30 KiB
This specification describes the API for consuming go-waku when built as a dynamic or static library
libgowaku.h
Introduction
Native applications that wish to integrate Waku may not be able to use nwaku and its JSON RPC API due to constraints on packaging, performance or executables.
An alternative is to link existing Waku implementation as a static or dynamic library in their application.
This specification describes the C API that SHOULD be implemented by native Waku library and that SHOULD be used to consume them.
The API
General
JsonResponse
type
All the API functions return a JsonResponse
unless specified otherwise.
JsonResponse
is a char *
whose format depends on whether the function was executed successfully or not.
On failure:
{
error: string;
}
For example:
{
"error": "the error message"
}
On success:
{
result: any
}
The type of the result
object depends on the function it was returned by.
JsonMessage
type
A Waku Message in JSON Format:
{
payload: string;
contentTopic: string;
version: number;
timestamp: number;
}
Fields:
payload
: base64 encoded payload,waku_utils_base64_encode
can be used for this.contentTopic
: The content topic to be set on the message.version
: The Waku Message version number.timestamp
: Unix timestamp in nanoseconds.
DecodedPayload
type
A payload once decoded, used when a received Waku Message is encrypted:
interface DecodedPayload {
pubkey?: string;
signature?: string;
data: string;
padding: string;
}
Fields:
pubkey
: Public key that signed the message (optional), hex encoded with0x
prefix,signature
: Message signature (optional), hex encoded with0x
prefix,data
: Decrypted message payload base64 encoded,padding
: Padding base64 encoded.
FilterSubscription
type
The criteria to create subscription to a light node in JSON Format:
{
contentFilters: ContentFilter[];
pubsubTopic: string?;
}
Fields:
contentFilters
: Array ofContentFilter
being subscribed to / unsubscribed from.topic
: Optional pubsub topic.
ContentFilter
type
{
contentTopic: string;
}
Fields:
contentTopic
: The content topic of a Waku message.
StoreQuery
type
Criteria used to retrieve historical messages
interface StoreQuery {
pubsubTopic?: string;
contentFilters?: ContentFilter[];
startTime?: number;
endTime?: number;
pagingOptions?: PagingOptions
}
Fields:
pubsubTopic
: The pubsub topic on which messages are published.contentFilters
: Array ofContentFilter
to query for historical messages,startTime
: The inclusive lower bound on the timestamp of queried messages. This field holds the Unix epoch time in nanoseconds.endTime
: The inclusive upper bound on the timestamp of queried messages. This field holds the Unix epoch time in nanoseconds.pagingOptions
: Paging information inPagingOptions
format.
StoreResponse
type
The response received after doing a query to a store node:
interface StoreResponse {
messages: JsonMessage[];
pagingOptions?: PagingOptions;
}
Fields:
messages
: Array of retrieved historical messages inJsonMessage
format.pagingOption
: Paging information inPagingOptions
format from which to resume further historical queries
PagingOptions
type
interface PagingOptions {
pageSize: number;
cursor?: Index;
forward: bool;
}
Fields:
pageSize
: Number of messages to retrieve per page.cursor
: Message Index from which to perform pagination. If not included and forward is set to true, paging will be performed from the beginning of the list. If not included and forward is set to false, paging will be performed from the end of the list.forward
:true
if paging forward,false
if paging backward
Index
type
interface Index {
digest: string;
receiverTime: number;
senderTime: number;
pubsubTopic: string;
}
Fields:
digest
: Hash of the message at thisIndex
.receiverTime
: UNIX timestamp in nanoseconds at which the message at thisIndex
was received.senderTime
: UNIX timestamp in nanoseconds at which the message is generated by its sender.pubsubTopic
: The pubsub topic of the message at thisIndex
.
Events
Asynchronous events require a callback to be registered.
An example of an asynchronous event that might be emitted is receiving a message.
When an event is emitted, this callback will be triggered receiving a JSON string of type JsonSignal
.
JsonSignal
type
{
type: string;
event: any;
}
Fields:
type
: Type of signal being emitted. Currently, onlymessage
is available.event
: Format depends on the type of signal.
