# REST API - Post This function block sends JSON POST requests to a HTTP server address and returns the server response. It is designed for integration with external REST APIs while keeping the user interface responsive. ## đŸ“Ĩ Inputs `Enable Condition` — Logic signal to start a POST request when True. `Server Address` — Text input for the full server endpoint (use full URL starting with http\:// or https\://). `Response Data ID` — Optional key name to extract a specific field from a JSON response. `Post Data` — Generic data payload that will be sent as JSON in the request body. ## 📤 Outputs `Status Code` — HTTP status code returned by the server. `Error` — Error message or reason when the request fails. `Response` — Server response body or the extracted value when `Response Data ID` is provided. ## 🕹ī¸ Controls `Timeout (s)` — Number of seconds to wait before the request times out (adjust to suit slow/fast servers). ## 🎨 Features * Asynchronous requests: POST operations run in the background so the interface remains responsive. * Optional response parsing: If you provide a `Response Data ID` the block will attempt to return that specific field from a JSON response. * Simple integration: Accepts a generic payload so you can send images, numbers, text or structured data prepared by other blocks. ## ⚙ī¸ Running mechanism When `Enable Condition` is True and a valid `Server Address` is provided, the block sends a POST request with the `Post Data` payload. The request uses the configured `Timeout (s)` and runs without blocking the UI. When the server responds, the block updates its outputs with `Status Code`, `Error` (if any), and `Response` (or the selected response field). ## 📝 Usage instructions 1. Provide the target endpoint in `Server Address` (include http\:// or https\://). 2. Connect or prepare the payload on the `Post Data` input (use other blocks to build structured data if needed). 3. Use a logic signal on `Enable Condition` to trigger sending (e.g., manual toggle or a conditional block). 4. Optionally set `Response Data ID` to extract a specific field from the server's JSON response. 5. Adjust `Timeout (s)` if the server is slow or to avoid long waits. ## 💡 Tips and Tricks * Use `Logic Input` or `Rising Edge` to control when the request is sent (single-shot triggers or manual control). * Prepare structured payloads with `Data to JSON` before feeding into `Post Data` for reliable JSON formatting. * Use `String Input` to provide the `Server Address` or `Number Input` for numeric fields inside the payload. * Log or persist responses with `CSV Export` or `Image Logger` (if your payload/response contains images or timestamps). * Pair with `REST API - Get` when you need both POST and GET interactions with the same service (e.g., send data then poll for results). * Include `Date-Time` or `Date-Time List` in your payload to timestamp requests. * Use `Debug Input` to inspect the request payload or server response during development. ## 🛠ī¸ Troubleshooting * No response / network error: Verify that `Server Address` is correct, reachable from the machine, and includes the protocol (http/https). Check firewall or network settings. * Authentication required: Ensure the target API accepts unauthenticated POSTs or add whatever authentication the service needs outside of this block (e.g., via headers managed by the server). * Invalid JSON or unexpected response: Use `Data to JSON` to ensure payload is valid JSON, and check the API documentation for expected field names. If you requested a specific `Response Data ID` and the field is missing, the `Response` output may be empty. * Timeouts: Increase `Timeout (s)` for slow endpoints or check server load. If requests frequently time out, test the service separately to confirm responsiveness. * Repeated triggers: If you only want to send a single POST per event, use `Rising Edge` to convert a continuous True signal into a single trigger. If you need examples of how to chain this block with data formatting, logging or trigger controls, combine it with blocks such as `Data to JSON`, `Logic Input`, `Rising Edge`, `CSV Export`, and `REST API - Get` for common integration patterns.