M3: OpenAI chat and responses codecs, provider, registry wiring

Adds both OpenAI codecs — chat completions and the newer responses API — plus the OpenAiProvider and registry wiring, so the same session can run against OpenAI in addition to Anthropic.
This commit is contained in:
2026-07-08 23:35:49 +02:00
parent d4a846f827
commit 607bd88ae3
6 changed files with 1097 additions and 1 deletions
+16 -1
View File
@@ -19,7 +19,7 @@ use harness_core::tool::ToolRegistry;
use harness_core::types::{
Message, MessageId, ModelRef, Part, PartBody, PartId, Session, SessionId,
};
use harness_providers::{AnthropicProvider, ProviderRegistry};
use harness_providers::{AnthropicProvider, OpenAiProvider, ProviderRegistry};
use tokio::task::JoinHandle;
use tokio_util::sync::CancellationToken;
@@ -122,6 +122,21 @@ impl EngineHandle {
{
providers.register(Arc::new(AnthropicProvider::new(key)));
}
if let Some(key) = config
.providers
.get("openai")
.and_then(|p| p.api_key.clone())
{
let provider = match config
.providers
.get("openai")
.and_then(|p| p.base_url.clone())
{
Some(base_url) => OpenAiProvider::with_base_url(key, base_url),
None => OpenAiProvider::new(key),
};
providers.register(Arc::new(provider));
}
let data_dir = dirs::data_dir()
.unwrap_or_else(std::env::temp_dir)
@@ -1 +1,3 @@
pub mod anthropic;
pub mod openai_chat;
pub mod openai_responses;
@@ -0,0 +1,502 @@
//! Request builder + SSE decoder for OpenAI's `/chat/completions` streaming API.
//!
//! Also used as the fallback codec for OpenAI-compatible endpoints (including Copilot models
//! whose `supported_endpoints` list `/chat/completions`).
use std::collections::HashMap;
use async_stream::try_stream;
use eventsource_stream::Eventsource;
use futures::Stream;
use harness_core::llm::{
FinishReason, LlmEvent, LlmEventStream, LlmRequest, ProviderError, ReasoningEffort, Role,
WireContent,
};
use harness_core::types::TokenUsage;
use serde_json::{json, Value};
fn effort_str(effort: ReasoningEffort) -> &'static str {
match effort {
ReasoningEffort::Low => "low",
ReasoningEffort::Medium => "medium",
ReasoningEffort::High => "high",
}
}
fn role_str(role: Role) -> &'static str {
match role {
Role::System => "system",
Role::User => "user",
Role::Assistant => "assistant",
Role::Tool => "tool",
}
}
/// Flattens our grouped `WireMessage`s into the flat chat-completions message list. Tool
/// results become their own `role: "tool"` messages (one per result), which is what the API
/// expects regardless of how the engine grouped them.
fn build_messages(system: &[String], messages: &[harness_core::llm::WireMessage]) -> Vec<Value> {
let mut out: Vec<Value> = Vec::new();
if !system.is_empty() {
out.push(json!({"role": "system", "content": system.join("\n\n")}));
}
for m in messages {
// Tool results are always emitted as standalone `tool` messages.
for c in &m.content {
if let WireContent::ToolResult {
call_id, output, ..
} = c
{
out.push(json!({
"role": "tool",
"tool_call_id": call_id,
"content": output,
}));
}
}
let mut text = String::new();
let mut images: Vec<Value> = Vec::new();
let mut tool_calls: Vec<Value> = Vec::new();
for c in &m.content {
match c {
WireContent::Text { text: t } => {
if !text.is_empty() {
text.push('\n');
}
text.push_str(t);
}
WireContent::ToolCall {
call_id,
name,
input,
} => tool_calls.push(json!({
"id": call_id,
"type": "function",
"function": {"name": name, "arguments": input.to_string()},
})),
WireContent::Image { mime_type, data } => images.push(json!({
"type": "image_url",
"image_url": {"url": format!("data:{mime_type};base64,{data}")},
})),
WireContent::ToolResult { .. } => {} // handled above
}
}
// A message that carried nothing but tool results contributes no further entry.
