Files
ds2api/api/chat-stream.js

1087 lines
29 KiB
JavaScript

'use strict';
const crypto = require('crypto');
const DEEPSEEK_COMPLETION_URL = 'https://chat.deepseek.com/api/v0/chat/completion';
const BASE_HEADERS = {
Host: 'chat.deepseek.com',
'User-Agent': 'DeepSeek/1.6.11 Android/35',
Accept: 'application/json',
'Content-Type': 'application/json',
'x-client-platform': 'android',
'x-client-version': '1.6.11',
'x-client-locale': 'zh_CN',
'accept-charset': 'UTF-8',
};
const SKIP_PATTERNS = [
'quasi_status',
'elapsed_secs',
'token_usage',
'pending_fragment',
'conversation_mode',
'fragments/-1/status',
'fragments/-2/status',
'fragments/-3/status',
];
module.exports = async function handler(req, res) {
setCorsHeaders(res);
if (req.method === 'OPTIONS') {
res.statusCode = 204;
res.end();
return;
}
if (req.method !== 'POST') {
writeOpenAIError(res, 405, 'method not allowed');
return;
}
const rawBody = await readRawBody(req);
// Hard guard: only use Node data path for streaming on Vercel runtime.
// Any non-Vercel runtime always falls back to Go for full behavior parity.
if (!isVercelRuntime()) {
await proxyToGo(req, res, rawBody);
return;
}
let payload;
try {
payload = JSON.parse(rawBody.toString('utf8') || '{}');
} catch (_err) {
writeOpenAIError(res, 400, 'invalid json');
return;
}
// Keep all non-stream behavior on Go side to avoid compatibility regressions.
if (!toBool(payload.stream) || (Array.isArray(payload.tools) && payload.tools.length > 0)) {
await proxyToGo(req, res, rawBody);
return;
}
const prep = await fetchStreamPrepare(req, rawBody);
if (!prep.ok) {
relayPreparedFailure(res, prep);
return;
}
const model = asString(prep.body.model) || asString(payload.model);
const sessionID = asString(prep.body.session_id) || `chatcmpl-${Date.now()}`;
const leaseID = asString(prep.body.lease_id);
const deepseekToken = asString(prep.body.deepseek_token);
const powHeader = asString(prep.body.pow_header);
const completionPayload = prep.body.payload && typeof prep.body.payload === 'object' ? prep.body.payload : null;
const finalPrompt = asString(prep.body.final_prompt);
const thinkingEnabled = toBool(prep.body.thinking_enabled);
const searchEnabled = toBool(prep.body.search_enabled);
const toolNames = extractToolNames(payload.tools);
if (!model || !leaseID || !deepseekToken || !powHeader || !completionPayload) {
writeOpenAIError(res, 500, 'invalid vercel prepare response');
return;
}
const releaseLease = createLeaseReleaser(req, leaseID);
try {
const completionRes = await fetch(DEEPSEEK_COMPLETION_URL, {
method: 'POST',
headers: {
...BASE_HEADERS,
authorization: `Bearer ${deepseekToken}`,
'x-ds-pow-response': powHeader,
},
body: JSON.stringify(completionPayload),
});
if (!completionRes.ok || !completionRes.body) {
const detail = await safeReadText(completionRes);
writeOpenAIError(res, 500, detail ? `Failed to get completion: ${detail}` : 'Failed to get completion.');
return;
}
res.statusCode = 200;
res.setHeader('Content-Type', 'text/event-stream');
res.setHeader('Cache-Control', 'no-cache, no-transform');
res.setHeader('Connection', 'keep-alive');
res.setHeader('X-Accel-Buffering', 'no');
if (typeof res.flushHeaders === 'function') {
res.flushHeaders();
}
const created = Math.floor(Date.now() / 1000);
