diff --git a/app/src/main/kotlin/com/x8bit/bitwarden/data/platform/datasource/network/di/PlatformNetworkModule.kt b/app/src/main/kotlin/com/x8bit/bitwarden/data/platform/datasource/network/di/PlatformNetworkModule.kt
index ed54531db2c..406fb7de784 100644
--- a/app/src/main/kotlin/com/x8bit/bitwarden/data/platform/datasource/network/di/PlatformNetworkModule.kt
+++ b/app/src/main/kotlin/com/x8bit/bitwarden/data/platform/datasource/network/di/PlatformNetworkModule.kt
@@ -7,6 +7,7 @@ import com.bitwarden.network.interceptor.BaseUrlsProvider
 import com.bitwarden.network.model.BitwardenServiceClientConfig
 import com.bitwarden.network.service.ConfigService
 import com.bitwarden.network.service.EventService
+import com.bitwarden.network.service.FillAssistService
 import com.bitwarden.network.service.PushService
 import com.x8bit.bitwarden.data.auth.datasource.disk.AuthDiskSource
 import com.x8bit.bitwarden.data.auth.manager.AuthTokenManager
@@ -32,6 +33,12 @@ import javax.inject.Singleton
 @InstallIn(SingletonComponent::class)
 object PlatformNetworkModule {
 
+    @Provides
+    @Singleton
+    fun providesFillAssistService(
+        bitwardenServiceClient: BitwardenServiceClient,
+    ): FillAssistService = bitwardenServiceClient.fillAssistService
+
     @Provides
     @Singleton
     fun providesConfigService(
diff --git a/app/src/test/kotlin/com/x8bit/bitwarden/data/auth/repository/AuthRepositoryTest.kt b/app/src/test/kotlin/com/x8bit/bitwarden/data/auth/repository/AuthRepositoryTest.kt
index d0b7dd2f488..908fdbe3e70 100644
--- a/app/src/test/kotlin/com/x8bit/bitwarden/data/auth/repository/AuthRepositoryTest.kt
+++ b/app/src/test/kotlin/com/x8bit/bitwarden/data/auth/repository/AuthRepositoryTest.kt
@@ -8106,6 +8106,7 @@ class AuthRepositoryTest {
                     identityUrl = "mockIdentityUrl",
                     notificationsUrl = "mockNotificationsUrl",
                     ssoUrl = "mockSsoUrl",
+                    fillAssistRulesUrl = null,
                 ),
                 featureStates = emptyMap(),
                 communication = null,
diff --git a/app/src/test/kotlin/com/x8bit/bitwarden/data/platform/datasource/sdk/ServerCommunicationConfigRepositoryTest.kt b/app/src/test/kotlin/com/x8bit/bitwarden/data/platform/datasource/sdk/ServerCommunicationConfigRepositoryTest.kt
index 8b2c98eff0f..82368ce2fc2 100644
--- a/app/src/test/kotlin/com/x8bit/bitwarden/data/platform/datasource/sdk/ServerCommunicationConfigRepositoryTest.kt
+++ b/app/src/test/kotlin/com/x8bit/bitwarden/data/platform/datasource/sdk/ServerCommunicationConfigRepositoryTest.kt
@@ -62,6 +62,7 @@ class ServerCommunicationConfigRepositoryTest {
                     identityUrl = null,
                     notificationsUrl = null,
                     ssoUrl = null,
+                    fillAssistRulesUrl = null,
                 ),
                 featureStates = null,
                 communication = ConfigResponseJson.CommunicationJson(
diff --git a/app/src/test/kotlin/com/x8bit/bitwarden/data/platform/manager/FeatureFlagManagerTest.kt b/app/src/test/kotlin/com/x8bit/bitwarden/data/platform/manager/FeatureFlagManagerTest.kt
index 2228c33b6a8..aeceb2ef29f 100644
--- a/app/src/test/kotlin/com/x8bit/bitwarden/data/platform/manager/FeatureFlagManagerTest.kt
+++ b/app/src/test/kotlin/com/x8bit/bitwarden/data/platform/manager/FeatureFlagManagerTest.kt
@@ -319,6 +319,7 @@ private val SERVER_CONFIG = ServerConfig(
             identityUrl = "http://localhost:33656",
             notificationsUrl = "http://localhost:61840",
             ssoUrl = "http://localhost:51822",
+            fillAssistRulesUrl = null,
         ),
         featureStates = mapOf(
             "dummy-boolean" to JsonPrimitive(true),
diff --git a/app/src/test/kotlin/com/x8bit/bitwarden/data/platform/repository/util/FakeServerConfigRepository.kt b/app/src/test/kotlin/com/x8bit/bitwarden/data/platform/repository/util/FakeServerConfigRepository.kt
index 07055353b56..5ce969386af 100644
--- a/app/src/test/kotlin/com/x8bit/bitwarden/data/platform/repository/util/FakeServerConfigRepository.kt
+++ b/app/src/test/kotlin/com/x8bit/bitwarden/data/platform/repository/util/FakeServerConfigRepository.kt
@@ -48,6 +48,7 @@ private val SERVER_CONFIG = ServerConfig(
             identityUrl = "http://localhost:33656",
             notificationsUrl = "http://localhost:61840",
             ssoUrl = "http://localhost:51822",
+            fillAssistRulesUrl = null,
         ),
         featureStates = mapOf(
             "duo-redirect" to JsonPrimitive(true),
