feat: Implement tool call sieving and formatting for streaming responses in Node.js, add Go fallback for non-Vercel environments, and update Vercel configuration.

This commit is contained in:
CJACK
2026-02-17 00:26:34 +08:00
parent 770f5719d8
commit 555df63fbc
9 changed files with 855 additions and 31 deletions

View File

@@ -1,5 +1,7 @@
'use strict';
const crypto = require('crypto');
const DEEPSEEK_COMPLETION_URL = 'https://chat.deepseek.com/api/v0/chat/completion';
const BASE_HEADERS = {
@@ -37,6 +39,14 @@ module.exports = async function handler(req, res) {
}
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') || '{}');
@@ -66,6 +76,7 @@ module.exports = async function handler(req, res) {
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');
@@ -103,6 +114,9 @@ module.exports = async function handler(req, res) {
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 = '';
@@ -115,11 +129,42 @@ module.exports = async function handler(req, res) {
}
};
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',
@@ -181,25 +226,27 @@ module.exports = async function handler(req, res) {
if (searchEnabled && isCitation(p.text)) {
continue;
}
const delta = {};
if (!firstChunkSent) {
delta.role = 'assistant';
firstChunkSent = true;
}
if (p.type === 'thinking') {
thinkingText += p.text;
delta.reasoning_content = p.text;
sendDeltaFrame({ reasoning_content: p.text });
} else {
outputText += p.text;
delta.content = 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 });
}
}
}
sendFrame({
id: sessionID,
object: 'chat.completion.chunk',
created,
model,
choices: [{ delta, index: 0 }],
});
}
}
}
@@ -612,6 +659,10 @@ 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();
@@ -624,3 +675,412 @@ function asString(v) {
}
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)}`;
}