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Webhooks

An HTTP endpoint is generated for each Webhook Handler. The handler receives a WebhookEvent which contains information about the request (path, headers, etc), and the data returned by the handler is forwarded as the response.

Use cases

  • Creating an HTTP API to interact with specific contracts.
  • Serve a frontend directly from Solidity.
  • Recursively register/remove other handler functions (of any type).

Examples

Return a JSON object with information about the request

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function handle(WebhookEvent calldata ev) external returns(JsonObject memory) {   
    JsonObject memory data = json
        .create(string(ev.body))
        .expect("Failed to parse json body");

    return json
        .create()
        .set("timestamp", ev.timestamp)
        .set("data", data)
        .set("path", ev.path);
}

Query a token's balance

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function handle(WebhookEvent calldata ev) external returns(JsonObject memory) {   
    JsonObject memory data = json
        .create(string(ev.body))
        .expect("Failed to parse json body");

    IERC20 token = IERC20(data.getAddress("token"));
    address wallet = data.getAddress("wallet");

    return json.create().set("balance", token.balanceOf(wallet));
}