diff --git a/lexicons/webhook/create.json b/lexicons/webhook/create.json
new file mode 100644
index 000000000..a2d844b37
--- /dev/null
+++ b/lexicons/webhook/create.json
@@ -0,0 +1,60 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.create",
+  "defs": {
+    "main": {
+      "type": "procedure",
+      "description": "Create a new webhook for a repository.",
+      "input": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["repoDid", "url", "events"],
+          "properties": {
+            "repoDid": {
+              "type": "string",
+              "format": "did",
+              "description": "DID of the repository as minted by the knot."
+            },
+            "url": {
+              "type": "string",
+              "format": "uri",
+              "description": "Endpoint URL that will receive webhook payloads."
+            },
+            "secret": {
+              "type": "string",
+              "description": "Optional HMAC secret used to sign payloads. If omitted, payloads are not signed."
+            },
+            "active": {
+              "type": "boolean",
+              "description": "Whether the webhook should be active immediately. Defaults to true."
+            },
+            "events": {
+              "type": "array",
+              "description": "Event types to subscribe to (e.g. 'push', 'repository:renamed').",
+              "items": {
+                "type": "string"
+              }
+            }
+          }
+        }
+      },
+      "output": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["id"],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "description": "ID of the newly created webhook."
+            }
+          }
+        }
+      },
+      "errors": [
+        { "name": "NoEventsSelected", "description": "At least one event type must be specified." }
+      ]
+    }
+  }
+}
diff --git a/lexicons/webhook/delete.json b/lexicons/webhook/delete.json
new file mode 100644
index 000000000..dce8bb4ad
--- /dev/null
+++ b/lexicons/webhook/delete.json
@@ -0,0 +1,31 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.delete",
+  "defs": {
+    "main": {
+      "type": "procedure",
+      "description": "Delete a webhook from a repository.",
+      "input": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["repoDid", "id"],
+          "properties": {
+            "repoDid": {
+              "type": "string",
+              "format": "did",
+              "description": "DID of the repository as minted by the knot."
+            },
+            "id": {
+              "type": "integer",
+              "description": "Webhook ID to delete."
+            }
+          }
+        }
+      },
+      "errors": [
+        { "name": "WebhookNotFound" }
+      ]
+    }
+  }
+}
diff --git a/lexicons/webhook/list.json b/lexicons/webhook/list.json
new file mode 100644
index 000000000..9dd121fa7
--- /dev/null
+++ b/lexicons/webhook/list.json
@@ -0,0 +1,71 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.list",
+  "defs": {
+    "main": {
+      "type": "query",
+      "description": "List webhooks configured for a repository.",
+      "parameters": {
+        "type": "params",
+        "required": ["repoDid"],
+        "properties": {
+          "repoDid": {
+            "type": "string",
+            "format": "did",
+            "description": "DID of the repository as minted by the knot."
+          }
+        }
+      },
+      "output": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["webhooks"],
+          "properties": {
+            "webhooks": {
+              "type": "array",
+              "items": {
+                "type": "ref",
+                "ref": "#webhook"
+              }
+            }
+          }
+        }
+      }
+    },
+    "webhook": {
+      "type": "object",
+      "required": ["id", "url", "active", "events", "createdAt"],
+      "properties": {
+        "id": {
+          "type": "integer",
+          "description": "Webhook identifier."
+        },
+        "url": {
+          "type": "string",
+          "format": "uri",
+          "description": "Endpoint URL that receives webhook payloads."
+        },
+        "active": {
+          "type": "boolean",
+          "description": "Whether the webhook is currently enabled."
+        },
+        "events": {
+          "type": "array",
+          "description": "Event types this webhook is subscribed to (e.g. 'push', 'repository:renamed').",
+          "items": {
+            "type": "string"
+          }
+        },
+        "createdAt": {
+          "type": "string",
+          "format": "datetime"
+        },
+        "updatedAt": {
+          "type": "string",
+          "format": "datetime"
+        }
+      }
+    }
+  }
+}
diff --git a/lexicons/webhook/listDeliveries.json b/lexicons/webhook/listDeliveries.json
new file mode 100644
index 000000000..92558bb0c
--- /dev/null
+++ b/lexicons/webhook/listDeliveries.json
@@ -0,0 +1,83 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.listDeliveries",
+  "defs": {
+    "main": {
+      "type": "query",
+      "description": "List recent delivery attempts for a webhook.",
+      "parameters": {
+        "type": "params",
+        "required": ["repoDid", "id"],
+        "properties": {
+          "repoDid": {
+            "type": "string",
+            "format": "did",
+            "description": "DID of the repository as minted by the knot."
