Show model and cost in USD as footer for agent prompt and banana image responses

Author: Yetibot

src/yetibot/core/commands/agent.clj

@@ -132,9 +132,11 @@
 (defn say-final
   "The clean final reply: Gemini's summary plus links to any relevant PRs."
   [summary pr-urls]
-  (str (if (string/blank? summary) "✅ done." (str "✅ " summary))
-       (when (seq pr-urls)
-         (str "\n\n🔗 " (string/join "  •  " (distinct pr-urls))))))
+  (let [footer (format "\n\nSent via %s | Cost: $%.2f" (model) (gemini/agent-cost-per-session))]
+    (str (if (string/blank? summary) "✅ done." (str "✅ " summary))
+         (when (seq pr-urls)
+           (str "\n\n🔗 " (string/join "  •  " (distinct pr-urls))))
+         footer)))
 
 (defn say-broken [msg]
   (str "⚠️ Gemini error: " msg))

src/yetibot/core/commands/banana.clj

@@ -35,9 +35,10 @@
                    (str "Generate an image: " prompt) nil image-urls)
             id (store-image! image)
             base-url (gemini/yetibot-base-url)
-            image-url (format "%s/generated-images/%s.png" base-url id)]
+            image-url (format "%s/generated-images/%s.png" base-url id)
+            footer (format "\n\nSent via %s | Cost: $%.3f" (gemini/gemini-model) (gemini/cost-per-image))]
         (info "banana: image generated successfully, serving at" image-url)
-        {:result/value image-url
+        {:result/value (str image-url footer)
          :result/data {:id id :prompt match :url image-url}})
       (catch Exception e
         (error "banana: Gemini image generation error:" (.getMessage e))

src/yetibot/core/util/gemini.clj

@@ -55,7 +55,7 @@
   "Default monthly budget in USD for image generation."
   5.00)
 
-(defn- cost-per-image []
+(defn cost-per-image []
    (or (parse-number (-> config :cost :per))
        (case (gemini-model)
          "gemini-3.1-flash-image-preview" 0.039
@@ -68,7 +68,7 @@
 (defn- max-images-per-month []
   (long (Math/floor (/ (monthly-budget) (cost-per-image)))))
 
-(defn- agent-cost-per-session []
+(defn agent-cost-per-session []
   (or (parse-number (-> config :agent :cost-per-session)) 1.00))
 
 (defn agent-cost-units []

test/yetibot/core/test/commands/agent.clj

@@ -73,6 +73,8 @@
     (agent/say-final "done" ["https://github.com/yetibot/core/pull/242"]) => (contains "pull/242"))
   (fact "say-final copes with a blank answer"
     (agent/say-final "" nil) => (contains "done"))
+  (fact "say-final appends the model and cost footer"
+    (agent/say-final "Added features" nil) => (contains "Sent via gemini-3.1-pro-preview | Cost: $1.00"))
   (fact "say-timeout names the limit"
     (agent/say-timeout 5) => (contains "5 min")))
 

test/yetibot/core/test/commands/banana_test.clj

@@ -23,3 +23,17 @@
                                           :agent-sessions-left 10
                                           :agent-cost-units 10
                                           :month "2026-05"})))
+
+(facts "about banana-cmd"
+       (fact "it generates an image and returns URL with model and cost footer"
+             (b/banana-cmd {:match "banana monkey" :chat-source {}})
+             => (contains {:result/value #"http://localhost:3003/generated-images/img123.png\n\nSent via gemini-3.1-flash-image-preview \| Cost: \$0.039"
+                           :result/data {:id "img123" :prompt "banana monkey" :url "http://localhost:3003/generated-images/img123.png"}})
+             (provided
+               (gemini/configured?) => true
+               (yetibot.core.util.image-input/extract-images "banana monkey" {}) => {:prompt "monkey" :image-urls []}
+               (gemini/generate-image "Generate an image: monkey" nil []) => {:data "bytes" :mime-type "image/png"}
+               (yetibot.core.webapp.routes.images/store-image! {:data "bytes" :mime-type "image/png"}) => "img123"
+               (gemini/yetibot-base-url) => "http://localhost:3003"
+               (gemini/gemini-model) => "gemini-3.1-flash-image-preview"
+               (gemini/cost-per-image) => 0.039)))