Fix (Ollama provider): Unsupported operation: streaming not implemented (#4303)

Signed-off-by: jovonni <jovonnipharr@gmail.com>
Co-authored-by: Michael Neale <michael.neale@gmail.com>

crates/goose/src/providers/ollama.rs

@@ -1,21 +1,30 @@
 use super::api_client::{ApiClient, AuthMethod};
-use super::base::{ConfigKey, Provider, ProviderMetadata, ProviderUsage, Usage};
+use super::base::{ConfigKey, MessageStream, Provider, ProviderMetadata, ProviderUsage, Usage};
 use super::errors::ProviderError;
 use super::retry::ProviderRetry;
-use super::utils::{get_model, handle_response_openai_compat};
+use super::utils::{get_model, handle_response_openai_compat, handle_status_openai_compat};
 use crate::config::custom_providers::CustomProviderConfig;
 use crate::conversation::message::Message;
 use crate::conversation::Conversation;
 use crate::impl_provider_default;
 use crate::model::ModelConfig;
-use crate::providers::formats::openai::{create_request, get_usage, response_to_message};
+use crate::providers::formats::openai::{
+    create_request, get_usage, response_to_message, response_to_streaming_message,
+};
 use crate::utils::safe_truncate;
 use anyhow::Result;
+use async_stream::try_stream;
 use async_trait::async_trait;
+use futures::TryStreamExt;
 use regex::Regex;
 use rmcp::model::Tool;
-use serde_json::Value;
+use serde_json::{json, Value};
+use std::io;
 use std::time::Duration;
+use tokio::pin;
+use tokio_stream::StreamExt;
+use tokio_util::codec::{FramedRead, LinesCodec};
+use tokio_util::io::StreamReader;
 use url::Url;
 
 pub const OLLAMA_HOST: &str = "localhost";
@@ -78,7 +87,7 @@ impl OllamaProvider {
         Ok(Self {
             api_client,
             model,
-            supports_streaming: false,
+            supports_streaming: true,
         })
     }
 
@@ -228,6 +237,45 @@ impl Provider for OllamaProvider {
     fn supports_streaming(&self) -> bool {
         self.supports_streaming
     }
+
+    async fn stream(
+        &self,
+        system: &str,
+        messages: &[Message],
+        tools: &[Tool],
+    ) -> Result<MessageStream, ProviderError> {
+        let mut payload = create_request(
+            &self.model,
+            system,
+            messages,
+            tools,
+            &super::utils::ImageFormat::OpenAi,
+        )?;
+        payload["stream"] = json!(true);
+        payload["stream_options"] = json!({
+            "include_usage": true,
+        });
+
+        let response = self
+            .api_client
+            .response_post("v1/chat/completions", &payload)
+            .await?;
+        let response = handle_status_openai_compat(response).await?;
+        let stream = response.bytes_stream().map_err(io::Error::other);
+        let model_config = self.model.clone();
+
+        Ok(Box::pin(try_stream! {
+            let stream_reader = StreamReader::new(stream);
+            let framed = FramedRead::new(stream_reader, LinesCodec::new()).map_err(anyhow::Error::from);
+            let message_stream = response_to_streaming_message(framed);
+            pin!(message_stream);
+            while let Some(message) = message_stream.next().await {
+                let (message, usage) = message.map_err(|e| ProviderError::RequestFailed(format!("Stream decode error: {}", e)))?;
+                super::utils::emit_debug_trace(&model_config, &payload, &message, &usage.as_ref().map(|f| f.usage).unwrap_or_default());
+                yield (message, usage);
+            }
+        }))
+    }
 }
 
 impl OllamaProvider {