diff --git a/authenticator/src/test/kotlin/com/bitwarden/authenticator/data/platform/manager/FeatureFlagManagerTest.kt b/authenticator/src/test/kotlin/com/bitwarden/authenticator/data/platform/manager/FeatureFlagManagerTest.kt
index b8e29a72510..ef0545cee72 100644
--- a/authenticator/src/test/kotlin/com/bitwarden/authenticator/data/platform/manager/FeatureFlagManagerTest.kt
+++ b/authenticator/src/test/kotlin/com/bitwarden/authenticator/data/platform/manager/FeatureFlagManagerTest.kt
@@ -262,6 +262,7 @@ private val SERVER_CONFIG = ServerConfig(
             identityUrl = "http://localhost:33656",
             notificationsUrl = "http://localhost:61840",
             ssoUrl = "http://localhost:51822",
+            fillAssistRulesUrl = null,
         ),
         featureStates = mapOf(
             "dummy-boolean" to JsonPrimitive(true),
diff --git a/authenticator/src/test/kotlin/com/bitwarden/authenticator/data/platform/repository/util/FakeServerConfigRepository.kt b/authenticator/src/test/kotlin/com/bitwarden/authenticator/data/platform/repository/util/FakeServerConfigRepository.kt
index aaf0ffa2c1b..e7e5ad94f60 100644
--- a/authenticator/src/test/kotlin/com/bitwarden/authenticator/data/platform/repository/util/FakeServerConfigRepository.kt
+++ b/authenticator/src/test/kotlin/com/bitwarden/authenticator/data/platform/repository/util/FakeServerConfigRepository.kt
@@ -48,6 +48,7 @@ private val SERVER_CONFIG = ServerConfig(
             identityUrl = "http://localhost:33656",
             notificationsUrl = "http://localhost:61840",
             ssoUrl = "http://localhost:51822",
+            fillAssistRulesUrl = null,
         ),
         featureStates = mapOf(
             "duo-redirect" to JsonPrimitive(true),
diff --git a/data/src/test/kotlin/com/bitwarden/data/datasource/disk/ConfigDiskSourceTest.kt b/data/src/test/kotlin/com/bitwarden/data/datasource/disk/ConfigDiskSourceTest.kt
index 6093171fbe7..062d57b5624 100644
--- a/data/src/test/kotlin/com/bitwarden/data/datasource/disk/ConfigDiskSourceTest.kt
+++ b/data/src/test/kotlin/com/bitwarden/data/datasource/disk/ConfigDiskSourceTest.kt
@@ -107,6 +107,7 @@ private val SERVER_CONFIG = ServerConfig(
             identityUrl = "http://localhost:33656",
             notificationsUrl = "http://localhost:61840",
             ssoUrl = "http://localhost:51822",
+            fillAssistRulesUrl = null,
         ),
         featureStates = mapOf(
             "duo-redirect" to JsonPrimitive(true),
diff --git a/data/src/test/kotlin/com/bitwarden/data/repository/ServerConfigRepositoryTest.kt b/data/src/test/kotlin/com/bitwarden/data/repository/ServerConfigRepositoryTest.kt
index 4e32741fb5e..abc7c4963fe 100644
--- a/data/src/test/kotlin/com/bitwarden/data/repository/ServerConfigRepositoryTest.kt
+++ b/data/src/test/kotlin/com/bitwarden/data/repository/ServerConfigRepositoryTest.kt
@@ -161,6 +161,7 @@ private val SERVER_CONFIG = ServerConfig(
             identityUrl = "http://localhost:33656",
             notificationsUrl = "http://localhost:61840",
             ssoUrl = "http://localhost:51822",
+            fillAssistRulesUrl = null,
         ),
         featureStates = mapOf(
             "duo-redirect" to JsonPrimitive(true),
@@ -185,6 +186,7 @@ private val CONFIG_RESPONSE_JSON = ConfigResponseJson(
         identityUrl = "http://localhost:33656",
         notificationsUrl = "http://localhost:61840",
         ssoUrl = "http://localhost:51822",
+        fillAssistRulesUrl = null,
     ),
     featureStates = mapOf(
         "duo-redirect" to JsonPrimitive(true),
diff --git a/network/src/main/kotlin/com/bitwarden/network/BitwardenServiceClient.kt b/network/src/main/kotlin/com/bitwarden/network/BitwardenServiceClient.kt
index 1824ea01a28..e1b0203a055 100644
--- a/network/src/main/kotlin/com/bitwarden/network/BitwardenServiceClient.kt
+++ b/network/src/main/kotlin/com/bitwarden/network/BitwardenServiceClient.kt
@@ -16,6 +16,7 @@ import com.bitwarden.network.service.DevicesService
 import com.bitwarden.network.service.DigitalAssetLinkService
 import com.bitwarden.network.service.DownloadService
 import com.bitwarden.network.service.EventService
+import com.bitwarden.network.service.FillAssistService
 import com.bitwarden.network.service.FolderService
 import com.bitwarden.network.service.HaveIBeenPwnedService
 import com.bitwarden.network.service.IdentityService
@@ -107,6 +108,11 @@ interface BitwardenServiceClient {
      */
     val eventService: EventService
 
+    /**
+     * Provides access to the Fill-Assist service.
