api.md

Eris DB web APIs (draft)

for eris-db version 0.11.x

Eris DB allows remote access to its functionality over http and websocket. It currently supports JSON-RPC 2.0, and REST-like http. There is also javascript bindings available in the erisdb-js library.

TOC

• HTTP Requests
• JSON-RPC 2.0
• REST-like HTTP
• Common objects and formatting
• Event-system
• Methods
• NameReg
• Filters

HTTP Requests

The only data format supported is JSON. All post requests needs to use Content-Type: application/json. The charset flag is not supported (json is utf-8 encoded by default).

JSON RPC 2.0

The default endpoints for JSON-RPC (2.0) is /rpc for http based, and /socketrpc for websocket. The namespace for the JSON-RPC service is erisdb.

It does not yet support notifications or batched requests.

Objects

Errors

PARSE_ERROR      = -32700
INVALID_REQUEST  = -32600
METHOD_NOT_FOUND = -32601
INVALID_PARAMS   = -32602
INTERNAL_ERROR   = -32603

#####Request

{
	jsonrpc: <string>
	method:  <string>
	params:  <Object>
	id:      <string>
}

#####Response

{
	jsonrpc: <string>
	id:      <string>
	result:  <Object>
	error:   <Error>
}

#####Error

{
    code:    <number>
    message: <string>
}

Id can be any string value. Parameters are named, and wrapped in objects. Also, params, result and error params may be null.

#####Example

Request:

{
	jsonrpc: "2.0", 
	method: "erisdb.getAccount", 
	params: {address: "37236DF251AB70022B1DA351F08A20FB52443E37"}, 
	id="25"
}

Response:

{
    address: "37236DF251AB70022B1DA351F08A20FB52443E37",
    pub_key: null,
    sequence: 0,
    balance: 110000000000,
    code: "",
    storage_root: ""
}

REST-like HTTP

The REST-like API provides the typical endpoint structure i.e. endpoints are named as resources, parameters can be put in the path, and queries are used for filtering and such. It is not fully compatible with REST; partly because some GET requests can contain sizable input so POST is used instead. There are also some modeling issues but those will most likely be resolved before version 1.0.

##Common objects and formatting

This section contains some common objects and explanations of how they work.

###Numbers and strings

Numbers are always numbers, and never strings. This is different from Ethereum where currency values are so high they need string representations. The only thing hex strings are used for is to represent byte arrays.

Hex strings are never prefixed.

#####Examples

"some_number_field" : 5892,
"another_number_field" : 0x52
"hex_string" : "37236DF251AB70022B1DA351F08A20FB52443E37"

###Keys and addresses

Public and Private keys in JSON data are either null, or on the form: [type, hex], where type is the public, or private key type, and hex is the hex-string representation of the key bytes.

• A public address is a 20 byte hex string.
• A public key is a 32 byte hex string.
• A private key is a 64 byte hex string.

#####WARNING

When using a client-server setup, do NOT send public keys over non-secure connections. The only time this is fine is during development when the keys are nothing but test data and does not protect anything of value. Normally they should either be kept locally and used to sign transactions locally, held on the server where the blockchain client is running, or be passed over secure channels.

#####Examples

A public address: "37236DF251AB70022B1DA351F08A20FB52443E37"

The corresponding Ed25519 public key: [1, "CB3688B7561D488A2A4834E1AEE9398BEF94844D8BDBBCA980C11E3654A45906"]

The corresponding Ed25519 private key: [1, "6B72D45EB65F619F11CE580C8CAED9E0BADC774E9C9C334687A65DCBAD2C4151CB3688B7561D488A2A4834E1AEE9398BEF94844D8BDBBCA980C11E3654A45906"]

###The transaction types

These are the types of transactions. Note that in DApp programming you would only use the CallTx, and maybe NameTx.