if text.is_empty() && images.is_empty() && tool_calls.is_empty() {
continue;
}
let mut msg = json!({"role": role_str(m.role)});
if images.is_empty() {
msg["content"] = json!(text);
} else {
let mut parts = vec![json!({"type": "text", "text": text})];
parts.extend(images);
msg["content"] = json!(parts);
}
if !tool_calls.is_empty() {
msg["tool_calls"] = json!(tool_calls);
}
out.push(msg);
}
out
}
pub fn build_request(req: &LlmRequest) -> Value {
let mut body = json!({
"model": req.model,
"messages": build_messages(&req.system, &req.messages),
"stream": true,
"stream_options": {"include_usage": true},
});
if !req.tools.is_empty() {
body["tools"] = Value::Array(
req.tools
.iter()
.map(|t| {
json!({
"type": "function",
"function": {
"name": t.name,
"description": t.description,
"parameters": t.parameters,
},
})
})
.collect(),
);
}
if let Some(temp) = req.temperature {
body["temperature"] = json!(temp);
}
if let Some(max) = req.max_tokens {
body["max_completion_tokens"] = json!(max);
}
if let Some(effort) = req.reasoning.as_ref().and_then(|r| r.effort) {
body["reasoning_effort"] = json!(effort_str(effort));
}
body
}
fn map_finish_reason(reason: &str) -> FinishReason {
match reason {
"stop" => FinishReason::Stop,
"tool_calls" | "function_call" => FinishReason::ToolCalls,
"length" => FinishReason::Length,
"content_filter" => FinishReason::ContentFilter,
other => FinishReason::Unknown(other.to_string()),
}
}
#[derive(Default)]
struct ToolAccum {
call_id: String,
name: String,
args: String,
}
/// Decodes a chat-completions SSE byte stream into normalized `LlmEvent`s. Tool-call deltas
/// are accumulated by their `index` and flushed as `ToolCall`s once the stream ends.
pub fn decode<S, E>(byte_stream: S) -> LlmEventStream
where
S: Stream<Item = Result<bytes::Bytes, E>> + Send + 'static,
E: std::error::Error + Send + Sync + 'static,
{
let events = byte_stream.eventsource();
Box::pin(try_stream! {
futures::pin_mut!(events);
let mut usage = TokenUsage::default();
let mut reason = FinishReason::Stop;
let mut text_open = false;
let mut reasoning_open = false;
let mut tools: HashMap<u64, ToolAccum> = HashMap::new();
let mut tool_order: Vec<u64> = Vec::new();
while let Some(item) = futures::StreamExt::next(&mut events).await {
let event = item.map_err(|e| ProviderError::Decode(e.to_string()))?;
let data = event.data.trim();
if data.is_empty() {
continue;
}
if data == "[DONE]" {
break;
}
let value: Value = serde_json::from_str(data)
.map_err(|e| ProviderError::Decode(format!("{e}: {data}")))?;
if let Some(u) = value.get("usage").filter(|u| u.is_object()) {
usage.input = u["prompt_tokens"].as_u64().unwrap_or(usage.input);
usage.output = u["completion_tokens"].as_u64().unwrap_or(usage.output);
usage.reasoning = u["completion_tokens_details"]["reasoning_tokens"]
.as_u64()
.unwrap_or(usage.reasoning);
usage.cache_read = u["prompt_tokens_details"]["cached_tokens"]
.as_u64()
.unwrap_or(usage.cache_read);
}
let choice = &value["choices"][0];
let delta = &choice["delta"];
if let Some(rc) = delta["reasoning_content"].as_str().filter(|s| !s.is_empty()) {
if !reasoning_open {
reasoning_open = true;
yield LlmEvent::ReasoningStart { id: "reasoning".into() };
}
yield LlmEvent::ReasoningDelta { id: "reasoning".into(), text: rc.to_string() };
}
if let Some(text) = delta["content"].as_str().filter(|s| !s.is_empty()) {
if reasoning_open {
reasoning_open = false;
yield LlmEvent::ReasoningEnd { id: "reasoning".into(), signature: None };
}
if !text_open {
text_open = true;
yield LlmEvent::TextStart { id: "0".into() };
}
yield LlmEvent::TextDelta { id: "0".into(), text: text.to_string() };
}
if let Some(calls) = delta["tool_calls"].as_array() {
for call in calls {
let index = call["index"].as_u64().unwrap_or(0);
let entry = tools.entry(index).or_insert_with(|| {
tool_order.push(index);
ToolAccum::default()
});
if let Some(id) = call["id"].as_str().filter(|s| !s.is_empty()) {
