Update readme with indexer

README.md

@@ -1,30 +1,40 @@
 # 0G Storage Client
-Go implementation for client to interact with storage nodes in 0G Storage network.
 
-# SDK
+Go implementation for client to interact with storage nodes in 0G Storage network. For more details, please read the [docs](https://docs.0g.ai/0g-doc/docs).
+
+## SDK
 
 Following packages can help applications to integrate with 0g storage network:
 
-**[transfer](transfer)** : defines data structures and functions for transferring data between local and 0g storage.
-**[kv]**: defines structures to interact with 0g storage kv.
-**[indexer]**: select storage nodes to upload data from indexer which maintains trusted node list.
-**[node]**: defines RPC client structures to facilitate RPC interactions with 0g storage nodes and 0g key-value (KV) nodes.
+- **[core](core)**: provides underlying utilities to build merkle tree for files or iteratable data, and defines data padding standard to interact with [Flow contract](contract/contract.go).
+- **[node](node)**: defines RPC client structures to facilitate RPC interactions with 0g storage nodes and 0g key-value (KV) nodes.
+- **[kv](kv)**: defines structures to interact with 0g storage kv.
+- **[transfer](transfer)** : defines data structures and functions for transferring data between local and 0g storage.
+- **[indexer](indexer)**: select storage nodes to upload data from indexer which maintains trusted node list. Besides, allow clients to download files via HTTP GET requests.
+
+## CLI
+
+Run `go build` under the root folder to compile the executable binary. There are several commands to interact with 0g storage node.
 
-# CLI
-Run `go build` under the root folder to compile the executable binary.
+**Global flags**
 
-**Global options**
+Run `./0g-storage-client --help` to view all available commands along with global flags:
 ```
-      --gas-limit uint     Custom gas limit to send transaction
-      --gas-price uint     Custom gas price to send transaction
-  -h, --help               help for 0g-storage-client
-      --log-force-color    Force to output colorful logs
-      --log-level string   Log level (default "info")
+Flags:
+      --gas-limit uint                Custom gas limit to send transaction
+      --gas-price uint                Custom gas price to send transaction
+  -h, --help                          help for 0g-storage-client
+      --log-color-disabled            Force to disable colorful logs
+      --log-level string              Log level (default "info")
+      --rpc-retry-count int           Retry count for rpc request (default 5)
+      --rpc-retry-interval duration   Retry interval for rpc request (default 5s)
+      --rpc-timeout duration          Timeout for single rpc request (default 30s)
+      --web3-log-enabled              Enable log for web3 RPC
 ```
 
 **Generate test file**
 
-To generate a file for test purpose, especially with a fixed file size or random file size (without `--size` option):
+To generate a file for test purpose, with a fixed file size or random file size (without `--size` option):
 
 ```
 ./0g-storage-client gen --size <file_size_in_bytes>
@@ -36,7 +46,7 @@ To generate a file for test purpose, especially with a fixed file size or random
 ./0g-storage-client upload --url <blockchain_rpc_endpoint> --contract <0g-storage_contract_address> --key <private_key> --indexer <storage_indexer_endpoint> --file <file_path>
 ```
 
-The client will submit the data segments to the storage nodes which is determined by the indexer according to their shard configurations. 
+The client will submit the data segments to the storage nodes which is determined by the indexer according to their shard configurations.
 
 **Download file**
 ```
@@ -60,4 +70,23 @@ By indexer:
 ./0g-storage-client kv-read --node <kv_node_rpc_endpoint> --stream-id <stream_id> --stream-keys <stream_keys>
 ```
 
-Please pay attention here `--node` is the url of a KV node.
+Please pay attention here `--node` is the url of a KV node.
+
+## Indexer
+
+Indexer service provides RPC to index storages nodes in two ways:
+
+- Trusted nodes: well maintained and provides stable service.
+- Discovered nodes: discovered in the whole P2P network.
+
+Please refer to the [RPC API](https://docs.0g.ai/0g-doc/docs/0g-storage/rpc/indexer-api) documentation for more details.
+
+Besides, indexer supports to download files via HTTP GET request:
+
+```
+/file?txSeq=7
+or
+/file?root=0x0376e0d95e483b62d5100968ed17fe1b1d84f0bc5d9bda8000cdfd3f39a59927
+```
+
+Note, user could specify `name=foo.log` parameter in GET URL to rename the downloaded file.