const OVERLOADED_ERROR_USER_MESSAGE =

"The AI service is temporarily overloaded. Please try again in a moment.";

const FINAL_TAG_RE = /<\s*\/?\s*final\s*>/gi;

const TOOL_CALLS_OMITTED_PLACEHOLDER_LINE_RE = /^[ \t]*\[tool calls omitted\][ \t]*$/i;

const ERROR_PREFIX_RE =

/^(?:error|(?:[a-z][\w-]*\s+)?api\s*error|openai\s*error|anthropic\s*error|gateway\s*error|codex\s*error|request failed|failed|exception)(?:\s+\d{3})?[:\s-]+/i;

const CONTEXT_OVERFLOW_ERROR_HEAD_RE =

return normalized.replace(FINAL_TAG_RE, "");

}

function stripToolCallsOmittedPlaceholderLines(text: string): string {

let result = "";

let start = 0;

while (start < text.length) {

const newlineIndex = text.indexOf("\n", start);

const end = newlineIndex === -1 ? text.length : newlineIndex + 1;

const chunk = text.slice(start, end);

const line = chunk.endsWith("\n") ? chunk.slice(0, -1).replace(/\r$/, "") : chunk;

if (!TOOL_CALLS_OMITTED_PLACEHOLDER_LINE_RE.test(line)) {

result += chunk;

}

start = end;

}

return result;

}

function collapseConsecutiveDuplicateBlocks(text: string): string {

const trimmed = text.trim();

if (!trimmed) {

}

const errorContext = opts?.errorContext ?? false;

const stripped = stripInboundMetadata(stripInternalRuntimeContext(stripFinalTagsFromText(raw)));

const trimmed = stripped.trim();

// Replay repair may synthesize this placeholder to keep provider transcripts valid.

// It is internal scaffolding, so drop standalone placeholder lines before delivery

// while preserving ordinary inline mentions a user may be discussing.

const withoutPlaceholder = stripToolCallsOmittedPlaceholderLines(stripped);

const trimmed = withoutPlaceholder.trim();

if (!trimmed) {

return "";

}

if (!errorContext && shouldRewriteRawPayloadWithoutErrorContext(trimmed)) {

return formatRawAssistantErrorForUi(trimmed);

}

if (errorContext) {

const execDeniedMessage = formatExecDeniedUserMessage(trimmed);

if (execDeniedMessage) {

if (isBillingErrorMessage(trimmed)) {

return BILLING_ERROR_USER_MESSAGE;

}

if (isInvalidStreamingEventOrderError(trimmed)) {

return "LLM request failed: provider returned an invalid streaming response. Please try again.";

}

if (isRawApiErrorPayload(trimmed) || isLikelyHttpErrorText(trimmed)) {

return formatRawAssistantErrorForUi(trimmed);

}

if (isStreamingJsonParseError(trimmed)) {

return "LLM streaming response contained a malformed fragment. Please try again.";

}

if (ERROR_PREFIX_RE.test(trimmed)) {

const prefixedCopy = formatRateLimitOrOverloadedErrorCopy(trimmed);

if (prefixedCopy) {

}

}

const withoutLeadingEmptyLines = stripped.replace(/^(?:[ \t]*\r?\n)+/, "");

const withoutLeadingEmptyLines = withoutPlaceholder.replace(/^(?:[ \t]*\r?\n)+/, "");

return collapseConsecutiveDuplicateBlocks(withoutLeadingEmptyLines);

}