Files
OmniRoute/open-sse/utils/stream.ts
mi 94682d2a76 perf(ram): reduce server memory footprint (#2903)
Integrated into release/v3.8.7
2026-05-29 13:21:36 -03:00

2343 lines
90 KiB
TypeScript

import { translateResponse, initState } from "../translator/index.ts";
import { FORMATS } from "../translator/formats.ts";
import { trackPendingRequest, appendRequestLog } from "@/lib/usageDb";
import {
extractUsage,
hasValidUsage,
estimateUsage,
logUsage,
addBufferToUsage,
filterUsageForFormat,
COLORS,
} from "./usageTracking.ts";
import {
parseSSELine,
hasValuableContent,
fixInvalidId,
formatSSE,
unwrapGeminiChunk,
} from "./streamHelpers.ts";
import { calculateCost } from "@/lib/usage/costCalculator";
import { buildOmniRouteSseMetadataComment } from "@/domain/omnirouteResponseMeta";
import {
createStructuredSSECollector,
buildStreamSummaryFromEvents,
} from "./streamPayloadCollector.ts";
import { STREAM_IDLE_TIMEOUT_MS, FETCH_BODY_TIMEOUT_MS, HTTP_STATUS } from "../config/constants.ts";
import {
sanitizeStreamingChunk,
extractThinkingFromContent,
} from "../handlers/responseSanitizer.ts";
import { buildErrorBody } from "./error.ts";
/**
* Race a response body read against a timeout.
* Prevents indefinite hangs when the upstream sends headers but stalls on the body.
*/
export function withBodyTimeout<T>(
promise: Promise<T>,
timeoutMs: number = FETCH_BODY_TIMEOUT_MS
): Promise<T> {
if (timeoutMs <= 0) return promise;
let timer: ReturnType<typeof setTimeout>;
const timeout = new Promise<never>((_, reject) => {
timer = setTimeout(() => {
const err = new Error(`Response body read timeout after ${timeoutMs}ms`);
err.name = "BodyTimeoutError";
reject(err);
}, timeoutMs);
});
return Promise.race([promise, timeout]).finally(() => clearTimeout(timer)) as Promise<T>;
}
export { COLORS, formatSSE };
type JsonRecord = Record<string, unknown>;
export const PENDING_REQUEST_CLEARED_MARKER = "__omniroutePendingRequestCleared";
function markPendingRequestCleared(error: Error): Error {
(error as Error & Record<string, unknown>)[PENDING_REQUEST_CLEARED_MARKER] = true;
return error;
}
function buildResponsesOutputItemKey(item: unknown): string | null {
if (!item || typeof item !== "object" || Array.isArray(item)) {
return null;
}
const record = item as JsonRecord;
const type = typeof record.type === "string" ? record.type : "";
const id = typeof record.id === "string" ? record.id : "";
const callId = typeof record.call_id === "string" ? record.call_id : "";
const outputIndex = typeof record.output_index === "number" ? record.output_index : "";
const name = typeof record.name === "string" ? record.name : "";
if (!type && !id && !callId) {
return null;
}
return `${type}:${id}:${callId}:${outputIndex}:${name}`;
}
function pushUniqueResponsesOutputItems(target: unknown[], items: readonly unknown[]) {
const seen = new Set<string>();
for (const existingItem of target) {
const key = buildResponsesOutputItemKey(existingItem);
if (key) {
seen.add(key);
}
}
for (const item of items) {
const key = buildResponsesOutputItemKey(item);
if (key && seen.has(key)) {
continue;
}
target.push(item);
if (key) {
seen.add(key);
}
}
}
type StreamLogger = {
appendProviderChunk?: (value: string) => void;
appendConvertedChunk?: (value: string) => void;
appendOpenAIChunk?: (value: string) => void;
};
type StreamCompletePayload = {
status: number;
usage: unknown;
/** Minimal response body for call log (streaming: usage + note; non-streaming not used) */
responseBody?: unknown;
providerPayload?: unknown;
clientPayload?: unknown;
};
type StreamFailurePayload = {
status: number;
message: string;
code?: string;
type?: string;
};
type StreamOptions = {
mode?: string;
targetFormat?: string;
sourceFormat?: string;
clientResponseFormat?: string | null;
copilotCompatibleReasoning?: boolean;
provider?: string | null;
reqLogger?: StreamLogger | null;
toolNameMap?: unknown;
model?: string | null;
connectionId?: string | null;
apiKeyInfo?: unknown;
body?: unknown;
onComplete?: ((payload: StreamCompletePayload) => void) | null;
onFailure?: ((payload: StreamFailurePayload) => void | Promise<void>) | null;
};
type TranslateState = ReturnType<typeof initState> & {
provider?: string | null;
toolNameMap?: unknown;
signatureNamespace?: string | null;
usage?: unknown;
finishReason?: unknown;
copilotCompatibleReasoning?: boolean;
/** Accumulated message content for call log response body */
accumulatedContent?: string;
upstreamError?: {
status: number;
type: string;
code: string;
message: string;
} | null;
};
type ToolCall = {
id: string | null;
index: number;
type: string;
function: { name: string; arguments: string };
};
type UsageTokenRecord = Record<string, number>;
function asRecord(value: unknown): JsonRecord {
return value && typeof value === "object" && !Array.isArray(value) ? (value as JsonRecord) : {};
}
const STREAM_SUMMARY_TEXT_LIMIT = 64 * 1024;
function appendBoundedText(current: string, next: string): string {
if (!next) return current;
const combined = current + next;
if (combined.length <= STREAM_SUMMARY_TEXT_LIMIT) return combined;
return combined.slice(-STREAM_SUMMARY_TEXT_LIMIT);
}
function stripZeroWidth(value: unknown): unknown {
if (typeof value === "string") {
return value.replace(/[\u200B-\u200D\uFEFF]/g, "");
}
if (Array.isArray(value)) {
return value.map((item) => stripZeroWidth(item));
}
if (value && typeof value === "object") {
return Object.fromEntries(
Object.entries(value as Record<string, unknown>).map(([key, item]) => [
key,
stripZeroWidth(item),
])
);
}
return value;
}
function parseTextualToolCallCandidate(
text: unknown
): { kind: "complete"; name: string; args: unknown } | { kind: "partial" } | null {
if (typeof text !== "string") return null;
const normalized = text.replace(/[\u200B-\u200D\uFEFF]/g, "");
const toolCallIndex = normalized.lastIndexOf("[Tool call:");
if (toolCallIndex < 0) return null;
const candidate = normalized.slice(toolCallIndex);
const headerMatch = candidate.match(/^\[Tool call:\s*([^\]\n]+)\]\s*\nArguments:\s*/);
if (!headerMatch) return { kind: "partial" };
const name = headerMatch[1]?.trim();
const rawArgs = candidate.slice(headerMatch[0].length).trim();
if (!name || !rawArgs) return { kind: "partial" };
const decoders = [
(value: string) => value,
(value: string) => {
if (value.startsWith('"') && value.endsWith('"')) {
const decoded = JSON.parse(value);
return typeof decoded === "string" ? decoded : value;
}
return value;
},
];
for (const decode of decoders) {
try {
const decoded = decode(rawArgs);
const parsed = JSON.parse(decoded);
return { kind: "complete", name, args: stripZeroWidth(parsed) };
} catch {}
}
return { kind: "partial" };
}
function parseTextualToolCallFromContent(text: unknown): { name: string; args: unknown } | null {
const candidate = parseTextualToolCallCandidate(text);
return candidate?.kind === "complete" ? { name: candidate.name, args: candidate.args } : null;
}
function containsTextualToolCallCandidate(text: unknown): boolean {
return parseTextualToolCallCandidate(text) !== null;
}
function containsMalformedTextualToolCall(text: unknown): boolean {
if (typeof text !== "string") return false;
return text.replace(/[\u200B-\u200D\uFEFF]/g, "").includes("[Tool call:");
}
function extractAllowedToolNames(body: unknown): Set<string> | null {
const record = asRecord(body);
const tools = record.tools;
if (!Array.isArray(tools)) return null;
const names = new Set<string>();
for (const tool of tools) {
if (!tool || typeof tool !== "object" || Array.isArray(tool)) continue;
const item = tool as JsonRecord;
const directName = typeof item.name === "string" ? item.name.trim() : "";
const fn =
item.function && typeof item.function === "object" && !Array.isArray(item.function)
? (item.function as JsonRecord)
: null;
const functionName = typeof fn?.name === "string" ? fn.name.trim() : "";
const name = functionName || directName;
if (name) names.add(name);
}
return names.size > 0 ? names : null;
}
function collectPassthroughTextualToolCall(
text: string,
toolCalls: Map<string, ToolCall>,
allowedToolNames?: Set<string> | null
): ToolCall | null {
const parsed = parseTextualToolCallFromContent(text);
if (!parsed) return null;
if (allowedToolNames?.size && !allowedToolNames.has(parsed.name)) return null;
const key = `textual:${toolCalls.size}`;
const toolCall: ToolCall = {
id: `call_${Date.now()}_${toolCalls.size}`,
index: toolCalls.size,
type: "function",
function: {
name: parsed.name,
arguments: JSON.stringify(parsed.args || {}),
},
};
toolCalls.set(key, toolCall);
return toolCall;
}
function toStreamingToolCallDelta(toolCall: ToolCall) {
return {
index: toolCall.index,
id: toolCall.id,
type: toolCall.type,
function: {
name: toolCall.function.name,
arguments: toolCall.function.arguments,
},
};
}
