diff --git a/Master-Server-API.md b/Master-Server-API.md
index ccfb73b..f676942 100644
--- a/Master-Server-API.md
+++ b/Master-Server-API.md
@@ -18,6 +18,22 @@ curl "http://localhost:9333/dir/assign?count=5"
 curl "http://localhost:9333/dir/assign?dataCenter=dc1"
 ```
 
+| Parameter | Description | Default |
+| ---- | -- | -- |
+| count | how many file ids to reserve | 1 |
+| collection | required collection name | empty |
+| dataCenter | preferred data center | empty |
+| rack | preferred rack | empty |
+| dataNode | preferred volume server, e.g. 127.0.0.1:8080 | empty |
+| replication | replica placement strategy | master defaultReplicaPlacement| 
+| ttl | file expiration time limit, example: 3m for 3 minutes. units: m-minute, h-hour, d-day, w-week, M-month, y-year | never expire| 
+| preallocate | If no matching volumes, pre-allocate this number of bytes on disk for new volumes.  | master preallocateSize |
+| memoryMapMaxSizeMb | Only implemented for windows. Use memory mapped files with specified size for new volumes.  | 0 |
+| writableVolumeCount | If no matching volumes, create specified number of new volumes.  | master preallocateSize |
+
+
+
+
 ### Lookup volume
 
 We would need to find out whether the volumes have moved.
@@ -39,6 +55,13 @@ curl "http://localhost:9333/dir/lookup?volumeId=3,01637037d6"
 curl "http://localhost:9333/dir/lookup?volumeId=3&collection=turbo"
 ```
 
+| Parameter | Description | Default |
+| ---- | -- | -- |
+| volumeId | volume id | empty |
+| collection | optionally to speed up the lookup | empty |
+| fileId | If provided, this returns the fileId location and a JWT to update or delete the file. | empty |
+| read | works together with "fileId", if read=yes, JWT is generated for reads. | empty |
+
 ### Force garbage collection
 
 If your system has many deletions, the deleted file's disk space will not be synchronously re-claimed. There is a background job to check volume disk usage. If empty space is more than the threshold, default to 0.3 which is 30%, the vacuum job will make the volume readonly, create a new volume with only existing files, and switch on the new volume. If you are impatient or doing some testing, vacuum the unused spaces this way.
@@ -47,6 +70,9 @@ If your system has many deletions, the deleted file's disk space will not be syn
 curl "http://localhost:9333/vol/vacuum"
 curl "http://localhost:9333/vol/vacuum?garbageThreshold=0.4"
 ```
+| Parameter | Description | Default |
+| ---- | -- | -- |
+| garbageThreshold | minimum garbage ratio | 0.3, which is 30% |
 
 The garbageThreshold=0.4 is optional, and will not change the default threshold. You can start volume master with a different default garbageThreshold.
 
@@ -68,7 +94,18 @@ curl "http://localhost:9333/vol/grow?dataCenter=dc1&count=4"
 curl "http://localhost:9333/vol/grow?ttl=5d&count=4"
 ```
 
-This generates 4 empty volumes.
+| Parameter | Description | Default |
+| ---- | -- | -- |
+| count | how many volumes to grow | required |
+| collection | required collection name | empty |
+| dataCenter | preferred data center | empty |
+| rack | preferred rack | empty |
+| dataNode | preferred volume server, e.g. 127.0.0.1:8080 | empty |
+| replication | replica placement strategy | master defaultReplicaPlacement| 
+| ttl | file expiration time limit, example: 3m for 3 minutes. units: m-minute, h-hour, d-day, w-week, M-month, y-year | never expire| 
+| preallocate | Pre-allocate this number of bytes on disk for new volumes.  | master preallocateSize |
+| memoryMapMaxSizeMb | Only implemented for windows. Use memory mapped files with specified size for new volumes.  | 0 |
+
 
 ### Delete Collection
 
@@ -77,6 +114,11 @@ This generates 4 empty volumes.
 curl "http://localhost:9333/col/delete?collection=benchmark&pretty=y"
 ```
 
+| Parameter | Description | Default |
+| ---- | -- | -- |
+| collection | collection name | required |
+
+
 ### Check System Status
 
 ```bash