let firstChunkSent = false;
let currentType = thinkingEnabled ? 'thinking' : 'text';
let thinkingText = '';
let outputText = '';
const toolSieveEnabled = toolNames.length > 0;
const toolSieveState = createToolSieveState();
let toolCallsEmitted = false;
const decoder = new TextDecoder();
const reader = completionRes.body.getReader();
let buffered = '';
let ended = false;
const sendFrame = (obj) => {
res.write(`data: ${JSON.stringify(obj)}\n\n`);
if (typeof res.flush === 'function') {
res.flush();
}
};
const sendDeltaFrame = (delta) => {
const payloadDelta = { ...delta };
if (!firstChunkSent) {
payloadDelta.role = 'assistant';
firstChunkSent = true;
}
sendFrame({
id: sessionID,
object: 'chat.completion.chunk',
created,
model,
choices: [{ delta: payloadDelta, index: 0 }],
});
};
const finish = async (reason) => {
if (ended) {
return;
}
ended = true;
if (toolSieveEnabled) {
const tailEvents = flushToolSieve(toolSieveState, toolNames);
for (const evt of tailEvents) {
if (evt.type === 'tool_calls') {
toolCallsEmitted = true;
sendDeltaFrame({ tool_calls: formatOpenAIStreamToolCalls(evt.calls) });
continue;
}
if (evt.text) {
sendDeltaFrame({ content: evt.text });
}
}
}
if (toolCallsEmitted) {
reason = 'tool_calls';
}
sendFrame({
id: sessionID,
object: 'chat.completion.chunk',
created,
model,
choices: [{ delta: {}, index: 0, finish_reason: reason }],
usage: buildUsage(finalPrompt, thinkingText, outputText),
});
res.write('data: [DONE]\n\n');
await releaseLease();
res.end();
};
try {
// eslint-disable-next-line no-constant-condition
while (true) {
const { value, done } = await reader.read();
if (done) {
break;
}
buffered += decoder.decode(value, { stream: true });
const lines = buffered.split('\n');
buffered = lines.pop() || '';
for (const rawLine of lines) {
const line = rawLine.trim();
if (!line.startsWith('data:')) {
continue;
}
const dataStr = line.slice(5).trim();
if (!dataStr) {
continue;
}
if (dataStr === '[DONE]') {
await finish('stop');
return;
}
let chunk;
try {
chunk = JSON.parse(dataStr);
} catch (_err) {
continue;
}
if (chunk.error || chunk.code === 'content_filter') {
await finish('content_filter');
return;
}
const parsed = parseChunkForContent(chunk, thinkingEnabled, currentType);
currentType = parsed.newType;
if (parsed.finished) {
await finish('stop');
return;
}
for (const p of parsed.parts) {
if (!p.text) {
continue;
}
if (searchEnabled && isCitation(p.text)) {
continue;
}
if (p.type === 'thinking') {
thinkingText += p.text;
sendDeltaFrame({ reasoning_content: p.text });
} else {
outputText += p.text;
if (!toolSieveEnabled) {
sendDeltaFrame({ content: p.text });
continue;
}
const events = processToolSieveChunk(toolSieveState, p.text, toolNames);
for (const evt of events) {
if (evt.type === 'tool_calls') {
toolCallsEmitted = true;
sendDeltaFrame({ tool_calls: formatOpenAIStreamToolCalls(evt.calls) });
continue;
}
if (evt.text) {
sendDeltaFrame({ content: evt.text });
}
}
}
}
}
}
await finish('stop');
} catch (_err) {
await finish('stop');
}
} finally {
await releaseLease();
}
};
function setCorsHeaders(res) {
res.setHeader('Access-Control-Allow-Origin', '*');
res.setHeader('Access-Control-Allow-Credentials', 'true');
res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, DELETE');
res.setHeader(