+     */
+    val fillAssistService: FillAssistService
+
     /**
      * Provides access to the Folder service.
      */
diff --git a/network/src/main/kotlin/com/bitwarden/network/BitwardenServiceClientImpl.kt b/network/src/main/kotlin/com/bitwarden/network/BitwardenServiceClientImpl.kt
index f054cb3e010..7afab54ab64 100644
--- a/network/src/main/kotlin/com/bitwarden/network/BitwardenServiceClientImpl.kt
+++ b/network/src/main/kotlin/com/bitwarden/network/BitwardenServiceClientImpl.kt
@@ -29,6 +29,8 @@ import com.bitwarden.network.service.DownloadService
 import com.bitwarden.network.service.DownloadServiceImpl
 import com.bitwarden.network.service.EventService
 import com.bitwarden.network.service.EventServiceImpl
+import com.bitwarden.network.service.FillAssistService
+import com.bitwarden.network.service.FillAssistServiceImpl
 import com.bitwarden.network.service.FolderService
 import com.bitwarden.network.service.FolderServiceImpl
 import com.bitwarden.network.service.HaveIBeenPwnedService
@@ -155,6 +157,12 @@ internal class BitwardenServiceClientImpl(
         )
     }
 
+    override val fillAssistService: FillAssistService by lazy {
+        FillAssistServiceImpl(
+            api = retrofits.createStaticRetrofit().create(),
+        )
+    }
+
     override val haveIBeenPwnedService: HaveIBeenPwnedService by lazy {
         HaveIBeenPwnedServiceImpl(
             api = retrofits
diff --git a/network/src/main/kotlin/com/bitwarden/network/api/FillAssistApi.kt b/network/src/main/kotlin/com/bitwarden/network/api/FillAssistApi.kt
new file mode 100644
index 00000000000..0ca1c93d239
--- /dev/null
+++ b/network/src/main/kotlin/com/bitwarden/network/api/FillAssistApi.kt
@@ -0,0 +1,29 @@
+package com.bitwarden.network.api
+
+import com.bitwarden.network.model.FillAssistFormsJson
+import com.bitwarden.network.model.FillAssistManifestJson
+import com.bitwarden.network.model.NetworkResult
+import retrofit2.http.GET
+import retrofit2.http.Url
+
+/**
+ * Defines endpoints for retrieving fill-assist targeting rules from the fill-assist service.
+ * Uses [Url] to support the dynamic base URL provided by server config at runtime.
+ */
+internal interface FillAssistApi {
+    /**
+     * Fetches the fill-assist manifest from the given [url].
+     */
+    @GET
+    suspend fun getManifest(
+        @Url url: String,
+    ): NetworkResult<FillAssistManifestJson>
+
+    /**
+     * Fetches and decodes the forms rules file from [url].
+     */
+    @GET
+    suspend fun getForms(
+        @Url url: String,
+    ): NetworkResult<FillAssistFormsJson>
+}
diff --git a/network/src/main/kotlin/com/bitwarden/network/model/ConfigResponseJson.kt b/network/src/main/kotlin/com/bitwarden/network/model/ConfigResponseJson.kt
index d0cb32cf9a2..834ab78bf32 100644
--- a/network/src/main/kotlin/com/bitwarden/network/model/ConfigResponseJson.kt
+++ b/network/src/main/kotlin/com/bitwarden/network/model/ConfigResponseJson.kt
@@ -82,6 +82,9 @@ data class ConfigResponseJson(
 
         @SerialName("sso")
         val ssoUrl: String?,
+
+        @SerialName("fillAssistRules")
+        val fillAssistRulesUrl: String?,
     )
 
     /**
diff --git a/network/src/main/kotlin/com/bitwarden/network/model/FillAssistFormsJson.kt b/network/src/main/kotlin/com/bitwarden/network/model/FillAssistFormsJson.kt
new file mode 100644
index 00000000000..9f56cca659a
--- /dev/null
+++ b/network/src/main/kotlin/com/bitwarden/network/model/FillAssistFormsJson.kt
@@ -0,0 +1,68 @@
+package com.bitwarden.network.model
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.JsonElement
+
+/**
+ * Represents the fill-assist forms rules file.
+ *
+ * @property schemaVersion The semantic version string for this file (e.g. "1.0.0").
+ * @property hosts Map of hostname (optionally with port) to [HostEntryJson], or null if the host
+ * is explicitly excluded from fill-assist.
+ */
+@Serializable
+data class FillAssistFormsJson(
+    @SerialName("schemaVersion")
+    val schemaVersion: String? = null,
+
+    @SerialName("hosts")
+    val hosts: Map<String, HostEntryJson?>? = null,
+) {
+    /**
+     * Form descriptions and pathname-specific overrides for a single host.
+     *
+     * @property forms Site-wide fallback form descriptions.
+     * @property pathnames Pathname-specific overrides; a null value means that path is excluded.