function toResponsesFunctionCallItem(toolCall: ToolCall) {
return {
type: "function_call",
id: toolCall.id || `fc_${toolCall.index}`,
call_id: toolCall.id || `call_${toolCall.index}`,
name: toolCall.function.name,
arguments: toolCall.function.arguments,
status: "completed",
};
}
function buildResponsesFunctionCallEvents(toolCall: ToolCall) {
const item = toResponsesFunctionCallItem(toolCall);
return [
{
type: "response.output_item.added",
output_index: toolCall.index,
item,
},
{
type: "response.function_call_arguments.done",
item_id: item.id,
output_index: toolCall.index,
arguments: toolCall.function.arguments,
},
{
type: "response.output_item.done",
output_index: toolCall.index,
item,
},
];
}
function formatSSEDataEvents(events: unknown[]) {
return events.map((event) => `data: ${JSON.stringify(event)}\n`).join("\n");
}
function toChatCompletionChunkWithToolCall(base: JsonRecord, toolCall: ToolCall) {
const choice = asRecord(Array.isArray(base.choices) ? base.choices[0] : null);
const delta = { ...asRecord(choice.delta) };
delete delta.content;
delete delta.reasoning_content;
return {
...base,
choices: [
{
...choice,
index: typeof choice.index === "number" ? choice.index : 0,
delta: {
...delta,
tool_calls: [toStreamingToolCallDelta(toolCall)],
},
finish_reason: null,
},
],
};
}
function toResponsesCompletedWithToolCalls(parsed: JsonRecord, toolCalls: ToolCall[]) {
const response = asRecord(parsed.response);
const existingOutput = Array.isArray(response.output) ? response.output : [];
return {
...parsed,
response: {
...response,
output: [
...existingOutput,
...toolCalls.map((toolCall) => toResponsesFunctionCallItem(toolCall)),
],
},
};
}
function toStreamFailureStatus(value: unknown): number | null {
if (typeof value === "number" && Number.isInteger(value) && value >= 400 && value <= 599) {
return value;
}
if (typeof value === "string" && /^\d{3}$/.test(value.trim())) {
const parsed = Number(value.trim());
return parsed >= 400 && parsed <= 599 ? parsed : null;
}
return null;
}
function looksLikeStreamRateLimit(code: string, type: string, message: string): boolean {
const haystack = `${code} ${type} ${message}`.toLowerCase();
return (
haystack.includes("usage_limit_reached") ||
haystack.includes("rate_limit") ||
haystack.includes("rate limit") ||
haystack.includes("quota") ||
haystack.includes("too many requests") ||
haystack.includes("limit reached") ||
haystack.includes("limit has been reached")
);
}
function normalizeStreamFailurePayload(payload: unknown): StreamFailurePayload | null {
const record = payload && typeof payload === "object" ? (payload as JsonRecord) : {};
const response = asRecord(record.response);
const error = Object.keys(asRecord(response.error)).length
? asRecord(response.error)
: Object.keys(asRecord(record.error)).length
? asRecord(record.error)
: record;
const code = typeof error.code === "string" ? error.code : "upstream_error";
const type = typeof error.type === "string" ? error.type : undefined;
const message =
typeof error.message === "string" && error.message.trim()
? error.message
: typeof record.message === "string" && record.message.trim()
? record.message
: "Upstream failure";
const status =
toStreamFailureStatus(error.status_code) ??
toStreamFailureStatus(error.status) ??
toStreamFailureStatus(response.status_code) ??
toStreamFailureStatus(response.status) ??
toStreamFailureStatus(record.status_code) ??
toStreamFailureStatus(record.status) ??
(looksLikeStreamRateLimit(code, type || "", message) ? 429 : 502);
return {
status,
message,
code,
...(type ? { type } : {}),
};
}
type ClaudeEmptyResponseLifecycle = {
hasMessageStart: boolean;
hasContentBlock: boolean;
hasMessageDelta: boolean;
hasMessageStop: boolean;
hasError: boolean;
syntheticContentInjected: boolean;
warningLogged: boolean;
};
const SYNTHETIC_CLAUDE_EMPTY_RESPONSE_TEXT =
"[Proxy Error] The upstream API returned an empty response. Please retry the request.";
function createClaudeEmptyResponseLifecycle(): ClaudeEmptyResponseLifecycle {
return {
hasMessageStart: false,
hasContentBlock: false,
hasMessageDelta: false,
hasMessageStop: false,
hasError: false,
syntheticContentInjected: false,
warningLogged: false,
};
}
function getClaudeEventType(payload: unknown): string | null {
if (!payload || typeof payload !== "object") return null;
const type = (payload as JsonRecord).type;
return typeof type === "string" ? type : null;
}
function isClaudeEventPayload(payload: unknown): payload is JsonRecord {
return getClaudeEventType(payload) !== null;
}
function updateClaudeEmptyResponseLifecycle(
lifecycle: ClaudeEmptyResponseLifecycle,
payload: unknown
) {
const type = getClaudeEventType(payload);
if (!type) return;
switch (type) {
case "message_start":
lifecycle.hasMessageStart = true;
break;
case "content_block_start":
case "content_block_delta":
case "content_block_stop":
lifecycle.hasContentBlock = true;
break;
case "message_delta":
lifecycle.hasMessageDelta = true;
break;
case "message_stop":
lifecycle.hasMessageStop = true;
break;
case "error":
lifecycle.hasError = true;
break;
default:
break;
}
}
function hasClaudeAssistantLifecycle(lifecycle: ClaudeEmptyResponseLifecycle): boolean {
return lifecycle.hasMessageStart || lifecycle.hasMessageDelta || lifecycle.hasMessageStop;
}
function shouldInjectClaudeEmptyResponseBeforeCurrentEvent(
lifecycle: ClaudeEmptyResponseLifecycle,
payload: unknown
): boolean {
const type = getClaudeEventType(payload);
if (!type || lifecycle.hasError || lifecycle.hasContentBlock) return false;
if (!hasClaudeAssistantLifecycle(lifecycle)) return false;
return type === "message_delta" || type === "message_stop";
}
function shouldInjectClaudeEmptyResponseOnFlush(lifecycle: ClaudeEmptyResponseLifecycle): boolean {
if (lifecycle.hasError || lifecycle.hasContentBlock) return false;
return hasClaudeAssistantLifecycle(lifecycle);
}
function shouldInjectClaudeMissingFinalizersOnFlush(
lifecycle: ClaudeEmptyResponseLifecycle
): boolean {
if (lifecycle.hasError || !lifecycle.syntheticContentInjected) return false;
return !lifecycle.hasMessageDelta || !lifecycle.hasMessageStop;
}
function buildSyntheticClaudeEmptyResponseEvents(
lifecycle: ClaudeEmptyResponseLifecycle,
model: string | null,
options: {
includeContentBlock?: boolean;
includeMessageDelta?: boolean;
includeMessageStop?: boolean;
} = {}
): JsonRecord[] {
const {
includeContentBlock = true,
includeMessageDelta = false,
includeMessageStop = false,
} = options;
const events: JsonRecord[] = [];
const resolvedModel = typeof model === "string" && model ? model : "unknown";
if (includeContentBlock) {
if (!lifecycle.hasMessageStart) {
events.push({
type: "message_start",
message: {
id: `msg_synthetic_${Date.now()}`,
type: "message",
role: "assistant",
model: resolvedModel,
content: [],
stop_reason: null,
stop_sequence: null,
usage: { input_tokens: 0, output_tokens: 0 },
},
});
}
events.push(
{
type: "content_block_start",
index: 0,
content_block: { type: "text", text: "" },
},
{
type: "content_block_delta",
index: 0,
delta: {
type: "text_delta",
text: SYNTHETIC_CLAUDE_EMPTY_RESPONSE_TEXT,
},
},
{
type: "content_block_stop",
index: 0,
}
);
}
if (includeMessageDelta) {
events.push({
type: "message_delta",
delta: { stop_reason: "end_turn", stop_sequence: null },
usage: { input_tokens: 0, output_tokens: 0 },
});
}
if (includeMessageStop) {
events.push({ type: "message_stop" });
}
return events;
}
function getOpenAIIntermediateChunks(value: unknown): unknown[] {
if (!value || typeof value !== "object") return [];
const candidate = (value as JsonRecord)._openaiIntermediate;
return Array.isArray(candidate) ? candidate : [];
}
function restoreClaudePassthroughToolUseName(parsed: JsonRecord, toolNameMap: unknown): boolean {
if (!(toolNameMap instanceof Map)) return false;
if (!parsed || typeof parsed !== "object") return false;
const block =
parsed.content_block && typeof parsed.content_block === "object"
? (parsed.content_block as JsonRecord)
: null;
if (!block || block.type !== "tool_use" || typeof block.name !== "string") return false;
const restoredName = toolNameMap.get(block.name) ?? block.name;
if (restoredName === block.name) return false;
block.name = restoredName;
return true;
}
// Note: TextDecoder/TextEncoder are created per-stream inside createSSEStream()
// to avoid shared state issues with concurrent streams (TextDecoder with {stream:true}
// maintains internal buffering state between decode() calls).
/**
* Stream modes
*/
const STREAM_MODE = {
TRANSLATE: "translate", // Full translation between formats
PASSTHROUGH: "passthrough", // No translation, normalize output, extract usage
};
/**
* Lifecycle event types in OpenAI Responses API streams whose `response`
* payload is a snapshot of the request (echoes back `instructions` + `tools`).