entry.call_id = id.to_string();
}
if let Some(name) = call["function"]["name"].as_str().filter(|s| !s.is_empty()) {
entry.name = name.to_string();
yield LlmEvent::ToolInputStart {
call_id: entry.call_id.clone(),
name: entry.name.clone(),
};
}
if let Some(args) = call["function"]["arguments"].as_str().filter(|s| !s.is_empty()) {
entry.args.push_str(args);
yield LlmEvent::ToolInputDelta {
call_id: entry.call_id.clone(),
json: args.to_string(),
};
}
}
}
if let Some(fr) = choice["finish_reason"].as_str() {
reason = map_finish_reason(fr);
}
}
if reasoning_open {
yield LlmEvent::ReasoningEnd { id: "reasoning".into(), signature: None };
}
if text_open {
yield LlmEvent::TextEnd { id: "0".into() };
}
for index in tool_order {
if let Some(entry) = tools.remove(&index) {
let input: Value = if entry.args.trim().is_empty() {
json!({})
} else {
serde_json::from_str(&entry.args).unwrap_or(Value::Null)
};
yield LlmEvent::ToolCall { call_id: entry.call_id, name: entry.name, input };
}
}
yield LlmEvent::Finish { reason, usage };
})
}
#[cfg(test)]
mod tests {
use super::*;
use futures::StreamExt;
use harness_core::llm::{Initiator, ReasoningOpts, ToolSchema, WireMessage};
fn sse_stream(raw: &'static str) -> LlmEventStream {
let chunks: Vec<Result<bytes::Bytes, std::io::Error>> =
vec![Ok(bytes::Bytes::from_static(raw.as_bytes()))];
decode(futures::stream::iter(chunks))
}
fn req(model: &str) -> LlmRequest {
LlmRequest {
model: model.into(),
system: vec![],
messages: vec![],
tools: vec![],
temperature: None,
max_tokens: None,
reasoning: None,
initiator: Initiator::User,
}
}
#[tokio::test]
async fn decodes_text_only_response() {
let raw = concat!(
"data: {\"choices\":[{\"delta\":{\"content\":\"Hel\"},\"finish_reason\":null}]}\n\n",
"data: {\"choices\":[{\"delta\":{\"content\":\"lo\"},\"finish_reason\":null}]}\n\n",
"data: {\"choices\":[{\"delta\":{},\"finish_reason\":\"stop\"}]}\n\n",
"data: {\"choices\":[],\"usage\":{\"prompt_tokens\":10,\"completion_tokens\":5}}\n\n",
"data: [DONE]\n\n",
);
let events: Vec<LlmEvent> = sse_stream(raw).map(|e| e.unwrap()).collect().await;
assert_eq!(
events,
vec![
LlmEvent::TextStart { id: "0".into() },
LlmEvent::TextDelta {
id: "0".into(),
text: "Hel".into()
},
LlmEvent::TextDelta {
id: "0".into(),
text: "lo".into()
},
LlmEvent::TextEnd { id: "0".into() },
LlmEvent::Finish {
reason: FinishReason::Stop,
usage: TokenUsage {
input: 10,
output: 5,
..Default::default()
},
},
]
);
}
#[tokio::test]
async fn decodes_tool_call_accumulated_by_index() {
let raw = concat!(
"data: {\"choices\":[{\"delta\":{\"tool_calls\":[{\"index\":0,\"id\":\"call_1\",\"function\":{\"name\":\"read\",\"arguments\":\"\"}}]}}]}\n\n",
"data: {\"choices\":[{\"delta\":{\"tool_calls\":[{\"index\":0,\"function\":{\"arguments\":\"{\\\"file\\\"\"}}]}}]}\n\n",
"data: {\"choices\":[{\"delta\":{\"tool_calls\":[{\"index\":0,\"function\":{\"arguments\":\":\\\"a.txt\\\"}\"}}]}}]}\n\n",
"data: {\"choices\":[{\"delta\":{},\"finish_reason\":\"tool_calls\"}],\"usage\":{\"prompt_tokens\":1,\"completion_tokens\":8}}\n\n",
"data: [DONE]\n\n",
);
let events: Vec<LlmEvent> = sse_stream(raw).map(|e| e.unwrap()).collect().await;
assert_eq!(
events,
vec![
LlmEvent::ToolInputStart {
call_id: "call_1".into(),
name: "read".into()
},
LlmEvent::ToolInputDelta {
call_id: "call_1".into(),
json: "{\"file\"".into()
},
LlmEvent::ToolInputDelta {
call_id: "call_1".into(),
json: ":\"a.txt\"}".into()
},
LlmEvent::ToolCall {
call_id: "call_1".into(),
name: "read".into(),
input: json!({"file": "a.txt"}),
},
LlmEvent::Finish {
reason: FinishReason::ToolCalls,
usage: TokenUsage {
input: 1,
output: 8,
..Default::default()
},
},
]
);
}
#[tokio::test]
async fn decodes_reasoning_content_before_text() {
let raw = concat!(
"data: {\"choices\":[{\"delta\":{\"reasoning_content\":\"hmm\"}}]}\n\n",
"data: {\"choices\":[{\"delta\":{\"content\":\"answer\"}}]}\n\n",