####SendTx

{
	inputs:  [<TxInput>]
	outputs: [<TxOutput>]
}

####CallTx

{
	input:     <TxInput>
	address:   <string>
	gas_limit: <number>
	fee:       <number>
	data:      <string>
}

####NameTx

{
	input:  <TxInput>
	name:   <string>
	data:   <string>
	amount: <number>
	fee:    <number>
}

####BondTx

{
	pub_key:   <PubKey>
	signature: <string>
	inputs:    [<TxInput>]
	unbond_to: [<TxOutput>]
}

####UnbondTx

{
	address:   <string>
	height:    <number>
	signature: <string>
}

####RebondTx

{
	address:   <string>
	height:    <number>
	signature: <string>
}

####DupeoutTx

{
	address: <string>
	vote_a:  <Vote>
	vote_b:  <Vote>
}

These are the support types that are referenced in the transactions:

####TxInput

{
	address:   <string>
	amount:    <number>
	sequence:  <number>
	signature: <string>
	pub_key:   <string>
}

####TxOutput

{
	address: <string>
	amount:  <number>
}

####Vote

{
	height:     <number>
	type:       <number>
	block_hash: <string>
	block_parts: {
		total: <number>
		hash:  <string>
	}
	signature: <string>
}

##Event system

Tendermint events can be subscribed to regardless of what connection type is used. There are three methods for this:

• EventSubscribe is used to subscribe to a given event, using an event-id string as argument. The response will contain a subscription ID, which can be used to close down the subscription later, or poll for new events if using HTTP. More on event-ids below.
• EventUnsubscribe is used to unsubscribe to an event. It requires you to pass the subscription ID as an argument.
• EventPoll is used to get all the events that has accumulated since the last time the subscription was polled. It takes the subscription ID as a parameter. NOTE: This only works over HTTP. Websocket connections will automatically receive events as they happen. They are sent as regular JSON-RPC 2.0 responses with the subscriber ID as response id.

There is another slight difference between polling and websocket, and that is the data you receive. If using sockets, it will always be one event at a time, whereas polling will give you an array of events.

Event types

These are the type of events you can subscribe to.

The "Account" events are triggered when someone transacts with the given account, and can be used to keep track of account activity.

NewBlock and Fork happens when a new block is committed or a fork happens, respectively.

The other events are directly related to consensus. You can find out more about the Tendermint consensus system in the Tendermint white paper. There is also information in the consensus sources, although a normal user would not be concerned with the consensus mechanisms, but would mostly just listen to account- and perhaps block-events.

Account Input

This notifies you when an account is receiving input.

Event ID: Acc/<address>/Input

Example: Acc/B4F9DA82738D37A1D83AD2CDD0C0D3CBA76EA4E7/Input will subscribe to input events from the account with address: B4F9DA82738D37A1D83AD2CDD0C0D3CBA76EA4E7.

Event object:

{
	tx:        <Tx>
	return:    <string>
	exception: <string>
}

Account Output

This notifies you when an account is yielding output.

Event ID: Acc/<address>/Output

Example: Acc/B4F9DA82738D37A1D83AD2CDD0C0D3CBA76EA4E7/Output will subscribe to output events from the account with address: B4F9DA82738D37A1D83AD2CDD0C0D3CBA76EA4E7.

Event object:

<Tx>

Account Call

This notifies you when an account is the target of a call. This event is emitted when CallTxs (transactions) that target the given account has been finalized. It is possible to listen to this event when creating new contracts as well; it will fire when the transaction is committed (or not, in which case the 'exception' field will explain why it failed).

NOTE: The naming here is a bit unfortunate. Ethereum uses 'transaction' for (state-changing) transactions to a contract account, and 'call' for read-only calls like is used for accessor functions and such. Tendermint on the other hand, which uses many types of transactions uses 'CallTx' for a transaction made to a contract account, since it calls the code in that contract, and refers to these simply as 'calls'. Read-only calls is normally referred to as 'simulated calls'.

