rfc/content/docs/rfcs/36

slug	title	name	status	tags	editor	contributors
36	36/WAKU2-BINDINGS-API	Waku v2 C Bindings API	draft	waku-core	Richard Ramos <richard@status.im>	Franck Royer <franck@status.im>

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.

Design requirements

The API should be generic enough, so:

• it can be implemented by both nwaku and go-waku C-Bindings,
• it can be consumed from a variety of languages such as C#, Kotlin, Swift, Rust, C++, etc.

The selected format to pass data to and from the API is JSON.

It has been selected due to its widespread usage and easiness of use. Other alternatives MAY replace it in the future (C structure, protobuf) if it brings limitations that need to be lifted.

The API

General

JsonResponse type

All the API functions return a JsonResponse unless specified otherwise. The returned JsonResponse is a char * whose format depends on whether the function was executed successfully or not. And it is important to notice that this returned JsonReponse is returned from the latest argument, instead of from the actual function's returned value.

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 with 0x prefix,
• signature: Message signature (optional), hex encoded with 0x 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 of ContentFilter 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 of ContentFilter 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 in PagingOptions 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 in JsonMessage format.
• pagingOption: Paging information in PagingOptions 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 this Index.
• receiverTime: UNIX timestamp in nanoseconds at which the message at this Index was received.
• senderTime: UNIX timestamp in nanoseconds at which the message is generated by its sender.
• pubsubTopic: The pubsub topic of the message at this Index.

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, only message 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 in JsonMessage 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

1. void* cb: callback that will be executed when an async event is emitted. The function signature for the callback should be void 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;
    relayTopics?: Array<string>;
    gossipsubParameters?: GossipSubParameters;
    minPeersToPublish?: number
    filter?: boolean;
    discV5?: boolean;
    discV5BootstrapNodes?: Array<string>;
    discV5UDPPort?: number;
    store?: boolean;
    databaseURL?: string;
    storeRetentionMaxMessages?: number;
    storeRetentionTimeSeconds?: number;
}

Fields:

All fields are optional. If a key is undefined, or null, a default value will be set.

• host: Listening IP address. Default 0.0.0.0.
• port: Libp2p TCP listening port. Default 60000. Use 0 for random.
• advertiseAddr: External address to advertise to other nodes. Can be ip4, ip6 or dns4, dns6. If null, 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. Default 20.
• relay: Enable relay protocol. Default true.
• relayTopics: Array of pubsub topics that WakuRelay will automatically subscribe to when the node starts Default []
• gossipSubParameters: custom gossipsub parameters. See GossipSubParameters section for defaults
• minPeersToPublish: The minimum number of peers required on a topic to allow broadcasting a message. Default 0.
• filter: Enable filter protocol. Default false.
• discV5: Enable DiscoveryV5. Default false
• discV5BootstrapNodes: Array of bootstrap nodes ENR
• discV5UDPPort: UDP port for DiscoveryV5 Default 9000
• store: Enable store protocol to persist message history Default false
• databaseURL: url connection string. Accepts SQLite and PostgreSQL connection strings Default: sqlite3://store.db
• storeRetentionMaxMessages: max number of messages to store in the database. Default 10000
• storeRetentionTimeSeconds: max number of seconds that a message will be persisted in the database. Default 2592000 (30d) For example:

{
  "host": "0.0.0.0",
  "port": 60000,
  "advertiseAddr": "1.2.3.4",
  "nodeKey": "0x123...567",
  "keepAliveInterval": 20,
  "relay": true,
  "minPeersToPublish": 0
}

GossipsubParameters type

Type holding custom gossipsub configuration:

interface GossipSubParameters {
    D?: number;
    D_low?: number;
    D_high?: number;
    D_score?: number;
    D_out?: number;
    HistoryLength?: number;
    HistoryGossip?: number;
    D_lazy?: number;
    GossipFactor?: number;
    GossipRetransmission?: number;
    HeartbeatInitialDelayMs?: number;
    HeartbeatIntervalSeconds?: number;
    SlowHeartbeatWarning?: number;
    FanoutTTLSeconds?: number;
    PrunePeers?: number;
    PruneBackoffSeconds?: number;
    UnsubscribeBackoffSeconds?: number;
    Connectors?: number;
    MaxPendingConnections?: number;
    ConnectionTimeoutSeconds?: number;
    DirectConnectTicks?: number;
    DirectConnectInitialDelaySeconds?: number;
    OpportunisticGraftTicks?: number;
    OpportunisticGraftPeers?: number;
    GraftFloodThresholdSeconds?: number;
    MaxIHaveLength?: number;
    MaxIHaveMessages?: number;
    IWantFollowupTimeSeconds?: number;
}

Fields:

All fields are optional. If a key is undefined, or null, a default value will be set.