"data: {\"choices\":[{\"delta\":{},\"finish_reason\":\"stop\"}]}\n\n",
"data: [DONE]\n\n",
);
let events: Vec<LlmEvent> = sse_stream(raw).map(|e| e.unwrap()).collect().await;
assert_eq!(
events,
vec![
LlmEvent::ReasoningStart {
id: "reasoning".into()
},
LlmEvent::ReasoningDelta {
id: "reasoning".into(),
text: "hmm".into()
},
LlmEvent::ReasoningEnd {
id: "reasoning".into(),
signature: None
},
LlmEvent::TextStart { id: "0".into() },
LlmEvent::TextDelta {
id: "0".into(),
text: "answer".into()
},
LlmEvent::TextEnd { id: "0".into() },
LlmEvent::Finish {
reason: FinishReason::Stop,
usage: TokenUsage::default()
},
]
);
}
#[test]
fn build_request_wraps_tools_in_function_envelope() {
let mut r = req("gpt-4o");
r.tools = vec![ToolSchema {
name: "read".into(),
description: "reads a file".into(),
parameters: json!({"type": "object"}),
}];
let body = build_request(&r);
assert_eq!(body["tools"][0]["type"], "function");
assert_eq!(body["tools"][0]["function"]["name"], "read");
assert_eq!(
body["tools"][0]["function"]["parameters"],
json!({"type": "object"})
);
assert_eq!(body["stream_options"]["include_usage"], true);
}
#[test]
fn build_request_prepends_system_message() {
let mut r = req("gpt-4o");
r.system = vec!["env".into(), "agent".into()];
r.messages = vec![WireMessage {
role: Role::User,
content: vec![WireContent::Text { text: "hi".into() }],
}];
let body = build_request(&r);
let msgs = body["messages"].as_array().unwrap();
assert_eq!(msgs[0]["role"], "system");
assert_eq!(msgs[0]["content"], "env\n\nagent");
assert_eq!(msgs[1]["role"], "user");
assert_eq!(msgs[1]["content"], "hi");
}
#[test]
fn build_request_expands_tool_results_to_tool_messages() {
let mut r = req("gpt-4o");
r.messages = vec![WireMessage {
role: Role::Tool,
content: vec![WireContent::ToolResult {
call_id: "call_1".into(),
output: "contents".into(),
is_error: false,
}],
}];
let body = build_request(&r);
let msgs = body["messages"].as_array().unwrap();
assert_eq!(msgs.len(), 1);
assert_eq!(msgs[0]["role"], "tool");
assert_eq!(msgs[0]["tool_call_id"], "call_1");
assert_eq!(msgs[0]["content"], "contents");
}
#[test]
fn build_request_emits_assistant_tool_calls() {
let mut r = req("gpt-4o");
r.messages = vec![WireMessage {
role: Role::Assistant,
content: vec![WireContent::ToolCall {
call_id: "call_1".into(),
name: "read".into(),
input: json!({"file": "a.txt"}),
}],
}];
let body = build_request(&r);
let msgs = body["messages"].as_array().unwrap();
assert_eq!(msgs[0]["tool_calls"][0]["id"], "call_1");
assert_eq!(msgs[0]["tool_calls"][0]["function"]["name"], "read");
assert_eq!(
msgs[0]["tool_calls"][0]["function"]["arguments"],
"{\"file\":\"a.txt\"}"
);
}
#[test]
fn build_request_sets_reasoning_effort() {
let mut r = req("o3");
r.reasoning = Some(ReasoningOpts {
effort: Some(ReasoningEffort::High),
budget_tokens: None,
});
let body = build_request(&r);
assert_eq!(body["reasoning_effort"], "high");
}
}
@@ -0,0 +1,402 @@
//! Request builder + SSE decoder for OpenAI's `/responses` streaming API.
//!
//! The responses API is the preferred surface for `gpt-*` / `o-*` models: it carries
//! reasoning items natively and reports reasoning-token usage separately.
use std::collections::HashMap;
use async_stream::try_stream;
use eventsource_stream::Eventsource;
use futures::Stream;
use harness_core::llm::{
FinishReason, LlmEvent, LlmEventStream, LlmRequest, ProviderError, ReasoningEffort, Role,
WireContent,
};
use harness_core::types::TokenUsage;
use serde_json::{json, Value};
fn effort_str(effort: ReasoningEffort) -> &'static str {
match effort {
ReasoningEffort::Low => "low",
ReasoningEffort::Medium => "medium",
ReasoningEffort::High => "high",
}
}
/// Builds the `input` item list. Text/image content become `message` items; tool calls and
/// their results become `function_call` / `function_call_output` items (the responses API
/// keeps these as top-level items rather than nesting them inside messages).