Event ID: Acc/<address>/Call

Example: Acc/B4F9DA82738D37A1D83AD2CDD0C0D3CBA76EA4E7/Call will subscribe to events from the account with address: B4F9DA82738D37A1D83AD2CDD0C0D3CBA76EA4E7.

{
	call_data: {
		caller: <string>
    	callee: <string>
    	data:   <string>
    	value:  <number>
    	gas:    <number>
	}
	origin:     <string>
	tx_id:      <string>
	return:     <string>
	exception:  <string>
}

Log

This notifies you when the VM fires a log-event. This happens for example when a solidity event is fired.

Event ID: Log/<address>

Example: Log/B4F9DA82738D37A1D83AD2CDD0C0D3CBA76EA4E7/Input will subscribe to all log events from the account with address: B4F9DA82738D37A1D83AD2CDD0C0D3CBA76EA4E7.

type Log struct { Address Word256 Topics []Word256 Data []byte Height uint64 }

Event object:

{
	address: <string>
	topics:  []<string>
	data:    <string>
	height   <number>
}

address is the address of the account that created the log event.

topics is the parameters listed as topics. In a (named) Solidity event they would be the hash of the event name, followed by each param with the indexed modifier.

data the data. In a Solidity event these would be the params without the indexed modifier.

height is the current block-height.

New Block

This notifies you when a new block is committed.

Event ID: NewBlock

Event object:

<Block>

Fork

This notifies you when a fork event happens.

Event ID: Fork

Event object:

TODO

<Block>

Bond

This notifies you when a bond event happens.

Event ID: Bond

Event object:

<Tx>

Unbond

This notifies you when an unbond event happens.

Event ID: Unbond

Event object:

<Tx>

Rebond

This notifies you when a rebond event happens.

Event ID: Rebond

Event object:

<Tx>

Dupeout

This notifies you when a dupeout event happens.

Event ID: Dupeout

Event object:

<Tx>

### Name-registry

The name-registry is a built-in key-value store that allow you to store bulk data in a different storage. It is currently regulated by the use of Tendermint tokens. The cost of storing some Data in the name-registry is this:

TotalCost = Cost*NumberOfBlocks

Cost = CostPerBlock*CostPerByte*(length(Data) + 32)

CostPerBlock = 1

CostPerByte = 1

length(Data) = the number of bytes in 'Data'.

To pay this cost you use the amount field in the namereg transaction. If you want to store a 3 kb document for 10 blocks, the total cost would be 1*1*(3000 + 32)*10 = 30320 tendermint tokens.

See the TransactNameReg method for more info about adding entries to the name-registry, and the methods in the Name-registry for accessing them.

##Methods

###Accounts

Name	RPC method name	HTTP method	HTTP endpoint
GetAccounts	erisdb.getAccounts	GET	/accounts
GetAccount	erisdb.getAccount	GET	/accounts/:address
GetStorage	erisdb.getStorage	GET	/accounts/:address/storage
GetStorageAt	erisdb.getStorageAt	GET	/accounts/:address/storage/:key

###Blockchain

Name	RPC method name	HTTP method	HTTP endpoint
GetBlockchainInfo	erisdb.getBlockchainInfo	GET	/blockchain
GetChainId	erisdb.getChainId	GET	/blockchain/chain_id
GetGenesisHash	erisdb.getGenesisHash	GET	/blockchain/genesis_hash
GetLatestBlockHeight	erisdb.getLatestBlockHeight	GET	/blockchain/latest_block/height
GetLatestBlock	erisdb.getLatestBlock	GET	/blockchain/latest_block
GetBlocks	erisdb.getBlocks	GET	/blockchain/blocks
GetBlock	erisdb.getBlock	GET	/blockchain/blocks/:height

###Consensus

Name	RPC method name	HTTP method	HTTP endpoint
GetConsensusState	erisdb.getConsensusState	GET	/consensus
GetValidators	erisdb.getValidators	GET	/consensus/validators