*/
const RESPONSES_LIFECYCLE_EVENT_TYPES = new Set([
"response.created",
"response.in_progress",
"response.completed",
]);
/**
* Backfill `parsed.response.output` on a `response.completed` event from the
* snapshots accumulated as the stream progressed (`response.output_item.done`).
*
* Why: when the upstream request runs with `store: false`, OpenAI's Responses
* API leaves `response.output` empty in the final `response.completed`
* snapshot — clients that rebuild assistant messages from that snapshot
* (notably the GitHub Copilot CLI 1.0.36) end up with `choices: []` and never
* trigger tool execution. Codex CLI and others that consume per-item events
* are unaffected; backfilling the array makes both styles work.
*
* Returns true when `parsed.response.output` was empty and got replaced, so
* the caller can re-serialize.
*/
export function backfillResponsesCompletedOutput(
parsed: unknown,
collectedItems: readonly unknown[]
): boolean {
if (!collectedItems.length) return false;
if (!parsed || typeof parsed !== "object" || Array.isArray(parsed)) return false;
const obj = parsed as Record<string, unknown>;
if (obj.type !== "response.completed") return false;
const resp = obj.response;
if (!resp || typeof resp !== "object" || Array.isArray(resp)) return false;
const r = resp as Record<string, unknown>;
const existing = r.output;
if (Array.isArray(existing) && existing.length > 0) return false;
r.output = collectedItems.slice();
return true;
}
/**
* Strip the request echo (`instructions`, `tools`) from `parsed.response`
* on Responses API lifecycle events.
*
* Why: those fields can balloon the SSE message past 100 KB when the request
* carries large tool definitions / instructions. Some clients (notably the
* GitHub Copilot CLI) cannot process oversized SSE events and stop rendering
* mid-stream. The fields are pure echo of the original request — clients
* already hold the original locally — so removing them is observably safe.
*
* Returns true when the payload was modified and must be re-serialized.
*/
export function stripResponsesLifecycleEcho(parsed: unknown): boolean {
if (!parsed || typeof parsed !== "object" || Array.isArray(parsed)) return false;
const obj = parsed as Record<string, unknown>;
if (typeof obj.type !== "string" || !RESPONSES_LIFECYCLE_EVENT_TYPES.has(obj.type)) {
return false;
}
const resp = obj.response;
if (!resp || typeof resp !== "object" || Array.isArray(resp)) return false;
const r = resp as Record<string, unknown>;
let changed = false;
if ("instructions" in r) {
delete r.instructions;
changed = true;
}
if ("tools" in r) {
delete r.tools;
changed = true;
}
return changed;
}
/**
* Create unified SSE transform stream with idle timeout protection.
* If the upstream provider stops sending data for STREAM_IDLE_TIMEOUT_MS,
* the stream emits an error event and closes to prevent indefinite hanging.
*
* @param {object} options
* @param {string} options.mode - Stream mode: translate, passthrough
* @param {string} options.targetFormat - Provider format (for translate mode)
* @param {string} options.sourceFormat - Client format (for translate mode)
* @param {string} options.provider - Provider name
* @param {object} options.reqLogger - Request logger instance
* @param {string} options.model - Model name
* @param {string} options.connectionId - Connection ID for usage tracking
* @param {object|null} options.apiKeyInfo - API key metadata for usage attribution
* @param {object} options.body - Request body (for input token estimation)
* @param {function} options.onComplete - Callback when stream finishes: ({ status, usage }) => void
*/
export function createSSEStream(options: StreamOptions = {}) {
const {
mode = STREAM_MODE.TRANSLATE,
targetFormat,
sourceFormat,
clientResponseFormat = null,
copilotCompatibleReasoning = false,
provider = null,
reqLogger = null,
toolNameMap = null,
model = null,
connectionId = null,
apiKeyInfo = null,
body = null,
onComplete = null,
onFailure = null,
} = options;
const signatureNamespace = connectionId;
const clientExpectsResponsesStream =
(mode === STREAM_MODE.PASSTHROUGH
? clientResponseFormat === FORMATS.OPENAI_RESPONSES
: sourceFormat === FORMATS.OPENAI_RESPONSES) === true;
// Clients whose SSE protocol terminates naturally on the last
// provider-shape event (not on a `data: [DONE]` line). Emitting
// `[DONE]` to these clients produces a parser error in the SDK and
// breaks follow-up turns (Capy/Anthropic SDK: text gets stuck in the
// "Thought" area; subsequent /v1/messages calls retry into a corrupt
// state). Skip the `[DONE]` for these formats.
const clientExpectsClaudeStream =
(mode === STREAM_MODE.PASSTHROUGH
? clientResponseFormat === FORMATS.CLAUDE
: sourceFormat === FORMATS.CLAUDE) === true;
// Single source of truth for the [DONE] decision, used at both emission
// sites below. Only OpenAI Chat Completions clients expect [DONE];
// Responses API and Anthropic SSE terminate on their own protocol events
// (response.completed / message_stop respectively).
const shouldEmitDoneTerminator = !clientExpectsResponsesStream && !clientExpectsClaudeStream;
let buffer = "";
let usage: UsageTokenRecord | null = null;
/** Passthrough (OpenAI CC shape): saw tool_calls in stream before finish_reason */
let passthroughHasToolCalls = false;
/** Passthrough: accumulate tool_calls deltas for call log responseBody */
const passthroughToolCalls = new Map<string, ToolCall>();
let passthroughToolCallSeq = 0;
const allowedToolNames = extractAllowedToolNames(body);
let skipPassthroughEvent = false;
// State for translate mode (accumulatedContent for call log response body)
const state: TranslateState | null =
mode === STREAM_MODE.TRANSLATE
? {
...(initState(sourceFormat) as TranslateState),
provider,
toolNameMap,
signatureNamespace,
copilotCompatibleReasoning,
accumulatedContent: "",
}
: null;
// Track content length for usage estimation (both modes)
let totalContentLength = 0;
// Passthrough: accumulate content and reasoning separately for call log response body
let passthroughAccumulatedContent = "";
let passthroughAccumulatedReasoning = "";
let passthroughBufferedTextualToolCallContent = "";
// Passthrough Responses SSE: snapshots of items seen via `response.output_item.done`,
// used to backfill `response.completed.response.output` when upstream returns it
// empty (which happens when `store: false` — see backfillResponsesCompletedOutput).
const passthroughResponsesOutputItems: unknown[] = [];
const passthroughResponsesPendingFunctionCalls = new Map<string, JsonRecord>();
let passthroughResponsesId: string | null = null;
let passthroughResponsesCurrentFunctionCallKey: string | null = null;
const passthroughResponsesReasoningSummarySeen = new Set<string>();
const streamStartedAt = Date.now();
// Guard against duplicate [DONE] events — ensures exactly one per stream
let doneSent = false;
const providerPayloadCollector = createStructuredSSECollector({
stage: "provider_response",
});
const clientPayloadCollector = createStructuredSSECollector({
stage: "client_response",
});
// Per-stream instances to avoid shared state with concurrent streams
const decoder = new TextDecoder();
const encoder = new TextEncoder();
// Idle timeout state — closes stream if provider stops sending data
let lastChunkTime = Date.now();
let idleTimer: ReturnType<typeof setInterval> | null = null;
let streamTimedOut = false;
const claudeEmptyResponseLifecycle = createClaudeEmptyResponseLifecycle();
let pendingPassthroughEventLine: string | null = null;
let pendingPassthroughEventEmitted = false;
const clearIdleTimer = () => {
if (idleTimer) {
clearInterval(idleTimer);
idleTimer = null;
}
};
const clearPendingPassthroughEvent = () => {
pendingPassthroughEventLine = null;
pendingPassthroughEventEmitted = false;
};
const maybePrefixPendingPassthroughEvent = (output: string, line: string) => {
if (!pendingPassthroughEventLine || !line.startsWith("data:")) {
return output;
}
if (!pendingPassthroughEventEmitted) {
pendingPassthroughEventEmitted = true;
return `${pendingPassthroughEventLine}\n${output}`;
}
return output;
};
const applyTextualToolCallStreamingGuard = (parsed: Record<string, unknown>) => {
const choice = Array.isArray((parsed as JsonRecord).choices)
? (((parsed as JsonRecord).choices as unknown[])[0] as JsonRecord | undefined)
: undefined;
const delta = asRecord(choice?.delta);
let textualToolCallConverted = false;
if (typeof delta?.content === "string") {
const incomingContent = delta.content;
const bufferedCandidate = passthroughBufferedTextualToolCallContent + incomingContent;
if (
passthroughBufferedTextualToolCallContent ||
containsTextualToolCallCandidate(incomingContent)
) {
const parsedCandidate = parseTextualToolCallCandidate(bufferedCandidate);
if (parsedCandidate?.kind === "complete") {
const collectedToolCall = collectPassthroughTextualToolCall(
bufferedCandidate,
passthroughToolCalls,
allowedToolNames
);
if (collectedToolCall) {
parsed = toChatCompletionChunkWithToolCall(
parsed as JsonRecord,
collectedToolCall
) as typeof parsed;
passthroughHasToolCalls = true;
} else {
delete delta.content;
delete delta.reasoning_content;
}
textualToolCallConverted = true;
passthroughBufferedTextualToolCallContent = "";
} else if (parsedCandidate?.kind === "partial") {
passthroughBufferedTextualToolCallContent = appendBoundedText(
passthroughBufferedTextualToolCallContent,
incomingContent
);
