API Documentation

Filecoin Snap API

configure

configure(configuration: Partial<SnapConfig>): Promise<void>;

Configures snap for the specific network. It is possible to send custom configuration or select one from a set of predefined configurations by defining specific network.

There are two predefined configurations for testnet "t" and for mainet "f". If selecting a predefined configuration only network property is required.

export interface SnapConfig {
  derivationPath: string;
  network: FilecoinNetwork;
  rpc: {
    token: string;
    url: string
  };
  unit?: UnitConfiguration;
}

It is also possible to choose a predefined configuration and only change some specific properties. In the example SnapConfig below we selected predefined configuration for testnet network and only changed URL for RPC endpoint (rpcUrl), all other properties will be the same as in predefined configuration for testnet network.

{
  network: "t",
  rpc: {
    token: "",
    url: "test.rpc.url"
  },
}

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getPublicKey

getPublicKey(): Promise<string>

Returns the public key for the generated account.

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getAddress

getAddress(): Promise<string>

Returns address for the generated account.

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getBalance

getBalance(): Promise<string>

Return balance for the generated account.

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exportPrivateKey

exportPrivateKey(): Promise<string>

Return private key for the generated account.

This method will invoke Metamask prompt to confirm action

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Messages

Sending a message is a two-step process (sign message, send message). First, create SignedMessage using signMessage method then send a signed message using sendMessage method. Additionally it is possible to estimate gas parameters with calculateGasForMessage method.

calculateGasForMessage

calculateGasForMessage(message: MessageRequest, maxFee?: string): Promise<MessageGasEstimate>

The function accepts message request object and additional optional parameter for maximum allowed fee (if omitted this will be set to 0.1 FIL)

interface MessageRequest {
  to: string;
  value: string;
  gaslimit?: number;   // leave empty
  gasfeecap?: string;  // leave empty
  gaspremium?: string; // leave empty
  nonce?: number;      // leave empty
}

Returns MessageGasEstimate with estimated values for gas parameters for the provided message, see below.

interface MessageGasEstimate {
  gaslimit: number;
  gasfeecap: string;
  gaspremium: string;
  maxfee: string
}

---

signMessage

signMessage(message: MessageRequest): Promise<SignMessageResponse>

If gas parameters are left out then they will be filled with estimates (see estimateMessageGas function).

interface MessageRequest {
  to: string;
  value: string;
  gaslimit?: number;
  gasfeecap?: string;
  gaspremium?: string;
  nonce?: number;
}

Returns SignMessageResponse with information on sign request status.

interface SignMessageResponse {
  signedMessage: SignedMessage // signed message if sucesfull, null otherwise
  confirmed: boolean // information if user accepted to sign message
  error: Error // null if everything was sucessfull
}

If signing was successful you can find all message details and generated signature inside signedMessage prop, see below.

interface SignedMessage {
  message: Message;
  signature: MessageSignature;
}

interface Message {
  to: string;
  from: string;
  nonce: number;
  value: string;
  gasfeecap: string;
  gaspremium: string;
  gaslimit: number;
  method: number;
  params?: string;
}

interface MessageSignature {
  data: string;
  type: number;
}

---

signMessageRaw

signMessageRaw(message: string): Promise<SignRawMessageResponse>

interface SignRawMessageResponse {
  signature: string
  confirmed: boolean
  error: Error
}

---

sendMessage

sendMessage(signedMessage: SignedMessage): Promise<MessageStatus>

export interface SignedMessage {
  message: Message;
  signature: {
    data: string;
    type: number;
  };
}

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getMessages

getMessages(): Promise<MessageStatus[]>

Returns all messages saved inside the snap state (all messages sent through Filecoin snap) as MessageStatus.

interface MessageStatus {
  message: Message;
  cid: string;
}

It holds information about message parameters as Message and a unique code identifier for the message or CID.

interface Message {
  to: string;
  from: string;
  nonce: number;
  value: string;
  gasfeecap: string;
  gaspremium: string;
  gaslimit: number;
  method: number;
  params?: string;
}

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Filecoin snap API usage examples

Send message

// snap is already installed
const api = await metamaskFilecoinSnap.getFilecoinSnapApi();

const toAddress = "t1wnanhvadbski2fru4l4kry3x2hqq4jobzzic6dq"
const amountAttoFIL = "100000"

const gasEstimate = await api.calculateGasForMessage({
  to: toAddress,
  value: amountAttoFIL,
});

const partialMessage: PartialMessage = {
  to: toAddress,
  value: amountAttoFIL,
  gaslimit: gasEstimate.gaslimit,
  gasfeecap: gasEstimate.gasfeecap,
  gaspremium: gasEstimate.gaspremium,
}

const response: SignMessageResponse = await api.signMessage(partialMessage);
const messageCid = await api.sendMessage(response.signedMessage);

console.log(`Message sent with cid: ${messageCid["/"]}`);