+          },
+          "id": {
+            "type": "integer",
+            "description": "Webhook ID."
+          },
+          "limit": {
+            "type": "integer",
+            "minimum": 1,
+            "maximum": 100
+          }
+        }
+      },
+      "output": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["deliveries"],
+          "properties": {
+            "deliveries": {
+              "type": "array",
+              "items": {
+                "type": "ref",
+                "ref": "#delivery"
+              }
+            }
+          }
+        }
+      }
+    },
+    "delivery": {
+      "type": "object",
+      "required": ["id", "deliveryId", "event", "url", "success", "createdAt"],
+      "properties": {
+        "id": {
+          "type": "integer"
+        },
+        "deliveryId": {
+          "type": "string",
+          "description": "UUID for tracking this delivery attempt."
+        },
+        "event": {
+          "type": "string",
+          "description": "Event type that triggered the delivery."
+        },
+        "url": {
+          "type": "string",
+          "format": "uri"
+        },
+        "requestBody": {
+          "type": "string"
+        },
+        "responseCode": {
+          "type": "integer"
+        },
+        "responseBody": {
+          "type": "string"
+        },
+        "success": {
+          "type": "boolean"
+        },
+        "createdAt": {
+          "type": "string",
+          "format": "datetime"
+        }
+      }
+    }
+  }
+}
diff --git a/lexicons/webhook/retryDelivery.json b/lexicons/webhook/retryDelivery.json
new file mode 100644
index 000000000..37c900596
--- /dev/null
+++ b/lexicons/webhook/retryDelivery.json
@@ -0,0 +1,36 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.retryDelivery",
+  "defs": {
+    "main": {
+      "type": "procedure",
+      "description": "Re-send a specific webhook delivery.",
+      "input": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["repoDid", "webhookId", "deliveryId"],
+          "properties": {
+            "repoDid": {
+              "type": "string",
+              "format": "did",
+              "description": "DID of the repository as minted by the knot."
+            },
+            "webhookId": {
+              "type": "integer",
+              "description": "Webhook ID that owns the delivery."
+            },
+            "deliveryId": {
+              "type": "string",
+              "description": "UUID of the delivery to retry."
+            }
+          }
+        }
+      },
+      "errors": [
+        { "name": "WebhookNotFound" },
+        { "name": "DeliveryNotFound" }
+      ]
+    }
+  }
+}
diff --git a/lexicons/webhook/toggle.json b/lexicons/webhook/toggle.json
new file mode 100644
index 000000000..e28ce4887
--- /dev/null
+++ b/lexicons/webhook/toggle.json
@@ -0,0 +1,44 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.toggle",
+  "defs": {
+    "main": {
+      "type": "procedure",
+      "description": "Toggle the active state of a webhook.",
+      "input": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["repoDid", "id"],
+          "properties": {
+            "repoDid": {
+              "type": "string",
+              "format": "did",
+              "description": "DID of the repository as minted by the knot."
+            },
+            "id": {
+              "type": "integer",
+              "description": "Webhook ID to toggle."
+            }
+          }
+        }
+      },
+      "output": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["active"],
+          "properties": {
+            "active": {
+              "type": "boolean",
+              "description": "New active state of the webhook."
+            }
+          }
+        }
+      },
+      "errors": [
+        { "name": "WebhookNotFound" }
+      ]
+    }
+  }
+}
diff --git a/lexicons/webhook/update.json b/lexicons/webhook/update.json
new file mode 100644
index 000000000..c853db7d2
--- /dev/null
+++ b/lexicons/webhook/update.json
@@ -0,0 +1,47 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.update",
+  "defs": {
+    "main": {
+      "type": "procedure",
+      "description": "Update an existing webhook. Only supplied fields are changed.",
+      "input": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["repoDid", "id"],
+          "properties": {
+            "repoDid": {
+              "type": "string",
+              "format": "did",
+              "description": "DID of the repository as minted by the knot."
+            },
+            "id": {
+              "type": "integer",
+              "description": "Webhook ID to update."
+            },
+            "url": {
+              "type": "string",
+              "format": "uri"
+            },
+            "secret": {
+              "type": "string"
+            },
+            "active": {
+              "type": "boolean"
+            },
+            "events": {
+              "type": "array",
+              "items": {
+                "type": "string"
+              }
+            }
+          }
+        }
+      },
+      "errors": [
+        { "name": "WebhookNotFound" }
+      ]
+    }
+  }
+}