diff --git a/dfdaemon/seed/manager.go b/dfdaemon/seed/manager.go
new file mode 100644
index 000000000..9e435e2b6
--- /dev/null
+++ b/dfdaemon/seed/manager.go
@@ -0,0 +1,53 @@
+/*
+ * Copyright The Dragonfly Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package seed
+
+import "time"
+
+// Manager is an interface which manages the seeds.
+type Manager interface {
+	// Register a seed.
+	Register(key string, info BaseInfo) (Seed, error)
+
+	// UnRegister seed by key.
+	UnRegister(key string) error
+
+	// RefreshExpireTime refreshes expire time of seed.
+	RefreshExpireTime(key string, expireTimeDur time.Duration) error
+
+	// NotifyExpired get the expired chan of seed, it will be notified if seed expired.
+	NotifyExpired(key string) (<-chan struct{}, error)
+
+	// Prefetch will add seed to the prefetch list, and then prefetch by the concurrent limit.
+	Prefetch(key string, perDownloadSize int64) (<-chan struct{}, error)
+
+	// GetPrefetchResult should be called after notify by prefetch chan.
+	GetPrefetchResult(key string) (PreFetchResult, error)
+
+	// SetPrefetchLimit limits the concurrency of prefetching seed.
+	// Default is defaultDownloadConcurrency.
+	SetConcurrentLimit(limit int) (validLimit int)
+
+	// Get gets the seed by key.
+	Get(key string) (Seed, error)
+
+	// List lists the seeds.
+	List() ([]Seed, error)
+
+	// Stop stops the SeedManager.
+	Stop()
+}
diff --git a/dfdaemon/seed/seed.go b/dfdaemon/seed/seed.go
new file mode 100644
index 000000000..9d923c8fa
--- /dev/null
+++ b/dfdaemon/seed/seed.go
@@ -0,0 +1,53 @@
+/*
+ * Copyright The Dragonfly Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package seed
+
+import "io"
+
+// Seed describes the seed file which represents the resource file defined by taskUrl.
+type Seed interface {
+	// Prefetch will start to download seed file to local cache.
+	Prefetch(perDownloadSize int64) (<-chan struct{}, error)
+
+	// GetPrefetchResult should be called after notify by prefetch chan.
+	GetPrefetchResult() (PreFetchResult, error)
+
+	// Delete will delete the local cache and release the resource.
+	Delete() error
+
+	// Download providers the range download, if local cache of seed do not include the range,
+	// it will download the range data from rss and reply to request.
+	Download(off int64, size int64) (io.ReadCloser, error)
+
+	// stop the internal loop and release execution resource.
+	Stop()
+
+	// GetFullSize gets the full size of seed file.
+	GetFullSize() int64
+
+	// GetStatus gets the status of seed file.
+	GetStatus() string
+
+	// GetURL gets the url of seed file.
+	GetURL() string
+
+	// GetHeaders gets the headers of seed file.
+	GetHeaders() map[string][]string
+
+	// GetHeaders gets the taskID of seed file.
+	GetTaskID() string
+}
diff --git a/dfdaemon/seed/types.go b/dfdaemon/seed/types.go
new file mode 100644
index 000000000..1ba8f7567
--- /dev/null
+++ b/dfdaemon/seed/types.go
@@ -0,0 +1,56 @@
+/*
+ * Copyright The Dragonfly Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package seed
+
+import (
+	"time"
+)
+
+// BaseInfo describes the base info of seed.
+type BaseInfo struct {
+	// the url of seed file.
+	URL string
+
+	// the taskID of seed file.
+	TaskID string
+
+	// the header of seed file.
+	Header map[string][]string
+
+	// URL may contains some changeful query parameters such as authentication parameters. Dragonfly will
+	// filter these parameter via 'filter'. The usage of it is that different URL may generate the same
+	// download url.
+	Filters []string
+
+	// the full length of seed file.
+	FullLength int64
+
+	// Seed will download data from rss which is divided by blocks.
+	// And block size is defined by BlockOrder. It should be limited [10, 31].
+	BlockOrder uint32
+
+	// expire time duration of seed file.
+	ExpireTimeDur time.Duration
+}
+
+// PreFetchResult shows the result of prefetch.
+type PreFetchResult struct {
+	Success bool
+	Err     error
+	// if canceled, caller need not to do other.
+	Canceled bool
+}