+     */
+    @Serializable
+    data class HostEntryJson(
+        @SerialName("forms")
+        val forms: List<FormJson>? = null,
+
+        @SerialName("pathnames")
+        val pathnames: Map<String, PathnameEntryJson?>? = null,
+    )
+
+    /**
+     * Form descriptions for a specific pathname.
+     *
+     * @property forms The form descriptions for this path.
+     */
+    @Serializable
+    data class PathnameEntryJson(
+        @SerialName("forms")
+        val forms: List<FormJson>? = null,
+    )
+
+    /**
+     * Describes one logical form on a page.
+     *
+     * @property category The categorical purpose of this form (e.g. "account-login").
+     * @property container Optional CSS selectors identifying the form's container element.
+     * @property fields Map of field key to [JsonElement] representing a compositeSelectorArray.
+     * Each array element is either a CSS selector string or an array of strings for composite
+     * multi-input fields. Unknown fields are gracefully ignored via [ignoreUnknownKeys].
+     */
+    @Serializable
+    data class FormJson(
+        @SerialName("category")
+        val category: String? = null,
+
+        @SerialName("container")
+        val container: List<String>? = null,
+
+        @SerialName("fields")
+        val fields: Map<String, JsonElement>? = null,
+    )
+}
diff --git a/network/src/main/kotlin/com/bitwarden/network/model/FillAssistManifestJson.kt b/network/src/main/kotlin/com/bitwarden/network/model/FillAssistManifestJson.kt
new file mode 100644
index 00000000000..460039ff032
--- /dev/null
+++ b/network/src/main/kotlin/com/bitwarden/network/model/FillAssistManifestJson.kt
@@ -0,0 +1,64 @@
+package com.bitwarden.network.model
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+/**
+ * Represents the fill-assist manifest returned by the fill-assist service.
+ *
+ * @property buildId The unique identifier for this build.
+ * @property timestamp The ISO-8601 timestamp when this build was produced.
+ * @property gitSha The git commit SHA for this build.
+ * @property maps The map data entries keyed by map type.
+ */
+@Serializable
+data class FillAssistManifestJson(
+    @SerialName("buildId")
+    val buildId: String? = null,
+
+    @SerialName("timestamp")
+    val timestamp: String? = null,
+
+    @SerialName("gitSha")
+    val gitSha: String? = null,
+
+    @SerialName("maps")
+    val maps: MapsJson? = null,
+) {
+    /**
+     * Container for all available maps.
+     *
+     * @property forms Map of schema version string (e.g. "v1", "v2") to [FileEntryJson].
+     * Using a [Map] allows new versions to appear automatically without model changes.
+     */
+    @Serializable
+    data class MapsJson(
+        @SerialName("forms")
+        val forms: Map<String, FileEntryJson?>?,
+    )
+
+    /**
+     * Metadata for a single versioned file in a map.
+     *
+     * @property filename The filename to fetch (e.g. "forms.v0.json").
+     * @property cid The SHA-256 content hash in "sha256:<hex>" format. Used as a staleness key
+     * to detect when the forms file has changed on the server, avoiding unnecessary re-downloads.
+     * @property schema The schema filename associated with this file version.
+     * @property deprecated When true, this version has entered its end-of-life support window.
+     * Consumers should plan migration but may continue using the version until it is removed.
+     */
+    @Serializable
+    data class FileEntryJson(
+        @SerialName("filename")
+        val filename: String? = null,
+
+        @SerialName("cid")
+        val cid: String? = null,
+
+        @SerialName("schema")
+        val schema: String? = null,
+
+        @SerialName("deprecated")
+        val deprecated: Boolean? = null,
+    )
+}
diff --git a/network/src/main/kotlin/com/bitwarden/network/service/FillAssistService.kt b/network/src/main/kotlin/com/bitwarden/network/service/FillAssistService.kt
new file mode 100644
index 00000000000..007a25f13df
--- /dev/null
+++ b/network/src/main/kotlin/com/bitwarden/network/service/FillAssistService.kt
@@ -0,0 +1,22 @@
+package com.bitwarden.network.service
+
+import com.bitwarden.network.model.FillAssistFormsJson
+import com.bitwarden.network.model.FillAssistManifestJson
+
+/**
+ * Provides access to the fill-assist targeting rules service.
+ */
+interface FillAssistService {
+    /**
+     * Fetches and parses the fill-assist manifest from [url].
+     */
+    suspend fun getManifest(url: String): Result<FillAssistManifestJson>
+
+    /**
+     * Downloads and parses the forms rules file from [formsUrl].
+     *
+     * Returns [Result.failure] if the network request fails or parsing fails.
+     * Version-agnostic: any forms file URL can be passed regardless of schema version.
+     */
+    suspend fun getForms(formsUrl: String): Result<FillAssistFormsJson>
+}
diff --git a/network/src/main/kotlin/com/bitwarden/network/service/FillAssistServiceImpl.kt b/network/src/main/kotlin/com/bitwarden/network/service/FillAssistServiceImpl.kt
new file mode 100644
index 00000000000..7668e4b346b
--- /dev/null
+++ b/network/src/main/kotlin/com/bitwarden/network/service/FillAssistServiceImpl.kt
@@ -0,0 +1,20 @@
+package com.bitwarden.network.service
+
+import com.bitwarden.network.api.FillAssistApi
+import com.bitwarden.network.model.FillAssistFormsJson
+import com.bitwarden.network.model.FillAssistManifestJson
+import com.bitwarden.network.util.toResult
+
+/**
+ * Default implementation of [FillAssistService].