For example:
{
"type": "message",
"event": {
"subscriptionId": 1,
"pubsubTopic": "/waku/2/default-waku/proto",
"messageId": "0x6496491e40dbe0b6c3a2198c2426b16301688a2daebc4f57ad7706115eac3ad1",
"wakuMessage": {
"payload": "TODO",
"contentTopic": "/my-app/1/notification/proto",
"version": 1,
"timestamp": 1647826358000000000
}
}
}
type |
event Type |
---|---|
message |
JsonMessageEvent |
JsonMessageEvent
type
Type of event
field for a message
event:
{
pubsubTopic: string;
messageId: string;
wakuMessage: JsonMessage;
}
pubsubTopic
: The pubsub topic on which the message was received.messageId
: The message id.wakuMessage
: The message inJsonMessage
format.
extern void waku_set_event_callback(void* cb)
Register callback to act as event handler and receive application signals, which are used to react to asynchronous events in Waku.
Parameters
void* cb
: callback that will be executed when an async event is emitted. The function signature for the callback should bevoid myCallback(char* jsonSignal)
Node management
JsonConfig
type
Type holding a node configuration:
interface JsonConfig {
host?: string;
port?: number;
advertiseAddr?: string;
nodeKey?: string;
keepAliveInterval?: number;
relay?: boolean;
minPeersToPublish?: number;
filter?: boolean;
discV5?: boolean;
discV5BootstrapNodes?: Array<string>;
discV5UDPPort?: number;
}
Fields:
All fields are optional.
If a key is undefined
, or null
, a default value will be set.
host
: Listening IP address. Default0.0.0.0
.port
: Libp2p TCP listening port. Default60000
. Use0
for random.advertiseAddr
: External address to advertise to other nodes. Can be ip4, ip6 or dns4, dns6. Ifnull
, the multiaddress(es) generated from the ip and port specified in the config (or default ones) will be used. Default:null
.nodeKey
: Secp256k1 private key in Hex format (0x123...abc
). Default random.keepAliveInterval
: Interval in seconds for pinging peers to keep the connection alive. Default20
.relay
: Enable relay protocol. Defaulttrue
.minPeersToPublish
: The minimum number of peers required on a topic to allow broadcasting a message. Default0
.filter
: Enable filter protocol. Defaultfalse
.discV5
: Enable DiscoveryV5. Defaultfalse
discV5BootstrapNodes
: Array of bootstrap nodes ENRdiscV5UDPPort
: UDP port for DiscoveryV5 Default9000
For example:
{
"host": "0.0.0.0",
"port": 60000,
"advertiseAddr": "1.2.3.4",
"nodeKey": "0x123...567",
"keepAliveInterval": 20,
"relay": true,
"minPeersToPublish": 0
}
extern char* waku_new(char* jsonConfig)
Instantiates a Waku node.
Parameters
char* jsonConfig
: JSON string containing the options used to initialize a go-waku node. TypeJsonConfig
. It can beNULL
to use defaults.
Returns
A JsonResponse
.
If the execution is successful, the result
field is set to true
.
For example:
{
"result": true
}
extern char* waku_start()
Start a Waku node mounting all the protocols that were enabled during the Waku node instantiation.
Returns
A JsonResponse
.
If the execution is successful, the result
field is set to true
.
For example:
{
"result": true
}
extern char* waku_stop()
Stops a Waku node.
Returns
A JsonResponse
.
If the execution is successful, the result
field is set to true
.
For example:
{
"result": true
}
extern char* waku_peerid()
Get the peer ID of the waku node.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains the peer ID as a string
(base58 encoded).
For example:
{
"result": "QmWjHKUrXDHPCwoWXpUZ77E8o6UbAoTTZwf1AD1tDC4KNP"
}
extern char* waku_listen_addresses()
Get the multiaddresses the Waku node is listening to.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains an array of multiaddresses.
The multiaddresses are string
s.