'Access-Control-Allow-Headers',
'Content-Type, Authorization, X-API-Key, X-Ds2-Target-Account, X-Vercel-Protection-Bypass',
);
}
function header(req, key) {
if (!req || !req.headers) {
return '';
}
return asString(req.headers[key.toLowerCase()]);
}
async function readRawBody(req) {
if (Buffer.isBuffer(req.body)) {
return req.body;
}
if (typeof req.body === 'string') {
return Buffer.from(req.body);
}
if (req.body && typeof req.body === 'object') {
return Buffer.from(JSON.stringify(req.body));
}
const chunks = [];
for await (const chunk of req) {
chunks.push(Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk));
}
return Buffer.concat(chunks);
}
async function fetchStreamPrepare(req, rawBody) {
const url = buildInternalGoURL(req);
url.searchParams.set('__stream_prepare', '1');
const upstream = await fetch(url.toString(), {
method: 'POST',
headers: buildInternalGoHeaders(req, { withInternalToken: true, withContentType: true }),
body: rawBody,
});
const text = await upstream.text();
let body = {};
try {
body = JSON.parse(text || '{}');
} catch (_err) {
body = {};
}
return {
ok: upstream.ok,
status: upstream.status,
contentType: upstream.headers.get('content-type') || 'application/json',
text,
body,
};
}
function relayPreparedFailure(res, prep) {
if (prep.status === 401 && looksLikeVercelAuthPage(prep.text)) {
writeOpenAIError(
res,
401,
'Vercel Deployment Protection blocked internal prepare request. Disable protection for this deployment or set VERCEL_AUTOMATION_BYPASS_SECRET.',
);
return;
}
res.statusCode = prep.status || 500;
res.setHeader('Content-Type', prep.contentType || 'application/json');
if (prep.text) {
res.end(prep.text);
return;
}
writeOpenAIError(res, prep.status || 500, 'vercel prepare failed');
}
async function safeReadText(resp) {
if (!resp) {
return '';
}
try {
const text = await resp.text();
return text.trim();
} catch (_err) {
return '';
}
}
function internalSecret() {
return asString(process.env.DS2API_VERCEL_INTERNAL_SECRET) || asString(process.env.DS2API_ADMIN_KEY) || 'admin';
}
function buildInternalGoURL(req) {
const proto = asString(header(req, 'x-forwarded-proto')) || 'https';
const host = asString(header(req, 'host'));
const url = new URL(`${proto}://${host}${req.url || '/v1/chat/completions'}`);
url.searchParams.set('__go', '1');
const protectionBypass = resolveProtectionBypass(req);
if (protectionBypass) {
url.searchParams.set('x-vercel-protection-bypass', protectionBypass);
}
return url;
}
function buildInternalGoHeaders(req, opts = {}) {
const headers = {
authorization: asString(header(req, 'authorization')),
'x-api-key': asString(header(req, 'x-api-key')),
'x-ds2-target-account': asString(header(req, 'x-ds2-target-account')),
'x-vercel-protection-bypass': resolveProtectionBypass(req),
};
if (opts.withInternalToken) {
headers['x-ds2-internal-token'] = internalSecret();
}
if (opts.withContentType) {
headers['content-type'] = asString(header(req, 'content-type')) || 'application/json';
}
return headers;
}
function createLeaseReleaser(req, leaseID) {
let released = false;
return async () => {
if (released || !leaseID) {
return;
}
released = true;
try {
await releaseStreamLease(req, leaseID);
} catch (_err) {
// Ignore release errors. Lease TTL cleanup on Go side still prevents permanent leaks.
