Merge pull request #103 from ChrAlpha/feat/add-gpt-5.2-codex-copilot

feat(openai): responses API support for GitHub Copilot provider

internal/runtime/executor/github_copilot_executor.go

@@ -23,6 +23,7 @@ import (
 const (
 	githubCopilotBaseURL       = "https://api.githubcopilot.com"
 	githubCopilotChatPath      = "/chat/completions"
+	githubCopilotResponsesPath = "/responses"
 	githubCopilotAuthType      = "github-copilot"
 	githubCopilotTokenCacheTTL = 25 * time.Minute
 	// tokenExpiryBuffer is the time before expiry when we should refresh the token.
@@ -106,7 +107,11 @@ func (e *GitHubCopilotExecutor) Execute(ctx context.Context, auth *cliproxyauth.
 	defer reporter.trackFailure(ctx, &err)
 
 	from := opts.SourceFormat
+	useResponses := useGitHubCopilotResponsesEndpoint(from)
 	to := sdktranslator.FromString("openai")
+	if useResponses {
+		to = sdktranslator.FromString("openai-response")
+	}
 	originalPayload := bytes.Clone(req.Payload)
 	if len(opts.OriginalRequest) > 0 {
 		originalPayload = bytes.Clone(opts.OriginalRequest)
@@ -117,7 +122,11 @@ func (e *GitHubCopilotExecutor) Execute(ctx context.Context, auth *cliproxyauth.
 	body = applyPayloadConfigWithRoot(e.cfg, req.Model, to.String(), "", body, originalTranslated)
 	body, _ = sjson.SetBytes(body, "stream", false)
 
-	url := githubCopilotBaseURL + githubCopilotChatPath
+	path := githubCopilotChatPath
+	if useResponses {
+		path = githubCopilotResponsesPath
+	}
+	url := githubCopilotBaseURL + path
 	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(body))
 	if err != nil {
 		return resp, err
@@ -172,6 +181,9 @@ func (e *GitHubCopilotExecutor) Execute(ctx context.Context, auth *cliproxyauth.
 	appendAPIResponseChunk(ctx, e.cfg, data)
 
 	detail := parseOpenAIUsage(data)
+	if useResponses && detail.TotalTokens == 0 {
+		detail = parseOpenAIResponsesUsage(data)
+	}
 	if detail.TotalTokens > 0 {
 		reporter.publish(ctx, detail)
 	}
@@ -194,7 +206,11 @@ func (e *GitHubCopilotExecutor) ExecuteStream(ctx context.Context, auth *cliprox
 	defer reporter.trackFailure(ctx, &err)
 
 	from := opts.SourceFormat
+	useResponses := useGitHubCopilotResponsesEndpoint(from)
 	to := sdktranslator.FromString("openai")
+	if useResponses {
+		to = sdktranslator.FromString("openai-response")
+	}
 	originalPayload := bytes.Clone(req.Payload)
 	if len(opts.OriginalRequest) > 0 {
 		originalPayload = bytes.Clone(opts.OriginalRequest)
@@ -205,9 +221,15 @@ func (e *GitHubCopilotExecutor) ExecuteStream(ctx context.Context, auth *cliprox
 	body = applyPayloadConfigWithRoot(e.cfg, req.Model, to.String(), "", body, originalTranslated)
 	body, _ = sjson.SetBytes(body, "stream", true)
 	// Enable stream options for usage stats in stream
-	body, _ = sjson.SetBytes(body, "stream_options.include_usage", true)
+	if !useResponses {
+		body, _ = sjson.SetBytes(body, "stream_options.include_usage", true)
+	}
 
-	url := githubCopilotBaseURL + githubCopilotChatPath
+	path := githubCopilotChatPath
+	if useResponses {
+		path = githubCopilotResponsesPath
+	}
+	url := githubCopilotBaseURL + path
 	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(body))
 	if err != nil {
 		return nil, err
@@ -283,6 +305,10 @@ func (e *GitHubCopilotExecutor) ExecuteStream(ctx context.Context, auth *cliprox
 				}
 				if detail, ok := parseOpenAIStreamUsage(line); ok {
 					reporter.publish(ctx, detail)
+				} else if useResponses {
+					if detail, ok := parseOpenAIResponsesStreamUsage(line); ok {
+						reporter.publish(ctx, detail)
+					}
 				}
 			}
 
@@ -393,6 +419,10 @@ func (e *GitHubCopilotExecutor) normalizeModel(_ string, body []byte) []byte {
 	return body
 }
 
+func useGitHubCopilotResponsesEndpoint(sourceFormat sdktranslator.Format) bool {
+	return sourceFormat.String() == "openai-response"
+}
+
 // isHTTPSuccess checks if the status code indicates success (2xx).
 func isHTTPSuccess(statusCode int) bool {
 	return statusCode >= 200 && statusCode < 300

internal/runtime/executor/usage_helpers.go

@@ -236,6 +236,44 @@ func parseOpenAIStreamUsage(line []byte) (usage.Detail, bool) {
 	return detail, true
 }
 
+func parseOpenAIResponsesUsageDetail(usageNode gjson.Result) usage.Detail {
+	detail := usage.Detail{
+		InputTokens:  usageNode.Get("input_tokens").Int(),
+		OutputTokens: usageNode.Get("output_tokens").Int(),
+		TotalTokens:  usageNode.Get("total_tokens").Int(),
+	}
+	if detail.TotalTokens == 0 {
+		detail.TotalTokens = detail.InputTokens + detail.OutputTokens
+	}
+	if cached := usageNode.Get("input_tokens_details.cached_tokens"); cached.Exists() {
+		detail.CachedTokens = cached.Int()
+	}
+	if reasoning := usageNode.Get("output_tokens_details.reasoning_tokens"); reasoning.Exists() {
+		detail.ReasoningTokens = reasoning.Int()
+	}
+	return detail
+}
+
+func parseOpenAIResponsesUsage(data []byte) usage.Detail {
+	usageNode := gjson.ParseBytes(data).Get("usage")
+	if !usageNode.Exists() {
+		return usage.Detail{}
+	}
+	return parseOpenAIResponsesUsageDetail(usageNode)
+}
+
+func parseOpenAIResponsesStreamUsage(line []byte) (usage.Detail, bool) {
+	payload := jsonPayload(line)
+	if len(payload) == 0 || !gjson.ValidBytes(payload) {
+		return usage.Detail{}, false
+	}
+	usageNode := gjson.GetBytes(payload, "usage")
+	if !usageNode.Exists() {
+		return usage.Detail{}, false
+	}
+	return parseOpenAIResponsesUsageDetail(usageNode), true
+}
+
 func parseClaudeUsage(data []byte) usage.Detail {
 	usageNode := gjson.ParseBytes(data).Get("usage")
 	if !usageNode.Exists() {