> ## Documentation Index > Fetch the complete documentation index at: https://villagesql.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Sending Webhooks from Triggers > How to send HTTP webhooks from MySQL triggers using VillageSQL's vsql_http extension — push row changes to external services automatically on INSERT, UPDATE, or DELETE. All examples in this guide work on VillageSQL. Install Now → Keeping external systems in sync with your database usually means polling — the external service periodically queries your API for changes, or your application code publishes events after every write. With VillageSQL's `vsql_http` extension, triggers can send HTTP requests directly, so external systems get notified the moment a row changes, with no application-layer event publishing required. ## Setup ```sql theme={null} INSTALL EXTENSION vsql_http; ``` ## Basic Webhook Trigger An `AFTER INSERT` trigger that POSTs a payload to a webhook endpoint: ```sql theme={null} DELIMITER $$ CREATE TRIGGER after_order_insert AFTER INSERT ON orders FOR EACH ROW BEGIN SET @payload = JSON_OBJECT( 'event', 'order.created', 'id', NEW.id, 'customer', NEW.customer_id, 'total', NEW.total, 'status', NEW.status ); SET @ignored = vsql_http.http_post( 'https://hooks.example.com/orders', 'application/json', @payload ); END$$ DELIMITER ; ``` The result is assigned to `@ignored` — the trigger doesn't use the response, but the assignment suppresses the "result not used" warning. NULL means the connection failed; the trigger completes either way and the INSERT goes through. ## Controlling Timeouts By default, `vsql_http` uses a 30-second timeout. A slow or unavailable webhook endpoint blocks the write for that long. Use `http_request()` with an options JSON to set a tighter deadline: ```sql theme={null} DELIMITER $$ CREATE TRIGGER after_order_insert AFTER INSERT ON orders FOR EACH ROW BEGIN SET @payload = JSON_OBJECT( 'event', 'order.created', 'id', NEW.id, 'customer', NEW.customer_id, 'total', NEW.total ); SET @ignored = vsql_http.http_request( 'POST', 'https://hooks.example.com/orders', NULL, @payload, 'application/json', '{"timeout": 3}' ); END$$ DELIMITER ; ``` A 3-second timeout caps how long a webhook delay can hold up a write. The request either completes or gives up — the INSERT is not rolled back. ## UPDATE and DELETE Triggers The same pattern works for updates and deletes. Use `OLD` to include the previous values: ```sql theme={null} DELIMITER $$ CREATE TRIGGER after_order_update AFTER UPDATE ON orders FOR EACH ROW BEGIN IF NEW.status != OLD.status THEN SET @payload = JSON_OBJECT( 'event', 'order.status_changed', 'id', NEW.id, 'old_status', OLD.status, 'new_status', NEW.status ); SET @ignored = vsql_http.http_request( 'POST', 'https://hooks.example.com/orders', NULL, @payload, 'application/json', '{"timeout": 3}' ); END IF; END$$ DELIMITER ; ``` The `IF NEW.status != OLD.status` guard avoids firing the webhook on UPDATE statements that don't change the status — keeping webhook volume proportional to meaningful changes. ## Authentication Pass API keys or bearer tokens in the `headers_json` argument of `http_request()`: ```sql theme={null} DELIMITER $$ CREATE TRIGGER after_order_insert AFTER INSERT ON orders FOR EACH ROW BEGIN SET @payload = JSON_OBJECT('id', NEW.id, 'total', NEW.total); SET @ignored = vsql_http.http_request( 'POST', 'https://hooks.example.com/orders', '{"Authorization": "Bearer your-webhook-secret"}', @payload, 'application/json', '{"timeout": 3}' ); END$$ DELIMITER ; ``` Store secrets in a configuration table and retrieve them into a variable at trigger time rather than hardcoding them in the trigger body. ## Important Caveats **Triggers are synchronous.** The HTTP call blocks until it completes or times out. A webhook endpoint that's slow or down will hold up every write to that table. Always set a short timeout (2–5 seconds) and design the endpoint to respond immediately (queue the work, don't process it inline). **Failures are silent by default.** If the HTTP call returns NULL (connection failure), the trigger doesn't raise an error and the write succeeds. A non-2xx response also returns silently — `http_post()` returns JSON regardless of status code, and the trigger doesn't inspect it. If reliable delivery matters, use a transactional outbox pattern instead: write events to an `outbox` table in the same transaction, then deliver them with a separate process. **Triggers fire once per row.** `FOR EACH ROW` means a bulk `UPDATE orders SET status = 'shipped'` hits 1000 rows sends 1000 webhook calls. That can overload the endpoint and exhaust connection limits. For bulk operations, suppress the trigger or use the outbox pattern. **No retry logic.** A failed request stays failed. Build retry and dead-letter handling in the receiving system or the outbox process, not in the trigger. ## Troubleshooting | Problem | Solution | | :------------------------------------ | :--------------------------------------------------------------------------- | | Writes become slow | Webhook endpoint is slow — set a short timeout in `http_request()` options | | Trigger body error on creation | Check `DELIMITER $$` is set before `CREATE TRIGGER` | | No webhook received | NULL return means connection failed — verify network access from server host | | Too many webhook calls on bulk UPDATE | Guard with `IF NEW.col != OLD.col` or suppress trigger for batch operations | ## Next Steps * [Making HTTP requests from SQL](/guides/http-requests-in-mysql) — full function reference including response parsing * [Enriching rows with API data](/guides/rest-api-enrichment) — pull external data into your tables * [Triggers in MySQL](/guides/triggers) — general trigger patterns and BEFORE vs AFTER semantics ## See also * [Making HTTP Requests from SQL](/guides/http-requests-in-mysql) — the vsql\_http functions used in webhook triggers * [MySQL Triggers](/guides/triggers) — the trigger mechanics that fire webhooks * [HMAC Signatures in MySQL](/guides/hmac-mysql) — signing webhook payloads for recipient verification