Support OpenAI-style plugins by default

Author: keithwhor

lib/gateway.js

@@ -11,6 +11,7 @@ const uuid = require('uuid');
 
 const backgroundValidator = require('./background_validator.js');
 const types = require('./types.js');
+const wellKnowns = require('./well-knowns.js');
 
 const AsyncFunction = Object.getPrototypeOf(async function () {}).constructor;
 
@@ -212,6 +213,19 @@ class Gateway extends EventEmitter {
     this._serverSentEvents[req._uuid] = sseInstance;
   }
 
+  __wellKnownResponse__ (req, res, body, headers) {
+    headers = headers || {};
+    headers = this.__createHeaders__(req, headers);
+    headers['content-type'] = 'application/json';
+    return this.__endRequest__(
+      200,
+      this.__formatHeaders__(headers),
+      req,
+      res,
+      body
+    );
+  }
+
   __clientError__ (req, res, message, status, headers) {
     headers = headers || {};
     headers = this.__createHeaders__(req, headers);
@@ -1298,6 +1312,26 @@ class Gateway extends EventEmitter {
           return this.__clientError__(req, res, err.message, err.statusCode || 400);
         }
 
+        if (definition.hasOwnProperty('wellKnown')) {
+          const wellKnown = definition.wellKnown;
+          const definitions = definition.definitions;
+          let httpResponse;
+          try {
+            if (wellKnown === 'ai-plugin') {
+              httpResponse = this.wellKnownAIPlugin(definitions, data);
+            } else if (wellKnown === 'api') {
+              httpResponse = this.wellKnownAPIDefinition(definitions, data);
+            } else if (wellKnown === 'openapi') {
+              httpResponse = this.wellKnownOpenAPIDefinition(definitions, data);
+            } else {
+              return this.__fatalError__(req, res, `No .well-known handler for "${wellKnown}"`);
+            }
+          } catch (e) {
+            return this.__fatalError__(req, res, `Error running .well-known handler for "${wellKnown}"`, e.stack);
+          }
+          return this.__wellKnownResponse__(req, res, httpResponse.body, httpResponse.headers);
+        }
+
         let headers = {};
         headers['x-execution-uuid'] = req._uuid;
         if (definition.origins) {
@@ -1634,11 +1668,18 @@ class Gateway extends EventEmitter {
     name = name.replace(/^\/?(.*?)\/?$/gi, '$1');
     let definition = definitions[name];
     if (!definition) {
-      let subname = name;
-      definition = definitions[`${subname}:notfound`];
-      while (subname && !definition) {
-        subname = subname.substr(0, subname.lastIndexOf('/'));
+      if (wellKnowns[name]) {
+        return {
+          wellKnown: wellKnowns[name],
+          definitions: definitions
+        };
+      } else {
+        let subname = name;
         definition = definitions[`${subname}:notfound`];
+        while (subname && !definition) {
+          subname = subname.substr(0, subname.lastIndexOf('/'));
+          definition = definitions[`${subname}:notfound`];
+        }
       }
     }
     if (!definition) {
@@ -2119,6 +2160,53 @@ class Gateway extends EventEmitter {
     }
   }
 
+  wellKnownAIPlugin (definitions, data) {
+    return {
+      headers: {},
+      body: Buffer.from(
+        JSON.stringify(
+          {
+            "schema_version": "v1",
+            "name_for_human": "TODO List (service auth)",
+            "name_for_model": "todo",
+            "description_for_human": "Manage your TODO list. You can add, remove and view your TODOs.",
+            "description_for_model": "Plugin for managing a TODO list, you can add, remove and view your TODOs.",
+            "auth": {
+              "type": "service_http",
+              "authorization_type": "bearer",
+              "verification_tokens": {
+                "openai": "Replace_this_string_with_the_verification_token_generated_in_the_ChatGPT_UI"
+              }
+            },
+            "api": {
+              "type": "openapi",
+              "url": "https://example.com/openapi.yaml"
+            },
+            "logo_url": "https://example.com/logo.png",
+            "contact_email": "support@example.com",
+            "legal_info_url": "https://example.com/legal"
+          },
+          null,
+          2
+        )
+      )
+    };
+  }
+
+  wellKnownAPIDefinition (definitions, data) {
+    return {
+      headers: {},
+      body: Buffer.from(JSON.stringify(definitions, null, 2))
+    }
+  }
+
+  wellKnownOpenAPIDefinition (definitions, data) {
+    return {
+      headers: {},
+      body: Buffer.from('OpenAPI Spec')
+    }
+  }
+
   end (req, value) {
     // do nothing, response completed
     // this.log(req, value, 'result');

lib/well-knowns.js

@@ -0,0 +1,7 @@
+const wellKnown = {
+  '.well-known/ai-plugin.json': 'ai-plugin',
+  '.well-known/api.json': 'api',
+  '.well-known/openapi.yaml': 'openapi'
+};
+
+module.exports = wellKnown;