textualToolCallConverted = true;
delta.content = "";
} else {
passthroughAccumulatedContent = appendBoundedText(
passthroughAccumulatedContent,
passthroughBufferedTextualToolCallContent + incomingContent
);
passthroughBufferedTextualToolCallContent = "";
}
} else {
passthroughAccumulatedContent = appendBoundedText(
passthroughAccumulatedContent,
incomingContent
);
}
}
return { parsed, textualToolCallConverted };
};
const emitSyntheticClaudeEmptyResponse = (
controller: TransformStreamDefaultController,
options: {
includeContentBlock?: boolean;
includeMessageDelta?: boolean;
includeMessageStop?: boolean;
} = {}
) => {
const events = buildSyntheticClaudeEmptyResponseEvents(
claudeEmptyResponseLifecycle,
model,
options
);
if (events.length === 0) return;
if (!claudeEmptyResponseLifecycle.warningLogged) {
claudeEmptyResponseLifecycle.warningLogged = true;
console.warn(
`[STREAM] Injecting synthetic Claude SSE response for empty upstream output (${provider || "provider"}:${model || "unknown"})`
);
}
if (options.includeContentBlock !== false) {
claudeEmptyResponseLifecycle.syntheticContentInjected = true;
if (!passthroughAccumulatedContent.trim()) {
passthroughAccumulatedContent = SYNTHETIC_CLAUDE_EMPTY_RESPONSE_TEXT;
}
if (state?.accumulatedContent !== undefined && !state.accumulatedContent.trim()) {
state.accumulatedContent = SYNTHETIC_CLAUDE_EMPTY_RESPONSE_TEXT;
}
}
for (const event of events) {
updateClaudeEmptyResponseLifecycle(claudeEmptyResponseLifecycle, event);
clientPayloadCollector.push(event);
const output = formatSSE(event, FORMATS.CLAUDE);
reqLogger?.appendConvertedChunk?.(output);
controller.enqueue(encoder.encode(output));
}
};
const emitTranslatedClientItem = (
controller: TransformStreamDefaultController,
item: Record<string, unknown>
) => {
let itemSanitized: Record<string, unknown> = item;
const isResponsesEvent = typeof item?.event === "string" && item.event.startsWith("response.");
if (sourceFormat === FORMATS.OPENAI && !isResponsesEvent) {
itemSanitized = sanitizeStreamingChunk(itemSanitized) as Record<string, unknown>;
const delta = itemSanitized?.choices?.[0]?.delta;
if (delta?.content && typeof delta.content === "string") {
const { content, thinking } = extractThinkingFromContent(delta.content);
delta.content = content;
if (thinking && !delta.reasoning_content) {
delta.reasoning_content = thinking;
}
}
}
if (!hasValuableContent(itemSanitized, sourceFormat)) {
return;
}
const isFinishChunk =
itemSanitized.type === "message_delta" || itemSanitized.choices?.[0]?.finish_reason;
if (
state?.finishReason &&
isFinishChunk &&
!hasValidUsage(itemSanitized.usage) &&
totalContentLength > 0
) {
const estimated = estimateUsage(body, totalContentLength, sourceFormat);
itemSanitized.usage = filterUsageForFormat(estimated, sourceFormat);
state.usage = estimated;
} else if (state?.finishReason && isFinishChunk && state.usage) {
const buffered = addBufferToUsage(state.usage);
itemSanitized.usage = filterUsageForFormat(buffered, sourceFormat);
}
if (
sourceFormat === FORMATS.CLAUDE &&
shouldInjectClaudeEmptyResponseBeforeCurrentEvent(claudeEmptyResponseLifecycle, itemSanitized)
) {
const eventType = getClaudeEventType(itemSanitized);
emitSyntheticClaudeEmptyResponse(controller, {
includeContentBlock: true,
includeMessageDelta:
eventType === "message_stop" && !claudeEmptyResponseLifecycle.hasMessageDelta,
includeMessageStop: false,
});
}
if (sourceFormat === FORMATS.CLAUDE && isClaudeEventPayload(itemSanitized)) {
updateClaudeEmptyResponseLifecycle(claudeEmptyResponseLifecycle, itemSanitized);
}
const output = formatSSE(itemSanitized, sourceFormat);
clientPayloadCollector.push(itemSanitized);
reqLogger?.appendConvertedChunk?.(output);
controller.enqueue(encoder.encode(output));
};
const emitFinalSseMetadata = async (
controller: TransformStreamDefaultController,
finalUsage: UsageTokenRecord | Record<string, unknown> | null | undefined
) => {
const costUsd = finalUsage ? await calculateCost(provider, model, finalUsage) : 0;
const comment = buildOmniRouteSseMetadataComment({
provider,
model,
cacheHit: false,
latencyMs: Date.now() - streamStartedAt,
usage: finalUsage,
costUsd,
});
if (!comment) return;
reqLogger?.appendConvertedChunk?.(comment);
controller.enqueue(encoder.encode(comment));
};
const getResponsesReasoningKey = (payload: Record<string, unknown>): string | null => {
if (typeof payload.item_id === "string" && payload.item_id) {
return payload.item_id;
}
const item =
payload.item && typeof payload.item === "object" && !Array.isArray(payload.item)
? (payload.item as Record<string, unknown>)
: null;
if (item && typeof item.id === "string" && item.id) {
return item.id;
}
const responseId =
typeof payload.response_id === "string" && payload.response_id
? payload.response_id
: passthroughResponsesId;
const outputIndex =
typeof payload.output_index === "number" && Number.isInteger(payload.output_index)
? payload.output_index
: null;
return responseId !== null && outputIndex !== null ? `${responseId}:${outputIndex}` : null;
};
const getResponsesReasoningSummaryText = (item: Record<string, unknown>): string => {
return Array.isArray(item.summary)
? item.summary
.map((part) => {
if (!part || typeof part !== "object" || Array.isArray(part)) {
return "";
}
return typeof (part as Record<string, unknown>).text === "string"
? ((part as Record<string, unknown>).text as string)
: "";
})
.join("")
: "";
};
const ensureVisibleResponsesReasoningSummary = (payload: Record<string, unknown>): boolean => {
const item =
payload.item && typeof payload.item === "object" && !Array.isArray(payload.item)
? (payload.item as Record<string, unknown>)
: null;
if (!item || item.type !== "reasoning") {
return false;
}
if (getResponsesReasoningSummaryText(item)) {
return false;
}
const hasEncryptedReasoning =
typeof item.encrypted_content === "string" && item.encrypted_content.length > 0;
if (!hasEncryptedReasoning) {
return false;
}
item.summary = [
{
type: "summary_text",
text: "Codex is reasoning, but the upstream Responses API exposed this reasoning block only as encrypted state. OmniRoute cannot recover the private reasoning text.",
},
];
return true;
};
const emitSyntheticResponsesReasoningSummary = (
controller: TransformStreamDefaultController,
payload: Record<string, unknown>
) => {
const item =
payload.item && typeof payload.item === "object" && !Array.isArray(payload.item)
? (payload.item as Record<string, unknown>)
: null;
if (!item || item.type !== "reasoning") {
return;
}
ensureVisibleResponsesReasoningSummary(payload);
const visibleSummary = getResponsesReasoningSummaryText(item);
if (!visibleSummary) {
return;
}
const reasoningKey = getResponsesReasoningKey(payload);
if (!reasoningKey || passthroughResponsesReasoningSummarySeen.has(reasoningKey)) {
return;
}
passthroughResponsesReasoningSummarySeen.add(reasoningKey);
const itemId = typeof item.id === "string" && item.id ? item.id : reasoningKey;
const outputIndex =
typeof payload.output_index === "number" && Number.isInteger(payload.output_index)
? payload.output_index
: 0;
const syntheticEvents = [
{
event: "response.reasoning_summary_text.delta",
body: {
type: "response.reasoning_summary_text.delta",
item_id: itemId,
output_index: outputIndex,
summary_index: 0,
delta: visibleSummary,
},
},
{
event: "response.reasoning_summary_part.done",
body: {
type: "response.reasoning_summary_part.done",
item_id: itemId,
output_index: outputIndex,
summary_index: 0,
part: { type: "summary_text", text: visibleSummary },
},
},
];
for (const syntheticEvent of syntheticEvents) {
clientPayloadCollector.push(syntheticEvent.body);
const output = `event: ${syntheticEvent.event}\ndata: ${JSON.stringify(syntheticEvent.body)}\n\n`;
reqLogger?.appendConvertedChunk?.(output);
controller.enqueue(encoder.encode(output));
}
};
return new TransformStream(
{
start(controller) {
// Start idle watchdog — checks every 10s if provider has stopped sending
if (STREAM_IDLE_TIMEOUT_MS > 0) {
idleTimer = setInterval(() => {
if (!streamTimedOut && Date.now() - lastChunkTime > STREAM_IDLE_TIMEOUT_MS) {
streamTimedOut = true;
clearIdleTimer();
const timeoutMsg = `[STREAM] Idle timeout: no data from ${provider || "provider"} for ${STREAM_IDLE_TIMEOUT_MS}ms (model: ${model || "unknown"})`;
console.warn(timeoutMsg);
trackPendingRequest(model, provider, connectionId, false);
appendRequestLog({
model,
provider,
connectionId,
status: `FAILED ${HTTP_STATUS.GATEWAY_TIMEOUT}`,
}).catch(() => {});
const timeoutError = new Error(timeoutMsg);
timeoutError.name = "StreamIdleTimeoutError";
controller.error(markPendingRequestCleared(timeoutError));
}
}, 10_000);
}
},
transform(chunk, controller) {
if (streamTimedOut) return;
lastChunkTime = Date.now();
const text = decoder.decode(chunk, { stream: true });
buffer += text;
reqLogger?.appendProviderChunk?.(text);
const lines = buffer.split("\n");
buffer = lines.pop() || "";
for (const line of lines) {
const trimmed = line.trim();
// Passthrough mode: normalize and forward
if (mode === STREAM_MODE.PASSTHROUGH) {
let output;
let injectedUsage = false;
let clientPayload: unknown = null;
let failurePayload: StreamFailurePayload | null = null;
if (skipPassthroughEvent) {
if (!trimmed) {
skipPassthroughEvent = false;
clearPendingPassthroughEvent();
}
continue;
}
// Drop whole keepalive event blocks — strict OpenAI-compatible SDKs
// try to JSON.parse empty keepalive payloads and crash.
