diff --git a/lexicons/org/tangled/webhook/createWebhook.json b/lexicons/org/tangled/webhook/createWebhook.json
new file mode 100644
index 00000000..b074a49c
--- /dev/null
+++ b/lexicons/org/tangled/webhook/createWebhook.json
@@ -0,0 +1,62 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.createWebhook",
+  "defs": {
+    "main": {
+      "type": "procedure",
+      "description": "Create a new webhook for a repository.",
+      "input": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["repo", "url", "events"],
+          "properties": {
+            "repo": {
+              "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."
+            },
+            "active": {
+              "type": "boolean",
+              "default": true,
+              "description": "Whether the webhook should be active immediately."
+            },
+            "events": {
+              "type": "array",
+              "description": "Event types to subscribe to.",
+              "items": {
+                "type": "ref",
+                "ref": "org.tangled.webhook.defs#eventType"
+              }
+            },
+            "secret": {
+              "type": "string",
+              "description": "Optional HMAC secret used to sign payloads. If omitted, payloads are not signed."
+            }
+          }
+        }
+      },
+      "output": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["id"],
+          "properties": {
+            "id": {
+              "type": "string",
+              "description": "ID of the newly created webhook."
+            }
+          }
+        }
+      },
+      "errors": [
+        { "name": "NoEventsSelected", "description": "At least one event type must be specified." }
+      ]
+    }
+  }
+}
diff --git a/lexicons/org/tangled/webhook/defs.json b/lexicons/org/tangled/webhook/defs.json
new file mode 100644
index 00000000..dafc4ee3
--- /dev/null
+++ b/lexicons/org/tangled/webhook/defs.json
@@ -0,0 +1,19 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.defs",
+  "defs": {
+    "eventType": {
+      "type": "string",
+      "knownValues": [
+        "push",
+        "repository:renamed",
+        "pull_request:created",
+        "pull_request:resubmitted",
+        "pull_request:merged",
+        "pull_request:closed",
+        "pull_request:reopened",
+        "org.tangled.event.pullRequest"
+      ]
+    }
+  }
+}
diff --git a/lexicons/org/tangled/webhook/deleteWebhook.json b/lexicons/org/tangled/webhook/deleteWebhook.json
new file mode 100644
index 00000000..ddfa59ea
--- /dev/null
+++ b/lexicons/org/tangled/webhook/deleteWebhook.json
@@ -0,0 +1,31 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.deleteWebhook",
+  "defs": {
+    "main": {
+      "type": "procedure",
+      "description": "Delete a webhook from a repository.",
+      "input": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["repo", "webhook"],
+          "properties": {
+            "repo": {
+              "type": "string",
+              "format": "did",
+              "description": "DID of the repository as minted by the knot."
+            },
+            "webhook": {
+              "type": "string",
+              "description": "Webhook ID to delete."
+            }
+          }
+        }
+      },
+      "errors": [
+        { "name": "WebhookNotFound" }
+      ]
+    }
+  }
+}
diff --git a/lexicons/org/tangled/webhook/listWebhookDeliveries.json b/lexicons/org/tangled/webhook/listWebhookDeliveries.json
new file mode 100644
index 00000000..5d17e5b1
--- /dev/null
+++ b/lexicons/org/tangled/webhook/listWebhookDeliveries.json
@@ -0,0 +1,68 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.listWebhookDeliveries",
+  "defs": {
+    "main": {
+      "type": "query",
+      "description": "List recent delivery attempts for a webhook.",
+      "parameters": {
+        "type": "params",
+        "required": ["repo", "webhook"],
+        "properties": {
+          "repo": {
+            "type": "string",
+            "format": "did",
+            "description": "DID of the repository as minted by the knot."
+          },
+          "webhook": {
+            "type": "string",
+            "description": "Webhook ID."
+          },
+          "limit": {
+            "type": "integer",
+            "minimum": 1,
+            "maximum": 100,
+            "default": 50
+          }
+        }
+      },
+      "output": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["deliveries"],
+          "properties": {
+            "deliveries": {
+              "type": "array",
+              "items": {
+                "type": "ref",
+                "ref": "#delivery"
+              }
+            }
+          }
+        }
+      }
+    },
+    "delivery": {
+      "type": "object",
+      "required": ["id", "event", "url", "success", "createdAt"],
+      "properties": {
+        "id": {
+          "type": "string",
+          "description": "Unique ID for tracking this delivery attempt."