###Events

Name	RPC method name	HTTP method	HTTP endpoint
EventSubscribe	erisdb.eventSubscribe	POST	/event_subs
EventUnsubscribe	erisdb.eventUnsubscribe	DELETE	/event_subs/:id
EventPoll	erisdb.eventPoll	GET	/event_subs/:id

###Name-registry

Name	RPC method name	HTTP method	HTTP endpoint
GetNameRegEntry	erisdb.getNameRegEntry	GET	/namereg/:key
GetNameRegEntries	erisdb.getNameRegEntries	GET	/namereg

###Network

Name	RPC method name	HTTP method	HTTP endpoint
GetNetworkInfo	erisdb.getNetworkInfo	GET	/network
GetClientVersion	erisdb.getClientVersion	GET	/network/client_version
GetMoniker	erisdb.getMoniker	GET	/network/moniker
IsListening	erisdb.isListening	GET	/network/listening
GetListeners	erisdb.getListeners	GET	/network/listeners
GetPeers	erisdb.getPeers	GET	/network/peers
GetPeer	erisdb.getPeer	GET	/network/peer/:address

NOTE: Get peer is not fully implemented.

###Transactions

Name	RPC method name	HTTP method	HTTP endpoint
BroadcastTx	erisdb.broadcastTx	POST	/txpool
GetUnconfirmedTxs	erisdb.getUnconfirmedTxs	GET	/txpool

###Code execution

Name	RPC method name	HTTP method	HTTP endpoint
Call	erisdb.call	POST	/calls
CallCode	erisdb.callCode	POST	/codecalls

####Unsafe

Name	RPC method name	HTTP method	HTTP endpoint
Transact	erisdb.transact	POST	/unsafe/txpool
Transact	erisdb.transactAndHold	POST	/unsafe/txpool?hold=true
TransactNameReg	erisdb.transactNameReg	POST	/unsafe/namereg/txpool
GenPrivAccount	erisdb.genPrivAccount	GET	/unsafe/pa_generator

Here are the catagories.

• Accounts
• BlockChain
• Consensus
• Events
• Name-registry
• Network
• Transactions
• Code Execution (calls)
• Unsafe

In the case of JSON-RPC, the parameters are wrapped in a request object, and the return value is wrapped in a response object.

In the case of REST-like HTTP GET requests, the params (and query) is provided in the url. If it's a POST, PATCH or PUT request, the parameter object should be written to the body of the request as JSON. It is normally the same params object as in JSON-RPC.

Unsafe is methods that require a private key to be sent either to or from the client, and should therefore be used only during development/testing, or with extreme care. They may be phased out entirely.

###Accounts

---

####GetAccounts

Get accounts will return a list of accounts. If no filtering is used, it will return all existing accounts.

#####HTTP

Method: GET

Endpoint: /accounts

#####JSON-RPC

Method: erisdb.getAccounts

Parameter:

{
	filters: [<FilterData>]
}

Filters

Field	Underlying type	Ops	Example Queries
balance	uint64	<, >, <=, >=, ==	q=balance:<=11
code	byte[]	==, !=	q=code:1FA872

#####Return value

{
	accounts: [<Account>]
}

#####Additional info

See GetAccount below for more info on the Account object.

See the section on Filters for info on the FilterData object.

---

####GetAccount

Get an account by its address.

#####HTTP

Method: GET

Endpoint: /accounts/:address

Params: The public address as a hex string.

#####JSON-RPC

Method: erisdb.getAccount

Parameter:

{
	address: <string>
}

#####Return value

{
	address:      <string>
	pub_key:      <PubKey>
	sequence:     <number>
	balance:      <number>
	code:         <string>
	storage_root: <string>
}

address is a public address. pub_key is a public key.

#####Additional info

Sequence is sometimes referred to as the "nonce".

There are two types of objects used to represent accounts, one is public accounts (like the one here), the other is private accounts, which only holds information about an accounts address, public and private key.

---

####GetStorage

Get the complete storage of a contract account. Non-contract accounts has no storage.