• d: optimal degree for a GossipSub topic mesh. Default 6
• dLow: lower bound on the number of peers we keep in a GossipSub topic mesh Default 5
• dHigh: upper bound on the number of peers we keep in a GossipSub topic mesh. Default 12
• dScore: affects how peers are selected when pruning a mesh due to over subscription. Default 4
• dOut: sets the quota for the number of outbound connections to maintain in a topic mesh. Default 2
• historyLength: controls the size of the message cache used for gossip. Default 5
• historyGossip: controls how many cached message ids we will advertise in IHAVE gossip messages. Default 3
• dLazy: affects how many peers we will emit gossip to at each heartbeat. Default 6
• gossipFactor: affects how many peers we will emit gossip to at each heartbeat. Default 0.25
• gossipRetransmission: controls how many times we will allow a peer to request the same message id through IWANT gossip before we start ignoring them. Default 3
• heartbeatInitialDelayMs: short delay in milliseconds before the heartbeat timer begins after the router is initialized. Default 100 milliseconds
• heartbeatIntervalSeconds: controls the time between heartbeats. Default 1 second
• slowHeartbeatWarning: duration threshold for heartbeat processing before emitting a warning. Default 0.1
• fanoutTTLSeconds: controls how long we keep track of the fanout state. Default 60 seconds
• prunePeers: controls the number of peers to include in prune Peer eXchange. Default 16
• pruneBackoffSeconds: controls the backoff time for pruned peers. Default 60 seconds
• unsubscribeBackoffSeconds: controls the backoff time to use when unsuscribing from a topic. Default 10 seconds
• connectors: number of active connection attempts for peers obtained through PX. Default 8
• maxPendingConnections: maximum number of pending connections for peers attempted through px. Default 128
• connectionTimeoutSeconds: timeout in seconds for connection attempts. Default 30 seconds
• directConnectTicks: the number of heartbeat ticks for attempting to reconnect direct peers that are not currently connected. Default 300
• directConnectInitialDelaySeconds: initial delay before opening connections to direct peers. Default 1 second
• opportunisticGraftTicks: number of heartbeat ticks for attempting to improve the mesh with opportunistic grafting. Default 60
• opportunisticGraftPeers: the number of peers to opportunistically graft. Default 2
• graftFloodThresholdSeconds: If a GRAFT comes before GraftFloodThresholdSeconds has elapsed since the last PRUNE, then there is an extra score penalty applied to the peer through P7. Default 10 seconds
• maxIHaveLength: max number of messages to include in an IHAVE message, also controls the max number of IHAVE ids we will accept and request with IWANT from a peer within a heartbeat. Default 5000
• maxIHaveMessages: max number of IHAVE messages to accept from a peer within a heartbeat. Default 10
• iWantFollowupTimeSeconds: Time to wait for a message requested through IWANT following an IHAVE advertisement. Default 3 seconds
• seenMessagesTTLSeconds: configures when a previously seen message ID can be forgotten about. Default 120 seconds

extern unsigned int waku_new(char* jsonConfig, char* jsonResp)

Instantiates a Waku node.

Parameters

1. [input] char* jsonConfig: JSON string containing the options used to initialize a waku node. Type JsonConfig. It can be NULL to use defaults.

2. [output] char* jsonResp: JsonResponse. Provides information indicating whether the operation succeded or not. In case or error, it tries to give as much detail as possible.

   Ex1:

   {
     "result": true
   }
   

   Ex2:

   {
     "error": "The node key is missing."
   }
   

Returns

Unsigned int. Possible values:

• 1 - The operation was completed successfuly.
• 0 - The operation failed for any reason. It worth checking the value of jsonResp in this case.

extern unsigned int waku_start(char* jsonResp)

Starts a Waku node mounting all the protocols that were enabled during the Waku node instantiation.

Parameters

1. [output] char* jsonResp: JsonResponse. Provides information indicating whether the operation succeded or not. In case or error, it tries to give as much detail as possible.

   Ex:

   {
     "result": true
   }
   

Returns

Unsigned int. Possible values:

• 1 - The operation was completed successfuly.
• 0 - The operation failed for any reason. It worth checking the value of jsonResp in this case.

extern unsigned int waku_stop(char* jsonResp)

Stops a Waku node.

Parameters

1. [output] char* jsonResp: JsonResponse. Provides information indicating whether the operation succeded or not. In case or error, it tries to give as much detail as possible.

   Ex:

   {
     "result": true
   }
   

Returns

Unsigned int. Possible values:

• 1 - The operation was completed successfuly.
• 0 - The operation failed for any reason. It worth checking the value of jsonResp in this case.

