diff --git a/coq-nix-toolbox.nix.mustache b/coq-nix-toolbox.nix.mustache
new file mode 100644
index 0000000..0679266
--- /dev/null
+++ b/coq-nix-toolbox.nix.mustache
@@ -0,0 +1,4 @@
+# This file was generated from meta.yml, please do not edit manually.
+# Follow the instructions on https://github.com/coq-community/templates to regenerate.
+# However, it not handled by mustache, but by a special eval command
+\"$(git ls-remote https://github.com/coq-community/coq-nix-toolbox refs/heads/master | cut -f1)\"
\ No newline at end of file
diff --git a/default.nix.mustache b/default.nix.mustache
index a69ae3c..457bfd9 100644
--- a/default.nix.mustache
+++ b/default.nix.mustache
@@ -1,36 +1,36 @@
 # This file was generated from `meta.yml`, please do not edit manually.
 # Follow the instructions on https://github.com/coq-community/templates to regenerate.
-
-{ pkgs ? (import <nixpkgs> {}), coq-version-or-url, shell ? false }:
-
+{{# nix-default}}
+{ config ? {}, withEmacs ? false, print-env ? false, do-nothing ? false,
+  update-nixpkgs ? false, ci-matrix ? false, ci-job ? null,
+  override ? {}, ocaml-override ? {}, global-override ? {},
+  ci ? (!isNull ci-job), inNixShell ? null
+}@args:
 let
-  coq-version-parts = builtins.match "([0-9]+).([0-9]+)" coq-version-or-url;
-  coqPackages =
-    if coq-version-parts == null then
-      pkgs.mkCoqPackages (import (fetchTarball coq-version-or-url) {})
-    else
-      pkgs."coqPackages_${builtins.concatStringsSep "_" coq-version-parts}";
+{{# src}}
+  auto = {{src}};
+{{/ src}}
+{{^ src}}
+  auto = let p = ./nix/.coq-nix-toolbox.nix; in fetchGit {
+    url = "{{url}}{{^ url}}https://github.com/{{owner}}{{^ owner}}coq-community{{/ owner}}/coq-nix-toolbox.git{{/ url}}";
+    ref = "{{ref}}{{^ ref}}master{{/ ref}}";
+    rev = import ./.nix/coq-nix-toolbox.nix;
+  };
+{{/ src}}
 in
+(import auto ({src = ./.;} // args)).{{attribute}}{{^ attribute}}nix-auto{{/ attribute}}
+{{/ nix-default}}
+{{^ nix-default}}
+{ config ? {}, withEmacs ? false, print-env ? false, do-nothing ? false,
+  update-nixpkgs ? false, ci-matrix ? false,  ci-job ? null,
+  override ? {}, ocaml-override ? {}, global-override ? {},
+  ci ? (!isNull ci-job),  inNixShell ? null
+}@args:
+let auto = fetchGit {
+  url = "https://github.com/coq-community/coq-nix-toolbox.git";
+  ref = "master";
+  rev = import ./.nix/coq-nix-toolbox.nix;
+}; in
+(import auto ({src = ./.;} // args)).nix-auto
+{{/ nix-default}}
 
-with coqPackages;
-
-pkgs.stdenv.mkDerivation {
-
-  name = "{{ shortname }}";
-
-{{# plugin }}
-  buildInputs = with coq.ocamlPackages; [ ocaml findlib ]
-    ++ pkgs.lib.optionals shell [ merlin ocp-indent ocp-index ];
-
-{{/ plugin }}
-  propagatedBuildInputs = [
-    coq
-{{# dependencies }}
-    {{ nix }}
-{{/ dependencies }}
-  ];
-
-  src = if shell then null else ./.;
-
-  installFlags = "COQMF_COQLIB=$(out)/lib/coq/${coq.coq-version}/";
-}
diff --git a/fallback-config.nix.mustache b/fallback-config.nix.mustache
new file mode 100644
index 0000000..2ea2001
--- /dev/null
+++ b/fallback-config.nix.mustache
@@ -0,0 +1,77 @@
+# This file was generated from `meta.yml`, please do not edit manually.
+# Follow the instructions on https://github.com/coq-community/templates to regenerate.
+
+# *However*, you may copy paste it to `config.nix`
+# in the same subdirectory .nix and extend it as needed.
+# Note that this would completely deactivate this file.
+
+{
+  ## DO NOT CHANGE THIS
+  format = "1.0.0";
+  ## unless you made an automated or manual update
+  ## to another supported format.