if (/^event:\s*keepalive\b/i.test(trimmed)) {
skipPassthroughEvent = true;
clearPendingPassthroughEvent();
continue;
}
if (/^event:/i.test(trimmed)) {
if (pendingPassthroughEventLine && !pendingPassthroughEventEmitted) {
const pendingOutput = `${pendingPassthroughEventLine}\n`;
reqLogger?.appendConvertedChunk?.(pendingOutput);
controller.enqueue(encoder.encode(pendingOutput));
}
const eventType = trimmed.replace(/^event:\s*/i, "");
if (
shouldInjectClaudeEmptyResponseBeforeCurrentEvent(claudeEmptyResponseLifecycle, {
type: eventType,
})
) {
emitSyntheticClaudeEmptyResponse(controller, {
includeContentBlock: true,
includeMessageDelta:
eventType === "message_stop" && !claudeEmptyResponseLifecycle.hasMessageDelta,
includeMessageStop: false,
});
}
pendingPassthroughEventLine = line;
pendingPassthroughEventEmitted = false;
continue;
}
if (trimmed.startsWith("data:")) {
const providerPayload = parseSSELine(trimmed);
if (providerPayload) {
providerPayloadCollector.push(providerPayload);
if ((providerPayload as { done?: unknown }).done === true) {
continue;
}
}
}
if (trimmed.startsWith("data:") && trimmed.slice(5).trim() === "[DONE]") {
continue;
}
if (trimmed.startsWith("data:") && trimmed.slice(5).trim() !== "[DONE]") {
try {
let parsed = JSON.parse(trimmed.slice(5).trim());
// Detect Responses SSE payloads (have a `type` field like "response.created",
// "response.output_item.added", etc.) and skip Chat Completions-specific
// sanitization to avoid corrupting the stream for Responses-native clients.
const isResponsesSSE =
parsed.type &&
typeof parsed.type === "string" &&
parsed.type.startsWith("response.");
// Detect Claude SSE payloads. Includes "ping" and "error" to ensure
// they bypass the Chat Completions sanitization path which would
// incorrectly process or drop them.
const isClaudeSSE =
parsed.type &&
typeof parsed.type === "string" &&
(parsed.type.startsWith("message") ||
parsed.type.startsWith("content_block") ||
parsed.type === "ping" ||
parsed.type === "error");
if (isResponsesSSE) {
const responseId =
typeof parsed.response?.id === "string"
? parsed.response.id
: typeof parsed.response_id === "string"
? parsed.response_id
: null;
if (responseId) {
passthroughResponsesId = responseId;
}
// Responses SSE: only extract usage, forward payload as-is
const extracted = extractUsage(parsed);
if (extracted) {
usage = extracted;
}
// Keep generic Responses deltas for fallback usage estimates,
// but only visible text deltas may become assistant content in
// logs/replay payloads.
if (typeof parsed.delta === "string") {
totalContentLength += parsed.delta.length;
}
if (
parsed.type === "response.output_text.delta" &&
typeof parsed.delta === "string"
) {
const incomingDelta = parsed.delta;
const bufferedCandidate =
passthroughBufferedTextualToolCallContent + incomingDelta;
if (
passthroughBufferedTextualToolCallContent ||
containsTextualToolCallCandidate(incomingDelta)
) {
const parsedCandidate = parseTextualToolCallCandidate(bufferedCandidate);
if (parsedCandidate?.kind === "complete") {
const collectedToolCall = collectPassthroughTextualToolCall(
bufferedCandidate,
passthroughToolCalls,
allowedToolNames
);
if (collectedToolCall) {
passthroughHasToolCalls = true;
const responseToolCallEvents =
buildResponsesFunctionCallEvents(collectedToolCall);
output = formatSSEDataEvents(responseToolCallEvents);
clientPayloadCollector.push(...responseToolCallEvents);
reqLogger?.appendConvertedChunk?.(output);
controller.enqueue(encoder.encode(output));
injectedUsage = true;
} else {
output = `data: ${JSON.stringify(parsed)}
`;
injectedUsage = true;
}
passthroughBufferedTextualToolCallContent = "";
parsed.delta = "";
} else if (parsedCandidate?.kind === "partial") {
passthroughBufferedTextualToolCallContent = appendBoundedText(
passthroughBufferedTextualToolCallContent,
incomingDelta
);
parsed.delta = "";
output = `data: ${JSON.stringify(parsed)}\n`;
injectedUsage = true;
} else {
passthroughAccumulatedContent = appendBoundedText(
passthroughAccumulatedContent,
passthroughBufferedTextualToolCallContent + incomingDelta
);
passthroughBufferedTextualToolCallContent = "";
}
} else {
passthroughAccumulatedContent = appendBoundedText(
passthroughAccumulatedContent,
incomingDelta
);
}
}
if (parsed.type === "response.failed") {
failurePayload = normalizeStreamFailurePayload(parsed);
}
if (
parsed.type === "response.reasoning_summary_text.delta" ||
parsed.type === "response.reasoning_summary_text.done" ||
parsed.type === "response.reasoning_summary_part.done"
) {
const reasoningKey = getResponsesReasoningKey(parsed);
if (reasoningKey) {
passthroughResponsesReasoningSummarySeen.add(reasoningKey);
}
}
if (
parsed.type === "response.output_item.added" &&
parsed.item?.type === "function_call"
) {
const item =
parsed.item && typeof parsed.item === "object" && !Array.isArray(parsed.item)
? { ...(parsed.item as JsonRecord) }
: null;
const pendingKey =
item && typeof item.id === "string"
? item.id
: item && typeof item.call_id === "string"
? item.call_id
: null;
if (item && pendingKey) {
if (typeof item.arguments !== "string") {
item.arguments = "";
}
passthroughResponsesPendingFunctionCalls.set(pendingKey, item);
passthroughResponsesCurrentFunctionCallKey = pendingKey;
}
}
if (parsed.type === "response.function_call_arguments.delta") {
const pendingKey =
typeof parsed.item_id === "string"
? parsed.item_id
: passthroughResponsesCurrentFunctionCallKey;
const pending = pendingKey
? passthroughResponsesPendingFunctionCalls.get(pendingKey)
: undefined;
if (pending && typeof parsed.delta === "string") {
const previousArgs =
typeof pending.arguments === "string" ? pending.arguments : "";
pending.arguments = previousArgs + parsed.delta;
}
}
if (parsed.type === "response.function_call_arguments.done") {
const pendingKey =
typeof parsed.item_id === "string"
? parsed.item_id
: passthroughResponsesCurrentFunctionCallKey;
const pending = pendingKey
? passthroughResponsesPendingFunctionCalls.get(pendingKey)
: undefined;
if (pending) {
if (typeof parsed.arguments === "string") {
pending.arguments = parsed.arguments;
}
pushUniqueResponsesOutputItems(passthroughResponsesOutputItems, [pending]);
}
}
// Capture each completed output item so the final
// response.completed snapshot can be backfilled when upstream
// returns an empty `output` (happens with store: false).
if (parsed.type === "response.output_item.done" && parsed.item) {
const reasoningSummaryInjected = ensureVisibleResponsesReasoningSummary(parsed);
emitSyntheticResponsesReasoningSummary(controller, parsed);
pushUniqueResponsesOutputItems(passthroughResponsesOutputItems, [parsed.item]);
if (reasoningSummaryInjected) {
output = `data: ${JSON.stringify(parsed)}\n`;
injectedUsage = true;
}
if (parsed.item?.type === "function_call") {
const pendingKey =
typeof parsed.item.id === "string"
? parsed.item.id
: typeof parsed.item.call_id === "string"
? parsed.item.call_id
: null;
if (pendingKey) {
passthroughResponsesPendingFunctionCalls.delete(pendingKey);
if (passthroughResponsesCurrentFunctionCallKey === pendingKey) {
passthroughResponsesCurrentFunctionCallKey = null;
}
}
}
}
if (
parsed.type === "response.completed" &&
Array.isArray(parsed.response?.output) &&
parsed.response.output.length > 0
) {
pushUniqueResponsesOutputItems(
passthroughResponsesOutputItems,
parsed.response.output
);
}
if (
parsed.type === "response.completed" &&
passthroughResponsesPendingFunctionCalls.size > 0
) {
pushUniqueResponsesOutputItems(passthroughResponsesOutputItems, [
...passthroughResponsesPendingFunctionCalls.values(),
]);
passthroughResponsesPendingFunctionCalls.clear();
passthroughResponsesCurrentFunctionCallKey = null;
}
// Two transport-level fixes for Responses passthrough:
// 1) Strip echoed `instructions` + `tools` from lifecycle
// events — they can balloon a single SSE event past
// 100 KB and break parsers (e.g. GitHub Copilot CLI).
