diff --git a/front/src/AddBookToCollection.vue b/front/src/AddBookToCollection.vue
new file mode 100644
index 0000000..0a7fd79
--- /dev/null
+++ b/front/src/AddBookToCollection.vue
@@ -0,0 +1,95 @@
+<script setup>
+import { ref, computed } from 'vue'
+import { getSearchBooks, postCollectionAddBook, extractFormErrorFromField } from './api.js'
+
+const props = defineProps({
+  collectionId: Number,
+})
+
+const emit = defineEmits(['created'])
+
+const book = ref({
+  id: 0,
+  title: '',
+})
+const addingBook = ref(false)
+const data = ref(null)
+const error = ref(null)
+const titleError = computed(() => {
+  return extractFormErrorFromField('Title', error.value)
+})
+const vFocus = {
+  mounted: (el) => el.focus(),
+}
+
+const limit = 5
+
+function fetchBooks() {
+  if (!book || book.value.title.length < 3) {
+    return
+  }
+  const lang = navigator.language.substring(0, 2)
+  getSearchBooks(data, error, book.value.title, lang, 0, limit, 0)
+}
+
+function addBook(bookId) {
+  postCollectionAddBook(props.collectionId, bookId).then((res) => {
+    if (res.ok) {
+      addingBook.value = false
+      book.value.id = 0
+      book.value.title = ''
+      data.value = null
+      error.value = null
+      emit('created')
+    } else {
+      res.json().then((json) => {
+        console.log(json)
+        error.value = json
+      })
+    }
+  })
+}
+</script>
+
+<template>
+  <div class="field has-addons">
+    <div v-if="addingBook" class="control">
+      <input
+        :class="'input is-large ' + (titleError ? 'is-danger' : '')"
+        v-focus
+        @keyup="fetchBooks()"
+        type="text"
+        maxlength="300"
+        v-model="book.title"
+        :placeholder="$t('addbook.title')"
+      />
+      <p v-if="titleError" class="help is-danger">{{ titleError }}</p>
+      <ul v-if="data" class="popupresults has-background-dark">
+        <li v-for="book in data.books" @click="addBook(book.id)" class="bookresult p-2">
+          {{ book.title }}
+        </li>
+      </ul>
+    </div>
+    <div v-if="!addingBook" class="control">
+      <button @click="addingBook = true" class="button is-large mb-2">
+        <span class="icon" :title="$t('collections.add')">
+          <b-icon-plus />
+        </span>
+      </button>
+    </div>
+  </div>
+</template>
+
+<style scoped>
+.popupresults {
+  z-index: 999;
+}
+
+.bookresult {
+  cursor: pointer;
+}
+
+.bookresult:hover {
+  background-color: var(--bulma-text-40);
+}
+</style>
diff --git a/front/src/CollectionForm.vue b/front/src/CollectionForm.vue
index 7636d01..dbd9042 100644
--- a/front/src/CollectionForm.vue
+++ b/front/src/CollectionForm.vue
@@ -2,6 +2,7 @@
 import { computed, ref } from 'vue'
 import { getCollection } from './api.js'
 import CollectionFormBookItem from './CollectionFormBookItem.vue'
+import AddBookToCollection from './AddBookToCollection.vue'
 import Pagination from './Pagination.vue'
 
 const props = defineProps({
@@ -27,14 +28,20 @@ getCollection(data, error, props.id, limit, offset.value)
 function pageChange(newPageNumber) {
   pageNumber.value = newPageNumber
   data.value = null
+  error.value = null
   getCollection(data, error, props.id, limit, offset.value)
 }
+
+function fetchCollection() {
+  pageChange(1)
+}
 </script>
 
 <template>
   <div v-if="error">{{ $t('bookform.error', { error: error.message }) }}</div>
   <div v-if="data">
     <h2 class="title">{{ data.name }}</h2>
+    <AddBookToCollection :collection-id="props.id" @created="fetchCollection" />
     <div>
       <CollectionFormBookItem v-for="book in data.books" :key="book.id" v-bind="book" />
     </div>
diff --git a/front/src/SearchBook.vue b/front/src/SearchBook.vue
index b8f2f94..99738cd 100644
--- a/front/src/SearchBook.vue
+++ b/front/src/SearchBook.vue
@@ -36,7 +36,15 @@ function fetchData(searchTerm, authorId) {
   error.value = null
   if (searchTerm != null) {
     const lang = navigator.language.substring(0, 2)
-    getSearchBooks(data, error, searchTerm, lang, forceSearchInventaire.value, limit, offset.value)
+    getSearchBooks(
+      data,
+      error,
+      searchTerm,
+      lang,
+      forceSearchInventaire.value ? 2 : 1,
+      limit,
+      offset.value,
+    )
   } else if (authorId != null) {
     getAuthorBooks(data, error, authorId, limit, offset.value)
   }
diff --git a/front/src/api.js b/front/src/api.js
index 32c847d..edffebd 100644
--- a/front/src/api.js
+++ b/front/src/api.js
@@ -130,6 +130,14 @@ export function postCollection(collection) {
   return genericPayloadCall('/ws/collection', collection, 'POST')
 }
 