+
+  ## The attribute to build, either from nixpkgs
+  ## of from the overlays located in `.nix/coq-overlays`
+  coq-attribute = "{{nix_name}}";
+
+  ## If you want to select a different attribute
+  ## to serve as a basis for nix-shell edit this
+  # coq-shell-attribute = "{{nix_name}}";
+
+  ## Maybe the shortname of the library is different from
+  ## the name of the nixpkgs attribute, if so, set it here:
+  {{^ shortname}}#{{/ shortname}}pname = "{{ shortname }}";
+
+  ## Lists the dependencies, phrased in terms of nix attributes.
+  ## No need to list Coq, it is already included.
+  ## These dependencies will systematically be added to the currently
+  ## known dependencies, if any more than Coq.
+  ## /!\ Remove this field as soon as the package is available on nixpkgs.
+  ## /!\ Manual overlays in `.nix/coq-overlays` should be preferred then.
+  {{^ nix-dependencies}}#{{/ nix-dependencies}}buildInputs = [ {{# nix-dependencies }}"{{.}}" {{/ nix-dependencies }}];
+
+  ## Indicate the relative location of your _CoqProject
+  ## If not specified, it defaults to "_CoqProject"
+  # coqproject = "_CoqProject";
+
+  ## select an entry to build in the following `tasks` set
+  ## defaults to "default"
+  select = "default";
+
+  ## write one `tasks.name` attribute set per
+  ## alternative configuration, the can be used to
+  ## compute several ci jobs as well
+  tasks.default = {
+
+  ## You can override Coq and other Coq coqPackages
+  ## through the following attribute
+  # coqPackages.coq.override.version = "8.11";
+
+  ## In some cases, light overrides are not available/enough
+  ## in which case you can use either
+  # coqPackages.<coq-pkg>.overrideAttrs = o: <overrides>;
+  ## or a "long" overlay to put in `.nix/coq-overlays
+  ## you may use `nix-shell --run fetchOverlay <coq-pkg>`
+  ## to automatically retrieve the one from nixpkgs
+  ## if it exists and is correctly named/located
+
+  ## You can override Coq and other Coq coqPackages
+  ## throught the following attribute
+  ## If <ocaml-pkg> does not support lights overrides,
+  ## you may use `overrideAttrs` or long overlays
+  ## located in `.nix/ocaml-overlays`
+  ## (there is no automation for this one)
+  #  ocamlPackages.<ocaml-pkg>.override.version = "x.xx";
+
+  ## You can also override packages from the nixpkgs toplevel
+  # <nix-pkg>.override.overrideAttrs = o: <overrides>;
+  ## Or put an overlay in `.nix/overlays`
+
+  ## you may mark a package as a CI job as follows
+  #  coqPackages.<another-pkg>.ci.job = "test";
+  ## It can then be built throught
+  ## nix-build --argstr ci "default" --arg ci-job "test";
+
+  };
+}
diff --git a/generate.sh b/generate.sh
index 0402135..84f85a3 100755
--- a/generate.sh
+++ b/generate.sh
@@ -14,20 +14,21 @@ get_yaml() {
 
 for f in "$srcdir"/{,.}*.mustache; do
     target=$(basename "$f" .mustache)
+    eval_instead_of_mustache=false
     case "$target" in
         coq.opam)
             mustache='{{ opam_name }}'
             opam_name=$(get_yaml meta.yml <<<"$mustache")
-	    if [ -n "$opam_name" ]; then
-		target=${target/coq/$opam_name}
-	    else
-		mustache='{{ shortname }}'
-		shortname=$(get_yaml meta.yml <<<"$mustache")
-		if [ -n "$shortname" ]; then
-		    target=${target/coq/coq-$shortname}
+	        if [ -n "$opam_name" ]; then
+		    target=${target/coq/$opam_name}
 	        else
-		    continue
-		fi
+		    mustache='{{ shortname }}'
+		    shortname=$(get_yaml meta.yml <<<"$mustache")
+		        if [ -n "$shortname" ]; then
+		            target=${target/coq/coq-$shortname}
+	                else
+		            continue
+		        fi
             fi
             ;;
         extracted.opam)
@@ -95,20 +96,39 @@ for f in "$srcdir"/{,.}*.mustache; do
                 continue
             fi
             ;;
-	config.yml)
-	    mustache='{{ circleci }}'
-	    bool=$(get_yaml meta.yml <<<"$mustache")
+        config.yml)
+	        mustache='{{ circleci }}'
+	        bool=$(get_yaml meta.yml <<<"$mustache")
+                if [ -n "$bool" ] && [ "$bool" != false ]; then
+                    mkdir -p -v .circleci && target=".circleci/$target"
+                else
+                    continue