+ */
+internal class FillAssistServiceImpl(
+    private val api: FillAssistApi,
+) : FillAssistService {
+
+    override suspend fun getManifest(url: String): Result<FillAssistManifestJson> =
+        api.getManifest(url = url).toResult()
+
+    override suspend fun getForms(formsUrl: String): Result<FillAssistFormsJson> =
+        api.getForms(url = formsUrl).toResult()
+}
diff --git a/network/src/test/kotlin/com/bitwarden/network/model/FillAssistFormsJsonTest.kt b/network/src/test/kotlin/com/bitwarden/network/model/FillAssistFormsJsonTest.kt
new file mode 100644
index 00000000000..532154fbb98
--- /dev/null
+++ b/network/src/test/kotlin/com/bitwarden/network/model/FillAssistFormsJsonTest.kt
@@ -0,0 +1,305 @@
+package com.bitwarden.network.model
+
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonArray
+import kotlinx.serialization.json.JsonPrimitive
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertNull
+import org.junit.jupiter.api.Test
+
+class FillAssistFormsJsonTest {
+
+    private val json = Json { ignoreUnknownKeys = true }
+
+    @Test
+    fun `deserialize simple login form`() {
+        assertEquals(
+            SIMPLE_LOGIN_FORMS,
+            json.decodeFromString<FillAssistFormsJson>(SIMPLE_LOGIN_JSON),
+        )
+    }
+
+    @Test
+    fun `deserialize host with null value is excluded host`() {
+        val result = json.decodeFromString<FillAssistFormsJson>(NULL_HOST_JSON)
+        assertNull(result.hosts?.get("excluded.com"))
+    }
+
+    @Test
+    fun `deserialize null pathname is excluded path`() {
+        val result = json.decodeFromString<FillAssistFormsJson>(NULL_PATHNAME_JSON)
+        assertNull(result.hosts?.get("example.com")?.pathnames?.get("/excluded"))
+    }
+
+    @Test
+    fun `deserialize composite OTP field`() {
+        assertEquals(
+            OTP_FORMS,
+            json.decodeFromString<FillAssistFormsJson>(OTP_JSON),
+        )
+    }
+
+    @Test
+    fun `deserialize compound selector with multiple alternatives`() {
+        assertEquals(
+            HONEYPOT_FORMS,
+            json.decodeFromString<FillAssistFormsJson>(HONEYPOT_JSON),
+        )
+    }
+
+    @Test
+    fun `deserialize form with container`() {
+        assertEquals(
+            CONTAINER_FORMS,
+            json.decodeFromString<FillAssistFormsJson>(CONTAINER_JSON),
+        )
+    }
+
+    @Test
+    fun `deserialize form with actions field is graceful`() {
+        // actions is intentionally excluded from FormJson — handled by ignoreUnknownKeys.
+        assertEquals(
+            SIMPLE_LOGIN_FORMS,
+            json.decodeFromString<FillAssistFormsJson>(SIMPLE_LOGIN_WITH_ACTIONS_JSON),
+        )
+    }
+}
+
+private val SIMPLE_LOGIN_FORMS = FillAssistFormsJson(
+    schemaVersion = "1.0.0",
+    hosts = mapOf(
+        "example.com" to FillAssistFormsJson.HostEntryJson(
+            forms = listOf(
+                FillAssistFormsJson.FormJson(
+                    category = "account-login",
+                    container = null,
+                    fields = mapOf(
+                        "username" to JsonArray(listOf(JsonPrimitive("input#username"))),
+                        "password" to JsonArray(listOf(JsonPrimitive("input#password"))),
+                    ),
+                ),
+            ),
+            pathnames = null,
+        ),
+    ),
+)
+
+private val OTP_FORMS = FillAssistFormsJson(
+    schemaVersion = "1.0.0",
+    hosts = mapOf(
+        "example.com" to FillAssistFormsJson.HostEntryJson(
+            forms = null,
+            pathnames = mapOf(
+                "/login" to FillAssistFormsJson.PathnameEntryJson(
+                    forms = listOf(
+                        FillAssistFormsJson.FormJson(
+                            category = "account-login",
+                            container = null,
+                            fields = mapOf(
+                                "oneTimeCode" to JsonArray(
+                                    listOf(
+                                        JsonArray(
+                                            listOf(
+                                                JsonPrimitive("input[name='otp-0']"),
+                                                JsonPrimitive("input[name='otp-1']"),
+                                                JsonPrimitive("input[name='otp-2']"),
+                                                JsonPrimitive("input[name='otp-3']"),
+                                                JsonPrimitive("input[name='otp-4']"),
+                                                JsonPrimitive("input[name='otp-5']"),