fn build_input(messages: &[harness_core::llm::WireMessage]) -> Vec<Value> {
let mut out: Vec<Value> = Vec::new();
for m in messages {
let (role, text_type) = match m.role {
Role::Assistant => ("assistant", "output_text"),
_ => ("user", "input_text"),
};
let mut content_parts: Vec<Value> = Vec::new();
for c in &m.content {
match c {
WireContent::Text { text } => {
content_parts.push(json!({"type": text_type, "text": text}));
}
WireContent::Image { mime_type, data } => {
content_parts.push(json!({
"type": "input_image",
"image_url": format!("data:{mime_type};base64,{data}"),
}));
}
WireContent::ToolCall {
call_id,
name,
input,
} => out.push(json!({
"type": "function_call",
"call_id": call_id,
"name": name,
"arguments": input.to_string(),
})),
WireContent::ToolResult {
call_id, output, ..
} => out.push(json!({
"type": "function_call_output",
"call_id": call_id,
"output": output,
})),
}
}
if !content_parts.is_empty() {
out.push(json!({"type": "message", "role": role, "content": content_parts}));
}
}
out
}
pub fn build_request(req: &LlmRequest) -> Value {
let mut body = json!({
"model": req.model,
"input": build_input(&req.messages),
"stream": true,
"store": false,
});
if !req.system.is_empty() {
body["instructions"] = json!(req.system.join("\n\n"));
}
if !req.tools.is_empty() {
body["tools"] = Value::Array(
req.tools
.iter()
.map(|t| {
json!({
"type": "function",
"name": t.name,
"description": t.description,
"parameters": t.parameters,
})
})
.collect(),
);
}
if let Some(temp) = req.temperature {
body["temperature"] = json!(temp);
}
if let Some(max) = req.max_tokens {
body["max_output_tokens"] = json!(max);
}
if let Some(effort) = req.reasoning.as_ref().and_then(|r| r.effort) {
body["reasoning"] = json!({"effort": effort_str(effort), "summary": "auto"});
}
body
}
fn map_status(status: Option<&str>, had_tool_call: bool) -> FinishReason {
match status {
Some("completed") if had_tool_call => FinishReason::ToolCalls,
Some("completed") => FinishReason::Stop,
Some("incomplete") => FinishReason::Length,
Some(other) => FinishReason::Unknown(other.to_string()),
None if had_tool_call => FinishReason::ToolCalls,
None => FinishReason::Stop,
}
}
/// Tracks which normalized stream an `item_id` belongs to so deltas route correctly.
enum ItemKind {
Text,
Reasoning,
FunctionCall { call_id: String, name: String },
}
/// Decodes a `/responses` SSE byte stream into normalized `LlmEvent`s.
pub fn decode<S, E>(byte_stream: S) -> LlmEventStream
where
S: Stream<Item = Result<bytes::Bytes, E>> + Send + 'static,
E: std::error::Error + Send + Sync + 'static,
{
let events = byte_stream.eventsource();
Box::pin(try_stream! {
futures::pin_mut!(events);
let mut items: HashMap<String, ItemKind> = HashMap::new();
let mut fn_args: HashMap<String, String> = HashMap::new();
let mut usage = TokenUsage::default();
let mut had_tool_call = false;
while let Some(item) = futures::StreamExt::next(&mut events).await {
let event = item.map_err(|e| ProviderError::Decode(e.to_string()))?;
if event.data.trim().is_empty() {
continue;
}
let value: Value = serde_json::from_str(&event.data)
.map_err(|e| ProviderError::Decode(format!("{e}: {}", event.data)))?;
let kind = value["type"].as_str().unwrap_or_default();
match kind {
"response.output_item.added" => {
let item = &value["item"];
let id = item["id"].as_str().unwrap_or_default().to_string();
match item["type"].as_str().unwrap_or_default() {
"message" => {
items.insert(id.clone(), ItemKind::Text);
yield LlmEvent::TextStart { id };
}
"reasoning" => {
items.insert(id.clone(), ItemKind::Reasoning);
yield LlmEvent::ReasoningStart { id };
}
"function_call" => {
let call_id = item["call_id"].as_str().unwrap_or_default().to_string();
let name = item["name"].as_str().unwrap_or_default().to_string();
fn_args.insert(id.clone(), String::new());
items.insert(id, ItemKind::FunctionCall { call_id: call_id.clone(), name: name.clone() });