+                fi
+                ;;
+        default.nix)
+            mustache='{{ nix }}'
+            bool=$(get_yaml meta.yml <<<"$mustache")
             if [ -n "$bool" ] && [ "$bool" != false ]; then
-                mkdir -p -v .circleci && target=".circleci/$target"
+                : noop
             else
                 continue
             fi
             ;;
-        default.nix)
+        coq-nix-toolbox.nix)
             mustache='{{ nix }}'
             bool=$(get_yaml meta.yml <<<"$mustache")
             if [ -n "$bool" ] && [ "$bool" != false ]; then
-                : noop
+                mkdir -p -v .nix && target=".nix/$target"
+                eval_instead_of_mustache=true
+            else
+                continue
+            fi
+            ;;
+        fallback-config.nix)
+            mustache='{{ nix }}'
+            bool=$(get_yaml meta.yml <<<"$mustache")
+            if [ -n "$bool" ] && [ "$bool" != false ]; then
+                mkdir -p -v .nix && target=".nix/$target"
             else
                 continue
             fi
@@ -123,6 +143,10 @@ for f in "$srcdir"/{,.}*.mustache; do
     if [ $# -gt 0 ] && [ $listed != true ]; then
 	continue
     fi
-    echo "Generating $target..."
-    mustache meta.yml "$f" > "$target"
+    echo "Generating $target"
+    if [ "$eval_instead_of_mustache" = true ]; then
+        eval "echo \"$(cat $f)\"" > "$target"
+    else
+        mustache meta.yml "$f" > "$target"
+    fi
 done
diff --git a/nix-action.yml.mustache b/nix-action.yml.mustache
index 68b52fa..8bdc694 100644
--- a/nix-action.yml.mustache
+++ b/nix-action.yml.mustache
@@ -1,39 +1,139 @@
 # This file was generated from `meta.yml`, please do not edit manually.
 # Follow the instructions on https://github.com/coq-community/templates to regenerate.
+{{!# From now on we switch template variable syntax to <%X%>}}
+{{=<% %>=}}
 name: Nix CI
 
 on:
   push:
     branches:
-      - {{branch}}{{^branch}}master{{/branch}}
+      - <%branch%><%^branch%>master<%/branch%>
   pull_request:
     branches:
       - '**'
 
 jobs:
-  build:
+  dependencies:
     runs-on: ubuntu-latest
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+    steps:
+    - name: Cachix install
+      uses: cachix/install-nix-action@v12
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+<%# cachix%>
+    - name: Cachix setup <%name%>
+      uses: cachix/cachix-action@v8
+      with:
+        # Name of a cachix cache to pull/substitute
+        name: <%name%>
+<%# key%>
+        signingKey: '${{ secrets.<%key%> }}'
+<%/ key%>
+<%# token%>
+        authToken: '${{ secrets.<%token%> }}'
+<%/ token%>
+<%/ cachix%>
+    - name: Git checkout
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+<%# submodule %>
+    - name: Checkout submodules
+      uses: textbook/git-checkout-submodule-action@2.1.1
+<%/ submodule %>
+<%! Change delimiters to avoid the next line being parsed as mustache syntax. %>
+    - name: Building/fetching dependencies
+      run: nix-build --no-out-link --argstr ci-job dependencies
+    - name: Setup build matrix
+      id: set-matrix
+      run: |
+        matrix=$(nix-shell --arg do-nothing true --run nixTasks)
+        echo ::set-output name=matrix::{\"task\":$(echo $matrix)}\"
+
+  main:
+    runs-on: ubuntu-latest
+    needs:
+    - dependencies
     strategy:
-      matrix:
-        version_or_url:
-{{# tested_coq_nix_versions }}
-          - '{{ version_or_url }}'
-{{/ tested_coq_nix_versions }}{{^ tested_coq_nix_versions }}          - 'https://github.com/coq/coq-on-cachix/tarball/master'
-{{/ tested_coq_nix_versions }}
-      fail-fast: false
+      matrix: ${{fromJson(needs.dependencies.outputs.matrix)}}
     steps:
-      - uses: cachix/install-nix-action@v12
-        with:
-          nix_path: nixpkgs=channel:nixpkgs-unstable
-      - uses: cachix/cachix-action@v8
-        with:
-          # Name of a cachix cache to pull/substitute
-          name: coq
-      - uses: actions/checkout@v2
-{{# submodule }}
-      - name: Checkout submodules
-        uses: textbook/git-checkout-submodule-action@2.1.1
-{{/ submodule }}
-{{! Change delimiters to avoid the next line being parsed as mustache syntax. }}
