[json-rpc] added client implementation guide

Closes: aptos-labs#5532

README.md

@@ -26,6 +26,7 @@ To begin contributing, [sign the CLA](https://libra.org/en-US/cla-sign/). You ca
 * [Welcome](https://developers.libra.org/docs/welcome-to-libra)
 * [Libra Protocol: Key Concepts](https://developers.libra.org/docs/libra-protocol)
 * [Life of a Transaction](https://developers.libra.org/docs/life-of-a-transaction)
+* [JSON-RPC SPEC](json-rpc/json-rpc-spec.md)
 
 ### Try Libra Core
 * [My First Transaction](https://developers.libra.org/docs/my-first-transaction)

json-rpc/docs/client_checklist.md

@@ -0,0 +1,85 @@
+
+# Basics
+
+- [ ] module structure:
+  - libra
+    - LibraClient: high level APIs interface, should support application to do easy mock / stub development.
+    - jsonrpc: jsonrpc client interface, include plain data classes / structs defined in Libra JSON-RPC SPEC document.
+      - types: data transfer object types for jsonrpc client, should match server side JSON-RPC spec data types.
+    - stdlib: move stdlib script utils.
+    - testnet: testnet utils, should include FaucetService for handing testnet mint.
+    - types: Libra onchain data structure types.
+    - utils: includes crypto, data types converting and other utils functions
+      - signing, sha3 hashing, address parsing and converting, hex encoding / decoding
+      - LCS utils
+- [ ] JSON-RPC 2.0 Spec:
+  - spec version validation.
+  - batch requests and responses handling.
+- [ ] JSON-RPC client error handling should distinguish the following 3 type errors:
+  - Transport layer error, e.g. HTTP call failure.
+  - JSON-RPC protocol error: e.g. server respond non json data, or can't be parsed into [Libra JSON-RPC SPEC][1] defined data structure, or missing result & error field.
+  - JSON-RPC error: error returned from server.
+- [ ] https
+- [ ] Client connection pool: keep connection alive for less likely getting inconsistent data from connecting to multiple servers.
+- [ ] Handle stale responses:
+  - [ ] client tracks latest server respond block version and timestamp, raise error when received server response contains stale version / timestamp.
+  - [ ] parse and use libra_chain_id, libra_ledger_version and libra_ledger_tiemstamp in the JSONRPC response.
+- [ ] Parsing and gen Libra Account Identifier (see [LIP-5][2])
+  - bech32 addresses/subaddresses support
+- [ ] language specific standard release publish: e.g. java maven central repo, python pip
+- [ ] Multi-network: initialize Client with chain id, JSON-RPC server URL
+- [ ] Handle unsigned int64 data type properly
+- [ ] Validate server chain id: client should be initialized with chain id and validate server respond chain id is same.
+- [ ] Validate input parameters, e.g. invalid account address: "kkk". Should return / raise InvalidArgumentError.
+
+# High Level API
+
+- [ ] transfer: wrap peer to peer transfer with metadata script and submit transaction
+  - may have option to wait until transaction executed successfully or failed.
+- [ ] waitForTransactionExecuted(String accountAddress, long sequence, String signedTranscationHash, long timeout):
+  - for given signed transaction sender address, sequence number, expiration time (or 5 sec timeout) to wait and validate execution result is executed, otherwise return/raise an error / flag to tell it is not executed.
+  - when signedTransactionHash validation failed, it should return / raise TransactionSequenceNumberConflictError
+  - when transaction execution vm_status is not "executed", it should return / raise TransactionExecutionFailure
+
+# Read from Blockchain
+
+- [ ] Get metadata
+- [ ] Get currencies
+- [ ] Get events
+- [ ] Get transactions
+- [ ] Get account
+- [ ] Get account transaction
+- [ ] Get account transactions
+- [ ] Get account events
+- [ ] Handle error response
+- [ ] Serialize result JSON to typed data structure
+
+# Submit Transaction
+
+- [ ] Submit [p2p transfer][3] transaction
+- [ ] Submit other [Move Stdlib scripts][4]
+- [ ] Wait for transaction executed:
+  - wait for a transaction by get_transaction by account and transaction sequence, no validation of vm_status and signature. (low level API, consider not expose, only for internal or test usage.)
+
+# Testnet support
+
+- [ ] Generate ed25519 private key, derive ed25519 public keys from private key. generate Single and MultiSig auth-keys
+- [ ] Mint coins through Faucet service
+
+See [doc][5] for above concepts.
+
+# Examples
+
+- [ ] Query blockchain example
+- [ ] Submit p2p transfer transaction example
+
+# Nice to have
+
+- [ ] Async client
+- [ ] CLI connects to testnet for trying out features.
+
+[1]: https://github.com/libra/libra/blob/master/json-rpc/json-rpc-spec.md "Libra JSON-RPC SPEC"
+[2]: https://github.com/libra/lip/blob/master/lips/lip-5.md "LIP-5"
+[3]: https://github.com/libra/libra/blob/master/language/stdlib/transaction_scripts/doc/peer_to_peer_with_metadata.md "P2P Transafer"
+[4]: https://github.com/libra/libra/tree/master/language/stdlib/transaction_scripts/doc "Move Stdlib scripts"
+[5]: https://github.com/libra/libra/blob/master/client/libra-dev/README.md "Libra Client Dev Doc"