had_tool_call = true;
yield LlmEvent::ToolInputStart { call_id, name };
}
_ => {}
}
}
"response.output_text.delta" => {
let id = value["item_id"].as_str().unwrap_or_default().to_string();
let text = value["delta"].as_str().unwrap_or_default().to_string();
yield LlmEvent::TextDelta { id, text };
}
"response.reasoning_summary_text.delta" => {
let id = value["item_id"].as_str().unwrap_or_default().to_string();
let text = value["delta"].as_str().unwrap_or_default().to_string();
yield LlmEvent::ReasoningDelta { id, text };
}
"response.function_call_arguments.delta" => {
let id = value["item_id"].as_str().unwrap_or_default().to_string();
let delta = value["delta"].as_str().unwrap_or_default();
if let (Some(buf), Some(ItemKind::FunctionCall { call_id, .. })) =
(fn_args.get_mut(&id), items.get(&id))
{
buf.push_str(delta);
yield LlmEvent::ToolInputDelta { call_id: call_id.clone(), json: delta.to_string() };
}
}
"response.output_item.done" => {
let id = value["item"]["id"].as_str().unwrap_or_default().to_string();
match items.remove(&id) {
Some(ItemKind::Text) => yield LlmEvent::TextEnd { id },
Some(ItemKind::Reasoning) => yield LlmEvent::ReasoningEnd { id, signature: None },
Some(ItemKind::FunctionCall { call_id, name }) => {
let raw = fn_args.remove(&id).unwrap_or_default();
let input: Value = if raw.trim().is_empty() {
json!({})
} else {
serde_json::from_str(&raw).unwrap_or(Value::Null)
};
yield LlmEvent::ToolCall { call_id, name, input };
}
None => {}
}
}
"response.completed" | "response.incomplete" => {
let response = &value["response"];
let u = &response["usage"];
usage.input = u["input_tokens"].as_u64().unwrap_or(0);
usage.output = u["output_tokens"].as_u64().unwrap_or(0);
usage.reasoning = u["output_tokens_details"]["reasoning_tokens"].as_u64().unwrap_or(0);
usage.cache_read = u["input_tokens_details"]["cached_tokens"].as_u64().unwrap_or(0);
let status = response["status"].as_str();
yield LlmEvent::Finish { reason: map_status(status, had_tool_call), usage };
}
"error" | "response.failed" => {
let message = value["response"]["error"]["message"]
.as_str()
.or_else(|| value["message"].as_str())
.unwrap_or("unknown error")
.to_string();
Err(ProviderError::Http { status: 0, body: message })?;
}
_ => {}
}
}
})
}
#[cfg(test)]
mod tests {
use super::*;
use futures::StreamExt;
use harness_core::llm::{Initiator, ReasoningOpts, ToolSchema, WireMessage};
fn sse_stream(raw: &'static str) -> LlmEventStream {
let chunks: Vec<Result<bytes::Bytes, std::io::Error>> =
vec![Ok(bytes::Bytes::from_static(raw.as_bytes()))];
decode(futures::stream::iter(chunks))
}
fn req(model: &str) -> LlmRequest {
LlmRequest {
model: model.into(),
system: vec![],
messages: vec![],
tools: vec![],
temperature: None,
max_tokens: None,
reasoning: None,
initiator: Initiator::User,
}
}
#[tokio::test]
async fn decodes_text_response() {
let raw = concat!(
"data: {\"type\":\"response.output_item.added\",\"item\":{\"id\":\"msg_1\",\"type\":\"message\"}}\n\n",
"data: {\"type\":\"response.output_text.delta\",\"item_id\":\"msg_1\",\"delta\":\"Hello\"}\n\n",
"data: {\"type\":\"response.output_item.done\",\"item\":{\"id\":\"msg_1\"}}\n\n",
"data: {\"type\":\"response.completed\",\"response\":{\"status\":\"completed\",\"usage\":{\"input_tokens\":10,\"output_tokens\":5}}}\n\n",
);
let events: Vec<LlmEvent> = sse_stream(raw).map(|e| e.unwrap()).collect().await;
assert_eq!(
events,
vec![
LlmEvent::TextStart { id: "msg_1".into() },
LlmEvent::TextDelta {
id: "msg_1".into(),
text: "Hello".into()
},
LlmEvent::TextEnd { id: "msg_1".into() },
LlmEvent::Finish {
reason: FinishReason::Stop,
usage: TokenUsage {
input: 10,
output: 5,
..Default::default()
},
},
]
);
}
#[tokio::test]
async fn decodes_function_call_with_reasoning_tokens() {
let raw = concat!(
"data: {\"type\":\"response.output_item.added\",\"item\":{\"id\":\"fc_1\",\"type\":\"function_call\",\"call_id\":\"call_1\",\"name\":\"read\"}}\n\n",
