feat(ai): add the chat capability to the platform contract

A platform can now implement chat, and each AI feature shows only when
the platform implements the capability it relies on.

packages/hoppscotch-common/src/components/http/PreRequestScript.vue

@@ -196,7 +196,7 @@ const currentRequest = computed(() =>
     : null
 )
 
-const { shouldEnableAIFeatures } = useAIExperiments()
+const { shouldEnableAIFeatures } = useAIExperiments("modifyPreRequestScript")
 const isModifyPreRequestModalOpen = ref(false)
 
 const currentUser = useReadonlyStream(

packages/hoppscotch-common/src/components/http/RawBody.vue

@@ -245,7 +245,7 @@ const showModifyBodyModal = () => {
   isModifyBodyModalOpen.value = true
 }
 
-const { shouldEnableAIFeatures } = useAIExperiments()
+const { shouldEnableAIFeatures } = useAIExperiments("modifyRequestBody")
 
 const prettifyXML = (xml: string) => {
   return xmlFormat(xml, {

packages/hoppscotch-common/src/components/http/Tests.vue

@@ -193,7 +193,7 @@ const currentRequest = computed(() =>
     : null
 )
 
-const { shouldEnableAIFeatures } = useAIExperiments()
+const { shouldEnableAIFeatures } = useAIExperiments("modifyTestScript")
 const isModifyTestScriptModalOpen = ref(false)
 
 const currentUser = useReadonlyStream(

packages/hoppscotch-common/src/composables/ai-experiments.ts

@@ -25,7 +25,10 @@ export const useRequestNameGeneration = (targetNameRef: Ref<string>) => {
   const ENABLE_AI_EXPERIMENTS = useSetting("ENABLE_AI_EXPERIMENTS")
 
   const canDoRequestNameGeneration = computed(() => {
-    return ENABLE_AI_EXPERIMENTS.value && !!platform.experiments?.aiExperiments
+    return (
+      ENABLE_AI_EXPERIMENTS.value &&
+      !!platform.experiments?.aiExperiments?.generateRequestName
+    )
   })
 
   const lastTraceID = ref<string | null>(null)
@@ -82,11 +85,28 @@ export const useRequestNameGeneration = (targetNameRef: Ref<string>) => {
   }
 }
 
-export const useAIExperiments = () => {
+/**
+ * The individual AI capabilities a platform may implement. Mirrors the
+ * function members of `ExperimentsPlatformDef["aiExperiments"]`.
+ */
+export type AIExperimentsCapability = keyof Omit<
+  NonNullable<NonNullable<typeof platform.experiments>["aiExperiments"]>,
+  "enableAIExperiments"
+>
+
+/**
+ * Whether AI features should be surfaced. Pass the capability a feature relies
+ * on so its UI only shows when the platform actually implements it — platforms
+ * may provide a subset (e.g. self-host implements only `chat`). With no
+ * capability given, checks only that AI experiments exist at all.
+ */
+export const useAIExperiments = (capability?: AIExperimentsCapability) => {
   const ENABLE_AI_EXPERIMENTS = useSetting("ENABLE_AI_EXPERIMENTS")
 
   const shouldEnableAIFeatures = computed(() => {
-    return ENABLE_AI_EXPERIMENTS.value && !!platform.experiments?.aiExperiments
+    const aiExperiments = platform.experiments?.aiExperiments
+    if (!ENABLE_AI_EXPERIMENTS.value || !aiExperiments) return false
+    return capability ? !!aiExperiments[capability] : true
   })
 
   return {

packages/hoppscotch-common/src/pages/settings.vue

@@ -80,7 +80,7 @@
                 </HoppSmartToggle>
               </div>
               <div
-                v-if="hasAIExperimentsSupport && ENABLE_AI_EXPERIMENTS"
+                v-if="hasAIRequestNamingSupport && ENABLE_AI_EXPERIMENTS"
                 class="flex items-center"
               >
                 <div class="flex flex-col space-y-2 w-full">
@@ -380,6 +380,12 @@ const confirmRemove = ref(false)
 const hasAIExperimentsSupport =
   !!platform.experiments?.aiExperiments?.enableAIExperiments
 
+// The naming-style preference only matters when the platform can generate
+// request names — platforms may implement just a subset of the AI features.
+const hasAIRequestNamingSupport =
+  hasAIExperimentsSupport &&
+  !!platform.experiments?.aiExperiments?.generateRequestName
+
 const showConfirmModal = () => {
   if (TELEMETRY_ENABLED.value) confirmRemove.value = true
   else toggleSetting("TELEMETRY_ENABLED")

packages/hoppscotch-common/src/platform/experiments.ts

@@ -43,5 +43,22 @@ export type ExperimentsPlatformDef = {
     ) => Promise<
       E.Either<string, { modified_script: string; trace_id: string }>
     >
+    chat?: (
+      messages: { role: "user" | "assistant"; content: string | unknown[] }[],
+      context: string
+    ) => Promise<
+      E.Either<
+        string,
+        {
+          content: string
+          tool_calls: {
+            id: string
+            name: string
+            input: Record<string, unknown>
+          }[]
+          trace_id: string
+        }
+      >
+    >
   }
 }