-{{=<% %>=}}
-      - run: nix-build --argstr coq-version-or-url "${{ matrix.version_or_url }}"
+    - name: Cachix install
+      uses: cachix/install-nix-action@v12
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+<%# cachix%>
+    - name: Cachix setup <%name%>
+      uses: cachix/cachix-action@v8
+      with:
+        # Name of a cachix cache to pull/substitute
+        name: <%name%>
+<%# key%>
+        signingKey: '${{ secrets.<%key%> }}'
+<%/ key%>
+<%# token%>
+        authToken: '${{ secrets.<%token%> }}'
+<%/ token%>
+<%/ cachix%>
+    - name: Git checkout
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+<%# submodule %>
+    - name: Checkout submodules
+      uses: textbook/git-checkout-submodule-action@2.1.1
+<%/ submodule %>
+<%! Change delimiters to avoid the next line being parsed as mustache syntax. %>
+    - name: Building/fetching dependencies
+      run: nix-build --no-out-link --argstr ci "${{ matrix.task }}" --argstr ci-job dependencies
+    - name: Building/fetching current project
+      run: nix-build --no-out-link --argstr ci "${{ matrix.task }}" --argstr ci-job main
+
+<%# nix-ci%>
+  <%name%><%^ name%><%job%><%^ job%>all<%/ job%><%/ name%>:
+    runs-on: ubuntu-latest
+    needs:
+    - dependencies
+<%# needs%>
+    - <%.%>
+<%/ needs%>
+<%^ needs%>
+    - main
+<%/ needs%>
+    strategy:
+      matrix: ${{fromJson(needs.dependencies.outputs.matrix)}}
+    steps:
+    - name: Cachix install
+      uses: cachix/install-nix-action@v12
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+<%# cachix%>
+    - name: Cachix setup <%name%>
+      uses: cachix/cachix-action@v8
+      with:
+        # Name of a cachix cache to pull/substitute
+        name: <%name%>
+<%# key%>
+        signingKey: '${{ secrets.<%key%> }}'
+<%/ key%>
+<%# token%>
+        authToken: '${{ secrets.<%token%> }}'
+<%/ token%>
+<%/ cachix%>
+    - name: Git checkout
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+<%# submodule %>
+    - name: Checkout submodules
+      uses: textbook/git-checkout-submodule-action@2.1.1
+<%/ submodule %>
+<%! Change delimiters to avoid the next line being parsed as mustache syntax. %>
+    - name: Building/fetching dependencies
+      run: nix-build --no-out-link --argstr ci "${{ matrix.task }}" --argstr ci-job dependencies
+    - name: Building/fetching current project
+      run: nix-build --no-out-link --argstr ci "${{ matrix.task }}" --argstr ci-job main
+    - name: Building/fetching current CI target
+      run: nix-build --no-out-link --argstr ci "${{ matrix.task }}" --argstr ci-job <%job%><%^ job%>all<%/ job%>
+<%/ nix-ci%>
\ No newline at end of file
diff --git a/ref.yml b/ref.yml
index 19d4325..e2a6fab 100644
--- a/ref.yml
+++ b/ref.yml
@@ -40,6 +40,11 @@ fields:
         - docker-action.yml
         - dune-project
         - dune
+  - nix_name:
+      required: false
+      default: "{{ shortname }}"
+      used:
+        - fallback-config.nix
   - organization:
       required: true
       used:
@@ -246,7 +251,8 @@ fields:
             required: true
             description: >
               The list of Coq packages in nixpkgs can be seen here:
-              https://github.com/NixOS/nixpkgs/blob/nixpkgs-unstable/pkgs/top-level/coq-packages.nix
+              https://github.com/NixOS/nixpkgs/blob/\
+              nixpkgs-unstable/pkgs/top-level/coq-packages.nix
               Casing matters and might differ from the opam name.  The
               leading coq- is present only if it is really an integral
               part of the package name.
@@ -341,7 +347,7 @@ fields:
             type: list
             item_fields:
               - description:
-                  requied: true
+                  required: true
             used:
               - README.md
               - extracted.opam
@@ -360,7 +366,8 @@ fields:
                   required: true
                   description: >
                     Docker tag supported by coqorg/coq:
-                    https://github.com/coq-community/docker-coq/wiki#supported-tags
+                    https://github.com/coq-community/docker-coq/wiki\
+                    #supported-tags.