"data: {\"type\":\"response.function_call_arguments.delta\",\"item_id\":\"fc_1\",\"delta\":\"{\\\"file\\\":\"}\n\n",
"data: {\"type\":\"response.function_call_arguments.delta\",\"item_id\":\"fc_1\",\"delta\":\"\\\"a.txt\\\"}\"}\n\n",
"data: {\"type\":\"response.output_item.done\",\"item\":{\"id\":\"fc_1\"}}\n\n",
"data: {\"type\":\"response.completed\",\"response\":{\"status\":\"completed\",\"usage\":{\"input_tokens\":3,\"output_tokens\":9,\"output_tokens_details\":{\"reasoning_tokens\":4}}}}\n\n",
);
let events: Vec<LlmEvent> = sse_stream(raw).map(|e| e.unwrap()).collect().await;
assert_eq!(
events,
vec![
LlmEvent::ToolInputStart {
call_id: "call_1".into(),
name: "read".into()
},
LlmEvent::ToolInputDelta {
call_id: "call_1".into(),
json: "{\"file\":".into()
},
LlmEvent::ToolInputDelta {
call_id: "call_1".into(),
json: "\"a.txt\"}".into()
},
LlmEvent::ToolCall {
call_id: "call_1".into(),
name: "read".into(),
input: json!({"file": "a.txt"}),
},
LlmEvent::Finish {
reason: FinishReason::ToolCalls,
usage: TokenUsage {
input: 3,
output: 9,
reasoning: 4,
..Default::default()
},
},
]
);
}
#[tokio::test]
async fn failed_response_surfaces_as_err() {
let raw = "data: {\"type\":\"response.failed\",\"response\":{\"error\":{\"message\":\"boom\"}}}\n\n";
let events: Vec<Result<LlmEvent, ProviderError>> = sse_stream(raw).collect().await;
assert!(
matches!(events.last(), Some(Err(ProviderError::Http { body, .. })) if body == "boom")
);
}
#[test]
fn build_request_puts_system_in_instructions() {
let mut r = req("gpt-5");
r.system = vec!["env".into(), "agent".into()];
let body = build_request(&r);
assert_eq!(body["instructions"], "env\n\nagent");
assert!(body.get("messages").is_none());
}
#[test]
fn build_request_flattens_tool_calls_and_results_to_items() {
let mut r = req("gpt-5");
r.messages = vec![
WireMessage {
role: Role::Assistant,
content: vec![WireContent::ToolCall {
call_id: "call_1".into(),
name: "read".into(),
input: json!({"file": "a.txt"}),
}],
},
WireMessage {
role: Role::Tool,
content: vec![WireContent::ToolResult {
call_id: "call_1".into(),
output: "contents".into(),
is_error: false,
}],
},
];
let body = build_request(&r);
let input = body["input"].as_array().unwrap();
assert_eq!(input[0]["type"], "function_call");
assert_eq!(input[0]["call_id"], "call_1");
assert_eq!(input[0]["arguments"], "{\"file\":\"a.txt\"}");
assert_eq!(input[1]["type"], "function_call_output");
assert_eq!(input[1]["output"], "contents");
}
#[test]
fn build_request_uses_flat_function_tool_shape_and_reasoning() {
let mut r = req("o3");
r.tools = vec![ToolSchema {
name: "read".into(),
description: "reads a file".into(),
parameters: json!({"type": "object"}),
}];
r.reasoning = Some(ReasoningOpts {
effort: Some(ReasoningEffort::Medium),
budget_tokens: None,
});
let body = build_request(&r);
assert_eq!(body["tools"][0]["type"], "function");
assert_eq!(body["tools"][0]["name"], "read");
assert_eq!(body["reasoning"]["effort"], "medium");
assert_eq!(body["reasoning"]["summary"], "auto");
}
}
+2
View File
@@ -1,6 +1,8 @@
pub mod anthropic;
pub mod codec;
pub mod openai;
pub mod registry;
pub use anthropic::AnthropicProvider;
pub use openai::OpenAiProvider;
pub use registry::ProviderRegistry;
+173
View File
@@ -0,0 +1,173 @@
use std::time::Duration;
use async_trait::async_trait;
use harness_core::llm::{LlmEventStream, LlmRequest, Provider, ProviderError};
use harness_core::types::ModelInfo;
use tokio_util::sync::CancellationToken;
use crate::codec::{openai_chat, openai_responses};
const DEFAULT_BASE_URL: &str = "https://api.openai.com/v1";
/// Which OpenAI wire format to speak for a given model.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum ApiFlavor {
Responses,
Chat,
}
/// `gpt-*` and `o-*` models use the responses API; everything else (including
/// OpenAI-compatible third-party endpoints) falls back to chat completions.