// 2) Backfill `response.completed.response.output` when
// upstream sent it empty (store: false) — some clients
// build their tool-call list from that snapshot rather
// than from per-item events.
const textualToolCallBackfilled =
parsed.type === "response.completed" && passthroughToolCalls.size > 0;
if (textualToolCallBackfilled) {
parsed = toResponsesCompletedWithToolCalls(parsed as JsonRecord, [
...passthroughToolCalls.values(),
]) as typeof parsed;
}
const stripped = stripResponsesLifecycleEcho(parsed);
const backfilled = backfillResponsesCompletedOutput(
parsed,
passthroughResponsesOutputItems
);
if (stripped || backfilled || textualToolCallBackfilled) {
output = `data: ${JSON.stringify(parsed)}\n`;
injectedUsage = true;
}
} else if (isClaudeSSE) {
// Claude SSE: extract usage, track content, forward as-is
const extracted = extractUsage(parsed);
if (extracted) {
// Non-destructive merge: never overwrite a positive value with 0
// message_start carries input_tokens, message_delta carries output_tokens;
if (!usage) usage = {};
const u = usage;
const eu = extracted as UsageTokenRecord;
if (eu.prompt_tokens > 0) u.prompt_tokens = eu.prompt_tokens;
if (eu.completion_tokens > 0) u.completion_tokens = eu.completion_tokens;
if (eu.total_tokens > 0) u.total_tokens = eu.total_tokens;
if (eu.cache_read_input_tokens)
u.cache_read_input_tokens = eu.cache_read_input_tokens;
if (eu.cache_creation_input_tokens)
u.cache_creation_input_tokens = eu.cache_creation_input_tokens;
}
if (
shouldInjectClaudeEmptyResponseBeforeCurrentEvent(
claudeEmptyResponseLifecycle,
parsed
)
) {
emitSyntheticClaudeEmptyResponse(controller, {
includeContentBlock: true,
includeMessageDelta:
parsed.type === "message_stop" &&
!claudeEmptyResponseLifecycle.hasMessageDelta,
includeMessageStop: false,
});
}
updateClaudeEmptyResponseLifecycle(claudeEmptyResponseLifecycle, parsed);
const restoredToolName = restoreClaudePassthroughToolUseName(parsed, toolNameMap);
// Track content length and accumulate from Claude format
if (parsed.delta?.text) {
totalContentLength += parsed.delta.text.length;
passthroughAccumulatedContent = appendBoundedText(
passthroughAccumulatedContent,
parsed.delta.text
);
}
if (parsed.delta?.thinking) {
totalContentLength += parsed.delta.thinking.length;
passthroughAccumulatedContent = appendBoundedText(
passthroughAccumulatedContent,
parsed.delta.thinking
);
}
if (restoredToolName) {
output = `data: ${JSON.stringify(parsed)}\n`;
injectedUsage = true;
}
} else {
// Chat Completions: full sanitization pipeline
// Detect reasoning alias before sanitization strips it
const hadReasoningAlias = !!(
parsed.choices?.[0]?.delta?.reasoning &&
typeof parsed.choices[0].delta.reasoning === "string" &&
!parsed.choices[0].delta.reasoning_content
);
parsed = sanitizeStreamingChunk(parsed);
const idFixed = fixInvalidId(parsed);
if (!hasValuableContent(parsed, FORMATS.OPENAI)) {
continue;
}
const delta = parsed.choices?.[0]?.delta;
let textualToolCallConverted = false;
// Extract <think> tags from streaming content
if (delta?.content && typeof delta.content === "string") {
const { content, thinking } = extractThinkingFromContent(delta.content);
delta.content = content;
if (thinking && !delta.reasoning_content) {
delta.reasoning_content = thinking;
}
}
// Split combined reasoning+content deltas into separate SSE events.
// Standard OpenAI streaming never mixes both fields in one delta;
// clients (e.g. LobeChat) may skip content when reasoning_content
// is present, causing the first content token to be lost.
if (delta?.reasoning_content && delta?.content) {
const reasoningChunk = JSON.parse(JSON.stringify(parsed));
const rDelta = reasoningChunk.choices[0].delta;
delete rDelta.content;
reasoningChunk.choices[0].finish_reason = null;
delete reasoningChunk.usage;
const rOutput = `data: ${JSON.stringify(reasoningChunk)}\n`;
passthroughAccumulatedReasoning = appendBoundedText(
passthroughAccumulatedReasoning,
delta.reasoning_content
);
totalContentLength += delta.reasoning_content.length;
clientPayloadCollector.push(reasoningChunk);
reqLogger?.appendConvertedChunk?.(rOutput);
controller.enqueue(encoder.encode(rOutput));
controller.enqueue(encoder.encode("\n"));
delete delta.reasoning_content;
}
// Track whether we need to re-serialize (separate from injectedUsage
// to avoid blocking subsequent finish_reason / usage mutations)
const needsReserialization =
hadReasoningAlias || (delta?.content === "" && delta?.reasoning_content);
// T18: Track if we saw tool calls & accumulate for call log
if (delta?.tool_calls && delta.tool_calls.length > 0) {
passthroughHasToolCalls = true;
for (const tc of delta.tool_calls) {
// Key by index first — id only appears on the first delta in OpenAI streaming
let key: string;
if (Number.isInteger(tc?.index)) {
key = `idx:${tc.index}`;
} else if (tc?.id) {
key = `id:${tc.id}`;
} else {
key = `seq:${++passthroughToolCallSeq}`;
}
const existing = passthroughToolCalls.get(key);
const deltaArgs =
typeof tc?.function?.arguments === "string" ? tc.function.arguments : "";
if (!existing) {
passthroughToolCalls.set(key, {
id: tc?.id ?? null,
index: Number.isInteger(tc?.index) ? tc.index : passthroughToolCalls.size,
type: tc?.type || "function",
function: {
name: tc?.function?.name || "",
arguments: deltaArgs,
},
});
} else {
if (tc?.id) existing.id = existing.id || tc.id;
if (tc?.function?.name && !existing.function.name)
existing.function.name = tc.function.name;
existing.function.arguments += deltaArgs;
}
}
}
const content = delta?.content || delta?.reasoning_content;
if (content && typeof content === "string") {
totalContentLength += content.length;
}
{
const guarded = applyTextualToolCallStreamingGuard(
parsed as Record<string, unknown>
);
parsed = guarded.parsed as typeof parsed;
textualToolCallConverted = guarded.textualToolCallConverted;
}
if (typeof delta?.reasoning_content === "string")
passthroughAccumulatedReasoning = appendBoundedText(
passthroughAccumulatedReasoning,
delta.reasoning_content
);
const extracted = extractUsage(parsed);
if (extracted) {
usage = extracted;
}
const isFinishChunk = parsed.choices?.[0]?.finish_reason;
// T18: Normalize finish_reason to 'tool_calls' if tool calls were used
if (
isFinishChunk &&
passthroughHasToolCalls &&
parsed.choices[0].finish_reason !== "tool_calls"
) {
parsed.choices[0].finish_reason = "tool_calls";
// If we modify it, we must output the modified object
if (!injectedUsage && hasValidUsage(parsed.usage)) {
output = `data: ${JSON.stringify(parsed)}\n`;
injectedUsage = true;
}
}
if (isFinishChunk && !hasValidUsage(parsed.usage)) {
const estimated = estimateUsage(body, totalContentLength, FORMATS.OPENAI);
parsed.usage = filterUsageForFormat(estimated, FORMATS.OPENAI);
output = `data: ${JSON.stringify(parsed)}\n`;
usage = estimated;
injectedUsage = true;
} else if (isFinishChunk && usage) {
const buffered = addBufferToUsage(usage);
parsed.usage = filterUsageForFormat(buffered, FORMATS.OPENAI);
output = `data: ${JSON.stringify(parsed)}\n`;
injectedUsage = true;
} else if (textualToolCallConverted) {
output = `data: ${JSON.stringify(parsed)}\n`;
injectedUsage = true;
} else if (idFixed || needsReserialization) {
output = `data: ${JSON.stringify(parsed)}\n`;
injectedUsage = true;
}
}
clientPayload = parsed;
} catch {}
}
if (!injectedUsage) {
if (line.startsWith("data:") && !line.startsWith("data: ")) {
output = "data: " + line.slice(5) + "\n";
} else {
output = line + "\n";
}
}
if (!trimmed && pendingPassthroughEventLine && !pendingPassthroughEventEmitted) {
output = `${pendingPassthroughEventLine}\n${output}`;
pendingPassthroughEventEmitted = true;
}
output = maybePrefixPendingPassthroughEvent(output, line);
if (clientPayload) {
clientPayloadCollector.push(clientPayload);
}
reqLogger?.appendConvertedChunk?.(output);
controller.enqueue(encoder.encode(output));
if (failurePayload) {
if (onFailure) {
try {
void onFailure(failurePayload);
} catch {}
}
clearIdleTimer();
trackPendingRequest(model, provider, connectionId, false);
controller.error(
markPendingRequestCleared(new Error(failurePayload.message || "Upstream failure"))
);
return;
}
if (!trimmed) {
clearPendingPassthroughEvent();
}
continue;
}
// Translate mode
if (!trimmed) continue;
if (state?.upstreamError) {
continue;
}
const parsed = parseSSELine(trimmed);
if (!parsed) continue;
providerPayloadCollector.push(parsed);
if (parsed && parsed.done) {
continue;
}
// Track content length and accumulate for call log (from raw provider chunk, so content is never missed)
// Do this before translation so we capture content regardless of translator output shape
// Claude format
if (parsed.delta?.text) {
const t = parsed.delta.text;
totalContentLength += t.length;
if (state?.accumulatedContent !== undefined && typeof t === "string")
state.accumulatedContent = appendBoundedText(state.accumulatedContent, t);
}
if (parsed.delta?.thinking) {
const t = parsed.delta.thinking;
totalContentLength += t.length;
if (state?.accumulatedContent !== undefined && typeof t === "string")
state.accumulatedContent = appendBoundedText(state.accumulatedContent, t);
}
// OpenAI format
if (parsed.choices?.[0]?.delta?.content) {
const c = parsed.choices[0].delta.content;
if (typeof c === "string") {
totalContentLength += c.length;
if (state?.accumulatedContent !== undefined)
state.accumulatedContent = appendBoundedText(state.accumulatedContent, c);
} else if (Array.isArray(c)) {
for (const part of c) {
if (part?.text && typeof part.text === "string") {
totalContentLength += part.text.length;
if (state?.accumulatedContent !== undefined)
state.accumulatedContent = appendBoundedText(
state.accumulatedContent,
part.text
);
}
}
}
}
if (parsed.choices?.[0]?.delta?.reasoning_content) {
const r = parsed.choices[0].delta.reasoning_content;
if (typeof r === "string") {
totalContentLength += r.length;
if (state?.accumulatedContent !== undefined)
state.accumulatedContent = appendBoundedText(state.accumulatedContent, r);
}
}
// Normalize `reasoning` alias → `reasoning_content` (NVIDIA kimi-k2.5 etc.)