                     Quote the strings, otherwise '8.10' becomes '8.1'.
                   examples:
                     - '8.11'
@@ -392,29 +399,119 @@ fields:
       used:
         - coq.opam
         - .travis.yml
-  - tested_coq_nix_versions:
+  - cachix:
+      used:
+        - nix-action.yml.nix
       type: list
-      description: If empty, the master branch of Coq will be tested.
+      description: Cachix repositories to use
       item_fields:
-        - version_or_url:
+        - name:
             required: true
-            description: >
-              This can be a version number of a version packaged in
-              nixpkgs (example: 8.5, 8.11).  Cf. the coqPackages_8_XX
-              attributes defined at the end of this file:
-              https://github.com/NixOS/nixpkgs/blob/nixpkgs-unstable/pkgs/top-level/coq-packages.nix
-              (Quote the version number, otherwise '8.10' becomes '8.1'.)
-
-              Or this can be a URL, to test your project with a
-              version of Coq under development.  Typically this is
-              https://github.com/coq/coq-on-cachix/tarball/master but
-              'master' may be replaced by any valid reference like one
-              of the branches available at
-              https://github.com/coq/coq-on-cachix/branches or a valid
-              commit hash.
+            description: Name of the cachix repository
+            examples:
+              - "coq"
+              - "math-comp"
+        - key:
+            required: false
+            description: |
+              Secret signingKey for the repository, the secret should
+              be set from GitHub interface in
+              https://github.com/OWNER/REPO/settings/secrets/actions
+              and generated from https://cachix.org
+              /!\ This is the legacy authentification method and
+              should be deprecated in favor of `token` below.
+            example:
+              - "CACHIX_SIGNING_KEY"
+        - token:
+            required: false
+            description: |
+              Secret authToken for the repository, the secret should
+              be set from GitHub interface in
+              https://github.com/OWNER/REPO/settings/secrets/actions
+              and generated from https://cachix.org
+            example:
+              - "CACHIX_AUTH_TOKEN"
+  - nix-default:
       used:
-        - .travis.yml
-        - nix-action.yml
+        - default.nix
+      description: >
+        Configure the default.nix to fetch from the generic coq nix toolbox
+      fields:
+        - src:
+            required: false
+            type: string
+            description: Sets a local path instead of a github source
+            examples:
+              - "~/git/coq-nix-toolbox/master"
+        - url:
+            required: false
+            type: string
+            description: Change the git url to fetch from
+            default: "https://github.com/coq-community/coq-nix-toolbox.git"
+        - owner:
+            required: false
+            type: string
+            description: Switch to the github fork of another "owner"
+            default: "coq-community"
+        - ref:
+            required: false
+            type: string
+            description: Change the branch of coq-nix-toolbox to clone
+            default: master
+  - nix-dependencies:
+      used:
+        - fallback-config.nix
+      description: |
+        Lists the dependencies, phrased in terms of nix attributes.
+        No need to list Coq, it is already included.
+        These dependencies will systematically be added to the currently
+        known dependencies, if any more than Coq.
+        /!\ Remove this field as soon as the package is available on nixpkgs.
+        /!\ Manual overlays in `.nix/coq-overlays` should be preferred then.
+      required: false
+      type: list
+      item_fields:
+        type: string
+        description: nix attribute of a dependency
+        example:
+          - "mathcomp"
+          - "coquelicot"
+  - nix-ci:
+      used:
+        - nix-action.yml.nix
+      description: |
+        Generate a nix github action using the following metadata and
+        the contents of the `.nix/config.nix` file, that the user must
+        create.  Otherwise, this attribute cannot be of any use.
+        /!\ It is strongly recommended to activate cachix with at least
+        /!\ the coq cachix activated `cachix: [ {"name": "coq" } ]``
+      type: list
+      item_fields:
+        - job:
+            required: false
+            type: string
+            description: |
+              The name of the job as described in `.nix/config.nix`
+              as in e.g. tasks.<t>.coqPackages.<mypkg>.ci.job = <job>;
+              The default is a `all` job which will run **everything**
+            default: "all"
+        - name:
+            required: false
+            type: string
+            description: |
+              The name to display in the github action web interface.
+              Defaults to the job above.
+            example: "My job"
+        - needs:
+            required: false
+            type: list
+            description: |
+              The list of jobs to wait for before executing these ones.
+            default: "main"
+            item_fields:
+              required: false
+              type: string
+              description: A job to wait for
   - tested_coq_opam_versions:
       type: list
       item_fields: