diff --git a/build.gradle.kts b/build.gradle.kts
index 116c242..861c159 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -44,7 +44,6 @@ dependencies {
     implementation(libs.micronaut.data.jdbc)
     implementation(libs.micronaut.jdbc.hikari)
     implementation(libs.micronaut.flyway)
-    implementation(libs.micronaut.redis.lettuce)
     implementation(libs.micronaut.kafka)
     implementation(libs.micronaut.discovery.eureka)
     // 指标：把管道积压/回填/水位等暴露为 MeterRegistry 指标（版本由 platform BOM 管）
diff --git a/docs/invariants.md b/docs/invariants.md
index 6fa7187..916495c 100644
--- a/docs/invariants.md
+++ b/docs/invariants.md
@@ -113,7 +113,7 @@
 | `G-PROC-HST` | `PROC_STATE_HST` 未建表，终态归档未落地 | US-11；归档能力 |
 | `G-FLOP-IDEMPOTENT` | 29 类 FLOP 幂等矩阵未补全 | `INV-20`、CLM-3 |
 | ~~`G-EVENT-RETENTION`~~ | ~~`MSG_EVENT` 已发送行的保留期与清理作业未实现~~ | 已关闭：`SENT_AT` 列 + 投递原子写 + `EventCleanupJob` 按 `eventRetention` 有界删除 |
-| `G-BACKFILL-BACKOFF` | 回填独立退避键（`backfill-backoff-ms` / `-cap-ms`）未实现，当前为代码内硬编码（取值见 reference） | 回填重试节奏 |
+| ~~`G-BACKFILL-BACKOFF`~~ | ~~回填独立退避键未实现，代码内硬编码~~ | 已关闭：`backfill-backoff-ms` / `backfill-backoff-cap-ms` 配置绑定落地，`BackfillService` 从 `PipelineProps` 读取 |
 | `G-KAFKA-D3` | ~~已闭合~~：`max-in-flight` 默认收敛到 1，启动自检钉住三项联合满足 D3 | ~~投递幂等前提~~ |
 | `G-REPLAY-CHANNEL` | 「打标即清除」语义下的独立原文保留通道未设计 | CLM-5 |
 | `G-MAFL` | 主航班 `MAFL` 派生投影及主/共享原子级联未实现（规则见 `INV-21`/`INV-22`）；`MAFL` 不是 SIS/XML 入站字段 | 航班完整态；删除与重建 |
diff --git a/docs/reference.md b/docs/reference.md
index d429a98..eda010b 100644
--- a/docs/reference.md
+++ b/docs/reference.md
@@ -22,8 +22,8 @@
 | `msgx.pipeline.backfill-batch` | `100` | 条 | 假定 | 回填扫描单批条数 |
 | `msgx.pipeline.backfill-scan-period` | `30s`（代码常量，无配置键） | Duration | 现役 | 回填扫描作业周期；批次积压与单行超时会延长实际标记延迟（`CLM-9`） |
 | `msgx.pipeline.backfill-max-attempts` | `100` | 次 | 假定 | 单行重试的**告警阈值**；放弃判据是 `R` 超期，不是次数（见 design「回填」） |
-| `msgx.pipeline.backfill-backoff-ms` | 目标参数（未实现） | ms / 档 | 假定 | 回填独立退避表；**当前不存在**，`BackfillService` 内硬编码 30 秒起步、封顶 15 分钟 `[G-BACKFILL-BACKOFF]` |
-| `msgx.pipeline.backfill-backoff-cap-ms` | 目标参数（未实现） | ms | 假定 | 回填退避封顶；对应实现是代码内常量，尚无配置键 `[G-BACKFILL-BACKOFF]` |
+| `msgx.pipeline.backfill-backoff-ms` | `30000` | ms | 假定 | 回填独立退避起步间隔；`BackfillService` 指数退避的首档 `[G-BACKFILL-BACKOFF ✓]` |
+| `msgx.pipeline.backfill-backoff-cap-ms` | `900000` | ms | 假定 | 回填退避封顶（15 分钟）`[G-BACKFILL-BACKOFF ✓]` |
 | `msgx.pipeline.cutover-watermark` | 不设置 | `min\|zero\|max\|<id>` | 一次性运维决策 | 显式播种水位；非法值由启动自检挡下；升级实例拒绝重新播种 |
 | `msgx.pipeline.delivery-batch` | `200` | 条 | 假定 | `KAFKA:msg` 每轮每目标领取上限 |
 | `msgx.pipeline.delivery-drain-rounds` | `10` | 轮 | 假定 | 连取批数上限，让出循环跑 `schd` flush，防状态通知被积压饿死 |
diff --git a/docs/user-stories.md b/docs/user-stories.md
index b466039..137da14 100644
--- a/docs/user-stories.md
+++ b/docs/user-stories.md
@@ -190,7 +190,7 @@
 4. 重复补偿效果幂等，保留稳定的完成时间与审计；重放后的新处理结果不能被旧回填任务覆盖。非法报文缺 META 时也有明确回填方式。
 5. 影子模式禁写，双跑仅一个系统持有标记写权；暴露 PG 终态、回填状态、积压、最老年龄与持续失败告警。
 
-**当前基础与落点**：回填意图与处理终态同体同行（`PROC_STATE.BACKFILL_*`），随业务事务提交，`BACKFILL_TODO` 已随 V2 迁移下线；终态落库后回填一律由定时扫描驱动（`BackfillService.sweep`，扫描周期与退避取值见 [reference.md](reference.md)；独立退避键尚未落地 `[G-BACKFILL-BACKOFF]`），处理关键路径不做跨库写；本地入队时间（`ENQUEUED_AT`）超过超期期限 `R` 时强制补写（见 design「回填」）。死信同样可补写——回填只需消息 ID，不依赖 META。剩余：Q7 的标记值集与写权限书面确认；影子环境禁写尚未实装。
+**当前基础与落点**：回填意图与处理终态同体同行（`PROC_STATE.BACKFILL_*`），随业务事务提交，`BACKFILL_TODO` 已随 V2 迁移下线；终态落库后回填一律由定时扫描驱动（`BackfillService.sweep`，扫描周期与退避取值见 [reference.md](reference.md)；独立退避键 `backfill-backoff-ms` / `backfill-backoff-cap-ms` 已落地），处理关键路径不做跨库写；本地入队时间（`ENQUEUED_AT`）超过超期期限 `R` 时强制补写（见 design「回填」）。死信同样可补写——回填只需消息 ID，不依赖 META。剩余：Q7 的标记值集与写权限书面确认；影子环境禁写尚未实装。
 
 **前置**：US-03 终态接口；Q7、共享库更新权限。覆盖四类终态、事务回滚、重复补偿和重放竞争；生命周期与超期补写以 [design.md](design.md)「中断恢复」「回填」为准，清除口径以 [contracts.md](contracts.md)「保留与清除」为准。
 
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index e55d991..c55d045 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -29,7 +29,6 @@ micronaut-jackson-databind = { module = "io.micronaut:micronaut-jackson-databind
 micronaut-data-jdbc = { module = "io.micronaut.data:micronaut-data-jdbc" }
 micronaut-jdbc-hikari = { module = "io.micronaut.sql:micronaut-jdbc-hikari" }
 micronaut-flyway = { module = "io.micronaut.flyway:micronaut-flyway" }
-micronaut-redis-lettuce = { module = "io.micronaut.redis:micronaut-redis-lettuce" }
 micronaut-kafka = { module = "io.micronaut.kafka:micronaut-kafka" }
 micronaut-discovery-eureka = { module = "io.micronaut.discovery:micronaut-discovery-client" }
 micronaut-management = { module = "io.micronaut:micronaut-management" }
diff --git a/src/main/kotlin/com/gzzn/omms/msgexchange/config/PipelineProps.kt b/src/main/kotlin/com/gzzn/omms/msgexchange/config/PipelineProps.kt
index d0022a3..e969b79 100644
--- a/src/main/kotlin/com/gzzn/omms/msgexchange/config/PipelineProps.kt
+++ b/src/main/kotlin/com/gzzn/omms/msgexchange/config/PipelineProps.kt
@@ -54,6 +54,12 @@ class PipelineProps {
          */
         var backfillMaxAttempts: Int = 100
 
+        /** 回填独立退避的起步间隔 `[G-BACKFILL-BACKOFF]`。 */
+        var backfillBackoffMs: Long = 30_000
+
+        /** 回填独立退避的封顶间隔 `[G-BACKFILL-BACKOFF]`。 */
+        var backfillBackoffCapMs: Long = 900_000
+
         /**
          * 切流水位播种（一次性、显式）。取值：
          * `min` = `W:MIN(ID)−1`（读当前全部现存行）、`zero` = `W:0`（按空洞规则从 0 扫）、
diff --git a/src/main/kotlin/com/gzzn/omms/msgexchange/infra/kafka/KafkaDeliveryPort.kt b/src/main/kotlin/com/gzzn/omms/msgexchange/infra/kafka/KafkaDeliveryPort.kt
new file mode 100644
index 0000000..e76bcd2
--- /dev/null
+++ b/src/main/kotlin/com/gzzn/omms/msgexchange/infra/kafka/KafkaDeliveryPort.kt
@@ -0,0 +1,46 @@
+package com.gzzn.omms.msgexchange.infra.kafka
+
+import com.gzzn.omms.msgexchange.delivery.DeliveryPort
+import io.micronaut.configuration.kafka.ProducerRegistry
+import io.micronaut.context.annotation.Requires
+import io.micronaut.core.type.Argument
+import jakarta.inject.Singleton
+import org.apache.kafka.clients.producer.Producer
+import org.apache.kafka.clients.producer.ProducerRecord
+
+/**
+ * Kafka 真实投递端口：通过 [ProducerRegistry] 拿 default 生产者，D3 参数
+ * （acks=all / enable-idempotence=true / max-in-flight=1）由 `KafkaD3Check` 启动自检。
+ *
+ * 发送同步等 broker 确认（`Future.get()`），语义是至少一次——满足 INV-10 / C-29。
+ * 仅在 `msgx.stubs != true` 时装配；stub 模式走 `StubDeliveryPort`。
+ */
+@Requires(property = "msgx.stubs", notEquals = "true")
+@Singleton
+class KafkaDeliveryPort(
+    private val registry: ProducerRegistry,
+) : DeliveryPort {
+
+    private val producer: Producer<String, String> by lazy {
+        registry.getProducer("default", Argument.of(String::class.java), Argument.of(String::class.java))
+    }
+
+    override fun sendKafka(topic: String, key: String, payloadJson: String) {
+        producer.send(ProducerRecord(topic, key, payloadJson)).get()
+    }
+
+    override fun sendKafkaSchd(topic: String, key: String, payloadJson: String) {
+        producer.send(ProducerRecord(topic, key, payloadJson)).get()
+    }
+
+    override fun sendKafkaNull(topic: String, key: String) {
+        producer.send(ProducerRecord<String, String>(topic, key, null)).get()
+    }
+
+    override fun ping(): Boolean = try {
+        producer.partitionsFor("msg")
+        true
+    } catch (_: Exception) {
+        false
+    }
+}
diff --git a/src/main/kotlin/com/gzzn/omms/msgexchange/processing/BackfillService.kt b/src/main/kotlin/com/gzzn/omms/msgexchange/processing/BackfillService.kt
index c0cf106..7af5a3f 100644
--- a/src/main/kotlin/com/gzzn/omms/msgexchange/processing/BackfillService.kt
+++ b/src/main/kotlin/com/gzzn/omms/msgexchange/processing/BackfillService.kt
@@ -42,8 +42,6 @@ class BackfillService(
     private val log = org.slf4j.LoggerFactory.getLogger(BackfillService::class.java)
 
     companion object {
-        private val INITIAL_BACKOFF: Duration = Duration.ofSeconds(30)
-        private val MAX_BACKOFF: Duration = Duration.ofMinutes(15)
         private val TERMINAL_STATES = setOf(ProcStatus.SUCCEEDED, ProcStatus.SKIPPED, ProcStatus.DEAD)
 
         /** 放弃原因：运行时查询确认信箱行不存在（确定性结论，重试不会改变结果）。 */
@@ -51,11 +49,13 @@ class BackfillService(
 
         /** 放弃原因：暂时性故障持续到 `R` 仍未打标；停止自动重试，但保留人工恢复能力。 */
         const val ABANDON_TRANSIENT_DEADLINE = "TRANSIENT_DEADLINE"
+    }
 
-        fun backoffDelayFor(attempts: Int): Duration {
-            val shift = (attempts - 1).coerceIn(0, 20)
-            return INITIAL_BACKOFF.multipliedBy(1L shl shift).coerceAtMost(MAX_BACKOFF)
-        }
+    internal fun backoffDelayFor(attempts: Int): Duration {
+        val initial = Duration.ofMillis(props.pipeline.backfillBackoffMs)
+        val cap = Duration.ofMillis(props.pipeline.backfillBackoffCapMs)
+        val shift = (attempts - 1).coerceIn(0, 20)
+        return initial.multipliedBy(1L shl shift).coerceAtMost(cap)
     }
 
     /**
diff --git a/src/test/kotlin/com/gzzn/omms/msgexchange/processing/BackfillServiceTest.kt b/src/test/kotlin/com/gzzn/omms/msgexchange/processing/BackfillServiceTest.kt
index 1243c71..a7f9144 100644
--- a/src/test/kotlin/com/gzzn/omms/msgexchange/processing/BackfillServiceTest.kt
+++ b/src/test/kotlin/com/gzzn/omms/msgexchange/processing/BackfillServiceTest.kt
@@ -221,10 +221,11 @@ class BackfillServiceTest {
 
     @Test
     fun `backoff delay doubles per attempt and caps at fifteen minutes`() {
-        assertEquals(Duration.ofSeconds(30), BackfillService.backoffDelayFor(1))
-        assertEquals(Duration.ofMinutes(2), BackfillService.backoffDelayFor(3))
-        assertEquals(Duration.ofMinutes(15), BackfillService.backoffDelayFor(10))
-        assertEquals(Duration.ofMinutes(15), BackfillService.backoffDelayFor(50))
+        val svc = BackfillService(StubProcState(), StubInbox(), MailboxProps(), props, Clock.fixed(t0, ZoneOffset.UTC), MessageLifecycleGate())
+        assertEquals(Duration.ofSeconds(30), svc.backoffDelayFor(1))
+        assertEquals(Duration.ofMinutes(2), svc.backoffDelayFor(3))
+        assertEquals(Duration.ofMinutes(15), svc.backoffDelayFor(10))
+        assertEquals(Duration.ofMinutes(15), svc.backoffDelayFor(50))
     }
 
     @Test