For example:
{
"result": [
"/ip4/127.0.0.1/tcp/30303",
"/ip4/1.2.3.4/tcp/30303",
"/dns4/waku.node.example/tcp/8000/wss"
]
}
Connecting to peers
extern char* waku_add_peer(char* address, char* protocolId)
Add a node multiaddress and protocol to the waku node's peerstore.
Parameters
char* address
: A multiaddress (with peer id) to reach the peer being added.char* protocolId
: A protocol we expect the peer to support.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains the peer ID as a base58 string
of the peer that was added.
For example:
{
"result": "QmWjHKUrXDHPCwoWXpUZ77E8o6UbAoTTZwf1AD1tDC4KNP"
}
extern char* waku_connect(char* address, int timeoutMs)
Dial peer using a multiaddress.
Parameters
char* address
: A multiaddress to reach the peer being dialed.int timeoutMs
: Timeout value in milliseconds to execute the call. If the function execution takes longer than this value, the execution will be canceled and an error returned. Use0
for no timeout.
Returns
A JsonResponse
.
If the execution is successful, the result
field is set to true
.
For example:
{
"result": true
}
extern char* waku_connect_peerid(char* peerId, int timeoutMs)
Dial peer using its peer ID.
Parameters
1char* peerID
: Peer ID to dial.
The peer must be already known.
It must have been added before with waku_add_peer
or previously dialed with waku_connect
.
2. int timeoutMs
: Timeout value in milliseconds to execute the call.
If the function execution takes longer than this value,
the execution will be canceled and an error returned.
Use 0
for no timeout.
Returns
A JsonResponse
.
If the execution is successful, the result
field is set to true
.
For example:
{
"result": true
}
extern char* waku_disconnect(char* peerId)
Disconnect a peer using its peerID
Parameters
char* peerID
: Peer ID to disconnect.
Returns
A JsonResponse
.
If the execution is successful, the result
field is set to true
.
For example:
{
"result": true
}
extern char* waku_peer_count()
Get number of connected peers.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains an integer
which represents the number of connected peers.
For example:
{
"result": 0
}
extern char* waku_peers()
Retrieve the list of peers known by the Waku node.
Returns
A JsonResponse
containing a list of peers.
The list of peers has this format:
{
"result": [
{
"peerID": "16Uiu2HAmJb2e28qLXxT5kZxVUUoJt72EMzNGXB47RedcBafeDCBA",
"protocols": [
"/ipfs/id/1.0.0",
"/vac/waku/relay/2.0.0",
"/ipfs/ping/1.0.0"
],
"addrs": [
"/ip4/1.2.3.4/tcp/30303"
],
"connected": true
}
]
}
Waku Relay
extern char* waku_content_topic(char* applicationName, unsigned int applicationVersion, char* contentTopicName, char* encoding)
Create a content topic string according to RFC 23.
Parameters
char* applicationName
unsigned int applicationVersion
char* contentTopicName
char* encoding
: depending on the payload, useproto
,rlp
orrfc26
Returns
char *
containing a content topic formatted according to RFC 23.
/{application-name}/{version-of-the-application}/{content-topic-name}/{encoding}
extern char* waku_pubsub_topic(char* name, char* encoding)
Create a pubsub topic string according to RFC 23.
Parameters
char* name
char* encoding
: depending on the payload, useproto
,rlp
orrfc26
Returns
char *
containing a content topic formatted according to RFC 23.
/waku/2/{topic-name}/{encoding}
extern char* waku_default_pubsub_topic()
Returns the default pubsub topic used for exchanging waku messages defined in RFC 10.
Returns
char *
containing the default pubsub topic:
/waku/2/default-waku/proto
extern char* waku_relay_publish(char* messageJson, char* pubsubTopic, int timeoutMs)
Publish a message using Waku Relay.
Parameters
char* messageJson
: JSON string containing the Waku Message asJsonMessage
.char* pubsubTopic
: pubsub topic on which to publish the message. IfNULL
, it uses the default pubsub topic.int timeoutMs
: Timeout value in milliseconds to execute the call. If the function execution takes longer than this value, the execution will be canceled and an error returned. Use0
for no timeout.