NOTE: This is mainly used for debugging. In most cases the storage of an account would be accessed via public accessor functions defined in the contracts ABI.

#####HTTP

Method: GET

Endpoint: /accounts/:address/storage

Params: The public address as a hex string.

#####JSON-RPC

Method: erisdb.getStorage

Parameter:

{
	address: <string>
}

#####Return value

{
	storage_root:  <string>
	storage_items: [<StorageItem>]
}

storage_root is a public address. See GetStorageAt below for more info on the StorageItem object.

---

####GetStorageAt

Get a particular entry in the storage of a contract account. Non-contract accounts has no storage.

NOTE: This is mainly used for debugging. In most cases the storage of an account would be accessed via public accessor functions defined in the contracts ABI.

#####HTTP

Method: GET

Endpoint: /accounts/:address/storage/:key

Params: The public address as a hex string, and the key as a hex string.

#####JSON-RPC

Method: erisdb.getStorageAt

Parameter:

{
	address: <string>
	key:     <string>
}

#####Return value

{
	key:   <string>
	value: <string>
}

Both key and value are hex strings.

---

###Blockchain

---

####GetBlockchainInfo

Get the current state of the blockchain. This includes things like chain-id and latest block height. There are individual getters for all fields as well.

#####HTTP

Method: GET

Endpoint: /blockchain

#####JSON-RPC

Method: erisdb.getBlockchainInfo

Parameter: -

#####Return value

{
	chain_id:            <string>
	genesis_hash:        <string>
	latest_block:        <BlockMeta>
	latest_block_height: <number> 
}

#####Additional info

chain_id is the name of the chain. genesis_hash is a 32 byte hex-string. It is the hash of the genesis block, which is the first block on the chain. latest_block contains block metadata for the latest block. See the GetBlock method for more info. latest_block_height is the height of the latest block, and thus also the height of the entire chain.

The block height is sometimes referred to as the block number.

See GetBlock for more info on the BlockMeta type.

---

####GetChainId

Get the chain id.

#####HTTP

Method: GET

Endpoint: /blockchain/chain_id

#####JSON-RPC

Method: erisdb.getChainId

Parameter: -

#####Return value

{
	chain_id:            <string>
}

---

####GetGenesisHash

Get the genesis hash. This is a 32 byte hex-string representation of the hash of the genesis block. The genesis block is the first block on the chain.

#####HTTP

Method: GET

Endpoint: /blockchain/genesis_hash

#####JSON-RPC

Method: erisdb.getGenesisHash

Parameter: -

#####Return value

{
	genesis_hash:        <string> 
}

---

####GetLatestBlockHeight

Get the height of the latest block. This would also be the height of the entire chain.

#####HTTP

Method: GET

Endpoint: /blockchain/latest_block/height

#####JSON-RPC

Method: erisdb.getLatestBlockHeight

Parameter: -

#####Return value

{
	latest_block_height: <number> 
}

---

####GetLatestBlock

Gets the block that was added to the chain most recently.

#####HTTP

Method: GET

Endpoint: /blockchain/latest_block

#####JSON-RPC

Method: erisdb.getLatestBlock

Parameter: -

#####Return value

{
	latest_block:        <BlockMeta> 
}

#####Additional info

See GetBlock for more info on the BlockMeta type.

---

####GetBlocks

Get a series of blocks from the chain.

#####HTTP

Method: GET

Endpoint: /blockchain/blocks

#####JSON-RPC

Method: erisdb.getBlocks

Parameter:

{
	filters: [<FilterData>]
}

Filters

Field	Underlying type	Ops	Example Queries
height	uint	<, >, <=, >=, ==	q=height:>4, q=height:10..*

#####Return value

{
	min_height:  <number>
	max_height:  <number>
	block_metas: [<BlockMeta>]
}

The BlockMeta object:

{
	hash: <string>
	header: {
		chain_id:        <string>
		height:          <number>
		time:            <string>
		fees:            <number>
		num_txs:         <number>
		last_block_hash: <string>
		last_block_parts: {
			total: <number>
			hash:  <string>
		}
		state_hash: <string>
	}
	parts: {
		total: <number>
		hash:  <string>
	}
}

#####Additional info

TODO

See the section on Filters for info on the FilterData object.

min_height and max_height is the two actual values used for min and max height when fetching the blocks. The reason they are included is because the heights might have been modified, like for example when the blockchain height is lower then the max height provided in the query.