+                                            ),
+                                        ),
+                                    ),
+                                ),
+                            ),
+                        ),
+                    ),
+                ),
+            ),
+        ),
+    ),
+)
+
+private val HONEYPOT_FORMS = FillAssistFormsJson(
+    schemaVersion = "1.0.0",
+    hosts = mapOf(
+        "example.com" to FillAssistFormsJson.HostEntryJson(
+            forms = listOf(
+                FillAssistFormsJson.FormJson(
+                    category = "account-login",
+                    container = null,
+                    fields = mapOf(
+                        "username" to JsonArray(
+                            listOf(
+                                JsonPrimitive("input#password[name='password']"),
+                                JsonPrimitive("input[name='password']"),
+                            ),
+                        ),
+                        "password" to JsonArray(
+                            listOf(
+                                JsonPrimitive("input#username[name='username']"),
+                                JsonPrimitive("input[name='username']"),
+                            ),
+                        ),
+                    ),
+                ),
+            ),
+            pathnames = null,
+        ),
+    ),
+)
+
+private val CONTAINER_FORMS = FillAssistFormsJson(
+    schemaVersion = "1.0.0",
+    hosts = mapOf(
+        "example.com" to FillAssistFormsJson.HostEntryJson(
+            forms = null,
+            pathnames = mapOf(
+                "/login" to FillAssistFormsJson.PathnameEntryJson(
+                    forms = listOf(
+                        FillAssistFormsJson.FormJson(
+                            category = "account-login",
+                            container = listOf("div#login-container"),
+                            fields = mapOf(
+                                "username" to JsonArray(listOf(JsonPrimitive("input#user"))),
+                                "password" to JsonArray(listOf(JsonPrimitive("input#pass"))),
+                            ),
+                        ),
+                    ),
+                ),
+            ),
+        ),
+    ),
+)
+
+private const val SIMPLE_LOGIN_JSON = """
+{
+  "schemaVersion": "1.0.0",
+  "hosts": {
+    "example.com": {
+      "forms": [
+        {
+          "category": "account-login",
+          "fields": {
+            "username": ["input#username"],
+            "password": ["input#password"]
+          }
+        }
+      ]
+    }
+  }
+}
+"""
+
+private const val NULL_HOST_JSON = """
+{
+  "schemaVersion": "1.0.0",
+  "hosts": {
+    "excluded.com": null
+  }
+}
+"""
+
+private const val NULL_PATHNAME_JSON = """
+{
+  "schemaVersion": "1.0.0",
+  "hosts": {
+    "example.com": {
+      "pathnames": {
+        "/excluded": null
+      }
+    }
+  }
+}
+"""
+
+private const val OTP_JSON = """
+{
+  "schemaVersion": "1.0.0",
+  "hosts": {
+    "example.com": {
+      "pathnames": {
+        "/login": {
+          "forms": [
+            {
+              "category": "account-login",
+              "fields": {
+                "oneTimeCode": [
+                  ["input[name='otp-0']","input[name='otp-1']","input[name='otp-2']",
+                   "input[name='otp-3']","input[name='otp-4']","input[name='otp-5']"]
+                ]
+              }
+            }
+          ]
+        }
+      }
+    }
+  }
+}
+"""
+
+private const val HONEYPOT_JSON = """
+{
+  "schemaVersion": "1.0.0",
+  "hosts": {
+    "example.com": {
+      "forms": [
+        {
+          "category": "account-login",
+          "fields": {
+            "username": ["input#password[name='password']", "input[name='password']"],
+            "password": ["input#username[name='username']", "input[name='username']"]
+          }
+        }
+      ]
+    }
+  }
+}
+"""
+
+private const val CONTAINER_JSON = """
+{
+  "schemaVersion": "1.0.0",
+  "hosts": {
+    "example.com": {
+      "pathnames": {
+        "/login": {
+          "forms": [
+            {
+              "category": "account-login",
+              "container": ["div#login-container"],
+              "fields": {
+                "username": ["input#user"],
+                "password": ["input#pass"]
+              }
+            }
+          ]
+        }
+      }
+    }
+  }
+}
+"""
+
+// Same structure as SIMPLE_LOGIN_JSON with the actions field present — verifies that
+// actions (intentionally omitted from FormJson) is handled by ignoreUnknownKeys = true.