fn flavor_for(model: &str) -> ApiFlavor {
let is_native = model.starts_with("gpt-")
|| model.starts_with("o1")
|| model.starts_with("o3")
|| model.starts_with("o4")
|| model == "o1"
|| model == "o3";
if is_native {
ApiFlavor::Responses
} else {
ApiFlavor::Chat
}
}
pub struct OpenAiProvider {
api_key: String,
base_url: String,
client: reqwest::Client,
}
impl OpenAiProvider {
pub fn new(api_key: impl Into<String>) -> Self {
Self {
api_key: api_key.into(),
base_url: DEFAULT_BASE_URL.to_string(),
client: reqwest::Client::new(),
}
}
pub fn with_base_url(api_key: impl Into<String>, base_url: impl Into<String>) -> Self {
Self {
api_key: api_key.into(),
base_url: base_url.into(),
client: reqwest::Client::new(),
}
}
fn classify_error(
status: reqwest::StatusCode,
body: String,
retry_after: Option<Duration>,
) -> ProviderError {
match status.as_u16() {
400 if body.contains("context_length_exceeded")
|| body.contains("maximum context length") =>
{
ProviderError::ContextOverflow
}
401 | 403 => ProviderError::Auth(body),
429 => ProviderError::RateLimited { retry_after },
s if (500..600).contains(&s) => ProviderError::Overloaded,
s => ProviderError::Http { status: s, body },
}
}
}
#[async_trait]
impl Provider for OpenAiProvider {
fn id(&self) -> &str {
"openai"
}
async fn list_models(&self) -> Result<Vec<ModelInfo>, ProviderError> {
// models.dev metadata is layered on top by the caller (see `modelsdev.rs`).
Ok(Vec::new())
}
async fn stream(
&self,
req: LlmRequest,
cancel: CancellationToken,
) -> Result<LlmEventStream, ProviderError> {
let (path, body) = match flavor_for(&req.model) {
ApiFlavor::Responses => ("/responses", openai_responses::build_request(&req)),
ApiFlavor::Chat => ("/chat/completions", openai_chat::build_request(&req)),
};
let url = format!("{}{}", self.base_url, path);
let send = self
.client
.post(&url)
.header("authorization", format!("Bearer {}", self.api_key))
.json(&body)
.send();
let response = tokio::select! {
result = send => result.map_err(|e| ProviderError::Network(e.to_string()))?,
_ = cancel.cancelled() => return Err(ProviderError::Cancelled),
};
if !response.status().is_success() {
let status = response.status();
let retry_after = response
.headers()
.get("retry-after")
.and_then(|v| v.to_str().ok())
.and_then(|s| s.parse::<u64>().ok())
.map(Duration::from_secs);
let body = response.text().await.unwrap_or_default();
return Err(Self::classify_error(status, body, retry_after));
}
Ok(match flavor_for(&req.model) {
ApiFlavor::Responses => openai_responses::decode(response.bytes_stream()),
ApiFlavor::Chat => openai_chat::decode(response.bytes_stream()),
})
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn routes_gpt_and_o_series_to_responses() {
assert_eq!(flavor_for("gpt-4o"), ApiFlavor::Responses);
assert_eq!(flavor_for("gpt-5"), ApiFlavor::Responses);
assert_eq!(flavor_for("o1"), ApiFlavor::Responses);
assert_eq!(flavor_for("o3-mini"), ApiFlavor::Responses);
assert_eq!(flavor_for("o4-mini"), ApiFlavor::Responses);
}
#[test]
fn routes_other_models_to_chat() {
assert_eq!(flavor_for("llama-3.1-70b"), ApiFlavor::Chat);
assert_eq!(flavor_for("deepseek-chat"), ApiFlavor::Chat);
}
#[test]
fn id_is_openai() {
assert_eq!(OpenAiProvider::new("k").id(), "openai");
}
#[test]
fn classifies_context_overflow_from_400_body() {
assert!(matches!(
OpenAiProvider::classify_error(
reqwest::StatusCode::BAD_REQUEST,
"context_length_exceeded".into(),
None,
),
ProviderError::ContextOverflow
));
assert!(matches!(
OpenAiProvider::classify_error(
reqwest::StatusCode::BAD_REQUEST,
"some other error".into(),
None,
),
ProviderError::Http { status: 400, .. }
));
}
}