if (
parsed.choices?.[0]?.delta?.reasoning &&
!parsed.choices?.[0]?.delta?.reasoning_content
) {
const r = parsed.choices[0].delta.reasoning;
if (typeof r === "string") {
parsed.choices[0].delta.reasoning_content = r;
delete parsed.choices[0].delta.reasoning;
totalContentLength += r.length;
if (state?.accumulatedContent !== undefined)
state.accumulatedContent = appendBoundedText(state.accumulatedContent, r);
}
}
// Gemini / Cloud Code format - may have multiple parts
// Cloud Code API wraps in { response: { candidates: [...] } }, so unwrap.
// Only applies to Gemini-family formats — skip for OpenAI, Claude, etc.
const isGeminiFormat =
targetFormat === FORMATS.GEMINI ||
targetFormat === FORMATS.GEMINI_CLI ||
targetFormat === FORMATS.ANTIGRAVITY;
const geminiChunk = isGeminiFormat ? unwrapGeminiChunk(parsed) : parsed;
if (geminiChunk.candidates?.[0]?.content?.parts) {
for (const part of geminiChunk.candidates[0].content.parts) {
if (part.text && typeof part.text === "string") {
totalContentLength += part.text.length;
if (state?.accumulatedContent !== undefined)
state.accumulatedContent = appendBoundedText(state.accumulatedContent, part.text);
}
}
}
// Generic fallback: delta string, top-level content/text (e.g. some SSE payloads)
if (state?.accumulatedContent !== undefined) {
if (typeof (parsed as JsonRecord).delta === "string") {
const d = (parsed as JsonRecord).delta as string;
state.accumulatedContent = appendBoundedText(state.accumulatedContent, d);
totalContentLength += d.length;
}
if (typeof (parsed as JsonRecord).content === "string") {
const c = (parsed as JsonRecord).content as string;
state.accumulatedContent = appendBoundedText(state.accumulatedContent, c);
totalContentLength += c.length;
}
if (typeof (parsed as JsonRecord).text === "string") {
const t = (parsed as JsonRecord).text as string;
state.accumulatedContent = appendBoundedText(state.accumulatedContent, t);
totalContentLength += t.length;
}
}
// Extract usage
const extracted = extractUsage(parsed);
if (extracted) state.usage = extracted; // Keep original usage for logging
// Translate: targetFormat -> openai -> sourceFormat
const translated = translateResponse(targetFormat, sourceFormat, parsed, state);
// Log OpenAI intermediate chunks (if available)
for (const item of getOpenAIIntermediateChunks(translated)) {
const openaiOutput = formatSSE(item, FORMATS.OPENAI);
reqLogger?.appendOpenAIChunk?.(openaiOutput);
}
if (translated?.length > 0) {
for (const item of translated) {
emitTranslatedClientItem(controller, item);
}
}
}
},
async flush(controller) {
// Clean up idle watchdog timer
if (idleTimer) {
clearIdleTimer();
}
if (streamTimedOut) {
return;
}
trackPendingRequest(model, provider, connectionId, false);
try {
const remaining = decoder.decode();
if (remaining) buffer += remaining;
if (mode === STREAM_MODE.PASSTHROUGH) {
const bufferedLine = buffer.trim();
if (skipPassthroughEvent || /^event:\s*keepalive\b/i.test(bufferedLine)) {
skipPassthroughEvent = false;
clearPendingPassthroughEvent();
} else if (buffer) {
let output = buffer;
if (buffer.startsWith("data:") && !buffer.startsWith("data: ")) {
output = "data: " + buffer.slice(5);
}
const bufferedPayload = parseSSELine(bufferedLine);
if (bufferedPayload) {
providerPayloadCollector.push(bufferedPayload);
if (
shouldInjectClaudeEmptyResponseBeforeCurrentEvent(
claudeEmptyResponseLifecycle,
bufferedPayload
)
) {
const eventType = getClaudeEventType(bufferedPayload);
emitSyntheticClaudeEmptyResponse(controller, {
includeContentBlock: true,
includeMessageDelta:
eventType === "message_stop" && !claudeEmptyResponseLifecycle.hasMessageDelta,
includeMessageStop: false,
});
}
if (isClaudeEventPayload(bufferedPayload)) {
updateClaudeEmptyResponseLifecycle(claudeEmptyResponseLifecycle, bufferedPayload);
}
clientPayloadCollector.push(bufferedPayload);
}
if (!bufferedLine && pendingPassthroughEventLine && !pendingPassthroughEventEmitted) {
output = `${pendingPassthroughEventLine}\n${output}`;
pendingPassthroughEventEmitted = true;
}
output = maybePrefixPendingPassthroughEvent(output, buffer);
reqLogger?.appendConvertedChunk?.(output);
controller.enqueue(encoder.encode(output));
}
if (shouldInjectClaudeEmptyResponseOnFlush(claudeEmptyResponseLifecycle)) {
emitSyntheticClaudeEmptyResponse(controller, {
includeContentBlock: true,
includeMessageDelta: !claudeEmptyResponseLifecycle.hasMessageDelta,
includeMessageStop: !claudeEmptyResponseLifecycle.hasMessageStop,
});
} else if (shouldInjectClaudeMissingFinalizersOnFlush(claudeEmptyResponseLifecycle)) {
emitSyntheticClaudeEmptyResponse(controller, {
includeContentBlock: false,
includeMessageDelta: !claudeEmptyResponseLifecycle.hasMessageDelta,
includeMessageStop: !claudeEmptyResponseLifecycle.hasMessageStop,
});
}
clearPendingPassthroughEvent();
// Estimate usage if provider didn't return valid usage
if (!hasValidUsage(usage) && totalContentLength > 0) {
usage = estimateUsage(body, totalContentLength, sourceFormat || FORMATS.OPENAI);
}
if (hasValidUsage(usage)) {
logUsage(provider, usage, model, connectionId, apiKeyInfo);
} else {
appendRequestLog({
model,
provider,
connectionId,
tokens: null,
status: "200 OK",
}).catch(() => {});
}
if (!doneSent) {
await emitFinalSseMetadata(controller, usage);
doneSent = true;
if (shouldEmitDoneTerminator) {
clientPayloadCollector.push({ done: true });
const doneOutput = "data: [DONE]\n\n";
reqLogger?.appendConvertedChunk?.(doneOutput);
controller.enqueue(encoder.encode(doneOutput));
}
}
// Notify caller for call log persistence (include full response body with accumulated content)
if (onComplete) {
try {
const u = usage as Record<string, unknown> | null;
const prompt = Number(u?.prompt_tokens ?? u?.input_tokens ?? 0);
const completion = Number(u?.completion_tokens ?? u?.output_tokens ?? 0);
let content = passthroughAccumulatedContent.trim() || "";
const finalBufferedTextualToolCall =
passthroughBufferedTextualToolCallContent.trim();
if (finalBufferedTextualToolCall) {
if (
collectPassthroughTextualToolCall(
finalBufferedTextualToolCall,
passthroughToolCalls,
allowedToolNames
)
) {
passthroughHasToolCalls = true;
}
passthroughBufferedTextualToolCallContent = "";
}
if (
content &&
collectPassthroughTextualToolCall(content, passthroughToolCalls, allowedToolNames)
) {
passthroughHasToolCalls = true;
content = "";
} else if (containsMalformedTextualToolCall(content)) {
content = "";
}
const message: Record<string, unknown> = {
role: "assistant",
content: content || null,
};
const reasoning = passthroughAccumulatedReasoning.trim();
if (reasoning) {
message.reasoning_content = reasoning;
}
if (passthroughToolCalls.size > 0) {
message.tool_calls = [...passthroughToolCalls.values()].sort(
(a, b) => a.index - b.index
);
}
const responseBody = {
choices: [
{
message,
finish_reason: passthroughHasToolCalls ? "tool_calls" : "stop",
},
],
usage: {
prompt_tokens: prompt,
completion_tokens: completion,
total_tokens: prompt + completion,
},
_streamed: true,
};
onComplete({
status: 200,
usage,
responseBody,
providerPayload: providerPayloadCollector.build(
buildStreamSummaryFromEvents(
providerPayloadCollector.getEvents(),
sourceFormat,
model
),
{ includeEvents: false }
),
clientPayload: clientPayloadCollector.build(responseBody, {
includeEvents: false,
}),
});
} catch {}
}
return;
}
// Translate mode: process remaining buffer
if (buffer.trim()) {
const parsed = parseSSELine(buffer.trim());
if (parsed && !parsed.done) {
providerPayloadCollector.push(parsed);
// Extract usage from remaining buffer — if the usage-bearing event
// (e.g. response.completed) is the last SSE line, it ends up here
// in the flush handler where extractUsage was not called.
