diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 6122ac18cb..a08152824f 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -158,6 +158,7 @@ hilt-compiler = { module = "com.google.dagger:hilt-compiler", version.ref = "dag
 hilt-testing = { module = "com.google.dagger:hilt-android-testing", version.ref = "dagger" }
 javapoet = "com.squareup:javapoet:1.13.0"
 json = "org.json:json:20230618"
+jsonUnit-assertj = "net.javacrumbs.json-unit:json-unit-assertj:3.2.2"
 jsoup = "org.jsoup:jsoup:1.16.1"
 junit = "junit:junit:4.13.2"
 kotlin-coroutines = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-core", version.ref = "kotlinCoroutines" }
@@ -175,6 +176,7 @@ lottie-compose = { module = "com.airbnb.android:lottie-compose", version.ref = "
 materialComponents = "com.google.android.material:material:1.9.0"
 mockk = "io.mockk:mockk:1.13.8"
 okhttp3 = { module = "com.squareup.okhttp3:okhttp", version.ref = "okhttp3" }
+okhttp3-mockwebserver = { module = "com.squareup.okhttp3:mockwebserver", version.ref = "okhttp3" }
 onesky-gradlePlugin = "co.brainly:plugin:1.6.0"
 picasso = "com.squareup.picasso:picasso:2.8"
 picasso-transformations = "jp.wasabeef:picasso-transformations:2.4.0"
diff --git a/library/api/build.gradle.kts b/library/api/build.gradle.kts
index 3a04e12da5..3867cc1fc1 100644
--- a/library/api/build.gradle.kts
+++ b/library/api/build.gradle.kts
@@ -43,4 +43,7 @@ dependencies {
     kapt(libs.hilt.compiler)
 
     testImplementation(libs.json)
+    testImplementation(libs.jsonUnit.assertj)
+    testImplementation(libs.kotlin.coroutines.test)
+    testImplementation(libs.okhttp3.mockwebserver)
 }
diff --git a/library/api/src/main/kotlin/org/cru/godtools/api/ApiModule.kt b/library/api/src/main/kotlin/org/cru/godtools/api/ApiModule.kt
index 188e59a635..7ec8a0f9b1 100644
--- a/library/api/src/main/kotlin/org/cru/godtools/api/ApiModule.kt
+++ b/library/api/src/main/kotlin/org/cru/godtools/api/ApiModule.kt
@@ -148,6 +148,12 @@ object ApiModule {
         @Named(MOBILE_CONTENT_API_AUTHENTICATED) retrofit: Retrofit,
     ): UserCountersApi = retrofit.create()
 
+    @Provides
+    @Reusable
+    fun userFavoriteToolsApi(
+        @Named(MOBILE_CONTENT_API_AUTHENTICATED) retrofit: Retrofit,
+    ): UserFavoriteToolsApi = retrofit.create()
+
     @Provides
     @Reusable
     fun viewsApi(@Named(MOBILE_CONTENT_API) retrofit: Retrofit): ViewsApi = retrofit.create()
diff --git a/library/api/src/main/kotlin/org/cru/godtools/api/UserFavoriteToolsApi.kt b/library/api/src/main/kotlin/org/cru/godtools/api/UserFavoriteToolsApi.kt
new file mode 100644
index 0000000000..ecb11b89ba
--- /dev/null
+++ b/library/api/src/main/kotlin/org/cru/godtools/api/UserFavoriteToolsApi.kt
@@ -0,0 +1,33 @@
+package org.cru.godtools.api
+
+import org.ccci.gto.android.common.jsonapi.model.JsonApiObject
+import org.ccci.gto.android.common.jsonapi.retrofit2.JsonApiParams
+import org.ccci.gto.android.common.jsonapi.retrofit2.annotation.JsonApiFields
+import org.cru.godtools.model.Tool
+import retrofit2.Response
+import retrofit2.http.Body
+import retrofit2.http.HTTP
+import retrofit2.http.POST
+import retrofit2.http.QueryMap
+
+interface UserFavoriteToolsApi {
+    companion object {
+        internal const val PATH_FAVORITE_TOOLS = "$PATH_USER/relationships/favorite-tools"
+    }
+
+    @POST(PATH_FAVORITE_TOOLS)
+    suspend fun addFavoriteTools(
+        @QueryMap params: JsonApiParams = JsonApiParams(),
+        @Body
+        @JsonApiFields(Tool.JSONAPI_TYPE)
+        tools: List<Tool>,
+    ): Response<JsonApiObject<Tool>>
+
+    @HTTP(method = "DELETE", path = PATH_FAVORITE_TOOLS, hasBody = true)
+    suspend fun removeFavoriteTools(
+        @QueryMap params: JsonApiParams = JsonApiParams(),
+        @Body
+        @JsonApiFields(Tool.JSONAPI_TYPE)
+        tools: List<Tool>,
+    ): Response<JsonApiObject<Tool>>
+}
diff --git a/library/api/src/test/kotlin/org/cru/godtools/api/UserFavoriteToolsApiTest.kt b/library/api/src/test/kotlin/org/cru/godtools/api/UserFavoriteToolsApiTest.kt
new file mode 100644
index 0000000000..aba767550a
--- /dev/null
+++ b/library/api/src/test/kotlin/org/cru/godtools/api/UserFavoriteToolsApiTest.kt
@@ -0,0 +1,46 @@
+package org.cru.godtools.api
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNotNull
+import kotlinx.coroutines.test.runTest
+import net.javacrumbs.jsonunit.assertj.assertThatJson
+import okhttp3.mockwebserver.MockResponse
+import okhttp3.mockwebserver.MockWebServer
+import org.ccci.gto.android.common.jsonapi.retrofit2.JsonApiConverterFactory
+import org.cru.godtools.api.UserFavoriteToolsApi.Companion.PATH_FAVORITE_TOOLS
+import org.cru.godtools.model.Tool
+import org.junit.Rule
+import retrofit2.Retrofit
+
+private const val JSON_RESPONSE_FAVORITES = "{data:[{id:5,type:\"resource\"}]}"
+
+class UserFavoriteToolsApiTest {
+    @get:Rule
+    val server = MockWebServer()
+
+    private var api = Retrofit.Builder()
+        .baseUrl(server.url("/"))
+        .addConverterFactory(JsonApiConverterFactory(Tool::class.java))
+        .build()
+        .create(UserFavoriteToolsApi::class.java)
+
+    @Test
+    fun `removeFavoriteTools()`() = runTest {
+        server.enqueue(MockResponse().setBody(JSON_RESPONSE_FAVORITES))
+
+        val resp = api.removeFavoriteTools(tools = listOf(Tool("en") { id = 1 })).body()!!.data.single()
+        assertNotNull(resp) { assertEquals(5, it.id) }
+
+        val request = server.takeRequest()
+        assertEquals("DELETE", request.method)
+        assertEquals("/$PATH_FAVORITE_TOOLS", request.path)
+        assertThatJson(request.body.readUtf8()) {
+            isObject
+            node("data").isArray.hasSize(1)
+            node("data[0].id").isEqualTo(1)
+            node("data[0].attributes").isAbsent()
+            node("data[0].relationships").isAbsent()
+        }
+    }
+}