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 strings.

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

1. char* address: A multiaddress (with peer id) to reach the peer being added.
2. 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 unsigned int waku_connect(char* address, int timeoutMs, char* jsonResp)

Dial peer using a multiaddress.

Parameters

1. [input] char* address: A multiaddress to reach the peer being dialed.

2. [input] 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.

3. [output] JsonResponse. If the execution is successful, the result field is set to true.

   Ex1:

   {
      "result": true
   }
   

   Ex2:

   {
      "error": "Timeout expired."
   }
   

Returns

Unsigned int. Possible values:

• 1 - The operation was completed successfuly.
• 0 - The operation failed for any reason. It worth checking the value of jsonResp in this case.

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

1. 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 void waku_content_topic(char* applicationName, unsigned int applicationVersion, char* contentTopicName, char* encoding, char* outContentTopic)

Create a content topic string according to RFC 23.

Parameters

1. [input] char* applicationName
2. [input] unsigned int applicationVersion
3. [input] char* contentTopicName
4. [input] char* encoding: depending on the payload, use proto, rlp or rfc26
5. [output] char* outContentTopic. Gets populated with 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, char* outPubsubTopic)

Create a pubsub topic string according to RFC 23.

Parameters

1. [input] char* name
2. [input] char* encoding: depending on the payload, use proto, rlp or rfc26
3. [output] char* outPubsubTopic. Gets populated with a pubsub topic formatted according to RFC 23.

   /waku/2/{topic-name}/{encoding}
   

extern void waku_default_pubsub_topic(char* defaultPubsubTopic)

Returns the default pubsub topic used for exchanging waku messages defined in RFC 10.

Parameters

1. [output] char* defaultPubsubTopic. Gets populated with /waku/2/default-waku/proto

extern unsinged int waku_relay_publish(char* messageJson, char* pubsubTopic, int timeoutMs, char* jsonResp)

Publish a message using Waku Relay.

Parameters

1. [input] char* messageJson: JSON string containing the Waku Message as JsonMessage.
2. [input] char* pubsubTopic: pubsub topic on which to publish the message. If NULL, it uses the default pubsub topic.
3. [input] 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.
4. [output]: A JsonResponse. If the execution is successful, the result field contains the message ID.

Note: messageJson.version is overwritten to 0.

Returns Unsigned int. Possible values:

• 1 - The operation was completed successfuly.
• 0 - The operation failed for any reason. It worth checking the value of jsonResp in this case.

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

1. char* messageJson: JSON string containing the Waku Message as JsonMessage.
2. char* pubsubTopic: pubsub topic on which to publish the message. If NULL, it uses the default pubsub topic.
3. char* publicKey: hex encoded public key to be used for encryption.
4. char* optionalSigningKey: hex encoded private key to be used to sign the message.
5. 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.

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

1. char* messageJson: JSON string containing the Waku Message as JsonMessage.
2. char* pubsubTopic: pubsub topic on which to publish the message. If NULL, it uses the default pubsub topic.
3. char* symmetricKey: hex encoded secret key to be used for encryption.
4. char* optionalSigningKey: hex encoded private key to be used to sign the message.
5. 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.

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

1. char* pubsubTopic: Pubsub topic to verify. If NULL, 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 unsigned int waku_relay_subscribe(char* topic, char* jsonResp)

Subscribe to a Waku Relay pubsub topic to receive messages.

Parameters

1. [input] char* topic: Pubsub topic to subscribe to. If NULL, it subscribes to the default pubsub topic.

2. [output] char* jsonResp: A JsonResponse. If the execution is successful, the result field is set to true.

   Ex1:

   {
     "result": true
   }
   

   {
     "error": "Cannot subscribe without Waku Relay enabled."
   }
   

Returns Unsigned int. Possible values:

• 1 - The operation was completed successfuly.
• 0 - The operation failed for any reason. It worth checking the value of jsonResp in this case.

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 unsigned int waku_relay_unsubscribe(char* topic, char* jsonResp)

Closes the pubsub subscription to a pubsub topic. No more messages will be received from this pubsub topic.

Parameters

1. [input] char* pusubTopic: Pubsub topic to unsubscribe from. If NULL, unsubscribes from the default pubsub topic.

2. [output] A JsonResponse. If the execution is successful, the result field is set to true.

   For example:

   {
      "result": true
   }
   

Returns Unsigned int. Possible values:

• 1 - The operation was completed successfuly.
• 0 - The operation failed for any reason. It worth checking the value of jsonResp in this case.

extern char* waku_relay_topics()

Get the list of subscribed pubsub topics in Waku Relay.