// Non-destructive merge: some providers send usage across multiple
// events (e.g. prompt_tokens in message_start, completion_tokens
// in message_delta). Direct assignment would lose earlier data.
const extracted = extractUsage(parsed);
if (extracted) {
if (!state.usage) {
state.usage = extracted;
} else {
const su = state.usage as Record<string, number>;
const eu = extracted as Record<string, number>;
if (eu.prompt_tokens > 0) su.prompt_tokens = eu.prompt_tokens;
if (eu.completion_tokens > 0) su.completion_tokens = eu.completion_tokens;
if (eu.total_tokens > 0) su.total_tokens = eu.total_tokens;
if (eu.cache_read_input_tokens > 0)
su.cache_read_input_tokens = eu.cache_read_input_tokens;
if (eu.cache_creation_input_tokens > 0)
su.cache_creation_input_tokens = eu.cache_creation_input_tokens;
if (eu.cached_tokens > 0) su.cached_tokens = eu.cached_tokens;
if (eu.reasoning_tokens > 0) su.reasoning_tokens = eu.reasoning_tokens;
}
}
const translated = translateResponse(targetFormat, sourceFormat, parsed, state);
// Log OpenAI intermediate chunks
for (const item of getOpenAIIntermediateChunks(translated)) {
const openaiOutput = formatSSE(item, FORMATS.OPENAI);
reqLogger?.appendOpenAIChunk?.(openaiOutput);
}
if (translated?.length > 0) {
for (const item of translated) {
emitTranslatedClientItem(controller, item);
}
}
}
}
if (state?.upstreamError) {
const err = state.upstreamError;
trackPendingRequest(model, provider, connectionId, false);
if (onFailure) {
try {
void onFailure({
status: err.status,
message: err.message,
code: err.code,
type: err.type,
});
} catch {}
}
const errorBody = buildErrorBody(err.status, err.message);
if (onComplete) {
try {
onComplete({
status: err.status,
usage: state?.usage,
responseBody: errorBody,
providerPayload: providerPayloadCollector.build(
buildStreamSummaryFromEvents(
providerPayloadCollector.getEvents(),
targetFormat,
model
),
{ includeEvents: false }
),
clientPayload: clientPayloadCollector.build(errorBody, {
includeEvents: false,
}),
});
} catch {}
}
clearIdleTimer();
controller.error(
markPendingRequestCleared(new Error(err.message || "Upstream failure"))
);
return;
}
// Flush remaining events (only once at stream end)
const flushed = translateResponse(targetFormat, sourceFormat, null, state);
// Log OpenAI intermediate chunks for flushed events
for (const item of getOpenAIIntermediateChunks(flushed)) {
const openaiOutput = formatSSE(item, FORMATS.OPENAI);
reqLogger?.appendOpenAIChunk?.(openaiOutput);
}
if (flushed?.length > 0) {
for (const item of flushed) {
emitTranslatedClientItem(controller, item);
}
}
if (sourceFormat === FORMATS.CLAUDE) {
if (shouldInjectClaudeEmptyResponseOnFlush(claudeEmptyResponseLifecycle)) {
emitSyntheticClaudeEmptyResponse(controller, {
includeContentBlock: true,
includeMessageDelta: !claudeEmptyResponseLifecycle.hasMessageDelta,
includeMessageStop: !claudeEmptyResponseLifecycle.hasMessageStop,
});
} else if (shouldInjectClaudeMissingFinalizersOnFlush(claudeEmptyResponseLifecycle)) {
emitSyntheticClaudeEmptyResponse(controller, {
includeContentBlock: false,
includeMessageDelta: !claudeEmptyResponseLifecycle.hasMessageDelta,
includeMessageStop: !claudeEmptyResponseLifecycle.hasMessageStop,
});
}
}
/**
* Usage injection strategy:
* Usage data (input/output tokens) is injected into the last content chunk
* or the finish_reason chunk rather than sent as a separate SSE event.
* This ensures all major clients (Claude CLI, Continue, Cursor) receive
* usage data even if they stop reading after the finish signal.
* The usage buffer (state.usage) accumulates across chunks and is only
* emitted once at stream end when merged into the final translated chunk.
*/
// Send [DONE] (only if not already sent during transform)
if (!doneSent) {
await emitFinalSseMetadata(controller, state?.usage as Record<string, unknown> | null);
doneSent = true;
if (shouldEmitDoneTerminator) {
clientPayloadCollector.push({ done: true });
const doneOutput = "data: [DONE]\n\n";
reqLogger?.appendConvertedChunk?.(doneOutput);
controller.enqueue(encoder.encode(doneOutput));
}
}
// Estimate usage if provider didn't return valid usage (for translate mode)
if (!hasValidUsage(state?.usage) && totalContentLength > 0) {
state.usage = estimateUsage(body, totalContentLength, sourceFormat);
}
if (hasValidUsage(state?.usage)) {
logUsage(state.provider || targetFormat, state.usage, model, connectionId, apiKeyInfo);
} else {
appendRequestLog({
model,
provider,
connectionId,
tokens: null,
status: "200 OK",
}).catch(() => {});
}
// Notify caller for call log persistence (include full response body with accumulated content)
if (onComplete) {
try {
const u = state?.usage as Record<string, unknown> | null | undefined;
const prompt = Number(u?.prompt_tokens ?? u?.input_tokens ?? 0);
const completion = Number(u?.completion_tokens ?? u?.output_tokens ?? 0);
let content = (state?.accumulatedContent ?? "").trim() || "";
const normalizedToolCalls: ToolCall[] = state?.toolCalls?.size
? [...state.toolCalls.values()]
.map(
(tc: Record<string, unknown>): ToolCall => ({
id: (tc.id as string) ?? null,
index: (tc.index as number) ?? (tc.blockIndex as number) ?? 0,
type: (tc.type as string) ?? "function",
function: (tc.function as ToolCall["function"]) ?? {
name: (tc.name as string) ?? "",
arguments: "",
},
})
)
.sort((a, b) => a.index - b.index)
: [];
const textualToolCall = parseTextualToolCallFromContent(content);
if (textualToolCall) {
normalizedToolCalls.push({
id: `call_${Date.now()}_${normalizedToolCalls.length}`,
index: normalizedToolCalls.length,
type: "function",
function: {
name: textualToolCall.name,
arguments: JSON.stringify(textualToolCall.args || {}),
},
});
content = "";
} else if (containsMalformedTextualToolCall(content)) {
content = "";
}
const message: Record<string, unknown> = {
role: "assistant",
content: content || null,
};
const hasToolCalls = normalizedToolCalls.length > 0;
if (hasToolCalls) {
message.tool_calls = normalizedToolCalls;
}
const responseBody = {
choices: [
{
message,
finish_reason: hasToolCalls ? "tool_calls" : "stop",
},
],
usage: {
prompt_tokens: prompt,
completion_tokens: completion,
total_tokens: prompt + completion,
},
_streamed: true,
};
onComplete({
status: 200,
usage: state?.usage,
responseBody,
providerPayload: providerPayloadCollector.build(
buildStreamSummaryFromEvents(
providerPayloadCollector.getEvents(),
targetFormat,
model
),
{ includeEvents: false }
),
clientPayload: clientPayloadCollector.build(responseBody, {
includeEvents: false,
}),
});
} catch {}
}
} catch (error) {
console.log(`[STREAM] Error in flush (${model || "unknown"}):`, error.message || error);
}
},
},
{ highWaterMark: 16384 },
{ highWaterMark: 16384 }
);
}
// Convenience functions for backward compatibility
export function createSSETransformStreamWithLogger(
targetFormat: string,
sourceFormat: string,
provider: string | null = null,
reqLogger: StreamLogger | null = null,
toolNameMap: unknown = null,
model: string | null = null,
connectionId: string | null = null,
body: unknown = null,
onComplete: ((payload: StreamCompletePayload) => void) | null = null,
apiKeyInfo: unknown = null,
onFailure: ((payload: StreamFailurePayload) => void | Promise<void>) | null = null,
copilotCompatibleReasoning = false
) {
return createSSEStream({
mode: STREAM_MODE.TRANSLATE,
targetFormat,
sourceFormat,
provider,
reqLogger,
toolNameMap,
model,
connectionId,
apiKeyInfo,
body,
onComplete,
onFailure,
copilotCompatibleReasoning,
});
}
export function createPassthroughStreamWithLogger(
provider: string | null = null,
reqLogger: StreamLogger | null = null,
toolNameMap: unknown = null,
model: string | null = null,
connectionId: string | null = null,
body: unknown = null,
onComplete: ((payload: StreamCompletePayload) => void) | null = null,
apiKeyInfo: unknown = null,
onFailure: ((payload: StreamFailurePayload) => void | Promise<void>) | null = null,
clientResponseFormat: string | null = null
) {
return createSSEStream({
mode: STREAM_MODE.PASSTHROUGH,
provider,
reqLogger,
toolNameMap,
model,
connectionId,
apiKeyInfo,
body,
onComplete,
onFailure,
clientResponseFormat,
});
}