+export function postCollectionAddBook(collectionId, bookId) {
+  return genericPayloadCall(
+    '/ws/collection/' + collectionId + '/addbook',
+    { bookId: bookId },
+    'POST',
+  )
+}
+
 export function putBook(id, book) {
   return genericPayloadCall('/ws/book/edit/' + id, book.value, 'PUT')
 }
@@ -219,10 +227,9 @@ export function genericPayloadCall(apiRoute, object, method) {
 }
 
 export function extractFormErrorFromField(fieldName, errors) {
-  if (errors == null) {
+  if (errors == null || typeof errors == 'undefined' || !Array.isArray(errors)) {
     return ''
   }
-  console.log(errors.value)
   const titleErr = errors.find((e) => e['field'] === fieldName)
   if (typeof titleErr !== 'undefined') {
     return titleErr.error
diff --git a/internal/apitest/post_collection_addbook_test.go b/internal/apitest/post_collection_addbook_test.go
new file mode 100644
index 0000000..533abab
--- /dev/null
+++ b/internal/apitest/post_collection_addbook_test.go
@@ -0,0 +1,64 @@
+package apitest
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"git.artlef.fr/bibliomane/internal/testutils"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPostCollectionBookHandler_Ok(t *testing.T) {
+	payload :=
+		`{
+			"bookId": 9
+		}`
+	collectionId := "1"
+	status := testPostCollectionBookHandler(t, collectionId, payload)
+	assert.Equal(t, http.StatusOK, status)
+	_, collection := testGetCollection(t, collectionId, "10", "0")
+	assert.Equal(t, int64(7), collection.Count)
+}
+
+func TestPostCollectionBookHandler_CollectionNotFound(t *testing.T) {
+	payload :=
+		`{
+			"bookId": 9
+		}`
+	status := testPostCollectionBookHandler(t, "12", payload)
+	assert.Equal(t, http.StatusNotFound, status)
+}
+
+func TestPostCollectionBookHandler_BookNotFound(t *testing.T) {
+	payload :=
+		`{
+			"bookId": 14654
+		}`
+	status := testPostCollectionBookHandler(t, "1", payload)
+	assert.Equal(t, http.StatusNotFound, status)
+}
+
+func TestPostCollectionBookHandler_Unauthorized(t *testing.T) {
+	payload :=
+		`{
+			"bookId": 9
+		}`
+	status := testPostCollectionBookHandler(t, "3", payload)
+	assert.Equal(t, http.StatusUnauthorized, status)
+}
+
+func testPostCollectionBookHandler(t *testing.T, collectionId string, payload string) int {
+	router := testutils.TestSetup()
+	w := httptest.NewRecorder()
+
+	token := testutils.ConnectDemoUser(router)
+	req, _ := http.NewRequest("POST", "/ws/collection/"+collectionId+"/addbook",
+		strings.NewReader(payload))
+	req.Header.Add("Authorization", fmt.Sprintf("Bearer %s", token))
+	router.ServeHTTP(w, req)
+
+	return w.Code
+}
diff --git a/internal/apitest/search_book_test.go b/internal/apitest/search_book_test.go
index 1766951..655df34 100644
--- a/internal/apitest/search_book_test.go
+++ b/internal/apitest/search_book_test.go
@@ -3,6 +3,7 @@ package apitest
 import (
 	"encoding/json"
 	"fmt"
+	"strconv"
 
 	"net/http"
 	"net/http/httptest"
@@ -15,14 +16,14 @@ import (
 )
 
 func TestSearchBook_MultipleBooks(t *testing.T) {
-	result := testSearchBook(t, "san", "", "")
+	result := testSearchBook(t, "san", "", "", dto.NoInventaireSearch)
 
 	assert.Equal(t, int64(2), result.Count)
 	assert.Equal(t, 2, len(result.Books))
 }
 
 func TestSearchBook_OneBookNotUserBook(t *testing.T) {
-	result := testSearchBook(t, "iliade", "", "")
+	result := testSearchBook(t, "iliade", "", "", dto.NoInventaireSearch)
 	assert.Equal(t, int64(1), result.Count)
 	assert.Equal(t,
 		[]dto.BookItemGet{{
@@ -38,7 +39,7 @@ func TestSearchBook_OneBookNotUserBook(t *testing.T) {
 }
 
