diff --git a/app/services/demarches_publiques_export_service.rb b/app/services/demarches_publiques_export_service.rb
new file mode 100644
index 000000000..1d1dfbfda
--- /dev/null
+++ b/app/services/demarches_publiques_export_service.rb
@@ -0,0 +1,99 @@
+class DemarchesPubliquesExportService
+  attr_reader :io
+  def initialize(io)
+    @io = io
+  end
+
+  def call
+    end_cursor = nil
+    first = true
+    write_array_opening
+    loop do
+      write_demarches_separator if !first
+      execute_query(cursor: end_cursor)
+      end_cursor = last_cursor
+      io.write(jsonify(demarches))
+      first = false
+      break if !has_next_page?
+    end
+    write_array_closing
+    io.close
+  end
+
+  private
+
+  def execute_query(cursor: nil)
+    result = API::V2::Schema.execute(query, variables: { cursor: cursor }, context: { internal_use: true, admin: true })
+    raise DemarchesPubliquesExportService::Error.new(result["errors"]) if result["errors"]
+    @graphql_data = result["data"]
+  end
+
+  def query
+    "query($cursor: String) {
+      demarchesPubliques(after: $cursor) {
+        pageInfo {
+          endCursor
+          hasNextPage
+        }
+        edges {
+          node {
+            number
+            title
+            description
+            datePublication
+            service { nom organisme typeOrganisme }
+            cadreJuridique
+            deliberation
+            revision {
+              champDescriptors {
+                type
+                label
+                description
+                required
+                options
+                champDescriptors {
+                  type
+                  label
+                  description
+                  required
+                  options
+                }
+              }
+            }
+          }
+        }
+      }
+    }"
+  end
+
+  def last_cursor
+    @graphql_data["demarchesPubliques"]["pageInfo"]["endCursor"]
+  end
+
+  def has_next_page?
+    @graphql_data["demarchesPubliques"]["pageInfo"]["hasNextPage"]
+  end
+
+  def demarches
+    @graphql_data["demarchesPubliques"]["edges"].map { |edge| edge["node"] }
+  end
+
+  def jsonify(demarches)
+    demarches.map(&:to_json).join(',')
+  end
+
+  def write_array_opening
+    io.write('[')
+  end
+
+  def write_array_closing
+    io.write(']')
+  end
+
+  def write_demarches_separator
+    io.write(',')
+  end
+end
+
+class DemarchesPubliquesExportService::Error < StandardError
+end
diff --git a/spec/services/demarches_publiques_export_service_spec.rb b/spec/services/demarches_publiques_export_service_spec.rb
new file mode 100644
index 000000000..cbce8b9bd
--- /dev/null
+++ b/spec/services/demarches_publiques_export_service_spec.rb
@@ -0,0 +1,45 @@
+describe DemarchesPubliquesExportService do
+  let(:procedure) { create(:procedure, :published, :with_service, :with_type_de_champ) }
+  let(:io) { StringIO.new }
+
+  describe 'call' do
+    it 'generate json for all closed procedures' do
+      expected_result = {
+        number: procedure.id,
+        title: procedure.libelle,
+        description: "Demande de subvention à l'intention des associations",
+        service: {
+          nom: procedure.service.nom,
+          organisme: "organisme",
+          typeOrganisme: "association"
+        },
+        cadreJuridique: "un cadre juridique important",
+        deliberation: nil,
+        datePublication: procedure.published_at.iso8601,
+        revision: {
+          champDescriptors: [
+            {
+              description: procedure.types_de_champ.first.description,
+              label: procedure.types_de_champ.first.libelle,
+              options: nil,
+              required: false,
+              type: "text",
+              champDescriptors: nil
+            }
+          ]
+        }
+      }
+
+      DemarchesPubliquesExportService.new(io).call
+      expect(JSON.parse(io.string)[0]
+        .deep_symbolize_keys)
+        .to eq(expected_result)
+    end
+    it 'raises exception when procedure with bad data' do
+      procedure.libelle = nil
+      procedure.save(validate: false)
+
+      expect { DemarchesPubliquesExportService.new(io).call }.to raise_error(DemarchesPubliquesExportService::Error)
+    end
+  end
+end