See GetBlock for more info on the BlockMeta type.

---

####GetBlock

Get the block at the given height.

#####HTTP

Method: GET

Endpoint: /blockchain/block/:number

#####JSON-RPC

Method: erisdb.getBlock

Parameter:

{
	height: <number> 
}

#####Return value

{
	
	header: {
		chain_id:        <string>
		height:          <number>
		time:            <string>
		fees:            <number>
		num_txs:         <number>
		last_block_hash: <string>
		last_block_parts: {
			total: <number>
			hash:  <string>
		}
		state_hash: <string>
	}
	validation: {
		commits: [<Commit>]
		TODO those other two.
	}
	data: {
		txs: [<Tx>]
		TODO that other field.
	}
}

The Commit object:

{
	address:   <string>
	round:     <number>
	signature: <string>
}

#####Additional info

TODO

See The transaction types for more info on the Tx types.

---

###Consensus

---

####GetConsensusState

Get the current consensus state.

#####HTTP

Method: GET

Endpoint: /consensus

#####JSON-RPC

Method: erisdb.getConsensusState

Parameter: -

#####Return value

{
	height:      <number>
	round:       <number>
	step:        <number>
	start_time:  <string>
	commit_time: <string>
	validators:  [<Validator>]
	proposal: {
		height: <number>
		round:  <number>
		block_parts: {
			total: <number>
			hash:  <string>
		}
		pol_parts: {
			total: <number>
			hash:  <string>
		}
		signature: <string>
	}
}

#####Additional info

TODO

See the GetValidators method right below for info about the Validator object.

---

####GetValidators

Get the validators.

#####HTTP

Method: GET

Endpoint: /consensus/validators

#####JSON-RPC

Method: erisdb.getValidators

Parameter: -

#####Return value

{
	block_height:         <number>
	bonded_validators:    [<Validator>]
	unbonding_validators: [<Validator>]
}

The Validator object:

{
	address:            <string>
	pub_key:            <PubKey>
	bon_height:         <number>
	unbond_height:      <number>
	last_commit_height: <number>
	voting_power:       <number>
	accum:              <number>
}

#####Additional info

TODO

---

###Events

---

####EventSubscribe

Subscribe to a given type of event.

#####HTTP

Method: POST

Endpoint: /event_subs/

Body: See JSON-RPC parameter.

#####JSON-RPC

Method: erisdb.eventSubscribe

Parameter:

{
	event_id: <string>
}

#####Return value

{
	sub_id: <string>
}

#####Additional info

For more information about events and the event system, see the Event system section.

---

####EventUnubscribe

Unsubscribe to an event type.

#####HTTP

Method: DELETE

Endpoint: /event_subs/:id

#####JSON-RPC

Method: erisdb.eventUnsubscribe

Parameter: -

#####Return value

{
	result: <bool>
}

#####Additional info

For more information about events and the event system, see the Event system section.

---

####EventPoll

Poll a subscription. Note this cannot be done if using websockets, because then the events will be passed automatically over the socket.

#####HTTP

Method: GET

Endpoint: /event_subs/:id

#####JSON-RPC

Method: erisdb.eventPoll

#####Return value

{
	events: [<Event>]
}

#####Additional info

For more information about events and the event system, see the Event system section. This includes info about the Event object.

---

####Name-registry

####GetNameRegEntries

This will return a list of name reg entries. Filters may be used.

#####HTTP

Method: GET