}
};
}
async function releaseStreamLease(req, leaseID) {
const url = buildInternalGoURL(req);
url.searchParams.set('__stream_release', '1');
const body = Buffer.from(JSON.stringify({ lease_id: leaseID }));
const controller = new AbortController();
const timeout = setTimeout(() => controller.abort(), 1500);
try {
await fetch(url.toString(), {
method: 'POST',
headers: buildInternalGoHeaders(req, { withInternalToken: true, withContentType: true }),
body,
signal: controller.signal,
});
} finally {
clearTimeout(timeout);
}
}
function resolveProtectionBypass(req) {
const fromHeader = asString(header(req, 'x-vercel-protection-bypass'));
if (fromHeader) {
return fromHeader;
}
return asString(process.env.VERCEL_AUTOMATION_BYPASS_SECRET) || asString(process.env.DS2API_VERCEL_PROTECTION_BYPASS);
}
function looksLikeVercelAuthPage(text) {
const body = asString(text).toLowerCase();
if (!body) {
return false;
}
return body.includes('authentication required') && body.includes('vercel');
}
function parseChunkForContent(chunk, thinkingEnabled, currentType) {
if (!chunk || typeof chunk !== 'object' || !Object.prototype.hasOwnProperty.call(chunk, 'v')) {
return { parts: [], finished: false, newType: currentType };
}
const pathValue = asString(chunk.p);
if (shouldSkipPath(pathValue)) {
return { parts: [], finished: false, newType: currentType };
}
if (pathValue === 'response/status' && asString(chunk.v) === 'FINISHED') {
return { parts: [], finished: true, newType: currentType };
}
let newType = currentType;
const parts = [];
if (pathValue === 'response/fragments' && asString(chunk.o).toUpperCase() === 'APPEND' && Array.isArray(chunk.v)) {
for (const frag of chunk.v) {
if (!frag || typeof frag !== 'object') {
continue;
}
const fragType = asString(frag.type).toUpperCase();
const content = asString(frag.content);
if (!content) {
continue;
}
if (fragType === 'THINK' || fragType === 'THINKING') {
newType = 'thinking';
parts.push({ text: content, type: 'thinking' });
} else if (fragType === 'RESPONSE') {
newType = 'text';
parts.push({ text: content, type: 'text' });
} else {
parts.push({ text: content, type: 'text' });
}
}
}
if (pathValue === 'response' && Array.isArray(chunk.v)) {
for (const item of chunk.v) {
if (!item || typeof item !== 'object') {
continue;
}
if (item.p === 'fragments' && item.o === 'APPEND' && Array.isArray(item.v)) {
for (const frag of item.v) {
const fragType = asString(frag && frag.type).toUpperCase();
if (fragType === 'THINK' || fragType === 'THINKING') {
newType = 'thinking';
} else if (fragType === 'RESPONSE') {
newType = 'text';
}
}
}
}
}
let partType = 'text';
if (pathValue === 'response/thinking_content') {
partType = 'thinking';
} else if (pathValue === 'response/content') {
partType = 'text';
} else if (pathValue.includes('response/fragments') && pathValue.includes('/content')) {
partType = newType;
} else if (!pathValue && thinkingEnabled) {
partType = newType;
}
const val = chunk.v;
if (typeof val === 'string') {
if (val === 'FINISHED' && (!pathValue || pathValue === 'status')) {
return { parts: [], finished: true, newType };
}
if (val) {
parts.push({ text: val, type: partType });
}
return { parts, finished: false, newType };
}
if (Array.isArray(val)) {
for (const entry of val) {
if (typeof entry === 'string') {
if (entry) {
parts.push({ text: entry, type: partType });
}
continue;
}
if (!entry || typeof entry !== 'object') {
continue;
}
if (asString(entry.p) === 'status' && asString(entry.v) === 'FINISHED') {
return { parts: [], finished: true, newType };
}
const content = asString(entry.content);
if (!content) {
continue;
}
const t = asString(entry.type).toUpperCase();
if (t === 'THINK' || t === 'THINKING') {
parts.push({ text: content, type: 'thinking' });
} else if (t === 'RESPONSE') {
parts.push({ text: content, type: 'text' });
} else {
