Steem Coding - Python, API, Piston

This presentation gives a quick introduction to the Steem API and how to use piston to interact with the Steem network, post, vote and comment

Transcript

1. Steem Coding Steem Coding Python, API, Piston Python, API, Piston Dr.-Ing. Fabian (@xeroc) Schuh ChainSquad GmbH (i.Gr.) October 13, 2016
2. Requirements for this talk Requirements for this talk Coding Python: def main(): print("hello, world") Accessing APIs JSON {'expiration': '2016-11-09T11:09:01', 'operations': [['transfer', {.........}}]], 'ref_block_num': 17230, 'ref_block_prefix': 1220322455, 'signatures': ['.........']} Blockchain Technologies signed “Letters of intent” 1/26
3. Outline Outline 1 Steem’s Blockchain APIs 2 First Actions Registering to Other APIs Using advanced APIs 3 Abstraction Layer: Piston Signed Transactions Writing to Steem Monitoring the Blockchain 4 Live Coding 5 Further Reading 2/26
4. Steem’s Blockchain APIs Steem’s Blockchain APIs
5. Steem’s Blockchain API Steem’s Blockchain API blockchain p2p-network consensus protocol Blockchain Database Database API Account History API Market History API Tag API Follow API Broadcast API … steemd 4/26
6. Steem’s Blockchain API Steem’s Blockchain API blockchain p2p-network consensus protocol Blockchain Database Database API Account History API Market History API Tag API Follow API Broadcast API … steemd ✓ JSON formatted Remote Procedure Calls (RPC) via HTTP × No need to understand blockchain technology × No need to understand consensus schemes × No need to understand P2P networks × No need to know the protocol 4/26
7. What are the APIs good for? What are the APIs good for? Database API: Database API: get_trending_tags() get_state() get_block() get_account() … Market History API (Plugin): Market History API (Plugin): get_ticker() get_trade_history() get_recent_trades() get_volume() … Broadcast API (Plugin): Broadcast API (Plugin): broadcast_transaction() broadcast_transaction_synchronous() … Follow API (Plugin): Follow API (Plugin): get_followers() get_following() get_feed() … 5/26
8. First Actions First Actions
9. First Actions First Actions Simple Database Query curl --data '{"jsonrpc":"2.0", \ "method":"call", \ "params": \ [0, \ "get_dynamic_global_properties", \ [] \ ], \ "id":0}' \ this.piston.rocks Reply {"id":0, "result":{ "id":"2.0.0", "head_block_number":6574290, "head_block_id":"006450d2ed6f58bab8e7fca49dc1488de6dea768", "time":"2016-11-09T14:01:54", "current_witness":"jesta", "total_pow":313551, "num_pow_witnesses":108,% ..., } } 7/26
10. First Actions First Actions → Registering to Other APIs Registering to Other APIs
11. Using Other APIs Using Other APIs The database API (id: 0) is enabled and accessible by default! For every other API a identifier needs to be requested! The python-steem library simplifies this > {"method": "call", "jsonrpc": "2.0", "id": 1, "params": [1, "login", ["<user>","<password>"]]} < {"id":1,"result":true} > {"method": "call", "jsonrpc": "2.0", "id": 2, "params": [1, "get_api_by_name",["network_broadcast_api"]]} < {"id":2,"result":5} 9/26
12. First Actions First Actions → Using advanced APIs Using advanced APIs
13. Using other APIs Using other APIs Address specific APIs using the API number obtained in the previous step: > {"method": "call", "jsonrpc": "2.0", "id": 3, "params": [ 5, "broadcast_transaction_synchronous", ["<signed_transaction>"] ]} < {"id":1,"result":Null} 11/26
14. Abstraction Layer: Piston Abstraction Layer: Piston
15. Piston: Introduction Piston: Introduction The Swiss army knife for the Steem blockchain! Developed to make live easier for developers and user Multiple Abstraction Layers involved: python-graphene python-steem piston Uses public API server: this.piston.rocks and node.steem.ws 13/26