 func TestSearchBook_OneBookRead(t *testing.T) {
-	result := testSearchBook(t, "dieux", "", "")
+	result := testSearchBook(t, "dieux", "", "", dto.NoInventaireSearch)
 	assert.Equal(t, int64(1), result.Count)
 	assert.Equal(t,
 		[]dto.BookItemGet{{
@@ -55,7 +56,7 @@ func TestSearchBook_OneBookRead(t *testing.T) {
 }
 
 func TestSearchBook_OneBookStartRead(t *testing.T) {
-	result := testSearchBook(t, "Recherches", "", "")
+	result := testSearchBook(t, "Recherches", "", "", dto.NoInventaireSearch)
 	assert.Equal(t, int64(1), result.Count)
 	assert.Equal(t,
 		[]dto.BookItemGet{{
@@ -72,7 +73,7 @@ func TestSearchBook_OneBookStartRead(t *testing.T) {
 }
 
 func TestSearchBook_ISBN(t *testing.T) {
-	result := testSearchBook(t, "9782070337903", "", "")
+	result := testSearchBook(t, "9782070337903", "", "", dto.NoInventaireSearch)
 	assert.Equal(t, int64(1), result.Count)
 	assert.Equal(t,
 		[]dto.BookItemGet{{
@@ -88,7 +89,7 @@ func TestSearchBook_ISBN(t *testing.T) {
 }
 
 func TestSearchBook_ISBNInventaire(t *testing.T) {
-	result := testSearchBook(t, "9782253158400", "", "")
+	result := testSearchBook(t, "9782253158400", "", "", dto.InventaireIfNothingFound)
 	assert.Equal(t, int64(1), result.Count)
 	assert.Equal(t,
 		[]dto.BookItemGet{{
@@ -107,17 +108,17 @@ func TestSearchBook_ISBNInventaire(t *testing.T) {
 }
 
 func TestSearchBook_Limit(t *testing.T) {
-	result := testSearchBook(t, "a", "10", "")
+	result := testSearchBook(t, "a", "10", "", dto.NoInventaireSearch)
 	assert.Equal(t, 10, len(result.Books))
 }
 
 func TestSearchBook_Offset(t *testing.T) {
-	result := testSearchBook(t, "sa", "", "2")
+	result := testSearchBook(t, "sa", "", "2", dto.NoInventaireSearch)
 	assert.Equal(t, int64(5), result.Count)
 	assert.Equal(t, 3, len(result.Books))
 }
 
-func testSearchBook(t *testing.T, searchterm string, limit string, offset string) dto.BookItemsGet {
+func testSearchBook(t *testing.T, searchterm string, limit string, offset string, inventaireSearchType dto.InventaireSearchType) dto.BookItemsGet {
 	router := testutils.TestSetup()
 
 	u, err := url.Parse("/ws/search/" + searchterm)
@@ -137,6 +138,7 @@ func testSearchBook(t *testing.T, searchterm string, limit string, offset string
 
 	q := u.Query()
 	q.Set("lang", "fr")
+	q.Set("inventaire", strconv.Itoa(int(inventaireSearchType)))
 	u.RawQuery = q.Encode()
 
 	token := testutils.ConnectDemoUser(router)
diff --git a/internal/dto/in.go b/internal/dto/in.go
index fecd451..10fc867 100644
--- a/internal/dto/in.go
+++ b/internal/dto/in.go
@@ -5,9 +5,17 @@ type AuthorGet struct {
 	Description string `json:"description"`
 }
 
+type InventaireSearchType int
+
+const (
+	NoInventaireSearch InventaireSearchType = iota
+	InventaireIfNothingFound
+	ForceInventaireSearch
+)
+
 type BookSearchGetParam struct {
-	Lang       string `form:"lang" binding:"max=5"`
-	Inventaire bool   `form:"inventaire"`
+	Lang       string               `form:"lang" binding:"max=5"`
+	Inventaire InventaireSearchType `form:"inventaire"`
 }
 
 type BookFields struct {
@@ -39,6 +47,10 @@ type CollectionFields struct {
 	Name string `json:"name" binding:"required,max=300"`
 }
 
+type CollectionBook struct {
+	BookID uint `json:"bookId" binding:"required"`
+}
+
 type FileInfoPost struct {
 	FileID   uint   `json:"fileId"`
 	FilePath string `json:"filepath"`
diff --git a/internal/myvalidator/myvalidator.go b/internal/myvalidator/myvalidator.go
index 8ca8550..5b8ab41 100644
--- a/internal/myvalidator/myvalidator.go
+++ b/internal/myvalidator/myvalidator.go
@@ -57,6 +57,9 @@ func ReturnErrorsAsJsonResponse(ac *appcontext.AppContext, err error) {
 		ac.C.JSON(httpError.StatusCode, gin.H{"error": httpError.Err.Error()})
 		return
 	}
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		ac.C.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
+	}
 	ac.C.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
 }
 