Note: messageJson.version
is overwritten to 0
.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains the message ID.
extern char* waku_relay_publish_enc_asymmetric(char* messageJson, char* pubsubTopic, char* publicKey, char* optionalSigningKey, int timeoutMs)
Optionally sign, encrypt using asymmetric encryption and publish a message using Waku Relay.
Parameters
char* messageJson
: JSON string containing the Waku Message asJsonMessage
.char* pubsubTopic
: pubsub topic on which to publish the message. IfNULL
, it uses the default pubsub topic.char* publicKey
: hex encoded public key to be used for encryption.char* optionalSigningKey
: hex encoded private key to be used to sign the message.int timeoutMs
: Timeout value in milliseconds to execute the call. If the function execution takes longer than this value, the execution will be canceled and an error returned. Use0
for no timeout.
Note: messageJson.version
is overwritten to 1
.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains the message ID.
extern char* waku_relay_publish_enc_symmetric(char* messageJson, char* pubsubTopic, char* symmetricKey, char* optionalSigningKey, int timeoutMs)
Optionally sign, encrypt using symmetric encryption and publish a message using Waku Relay.
Parameters
char* messageJson
: JSON string containing the Waku Message asJsonMessage
.char* pubsubTopic
: pubsub topic on which to publish the message. IfNULL
, it uses the default pubsub topic.char* symmetricKey
: hex encoded secret key to be used for encryption.char* optionalSigningKey
: hex encoded private key to be used to sign the message.int timeoutMs
: Timeout value in milliseconds to execute the call. If the function execution takes longer than this value, the execution will be canceled and an error returned. Use0
for no timeout.
Note: messageJson.version
is overwritten to 1
.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains the message ID.
extern char* waku_relay_enough_peers(char* pubsubTopic)
Determine if there are enough peers to publish a message on a given pubsub topic.
Parameters
char* pubsubTopic
: Pubsub topic to verify. IfNULL
, it verifies the number of peers in the default pubsub topic.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains a boolean
indicating whether there are enough peers.
For example:
{
"result": true
}
extern char* waku_relay_subscribe(char* topic)
Subscribe to a Waku Relay pubsub topic to receive messages.
Parameters
char* topic
: Pubsub topic to subscribe to. IfNULL
, it subscribes to the default pubsub topic.
Returns
A JsonResponse
.
If the execution is successful, the result
field is set to true
.
For example:
{
"result": true
}
Events
When a message is received, a ``"message" event
is emitted containing the message, pubsub topic, and node ID in which
the message was received.
The event
type is JsonMessageEvent
.
For Example:
{
"type": "message",
"event": {
"pubsubTopic": "/waku/2/default-waku/proto",
"messageID": "0x6496491e40dbe0b6c3a2198c2426b16301688a2daebc4f57ad7706115eac3ad1",
"wakuMessage": {
"payload": "TODO",
"contentTopic": "/my-app/1/notification/proto",
"version": 1,
"timestamp": 1647826358000000000
}
}
}
extern char* waku_relay_unsubscribe(char* topic)
Closes the pubsub subscription to a pubsub topic. No more messages will be received from this pubsub topic.
Parameters
char* pusubTopic
: Pubsub topic to unsubscribe from. IfNULL
, unsubscribes from the default pubsub topic.
Returns
A JsonResponse
.
If the execution is successful, the result
field is set to true
.
For example:
{
"result": true
}
Waku Filter
extern char* waku_filter_subscribe(char* filterJSON, char* peerID, int timeoutMs)
Creates a subscription in a lightnode for messages that matches a content filter and optionally a PubSub topic
.
Parameters
char* filterJSON
: JSON string containing theFilterSubscription
to subscribe to.char* peerID
: Peer ID to subscribe to. The peer must be already known. It must have been added before withwaku_add_peer
or previously dialed withwaku_connect_peer
. UseNULL
to automatically select a node.int timeoutMs
: Timeout value in milliseconds to execute the call. If the function execution takes longer than this value, the execution will be canceled and an error returned. Use0
for no timeout.
Returns
A JsonResponse
.
If the execution is successful, the result
field is set to true
.