16. Simple Example Simple Example Reading from Steem: from piston.steem import Steem # piston.Steem abstraction steem = Steem() # RPC call get_account print(steem.rpc.get_account("chainsquad") # returns a piston.Post object print(steem.get_content("@xeroc/piston") 14/26
17. Abstraction Layer: Piston Abstraction Layer: Piston → Signed Transactions Signed Transactions
18. Writing to Steem! Writing to Steem! How about Writing to Steem? Writing to the blockchain requires: an account the (posting, or active) private key “letters of intent”: vote, or comment, or transfer, etc. Providing Keys to Piston: > piston addkeys # Shell command to use the internal wallet >>> steem = Steem(keys=["5xxxxx", "5xxxxx"]) # Provide a list of keys # Advanced users can force keys for signing >>> steem = Steem(keys={ "owner": "5xxxxx", "active": "5xxxxx", "posting": "5xxxxx", "memo": "5xxxxx", }) 16/26
19. Signed Transactions Signed Transactions All actions that “change” the blockchain (e.g. votes, comments, transfers, etc) require a signed transaction of this form: {'expiration': '2016-11-09T15:03:43', 'extensions': [], 'operations': [[<list of operations>]], 'ref_block_num': 21908, 'ref_block_prefix': 2930661658, 'signatures': ['1f3dba2ba.....bf3ea1a8a0b']} 17/26
20. Example signed Transaction Example signed Transaction The actual singing process is provided by python-graphene and is not part of this talk. All piston methods that “write to” the blockchain return a (partially) signed transaction of the above form. >>> from piston.steem import Steem >>> steem = Steem(nobroadcast=True) >>> print(steem.transfer(to="fabian", account="xeroc", amount=1, asset="SBD")) Passphrase: *********** Not broadcasting anything... {'ref_block_prefix': 2732406441, 'ref_block_num': 21994, 'expiration': '2016-11-09T15:08:00', 'operations': [['transfer', { 'from': 'xeroc', 'memo': '', 'to': 'fabian', 'amount': '1.000 SBD'}]], 'extensions': [], 'signatures': ['202ceb735d3c1e3b22be63b...96d5d136e41958156716de'] } 18/26
21. Abstraction Layer: Piston Abstraction Layer: Piston → Writing to Steem Writing to Steem
22. Writing to Steem Writing to Steem With the installed (posting, active) private key(s), we enable additional piston calls: steem.post() steem.edit() steem.reply() steem.vote() steem.transfer() # required active key steem.buy() # required active key steem.convert() # required active key steem.allow() # required active key ... 20/26
23. The Post class The Post class Posts themselves are consequently represented using the Post abstraction class which adds post-specific methods that correspond to this particular post: post = steem.get_content("@xeroc/piston") post.upvote() post.reply("You rock!") print(post.url) print(post["url"]) print(post.author) print(post.title) print(post.body) print(post.author_rewards) print(post.net_votes) print(post.get_comments()) # again returns Post instances ... 21/26
24. Abstraction Layer: Piston Abstraction Layer: Piston → Monitoring the Blockchain Monitoring the Blockchain
25. Monitoring the Blockchain Monitoring the Blockchain Monitoring Posts Monitoring Posts for post in steem.stream_comments(): if not post.depth: print(post.body) Monitoring Raw Blocks Monitoring Raw Blocks for block in steem.rpc.block_stream(): print(block["block_num"]) Monitoring Specific Operations Monitoring Specific Operations for op in steem.rpc.stream(["transfer", "vote"]): print(op) 23/26
26. Live Coding Live Coding
27. Further Reading Further Reading
28. Further reading Further reading http://piston.rocks > piston read @xeroc/piston-cli-quickstart 26/26
29. Questions? Questions? Thank you for your interest! Thank you for your interest!