parts.push({ text: content, type: partType });
}
}
return { parts, finished: false, newType };
}
if (val && typeof val === 'object') {
const resp = val.response && typeof val.response === 'object' ? val.response : val;
if (Array.isArray(resp.fragments)) {
for (const frag of resp.fragments) {
if (!frag || typeof frag !== 'object') {
continue;
}
const content = asString(frag.content);
if (!content) {
continue;
}
const t = asString(frag.type).toUpperCase();
if (t === 'THINK' || t === 'THINKING') {
newType = 'thinking';
parts.push({ text: content, type: 'thinking' });
} else if (t === 'RESPONSE') {
newType = 'text';
parts.push({ text: content, type: 'text' });
} else {
parts.push({ text: content, type: partType });
}
}
}
}
return { parts, finished: false, newType };
}
function shouldSkipPath(pathValue) {
if (pathValue === 'response/search_status') {
return true;
}
for (const p of SKIP_PATTERNS) {
if (pathValue.includes(p)) {
return true;
}
}
return false;
}
function isCitation(text) {
return asString(text).trim().startsWith('[citation:');
}
function buildUsage(prompt, thinking, output) {
const promptTokens = estimateTokens(prompt);
const reasoningTokens = estimateTokens(thinking);
const completionTokens = estimateTokens(output);
return {
prompt_tokens: promptTokens,
completion_tokens: reasoningTokens + completionTokens,
total_tokens: promptTokens + reasoningTokens + completionTokens,
completion_tokens_details: {
reasoning_tokens: reasoningTokens,
},
};
}
function estimateTokens(text) {
const t = asString(text);
if (!t) {
return 0;
}
const n = Math.floor(Array.from(t).length / 4);
return n < 1 ? 1 : n;
}
async function proxyToGo(req, res, rawBody) {
const url = buildInternalGoURL(req);
const upstream = await fetch(url.toString(), {
method: 'POST',
headers: buildInternalGoHeaders(req, { withContentType: true }),
body: rawBody,
});
res.statusCode = upstream.status;
upstream.headers.forEach((value, key) => {
if (key.toLowerCase() === 'content-length') {
return;
}
res.setHeader(key, value);
});
const bytes = Buffer.from(await upstream.arrayBuffer());
res.end(bytes);
}
function writeOpenAIError(res, status, message) {
res.statusCode = status;
res.setHeader('Content-Type', 'application/json');
res.end(
JSON.stringify({
error: {
message,
type: openAIErrorType(status),
},
}),
);
}
function openAIErrorType(status) {
switch (status) {
case 400:
return 'invalid_request_error';
case 401:
return 'authentication_error';
case 403:
return 'permission_error';
case 429:
return 'rate_limit_error';
case 503:
return 'service_unavailable_error';
default:
return status >= 500 ? 'api_error' : 'invalid_request_error';
}
}
function toBool(v) {
return v === true;
}
function isVercelRuntime() {
return asString(process.env.VERCEL) !== '' || asString(process.env.NOW_REGION) !== '';
}
function asString(v) {
if (typeof v === 'string') {
return v.trim();
}
if (Array.isArray(v)) {
return asString(v[0]);
}
if (v == null) {
return '';
}
return String(v).trim();
}
function extractToolNames(tools) {
if (!Array.isArray(tools) || tools.length === 0) {
return [];
}
const out = [];
for (const t of tools) {
if (!t || typeof t !== 'object') {
continue;
}
const fn = t.function && typeof t.function === 'object' ? t.function : t;
const name = asString(fn.name);
if (name) {
out.push(name);
}
}
return out;
}
function createToolSieveState() {
return {
pending: '',
capture: '',
capturing: false,
};
}
function processToolSieveChunk(state, chunk, toolNames) {
if (!state) {
return [];
}
if (chunk) {
state.pending += chunk;
}
const events = [];
// eslint-disable-next-line no-constant-condition
while (true) {
if (state.capturing) {
if (state.pending) {
state.capture += state.pending;
state.pending = '';
}
const consumed = consumeToolCapture(state.capture, toolNames);
if (!consumed.ready) {
break;
}
state.capture = '';
state.capturing = false;
if (consumed.prefix) {