+private const val SIMPLE_LOGIN_WITH_ACTIONS_JSON = """
+{
+  "schemaVersion": "1.0.0",
+  "hosts": {
+    "example.com": {
+      "forms": [
+        {
+          "category": "account-login",
+          "fields": {
+            "username": ["input#username"],
+            "password": ["input#password"]
+          },
+          "actions": {
+            "submit": ["button#submit"]
+          }
+        }
+      ]
+    }
+  }
+}
+"""
diff --git a/network/src/test/kotlin/com/bitwarden/network/model/FillAssistManifestJsonTest.kt b/network/src/test/kotlin/com/bitwarden/network/model/FillAssistManifestJsonTest.kt
new file mode 100644
index 00000000000..4aac50c46ad
--- /dev/null
+++ b/network/src/test/kotlin/com/bitwarden/network/model/FillAssistManifestJsonTest.kt
@@ -0,0 +1,165 @@
+package com.bitwarden.network.model
+
+import kotlinx.serialization.json.Json
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertNull
+import org.junit.jupiter.api.Test
+
+class FillAssistManifestJsonTest {
+
+    private val json = Json { ignoreUnknownKeys = true }
+
+    @Test
+    fun `deserialize full manifest with v0 entry`() {
+        assertEquals(
+            FULL_MANIFEST,
+            json.decodeFromString<FillAssistManifestJson>(MANIFEST_JSON),
+        )
+    }
+
+    @Test
+    fun `deserialize manifest with multiple version entries`() {
+        assertEquals(
+            MULTI_VERSION_MANIFEST,
+            json.decodeFromString<FillAssistManifestJson>(MANIFEST_MULTI_VERSION_JSON),
+        )
+    }
+
+    @Test
+    fun `deserialize manifest with unknown top-level fields is graceful`() {
+        assertEquals(
+            FULL_MANIFEST,
+            json.decodeFromString<FillAssistManifestJson>(MANIFEST_EXTRA_FIELDS_JSON),
+        )
+    }
+
+    @Test
+    fun `deserialize minimal manifest with null fields`() {
+        val result = json.decodeFromString<FillAssistManifestJson>("{}")
+        assertNull(result.buildId)
+        assertNull(result.maps)
+    }
+
+    @Test
+    fun `deserialize manifest with deprecated version entry`() {
+        assertEquals(
+            DEPRECATED_MANIFEST,
+            json.decodeFromString<FillAssistManifestJson>(MANIFEST_DEPRECATED_JSON),
+        )
+    }
+}
+
+private val FULL_MANIFEST = FillAssistManifestJson(
+    buildId = "local-build",
+    timestamp = "2026-05-20T15:01:02.956Z",
+    gitSha = "abc123",
+    maps = FillAssistManifestJson.MapsJson(
+        forms = mapOf(
+            "v0" to FillAssistManifestJson.FileEntryJson(
+                filename = "forms.v0.json",
+                cid = "sha256:abc123def456",
+                schema = "forms.v0.schema.json",
+            ),
+        ),
+    ),
+)
+
+private val MULTI_VERSION_MANIFEST = FillAssistManifestJson(
+    buildId = "local-build",
+    timestamp = null,
+    gitSha = null,
+    maps = FillAssistManifestJson.MapsJson(
+        forms = mapOf(
+            "v0" to FillAssistManifestJson.FileEntryJson(
+                filename = "forms.v0.json",
+                cid = "sha256:aaa",
+                schema = "forms.v0.schema.json",
+            ),
+            "v1" to FillAssistManifestJson.FileEntryJson(
+                filename = "forms.v1.json",
+                cid = "sha256:bbb",
+                schema = "forms.v1.schema.json",
+            ),
+        ),
+    ),
+)
+
+private const val MANIFEST_JSON = """
+{
+  "buildId": "local-build",
+  "timestamp": "2026-05-20T15:01:02.956Z",
+  "gitSha": "abc123",
+  "maps": {
+    "forms": {
+      "v0": {
+        "filename": "forms.v0.json",
+        "cid": "sha256:abc123def456",
+        "schema": "forms.v0.schema.json"
+      }
+    }
+  }
+}
+"""
+
+private const val MANIFEST_MULTI_VERSION_JSON = """
+{
+  "buildId": "local-build",
+  "maps": {
+    "forms": {
+      "v0": { "filename": "forms.v0.json", "cid": "sha256:aaa", "schema": "forms.v0.schema.json" },
+      "v1": { "filename": "forms.v1.json", "cid": "sha256:bbb", "schema": "forms.v1.schema.json" }
+    }
+  }
+}
+"""
+
+private val DEPRECATED_MANIFEST = FillAssistManifestJson(
+    buildId = "local-build",
+    timestamp = null,
+    gitSha = null,
+    maps = FillAssistManifestJson.MapsJson(
+        forms = mapOf(
+            "v0" to FillAssistManifestJson.FileEntryJson(
+                filename = "forms.v0.json",
+                cid = "sha256:abc123def456",
+                schema = "forms.v0.schema.json",
+                deprecated = true,
+            ),
+        ),
+    ),
+)
+
+private const val MANIFEST_DEPRECATED_JSON = """
+{
+  "buildId": "local-build",
+  "maps": {
+    "forms": {
+      "v0": {
+        "filename": "forms.v0.json",
+        "cid": "sha256:abc123def456",
+        "schema": "forms.v0.schema.json",
+        "deprecated": true
+      }
+    }
+  }
+}
+"""
+
+// Same structure as MANIFEST_JSON with an extra unknown key — verifies ignoreUnknownKeys = true.