+        },
+        "event": {
+          "type": "ref",
+          "ref": "org.tangled.webhook.defs#eventType",
+          "description": "Event type that triggered the delivery."
+        },
+        "url": { "type": "string", "format": "uri" },
+        "requestBody": { "type": "bytes" },
+        "responseCode": { "type": "integer" },
+        "responseBody": { "type": "bytes" },
+        "success": { "type": "boolean" },
+        "createdAt": { "type": "string", "format": "datetime" }
+      }
+    }
+  }
+}
diff --git a/lexicons/org/tangled/webhook/listWebhooks.json b/lexicons/org/tangled/webhook/listWebhooks.json
new file mode 100644
index 00000000..45802774
--- /dev/null
+++ b/lexicons/org/tangled/webhook/listWebhooks.json
@@ -0,0 +1,66 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.listWebhooks",
+  "defs": {
+    "main": {
+      "type": "query",
+      "description": "List webhooks configured for a repository.",
+      "parameters": {
+        "type": "params",
+        "required": ["repo"],
+        "properties": {
+          "repo": {
+            "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": "string",
+          "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.",
+          "items": {
+            "type": "ref",
+            "ref": "org.tangled.webhook.defs#eventType"
+          }
+        },
+        "createdAt": { "type": "string", "format": "datetime" },
+        "updatedAt": { "type": "string", "format": "datetime" }
+      }
+    }
+  }
+}
diff --git a/lexicons/org/tangled/webhook/retryWebhookDelivery.json b/lexicons/org/tangled/webhook/retryWebhookDelivery.json
new file mode 100644
index 00000000..960080af
--- /dev/null
+++ b/lexicons/org/tangled/webhook/retryWebhookDelivery.json
@@ -0,0 +1,36 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.retryWebhookDelivery",
+  "defs": {
+    "main": {
+      "type": "procedure",
+      "description": "Re-send a specific webhook delivery.",
+      "input": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["repo", "webhook", "delivery"],
+          "properties": {
+            "repo": {
+              "type": "string",
+              "format": "did",
+              "description": "DID of the repository as minted by the knot."
+            },
+            "webhook": {
+              "type": "string",
+              "description": "Webhook ID that owns the delivery."
+            },
+            "delivery": {
+              "type": "string",
+              "description": "Delivery ID to retry."
+            }
+          }
+        }
+      },
+      "errors": [
+        { "name": "WebhookNotFound" },
+        { "name": "DeliveryNotFound" }
+      ]
+    }
+  }
+}
diff --git a/lexicons/org/tangled/webhook/updateWebhook.json b/lexicons/org/tangled/webhook/updateWebhook.json
new file mode 100644
index 00000000..f881ed3a
--- /dev/null
+++ b/lexicons/org/tangled/webhook/updateWebhook.json
@@ -0,0 +1,48 @@
+{
+  "lexicon": 1,
+  "id": "org.tangled.webhook.updateWebhook",
+  "defs": {
+    "main": {
+      "type": "procedure",
+      "description": "Update an existing webhook. Only supplied fields are changed.",
+      "input": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["repo", "webhook"],
+          "properties": {
+            "repo": {
+              "type": "string",
+              "format": "did",
+              "description": "DID of the repository as minted by the knot."
+            },
+            "webhook": {
+              "type": "string",
+              "description": "Webhook ID to update."
+            },
+            "url": {
+              "type": "string",
+              "format": "uri"
+            },
+            "secret": {
+              "type": "string"
+            },
+            "active": {
+              "type": "boolean"
+            },
+            "events": {
+              "type": "array",
+              "items": {
+                "type": "ref",
+                "ref": "org.tangled.webhook.defs#eventType"
+              }
+            }
+          }
+        }
+      },
+      "errors": [
+        { "name": "WebhookNotFound" }
+      ]
+    }
+  }
+}