diff --git a/server/src/entities/connection/connection.module.ts b/server/src/entities/connection/connection.module.ts
index a128922e..dd2d94d6 100644
--- a/server/src/entities/connection/connection.module.ts
+++ b/server/src/entities/connection/connection.module.ts
@@ -1,6 +1,8 @@
 import { Module } from "@nestjs/common";
 import { MongooseModule } from "@nestjs/mongoose";
 import { Connection, ConnectionSchema } from "./connection.model";
+import { ConnectionResolver } from "./connection.resolver";
+import { ConnectionService } from "./connection.service";
 
 @Module({
   imports: [
@@ -8,6 +10,7 @@ import { Connection, ConnectionSchema } from "./connection.model";
       { name: Connection.name, schema: ConnectionSchema },
     ]),
   ],
-  exports: [MongooseModule],
+  providers: [ConnectionService, ConnectionResolver],
+  exports: [MongooseModule, ConnectionService],
 })
 export class ConnectionModule {}
diff --git a/server/src/entities/connection/connection.resolver.ts b/server/src/entities/connection/connection.resolver.ts
new file mode 100644
index 00000000..5865afc4
--- /dev/null
+++ b/server/src/entities/connection/connection.resolver.ts
@@ -0,0 +1,14 @@
+import { Args, Mutation, Resolver } from "@nestjs/graphql";
+import { Connection } from "./connection.model";
+import { ConnectionService } from "./connection.service";
+import { CreateConnection } from "./dto/create-connection.dto";
+
+@Resolver()
+export class ConnectionResolver {
+  constructor(private connectionService: ConnectionService) {}
+
+  @Mutation(() => Connection)
+  async createConnection(@Args("connection") connection: CreateConnection) {
+    return this.connectionService.create(connection);
+  }
+}
diff --git a/server/src/entities/connection/connection.service.ts b/server/src/entities/connection/connection.service.ts
new file mode 100644
index 00000000..cc298f16
--- /dev/null
+++ b/server/src/entities/connection/connection.service.ts
@@ -0,0 +1,44 @@
+import { Injectable } from "@nestjs/common";
+import { InjectModel } from "@nestjs/mongoose";
+import { pick } from "lodash";
+import { Model } from "mongoose";
+import { Connection, ConnectionDocument } from "./connection.model";
+import { CreateConnection } from "./dto/create-connection.dto";
+
+/**
+ * Main concern of this service is to maintain the two-way connection graph by
+ * keeping two mirrored connections in sync for each wormhole. This enables use
+ * of the `$graphLookup` aggregation stage to traverse the graph and build map
+ * trees.
+ */
+@Injectable()
+export class ConnectionService {
+  constructor(
+    @InjectModel(Connection.name) private connectionModel: Model<Connection>,
+  ) {}
+
+  /** Create `Connection` and its linked reverse `Connection`. */
+  async create(connection: CreateConnection): Promise<ConnectionDocument> {
+    const created = await this.connectionModel.create(connection);
+
+    const duplicateFields = pick(created.toObject(), [
+      "massStatus",
+      "eol",
+      "eolAt",
+      "type",
+    ]);
+
+    const reverse = await this.connectionModel.create({
+      ...duplicateFields,
+      from: created.to,
+      to: created.from,
+      k162: created.type && !created.k162,
+      reverse: created,
+    });
+
+    created.reverse = reverse;
+    await created.save();
+
+    return created.populate("reverse");
+  }
+}
diff --git a/server/src/entities/connection/dto/create-connection.dto.ts b/server/src/entities/connection/dto/create-connection.dto.ts
new file mode 100644
index 00000000..f23d1530
--- /dev/null
+++ b/server/src/entities/connection/dto/create-connection.dto.ts
@@ -0,0 +1,26 @@
+import { Field, InputType } from "@nestjs/graphql";
+import MassStatus from "../mass-status.enum";
+
+@InputType()
+export class CreateConnection {
+  @Field()
+  from: string;
+
+  @Field({ nullable: true })
+  to: string;
+
+  @Field({ nullable: true })
+  type: string;
+
+  @Field()
+  k162: boolean;
+
+  @Field()
+  eol: boolean;
+
+  @Field((type) => Date, { nullable: true })
+  eolAt?: Date;
+
+  @Field((type) => MassStatus)
+  massStatus: MassStatus;
+}