fix: zero out cost for local providers (ollama, local) (#9222)

Signed-off-by: Douwe Osinga <douwe@squareup.com>
Co-authored-by: Douwe Osinga <douwe@squareup.com>

crates/goose/src/providers/canonical/mod.rs

@@ -67,12 +67,39 @@ pub fn recommended_models_from_registry(provider: &str) -> Vec<String> {
 pub fn maybe_get_canonical_model(provider: &str, model: &str) -> Option<CanonicalModel> {
     let registry = CanonicalModelRegistry::bundled().ok()?;
 
-    // map_to_canonical_model returns the canonical ID (provider/model)
-    // Parse it to get provider and model parts for registry lookup
     let canonical_id = map_to_canonical_model(provider, model, registry)?;
-    if let Some((canon_provider, canon_model)) = canonical_id.split_once('/') {
-        registry.get(canon_provider, canon_model).cloned()
+    let mut canonical = if let Some((canon_provider, canon_model)) = canonical_id.split_once('/') {
+        registry.get(canon_provider, canon_model).cloned()?
     } else {
-        None
+        return None;
+    };
+
+    // TODO: replace with a flag on the provider once we have one
+    if matches!(provider, "ollama" | "local") {
+        canonical.cost = Pricing::default();
+    }
+
+    Some(canonical)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn ollama_models_have_zero_cost() {
+        let canonical = maybe_get_canonical_model("ollama", "mistral-nemo")
+            .expect("mistral-nemo should resolve via ollama");
+        assert_eq!(canonical.cost.input, None);
+        assert_eq!(canonical.cost.output, None);
+        assert!(canonical.limit.context > 0);
+    }
+
+    #[test]
+    fn cloud_provider_retains_cost() {
+        let canonical = maybe_get_canonical_model("anthropic", "claude-3-5-sonnet-20241022")
+            .expect("claude-3.5-sonnet should resolve");
+        assert!(canonical.cost.input.is_some());
+        assert!(canonical.cost.output.is_some());
     }
 }