diff --git a/internal/routes/booksearchget.go b/internal/routes/booksearchget.go
index 5908ccc..3f79230 100644
--- a/internal/routes/booksearchget.go
+++ b/internal/routes/booksearchget.go
@@ -38,7 +38,7 @@ func GetSearchBooksHandler(ac appcontext.AppContext) {
 		return
 	}
 	var returnedBooks dto.BookItemsGet
-	if !params.Inventaire {
+	if params.Inventaire != dto.ForceInventaireSearch {
 		books, err := query.FetchBookSearchGet(ac.Db, user.ID, searchterm, limit, offset)
 		if err != nil {
 			myvalidator.ReturnErrorsAsJsonResponse(&ac, err)
@@ -51,7 +51,7 @@ func GetSearchBooksHandler(ac appcontext.AppContext) {
 		}
 		returnedBooks = dto.BookItemsGet{Count: count, Inventaire: false, Books: books}
 	}
-	if params.Inventaire || len(returnedBooks.Books) == 0 {
+	if (params.Inventaire == dto.InventaireIfNothingFound && len(returnedBooks.Books) == 0) || (params.Inventaire == dto.ForceInventaireSearch) {
 		returnedBooksPtr, err := searchInInventaireAPI(ac.Config.InventaireUrl, searchterm, limit, offset, params)
 		if err != nil {
 			myvalidator.ReturnErrorsAsJsonResponse(&ac, err)
diff --git a/internal/routes/collectionaddbookpost.go b/internal/routes/collectionaddbookpost.go
new file mode 100644
index 0000000..f93d66d
--- /dev/null
+++ b/internal/routes/collectionaddbookpost.go
@@ -0,0 +1,62 @@
+package routes
+
+import (
+	"errors"
+	"net/http"
+	"strconv"
+
+	"git.artlef.fr/bibliomane/internal/appcontext"
+	"git.artlef.fr/bibliomane/internal/dto"
+	"git.artlef.fr/bibliomane/internal/i18nresource"
+	"git.artlef.fr/bibliomane/internal/model"
+	"git.artlef.fr/bibliomane/internal/myvalidator"
+	"github.com/gin-gonic/gin"
+)
+
+func PostCollectionBookHandler(ac appcontext.AppContext) {
+	collectionId, err := strconv.ParseUint(ac.C.Param("id"), 10, 64)
+	if err != nil {
+		ac.C.JSON(http.StatusBadRequest, gin.H{"error": err})
+		return
+	}
+
+	user, err := ac.GetAuthenticatedUser()
+	if err != nil {
+		myvalidator.ReturnErrorsAsJsonResponse(&ac, err)
+		return
+	}
+
+	var collection model.Collection
+	err = ac.Db.First(&collection, collectionId).Error
+	if err != nil {
+		myvalidator.ReturnErrorsAsJsonResponse(&ac, err)
+		return
+	}
+
+	if collection.UserID != user.ID {
+		err := myvalidator.HttpError{
+			StatusCode: http.StatusUnauthorized,
+			Err:        errors.New(i18nresource.GetTranslatedMessage(&ac, "Unauthorized")),
+		}
+		myvalidator.ReturnErrorsAsJsonResponse(&ac, err)
+		return
+	}
+
+	var collectionBook dto.CollectionBook
+	err = ac.C.ShouldBindJSON(&collectionBook)
+	if err != nil {
+		myvalidator.ReturnErrorsAsJsonResponse(&ac, err)
+		return
+	}
+
+	var book model.Book
+	err = ac.Db.First(&book, collectionBook.BookID).Error
+	if err != nil {
+		myvalidator.ReturnErrorsAsJsonResponse(&ac, err)
+		return
+	}
+
+	collection.Books = append(collection.Books, book)
+	ac.Db.Save(&collection)
+	ac.C.String(http.StatusOK, "Success")
+}
diff --git a/internal/setup/setup.go b/internal/setup/setup.go
index a63c7b0..3b78a4c 100644
--- a/internal/setup/setup.go
+++ b/internal/setup/setup.go
@@ -84,6 +84,9 @@ func Setup(config *config.Config) *gin.Engine {
 	ws.GET("/collection/:id", func(c *gin.Context) {
 		routes.GetCollectionHandler(appcontext.AppContext{C: c, Db: db, I18n: bundle, Config: config})
 	})
+	ws.POST("/collection/:id/addbook", func(c *gin.Context) {
+		routes.PostCollectionBookHandler(appcontext.AppContext{C: c, Db: db, I18n: bundle, Config: config})
+	})
 	ws.POST("/collection", func(c *gin.Context) {
 		routes.PostCollectionHandler(appcontext.AppContext{C: c, Db: db, I18n: bundle, Config: config})
 	})