+private const val MANIFEST_EXTRA_FIELDS_JSON = """
+{
+  "buildId": "local-build",
+  "timestamp": "2026-05-20T15:01:02.956Z",
+  "gitSha": "abc123",
+  "checksums": "ignored",
+  "maps": {
+    "forms": {
+      "v0": {
+        "filename": "forms.v0.json",
+        "cid": "sha256:abc123def456",
+        "schema": "forms.v0.schema.json"
+      }
+    }
+  }
+}
+"""
diff --git a/network/src/test/kotlin/com/bitwarden/network/service/ConfigServiceTest.kt b/network/src/test/kotlin/com/bitwarden/network/service/ConfigServiceTest.kt
index f6d3b757ab9..0a0380c3776 100644
--- a/network/src/test/kotlin/com/bitwarden/network/service/ConfigServiceTest.kt
+++ b/network/src/test/kotlin/com/bitwarden/network/service/ConfigServiceTest.kt
@@ -68,6 +68,7 @@ private val CONFIG_RESPONSE = ConfigResponseJson(
         notificationsUrl = "notificationsUrl",
         identityUrl = "identityUrl",
         ssoUrl = "ssoUrl",
+        fillAssistRulesUrl = null,
     ),
     featureStates = mapOf(
         "feature one" to JsonPrimitive(false),
diff --git a/network/src/test/kotlin/com/bitwarden/network/service/FillAssistServiceTest.kt b/network/src/test/kotlin/com/bitwarden/network/service/FillAssistServiceTest.kt
new file mode 100644
index 00000000000..80e625716d6
--- /dev/null
+++ b/network/src/test/kotlin/com/bitwarden/network/service/FillAssistServiceTest.kt
@@ -0,0 +1,115 @@
+package com.bitwarden.network.service
+
+import com.bitwarden.core.data.util.asSuccess
+import com.bitwarden.network.api.FillAssistApi
+import com.bitwarden.network.base.BaseServiceTest
+import com.bitwarden.network.model.FillAssistFormsJson
+import com.bitwarden.network.model.FillAssistManifestJson
+import kotlinx.coroutines.test.runTest
+import kotlinx.serialization.json.JsonArray
+import kotlinx.serialization.json.JsonPrimitive
+import okhttp3.mockwebserver.MockResponse
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Test
+import retrofit2.create
+
+class FillAssistServiceTest : BaseServiceTest() {
+
+    private val api: FillAssistApi = retrofit.create()
+    private val service = FillAssistServiceImpl(api = api)
+
+    @Test
+    fun `getManifest should parse manifest response`() = runTest {
+        server.enqueue(MockResponse().setBody(MANIFEST_JSON))
+        assertEquals(MANIFEST.asSuccess(), service.getManifest(url = "$urlPrefix/manifest.json"))
+    }
+
+    @Test
+    fun `getManifest should return failure on server error`() = runTest {
+        server.enqueue(MockResponse().setResponseCode(500))
+        assertTrue(service.getManifest(url = "$urlPrefix/manifest.json").isFailure)
+    }
+
+    @Test
+    fun `getForms should parse and return forms`() = runTest {
+        server.enqueue(MockResponse().setBody(FORMS_V1_JSON))
+        assertEquals(FORMS_V1.asSuccess(), service.getForms(formsUrl = "$urlPrefix/forms.v1.json"))
+    }
+
+    @Test
+    fun `getForms should return failure on server error`() = runTest {
+        server.enqueue(MockResponse().setResponseCode(404))
+        assertTrue(service.getForms(formsUrl = "$urlPrefix/forms.v1.json").isFailure)
+    }
+}
+
+private val MANIFEST = FillAssistManifestJson(
+    buildId = "local-build",
+    timestamp = "2026-05-20T15:01:02.956Z",
+    gitSha = "abc123",
+    maps = FillAssistManifestJson.MapsJson(
+        forms = mapOf(
+            "v1" to FillAssistManifestJson.FileEntryJson(
+                filename = "forms.v1.json",
+                cid = "sha256:5b8f688d24bb9c38b4094838fa2baacb3cc4ab302e3545adf016b05f6b6b96db",
+                schema = "forms.v1.schema.json",
+            ),
+        ),
+    ),
+)
+
+private val FORMS_V1 = FillAssistFormsJson(
+    schemaVersion = "1.0.0",
+    hosts = mapOf(
+        "example.com" to FillAssistFormsJson.HostEntryJson(
+            forms = listOf(
+                FillAssistFormsJson.FormJson(
+                    category = "account-login",
+                    container = null,
+                    fields = mapOf(
+                        "username" to JsonArray(listOf(JsonPrimitive("input#user"))),
+                        "password" to JsonArray(listOf(JsonPrimitive("input#pass"))),
+                    ),
+                ),
+            ),
+            pathnames = null,
+        ),
+    ),
+)
+
+private const val MANIFEST_JSON = """
+{
+  "buildId": "local-build",
+  "timestamp": "2026-05-20T15:01:02.956Z",
+  "gitSha": "abc123",
+  "maps": {
+    "forms": {
+      "v1": {
+        "filename": "forms.v1.json",
+        "cid": "sha256:5b8f688d24bb9c38b4094838fa2baacb3cc4ab302e3545adf016b05f6b6b96db",
+        "schema": "forms.v1.schema.json"
+      }
+    }
+  }
+}
+"""
+
+private const val FORMS_V1_JSON = """
+{
+  "schemaVersion": "1.0.0",
+  "hosts": {
+    "example.com": {
+      "forms": [
+        {
+          "category": "account-login",
+          "fields": {
+            "username": ["input#user"],
+            "password": ["input#pass"]
+          }
+        }
+      ]
+    }
+  }
+}
+"""