events.push({ type: 'text', text: consumed.prefix });
}
if (Array.isArray(consumed.calls) && consumed.calls.length > 0) {
events.push({ type: 'tool_calls', calls: consumed.calls });
}
if (consumed.suffix) {
state.pending += consumed.suffix;
}
continue;
}
if (!state.pending) {
break;
}
const start = findToolSegmentStart(state.pending);
if (start >= 0) {
const prefix = state.pending.slice(0, start);
if (prefix) {
events.push({ type: 'text', text: prefix });
}
state.capture = state.pending.slice(start);
state.pending = '';
state.capturing = true;
continue;
}
const [safe, hold] = splitSafeContent(state.pending, 64);
if (!safe) {
break;
}
state.pending = hold;
events.push({ type: 'text', text: safe });
}
return events;
}
function flushToolSieve(state, toolNames) {
if (!state) {
return [];
}
const events = processToolSieveChunk(state, '', toolNames);
if (state.capturing) {
const consumed = consumeToolCapture(state.capture, toolNames);
if (consumed.ready) {
if (consumed.prefix) {
events.push({ type: 'text', text: consumed.prefix });
}
if (Array.isArray(consumed.calls) && consumed.calls.length > 0) {
events.push({ type: 'tool_calls', calls: consumed.calls });
}
if (consumed.suffix) {
events.push({ type: 'text', text: consumed.suffix });
}
} else if (state.capture) {
events.push({ type: 'text', text: state.capture });
}
state.capture = '';
state.capturing = false;
}
if (state.pending) {
events.push({ type: 'text', text: state.pending });
state.pending = '';
}
return events;
}
function splitSafeContent(s, holdChars) {
const chars = Array.from(s || '');
if (chars.length <= holdChars) {
return ['', s];
}
return [chars.slice(0, chars.length - holdChars).join(''), chars.slice(chars.length - holdChars).join('')];
}
function findToolSegmentStart(s) {
if (!s) {
return -1;
}
const lower = s.toLowerCase();
const keyIdx = lower.indexOf('tool_calls');
if (keyIdx < 0) {
return -1;
}
const start = s.slice(0, keyIdx).lastIndexOf('{');
return start >= 0 ? start : keyIdx;
}
function consumeToolCapture(captured, toolNames) {
if (!captured) {
return { ready: false, prefix: '', calls: [], suffix: '' };
}
const lower = captured.toLowerCase();
const keyIdx = lower.indexOf('tool_calls');
if (keyIdx < 0) {
if (Array.from(captured).length >= 256) {
return { ready: true, prefix: captured, calls: [], suffix: '' };
}
return { ready: false, prefix: '', calls: [], suffix: '' };
}
const start = captured.slice(0, keyIdx).lastIndexOf('{');
if (start < 0) {
if (Array.from(captured).length >= 512) {
return { ready: true, prefix: captured, calls: [], suffix: '' };
}
return { ready: false, prefix: '', calls: [], suffix: '' };
}
const obj = extractJSONObjectFrom(captured, start);
if (!obj.ok) {
if (Array.from(captured).length >= 4096) {
return { ready: true, prefix: captured, calls: [], suffix: '' };
}
return { ready: false, prefix: '', calls: [], suffix: '' };
}
const parsed = parseToolCalls(captured.slice(start, obj.end), toolNames);
if (parsed.length === 0) {
return {
ready: true,
prefix: captured.slice(0, obj.end),
calls: [],
suffix: captured.slice(obj.end),
};
}
return {
ready: true,
prefix: captured.slice(0, start),
calls: parsed,
suffix: captured.slice(obj.end),
};
}
function extractJSONObjectFrom(text, start) {
if (!text || start < 0 || start >= text.length || text[start] !== '{') {
return { ok: false, end: 0 };
}
let depth = 0;
let quote = '';
let escaped = false;
for (let i = start; i < text.length; i += 1) {
const ch = text[i];
if (quote) {
if (escaped) {
escaped = false;
continue;
}
if (ch === '\\') {
escaped = true;
continue;
}
if (ch === quote) {
quote = '';
}
continue;
}
if (ch === '"' || ch === "'") {
quote = ch;
continue;
}
if (ch === '{') {
depth += 1;
continue;
}
if (ch === '}') {
depth -= 1;
if (depth === 0) {
return { ok: true, end: i + 1 };
}
}
}
return { ok: false, end: 0 };
}