Returns

A JsonResponse. If the execution is successful, the result field will contain an array of pubsub topics.

For example:

{
  "result": ["pubsubTopic1", "pubsubTopic2"]
}

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

1. char* filterJSON: JSON string containing the FilterSubscription to subscribe to.
2. char* peerID: Peer ID to subscribe to. The peer must be already known. It must have been added before with waku_add_peer or previously dialed with waku_connect_peer. Use NULL to automatically select a node.
3. 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
}

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

1. char* filterJSON: JSON string containing the FilterSubscription.
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
}

Waku Lightpush

extern char* waku_lightpush_publish(char* messageJSON, char* topic, char* peerID, int timeoutMs)

Publish a message using Waku Lightpush.

Parameters

1. char* messageJson: JSON string containing the Waku Message as JsonMessage.
2. char* pubsubTopic: pubsub topic on which to publish the message. If NULL, it uses the default pubsub topic.
3. char* peerID: Peer ID supporting the lightpush protocol. The peer must be already known. It must have been added before with waku_add_peer or previously dialed with waku_connect_peer. Use NULL to automatically select a node.
4. 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.

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

1. char* messageJson: JSON string containing the Waku Message as JsonMessage.
2. char* pubsubTopic: pubsub topic on which to publish the message. If NULL, it uses the default pubsub topic.
3. char* peerID: Peer ID supporting the lightpush protocol. The peer must be already known. It must have been added before with waku_add_peer or previously dialed with waku_connect_peer.
4. char* publicKey: hex encoded public key to be used for encryption.
5. char* optionalSigningKey: hex encoded private key to be used to sign the message.
6. 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.

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

1. char* messageJson: JSON string containing the Waku Message as JsonMessage.
2. char* pubsubTopic: pubsub topic on which to publish the message. If NULL, it uses the default pubsub topic.
3. char* peerID: Peer ID supporting the lightpush protocol. The peer must be already known. It must have been added before with waku_add_peer or previously dialed with waku_connect_peer.
4. char* symmetricKey: hex encoded secret key to be used for encryption.
5. char* optionalSigningKey: hex encoded private key to be used to sign the message.
6. 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.

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

1. char* queryJSON: JSON string containing the StoreQuery.
2. char* peerID: Peer ID supporting the store protocol. The peer must be already known. It must have been added before with waku_add_peer or previously dialed with waku_connect_peer.
3. 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 contains a StoreResponse..

Decrypting messages

extern char* waku_decode_symmetric(char* messageJson, char* symmetricKey)

Decrypt a message using a symmetric key

Parameters

1. char* messageJson: JSON string containing the Waku Message as JsonMessage.
2. 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

1. char* messageJson: JSON string containing the Waku Message as JsonMessage.
2. 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

1. char* url: URL containing a discoverable ENR tree
2. char* nameserver: The nameserver to resolve the ENR tree url. If NULL or empty, it will automatically use the default system dns.
3. 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 contains an array objects describing the multiaddresses, enr and peerID each node found. An error message otherwise.

{
  "result":[
    {
        "peerID":"16Uiu2HAmPLe7Mzm8TsYUubgCAW1aJoeFScxrLj8ppHFivPo97bUZ",
        "multiaddrs":[
            "/ip4/134.209.139.210/tcp/30303/p2p/16Uiu2HAmPLe7Mzm8TsYUubgCAW1aJoeFScxrLj8ppHFivPo97bUZ",
            "/dns4/node-01.do-ams3.wakuv2.test.statusim.net/tcp/8000/wss/p2p/16Uiu2HAmPLe7Mzm8TsYUubgCAW1aJoeFScxrLj8ppHFivPo97bUZ"
        ],
        "enr":"enr:-M-4QCtJKX2WDloRYDT4yjeMGKUCRRcMlsNiZP3cnPO0HZn6IdJ035RPCqsQ5NvTyjqHzKnTM6pc2LoKliV4CeV0WrgBgmlkgnY0gmlwhIbRi9KKbXVsdGlhZGRyc7EALzYobm9kZS0wMS5kby1hbXMzLndha3V2Mi50ZXN0LnN0YXR1c2ltLm5ldAYfQN4DiXNlY3AyNTZrMaEDnr03Tuo77930a7sYLikftxnuG3BbC3gCFhA4632ooDaDdGNwgnZfg3VkcIIjKIV3YWt1Mg8"
    },
    ...
}

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

1. 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

1. char* data: base64 encoded byte array to decode.

Returns

A JsonResponse. If the execution is successful, the result field contains the decoded payload.

Copyright

Copyright and related rights waived via CC0.