext = path.splitFile.ext
+      if ext == ".nimble":
+        result = path
+        inc hits
+  if hits >= 2:
+    quit("Only one .nimble file should be present in " & dir)
+  elif hits == 0:
+    quit("Could not find a file with a .nimble extension in " & dir)
+
+proc getEnvBool(key: string; default = false): bool =
+  ## Parse a boolean environmental variable.
+  let val = getEnv(key)
+  if val == "": default
+  else: parseBool(val)
+
+proc getNimbleFilePath(): string =
+  ## Get the Nimble file for the current package.
+  if existsEnv"nimbleFile":
+    getEnv"nimbleFile"
+  else:
+    findNimbleFile()
+
+proc getNimbleValue(filePath, key: string; default = ""): string =
+  ## Extract a string value from the Nimble file at ``filePath``.
+  var
+    fs = newFileStream(filePath, fmRead)
+    line: string
+  if fs.isNil:
+    quit("could not open " & filePath)
+  while fs.readline(line):
+    if line.startsWith(key):
+      var i = key.len
+      i.inc skipWhile(line, Whitespace, i)
+      if line[i] == '=':
+        inc i
+        i.inc skipWhile(line, Whitespace, i)
+        discard parseUntil(line, result, Newlines, i)
+        if result.len > 0 and result[0] == '"':
+          result = result.unescape
+        return
+  default
+
+proc getNimbleValues(filePath, key: string): seq[string] =
+  ## Extract a string sequence from the Nimble file at ``filePath``.
+  var gunk = getNimbleValue(filePath, key)
+  result = gunk.strip(chars = {'@', '[', ']'}).split(',')
+  if result == @[""]: reset result
+  apply(result) do (s: var string):
+    s = s.strip()
+    if s.len > 0 and s[0] == '"':
+      s = s.unescape()
+
+proc configurePhase*() =
+  ## Generate "config.nims" which will be read by the Nim
+  ## compiler during later phases.
+  const configFilePath = "config.nims"
+  echo "generating ", configFilePath
+  let
+    nf = getNimbleFilePath()
+    mode =
+      if fileExists configFilePath: fmAppend
+      else: fmWrite
+  var cfg = newFileStream(configFilePath, mode)
+  proc switch(key, val: string) =
+    cfg.writeLine("switch(", key.escape, ",", val.escape, ")")
+  switch("backend", nf.getNimbleValue("backend", "c"))
+  switch("nimcache", getEnv("NIX_BUILD_TOP", ".") / "nimcache")
+  if getEnvBool("nimRelease", true):
+    switch("define", "release")
+  for def in getEnv("nimDefines").split:
+    if def != "":
+      switch("define", def)
+  for input in getEnv("buildInputs").split:
+    if input != "":
+      for nimbleFile in walkFiles(input / "*.nimble"):
+        let inputSrc = normalizedPath(
+            input / nimbleFile.getNimbleValue("srcDir", "."))
+        echo "found nimble input ", inputSrc
+        switch("path", inputSrc)
+  close(cfg)
+
+proc buildPhase*() =
+  ## Build the programs listed in the Nimble file and
+  ## optionally some documentation.
+  var cmds: seq[string]
+  proc before(idx: int) =
+    echo "build job ", idx, ": ", cmds[idx]
+  let
+    nf = getNimbleFilePath()
+    bins = nf.getNimbleValues("bin")
+    srcDir = nf.getNimbleValue("srcDir", ".")
+    binDir = getenv("outputBin", getenv("out", "/dev/null")) / "bin"
+  if bins != @[]:
+    for bin in bins:
+      cmds.add("nim compile $# --outdir:$# $#" %
+          [getenv"nimFlags", binDir, normalizedPath(srcDir / bin)])
+  if getEnvBool"nimDoc":
+    echo "generating documentation"
+    let docDir = getenv("outputDoc", (getenv("out", "/dev/null") / "doc"))
+    for path in walkFiles(srcDir / "*.nim"):
+      cmds.add("nim doc --outdir:$# $#" % [docDir, path])
+  if cmds.len > 0:
+    let err = execProcesses(
+      cmds, n = 1,
+      beforeRunEvent = before)
+    if err != 0: quit("build phase failed", err)
+
+proc installPhase*() =
+  ## Install the Nim sources if ``nimBinOnly`` is not
+  ## set in the environment.
+  if not getEnvBool"nimBinOnly":
+    let
+      nf = getNimbleFilePath()
+      srcDir = nf.getNimbleValue("srcDir", ".")
+      devDir = getenv("outputDev", getenv("out", "/dev/null"))
+    echo "Install ", srcDir, " to ", devDir
+    copyDir(normalizedPath(srcDir), normalizedPath(devDir / srcDir))
+    copyFile(nf, devDir / nf.extractFilename)
+
+proc checkPhase*() =
+  ## Build and run the tests in ``tests``.
+  var cmds: seq[string]
+  proc before(idx: int) =
+    echo "check job ", idx, ": ", cmds[idx]
+  for path in walkPattern("tests/t*.nim"):
+    cmds.add("nim r $#" % [path])
+  let err = execProcesses(
+    cmds, n = 1,
+    beforeRunEvent = before)
+  if err != 0: quit("check phase failed", err)
+
+when isMainModule:
+  import std/parseopt
+  var phase: string
+
+  for kind, key, val in getopt():
+    case kind
+    of cmdLongOption:
+      case key.toLowerAscii
+      of "phase":
+        if phase != "": quit("only a single phase may be specified")
+        phase = val
+      else: quit("unhandled argument " & key)
+    of cmdEnd: discard
+    else: quit("unhandled argument " & key)
+
+  case phase
+  of "configure": configurePhase()
+  of "build": buildPhase()
+  of "install": installPhase()
+  of "check": checkPhase()
+  else: quit("unhandled phase " & phase)
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index e2be394d249c..1d74908ad9f4 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -12064,6 +12064,7 @@ with pkgs;
 
   inherit (callPackages ../development/compilers/nim { })
     nim-unwrapped nimble-unwrapped nim;
+  nimPackages = recurseIntoAttrs nim.pkgs;
 
   nrpl = callPackage ../development/tools/nrpl { };
 
diff --git a/pkgs/top-level/nim-packages.nix b/pkgs/top-level/nim-packages.nix
new file mode 100644
index 000000000000..f426870a6402
--- /dev/null
+++ b/pkgs/top-level/nim-packages.nix
@@ -0,0 +1,12 @@
+{ lib, pkgs, stdenv, newScope, nim, fetchFromGitHub }:
+
+lib.makeScope newScope (self:
+  let callPackage = self.callPackage;
+  in {
+    inherit nim;
+    nim_builder = callPackage ../development/nim-packages/nim_builder { };
+    buildNimPackage =
+      callPackage ../development/nim-packages/build-nim-package { };
+    fetchNimble = callPackage ../development/nim-packages/fetch-nimble { };
+
+  })