For example:
{
"result": true
}
Events
When a message is received, a ``"message" event
is emitted containing the message, pubsub topic, and node ID in which
the message was received.
The event
type is JsonMessageEvent
.
For Example:
{
"type": "message",
"event": {
"pubsubTopic": "/waku/2/default-waku/proto",
"messageId": "0x6496491e40dbe0b6c3a2198c2426b16301688a2daebc4f57ad7706115eac3ad1",
"wakuMessage": {
"payload": "TODO",
"contentTopic": "/my-app/1/notification/proto",
"version": 1,
"timestamp": 1647826358000000000
}
}
}
extern char* waku_filter_unsubscribe(char* filterJSON, int timeoutMs)
Removes subscriptions in a light node matching a content filter and, optionally, a PubSub topic
.
Parameters
char* filterJSON
: JSON string containing theFilterSubscription
.int timeoutMs
: Timeout value in milliseconds to execute the call. If the function execution takes longer than this value, the execution will be canceled and an error returned. Use0
for no timeout.
Returns
A JsonResponse
.
If the execution is successful, the result
field is set to true
.
For example:
{
"result": true
}
Waku Lightpush
extern char* waku_lightpush_publish(char* messageJSON, char* topic, char* peerID, int timeoutMs)
Publish a message using Waku Lightpush.
Parameters
char* messageJson
: JSON string containing the Waku Message asJsonMessage
.char* pubsubTopic
: pubsub topic on which to publish the message. IfNULL
, it uses the default pubsub topic.char* peerID
: Peer ID supporting the lightpush protocol. The peer must be already known. It must have been added before withwaku_add_peer
or previously dialed withwaku_connect_peer
. UseNULL
to automatically select a node.int timeoutMs
: Timeout value in milliseconds to execute the call. If the function execution takes longer than this value, the execution will be canceled and an error returned. Use0
for no timeout.
Note: messageJson.version
is overwritten to 0
.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains the message ID.
extern char* waku_lightpush_publish_enc_asymmetric(char* messageJson, char* pubsubTopic, char* peerID, char* publicKey, char* optionalSigningKey, int timeoutMs)
Optionally sign, encrypt using asymmetric encryption and publish a message using Waku Lightpush.
Parameters
char* messageJson
: JSON string containing the Waku Message asJsonMessage
.char* pubsubTopic
: pubsub topic on which to publish the message. IfNULL
, it uses the default pubsub topic.char* peerID
: Peer ID supporting the lightpush protocol. The peer must be already known. It must have been added before withwaku_add_peer
or previously dialed withwaku_connect_peer
.char* publicKey
: hex encoded public key to be used for encryption.char* optionalSigningKey
: hex encoded private key to be used to sign the message.int timeoutMs
: Timeout value in milliseconds to execute the call. If the function execution takes longer than this value, the execution will be canceled and an error returned. Use0
for no timeout.
Note: messageJson.version
is overwritten to 1
.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains the message ID.
extern char* waku_lightpush_publish_enc_symmetric(char* messageJson, char* pubsubTopic, char* peerID, char* symmetricKey, char* optionalSigningKey, int timeoutMs)
Optionally sign, encrypt using symmetric encryption and publish a message using Waku Lightpush.
Parameters
char* messageJson
: JSON string containing the Waku Message asJsonMessage
.char* pubsubTopic
: pubsub topic on which to publish the message. IfNULL
, it uses the default pubsub topic.char* peerID
: Peer ID supporting the lightpush protocol. The peer must be already known. It must have been added before withwaku_add_peer
or previously dialed withwaku_connect_peer
.char* symmetricKey
: hex encoded secret key to be used for encryption.char* optionalSigningKey
: hex encoded private key to be used to sign the message.int timeoutMs
: Timeout value in milliseconds to execute the call. If the function execution takes longer than this value, the execution will be canceled and an error returned. Use0
for no timeout.
Note: messageJson.version
is overwritten to 1
.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains the message ID.