function parseToolCalls(text, toolNames) {
if (!asString(text)) {
return [];
}
const candidates = buildToolCallCandidates(text);
let parsed = [];
for (const c of candidates) {
parsed = parseToolCallsPayload(c);
if (parsed.length > 0) {
break;
}
}
if (parsed.length === 0) {
return [];
}
const allowed = new Set((toolNames || []).filter(Boolean));
const out = [];
for (const tc of parsed) {
if (!tc || !tc.name) {
continue;
}
if (allowed.size > 0 && !allowed.has(tc.name)) {
continue;
}
out.push({ name: tc.name, input: tc.input || {} });
}
if (out.length === 0 && parsed.length > 0) {
for (const tc of parsed) {
if (!tc || !tc.name) {
continue;
}
out.push({ name: tc.name, input: tc.input || {} });
}
}
return out;
}
function buildToolCallCandidates(text) {
const trimmed = asString(text);
const candidates = [trimmed];
const fenced = trimmed.match(/```(?:json)?\s*([\s\S]*?)\s*```/gi) || [];
for (const block of fenced) {
const m = block.match(/```(?:json)?\s*([\s\S]*?)\s*```/i);
if (m && m[1]) {
candidates.push(asString(m[1]));
}
}
const keyIdx = trimmed.toLowerCase().indexOf('tool_calls');
if (keyIdx >= 0) {
const start = trimmed.slice(0, keyIdx).lastIndexOf('{');
if (start >= 0) {
const obj = extractJSONObjectFrom(trimmed, start);
if (obj.ok) {
candidates.push(asString(trimmed.slice(start, obj.end)));
}
}
}
const first = trimmed.indexOf('{');
const last = trimmed.lastIndexOf('}');
if (first >= 0 && last > first) {
candidates.push(asString(trimmed.slice(first, last + 1)));
}
return [...new Set(candidates.filter(Boolean))];
}
function parseToolCallsPayload(payload) {
let decoded;
try {
decoded = JSON.parse(payload);
} catch (_err) {
return [];
}
if (Array.isArray(decoded)) {
return parseToolCallList(decoded);
}
if (!decoded || typeof decoded !== 'object') {
return [];
}
if (decoded.tool_calls) {
return parseToolCallList(decoded.tool_calls);
}
const one = parseToolCallItem(decoded);
return one ? [one] : [];
}
function parseToolCallList(v) {
if (!Array.isArray(v)) {
return [];
}
const out = [];
for (const item of v) {
if (!item || typeof item !== 'object') {
continue;
}
const one = parseToolCallItem(item);
if (one) {
out.push(one);
}
}
return out;
}
function parseToolCallItem(m) {
let name = asString(m.name);
let inputRaw = m.input;
let hasInput = Object.prototype.hasOwnProperty.call(m, 'input');
const fn = m.function && typeof m.function === 'object' ? m.function : null;
if (fn) {
if (!name) {
name = asString(fn.name);
}
if (!hasInput && Object.prototype.hasOwnProperty.call(fn, 'arguments')) {
inputRaw = fn.arguments;
hasInput = true;
}
}
if (!hasInput) {
for (const k of ['arguments', 'args', 'parameters', 'params']) {
if (Object.prototype.hasOwnProperty.call(m, k)) {
inputRaw = m[k];
hasInput = true;
break;
}
}
}
if (!name) {
return null;
}
return {
name,
input: parseToolCallInput(inputRaw),
};
}
function parseToolCallInput(v) {
if (v == null) {
return {};
}
if (typeof v === 'string') {
const raw = asString(v);
if (!raw) {
return {};
}
try {
const parsed = JSON.parse(raw);
if (parsed && typeof parsed === 'object' && !Array.isArray(parsed)) {
return parsed;
}
} catch (_err) {
return { _raw: raw };
}
return {};
}
if (typeof v === 'object' && !Array.isArray(v)) {
return v;
}
try {
const parsed = JSON.parse(JSON.stringify(v));
if (parsed && typeof parsed === 'object' && !Array.isArray(parsed)) {
return parsed;
}
} catch (_err) {
return {};
}
return {};
}
function formatOpenAIStreamToolCalls(calls) {
if (!Array.isArray(calls) || calls.length === 0) {
return [];
}
return calls.map((c, idx) => ({
index: idx,
id: `call_${newCallID()}`,
type: 'function',
function: {
name: c.name,
arguments: JSON.stringify(c.input || {}),
},
}));
}
function newCallID() {
if (typeof crypto.randomUUID === 'function') {
return crypto.randomUUID().replace(/-/g, '');
}
return `${Date.now()}${Math.floor(Math.random() * 1e9)}`;
}