lexicons: new app.bsky.graph.getRelationships endpoint (#2059)

* lexicons: new app.bsky.graph.getRelationships endpoint

* getRelationships: maxLength 30

* getRelationships: camelCase, consistent, simplify

* getRelationships: remove blocks; and handle in return

* lex: move graph relationships to defs file

lexicons/app/bsky/graph/defs.json

@@ -67,6 +67,33 @@
         "muted": { "type": "boolean" },
         "blocked": { "type": "string", "format": "at-uri" }
       }
+    },
+    "notFoundActor": {
+      "type": "object",
+      "description": "indicates that a handle or DID could not be resolved",
+      "required": ["actor", "notFound"],
+      "properties": {
+        "actor": { "type": "string", "format": "at-identifier" },
+        "notFound": { "type": "boolean", "const": true }
+      }
+    },
+    "relationship": {
+      "type": "object",
+      "description": "lists the bi-directional graph relationships between one actor (not indicated in the object), and the target actors (the DID included in the object)",
+      "required": ["did"],
+      "properties": {
+        "did": { "type": "string", "format": "did" },
+        "following": {
+          "type": "string",
+          "format": "at-uri",
+          "description": "if the actor follows this DID, this is the AT-URI of the follow record"
+        },
+        "followedBy": {
+          "type": "string",
+          "format": "at-uri",
+          "description": "if the actor is followed by this DID, contains the AT-URI of the follow record"
+        }
+      }
     }
   }
 }

lexicons/app/bsky/graph/getRelationships.json

@@ -0,0 +1,51 @@
+{
+  "lexicon": 1,
+  "id": "app.bsky.graph.getRelationships",
+  "defs": {
+    "main": {
+      "type": "query",
+      "description": "Enumerates public relationships between one account, and a list of other accounts",
+      "parameters": {
+        "type": "params",
+        "required": ["actor"],
+        "properties": {
+          "actor": { "type": "string", "format": "at-identifier" },
+          "others": {
+            "type": "array",
+            "maxLength": 30,
+            "items": {
+              "type": "string",
+              "format": "at-identifier"
+            }
+          }
+        }
+      },
+      "output": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "required": ["relationships"],
+          "properties": {
+            "actor": { "type": "string", "format": "did" },
+            "relationships": {
+              "type": "array",
+              "items": {
+                "type": "union",
+                "refs": [
+                  "app.bsky.graph.def#relationship",
+                  "app.bsky.graph.defs#notFoundActor"
+                ]
+              }
+            }
+          }
+        }
+      },
+      "errors": [
+        {
+          "name": "ActorNotFound",
+          "description": "the primary actor at-identifier could not be resolved"
+        }
+      ]
+    }
+  }
+}