Waku Store
extern char* waku_store_query(char* queryJSON, char* peerID, int timeoutMs)
Retrieves historical messages on specific content topics. This method may be called with PagingOptions
,
to retrieve historical messages on a per-page basis. If the request included PagingOptions
, the node
must return messages on a per-page basis and include PagingOptions
in the response. These PagingOptions
must contain a cursor pointing to the Index from which a new page can be requested.
Parameters
char* queryJSON
: JSON string containing theStoreQuery
.char* peerID
: Peer ID supporting the store protocol. The peer must be already known. It must have been added before withwaku_add_peer
or previously dialed withwaku_connect_peer
.int timeoutMs
: Timeout value in milliseconds to execute the call. If the function execution takes longer than this value, the execution will be canceled and an error returned. Use0
for no timeout.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains a StoreResponse
..
Decrypting messages
extern char* waku_decode_symmetric(char* messageJson, char* symmetricKey)
Decrypt a message using a symmetric key
Parameters
char* messageJson
: JSON string containing the Waku Message asJsonMessage
.char* symmetricKey
: 32 byte symmetric key hex encoded.
Note: messageJson.version
is expected to be 1
.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains the decoded payload as a DecodedPayload
.
An error
message otherwise.
{
"result": {
"pubkey": "0x......",
"signature": "0x....",
"data": "...",
"padding": "..."
}
}
extern char* waku_decode_asymmetric(char* messageJson, char* privateKey)
Decrypt a message using a secp256k1 private key
Parameters
char* messageJson
: JSON string containing the Waku Message asJsonMessage
.char* privateKey
: secp256k1 private key hex encoded.
Note: messageJson.version
is expected to be 1
.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains the decoded payload as a DecodedPayload
.
An error
message otherwise.
{
"result": {
"pubkey": "0x......",
"signature": "0x....",
"data": "...",
"padding": "..."
}
}
DNS Discovery
extern char* waku_dns_discovery(char* url, char* nameserver, int timeoutMs)
Returns a list of multiaddress given a url to a DNS discoverable ENR tree
Parameters
char* url
: URL containing a discoverable ENR treechar* nameserver
: The nameserver to resolve the ENR tree url. IfNULL
or empty, it will automatically use the default system dns.int timeoutMs
: Timeout value in milliseconds to execute the call. If the function execution takes longer than this value, the execution will be canceled and an error returned. Use0
for no timeout.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains an array with multiaddresses.
An error
message otherwise.
{
"result": [
"/ip4/134.209.139.210/tcp/30303/p2p/16Uiu2HAmPLe7Mzm8TsYUubgCAW1aJoeFScxrLj8ppHFivPo97bUZ",
"/ip4/104.154.239.128/tcp/30303/p2p/16Uiu2HAmJb2e28qLXxT5kZxVUUoJt72EMzNGXB47Rxx5hw3q4YjS",
"/ip4/47.242.210.73/tcp/30303/p2p/16Uiu2HAkvWiyFsgRhuJEb9JfjYxEkoHLgnUQmr1N5mKWnYjxYRVm"
]
}
DiscoveryV5
extern char* waku_discv5_start()
Starts the DiscoveryV5 service to discover and connect to new peers
Returns
A JsonResponse
.
If the execution is successful, the result
field is set to true
.
For example:
{
"result": true
}
extern char* waku_discv5_stop()
Stops the DiscoveryV5 service
Returns
A JsonResponse
.
If the execution is successful, the result
field is set to true
.
For example:
{
"result": true
}
Utils
extern char* waku_utils_base64_encode(char* data)
Encode a byte array to base64.
Useful for creating the payload of a Waku Message in the format understood by waku_relay_publish
Parameters
char* data
: Byte array to encode
Returns
A char *
containing the base64 encoded byte array.
extern char* waku_utils_base64_decode(char* data)
Decode a base64 string (useful for reading the payload from Waku Messages).
Parameters
char* data
: base64 encoded byte array to decode.
Returns
A JsonResponse
.
If the execution is successful, the result
field contains the decoded payload.
extern void waku_utils_free(char* data)
Frees a char* since all strings returned by gowaku are allocated in the C heap using malloc.
Parameters
char* data
: variable to free
Copyright
Copyright and related rights waived via CC0.