Files
OmniRoute/open-sse/translator/helpers/toolCallHelper.ts
2026-08-06 22:58:51 -03:00

398 lines
13 KiB
TypeScript

import { createHash } from "node:crypto";
// Tool call helper functions for translator
const ALPHANUM9 = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
type JsonRecord = Record<string, unknown>;
type ToolNameAliases = Map<string, string>;
interface ToolFunction extends JsonRecord {
name?: unknown;
arguments?: unknown;
}
interface ToolCallRecord extends JsonRecord {
id?: unknown;
type?: unknown;
function?: ToolFunction;
}
interface ToolContentBlock extends JsonRecord {
type?: unknown;
id?: unknown;
tool_use_id?: unknown;
}
interface ToolMessage extends JsonRecord {
role?: unknown;
tool_calls?: ToolCallRecord[];
tool_call_id?: unknown;
content?: unknown;
}
interface ToolCallBody extends JsonRecord {
messages?: ToolMessage[];
}
function toRecord(value: unknown): JsonRecord | null {
return value && typeof value === "object" && !Array.isArray(value) ? (value as JsonRecord) : null;
}
function aliasOpenAIToolName(name: unknown, maxLength: number, aliases: ToolNameAliases): unknown {
if (typeof name !== "string" || name.length === 0) return name;
const safe = name.replace(/[^A-Za-z0-9_-]/g, "_");
if (safe === name && safe.length <= maxLength) return safe;
const hash = createHash("sha256").update(name).digest("hex").slice(0, 12);
const prefixLength = Math.max(0, maxLength - hash.length - 1);
const shortened =
prefixLength > 0 ? `${safe.slice(0, prefixLength)}_${hash}` : hash.slice(0, maxLength);
aliases.set(shortened, name);
return shortened;
}
/**
* Mutates an OpenAI-compatible request so every function name satisfies a
* provider's maximum length and `[A-Za-z0-9_-]` character constraints.
* Returns alias → original entries for response restoration.
*/
export function normalizeOpenAIToolNames(body: unknown, maxLength: number): ToolNameAliases {
const aliases: ToolNameAliases = new Map();
const root = toRecord(body);
if (!root || !Number.isInteger(maxLength) || maxLength < 1) return aliases;
const alias = (name: unknown): unknown => aliasOpenAIToolName(name, maxLength, aliases);
if (Array.isArray(root.tools)) {
for (const tool of root.tools) {
const fn = toRecord(toRecord(tool)?.function);
if (fn && typeof fn.name === "string") fn.name = alias(fn.name);
}
}
const toolChoiceFunction = toRecord(toRecord(root.tool_choice)?.function);
if (toolChoiceFunction && typeof toolChoiceFunction.name === "string") {
toolChoiceFunction.name = alias(toolChoiceFunction.name);
}
if (Array.isArray(root.messages)) {
for (const message of root.messages) {
const msg = toRecord(message);
if (!msg) continue;
if (Array.isArray(msg.tool_calls)) {
for (const toolCall of msg.tool_calls) {
const fn = toRecord(toRecord(toolCall)?.function);
if (fn && typeof fn.name === "string") fn.name = alias(fn.name);
}
}
if (msg.role === "tool" && typeof msg.name === "string") {
msg.name = alias(msg.name);
}
}
}
return aliases;
}
/**
* Case-insensitive fallback for tool name lookups from upstream responses.
*
* Many upstream providers/models return tool call names in lowercase (e.g., "bash")
* even when the tool definition used PascalCase ("Bash"). This helper tries an exact
* match first (fast path for well-behaved providers), then falls back to a
* case-insensitive scan over the map entries.
*
* Returns the mapped value on match, or `undefined` when no entry matches.
*/
export function caseInsensitiveToolNameLookup(
name: string,
map: Map<string, string> | null | undefined
): string | undefined {
if (!map || !name) return undefined;
// Fast path: exact match (PascalCase-preserving providers)
const exact = map.get(name);
if (exact !== undefined) return exact;
// Fallback: case-insensitive scan
const lowerName = name.toLowerCase();
for (const [key, value] of map) {
if (key.toLowerCase() === lowerName) {
return value;
}
}
return undefined;
}
/** Restore normalized function names in OpenAI Chat Completions responses. */
export function restoreOpenAIToolNames(body: unknown, aliases: unknown): boolean {
if (!(aliases instanceof Map) || aliases.size === 0) return false;
const root = toRecord(body);
if (!root || !Array.isArray(root.choices)) return false;
let changed = false;
const restoreCalls = (calls: unknown): void => {
if (!Array.isArray(calls)) return;
for (const toolCall of calls) {
const fn = toRecord(toRecord(toolCall)?.function);
if (!fn || typeof fn.name !== "string") continue;
const original = caseInsensitiveToolNameLookup(fn.name, aliases);
if (typeof original !== "string" || original === fn.name) continue;
fn.name = original;
changed = true;
}
};
for (const choice of root.choices) {
const record = toRecord(choice);
if (!record) continue;
restoreCalls(toRecord(record.delta)?.tool_calls);
restoreCalls(toRecord(record.message)?.tool_calls);
}
return changed;
}
// Fallback streaming tool_call id when a provider response omits one (index optional).
// `call_<ts>` when no index is given; `call_<index>_<ts>` when an index is supplied.
export function fallbackToolCallId(index?: number): string {
return index === undefined ? `call_${Date.now()}` : `call_${index}_${Date.now()}`;
}
// Generate unique tool call ID (default long form)
export function generateToolCallId() {
return `call_${Date.now().toString(36)}_${Math.random().toString(36).slice(2, 9)}`;
}
// Generate 9-char [a-zA-Z0-9] id for providers that require it (e.g. Mistral)
function generateToolCallId9(): string {
let s = "";
for (let i = 0; i < 9; i++) {
s += ALPHANUM9[Math.floor(Math.random() * ALPHANUM9.length)];
}
return s;
}
/** @param options.use9CharId - When true, normalize ids to 9-char [a-zA-Z0-9] (e.g. Mistral); when false, only fix type/arguments, leave ids as-is */
export function ensureToolCallIds<T extends ToolCallBody>(
body: T,
options?: { use9CharId?: boolean }
): T {
if (!body.messages || !Array.isArray(body.messages)) return body;
const use9CharId = options?.use9CharId === true;
for (let i = 0; i < body.messages.length; i++) {
const msg = body.messages[i];
if (msg.role !== "assistant" || !msg.tool_calls || !Array.isArray(msg.tool_calls)) continue;
const used9 = new Set<string>();
const newIdsInOrder: string[] = [];
for (const tc of msg.tool_calls) {
if (!tc.type) {
tc.type = "function";
}
if (tc.function?.arguments && typeof tc.function.arguments !== "string") {
tc.function.arguments = JSON.stringify(tc.function.arguments);
}
if (use9CharId) {
let newId: string;
do {
newId = generateToolCallId9();
} while (used9.has(newId));
used9.add(newId);
newIdsInOrder.push(newId);
tc.id = newId;
} else {
// Leave id as-is, only ensure it exists for later tool message matching
const id =
tc.id != null && String(tc.id).trim() !== "" ? String(tc.id) : generateToolCallId();
tc.id = id;
newIdsInOrder.push(id);
}
}
// Tool responses (role "tool") follow in the same order as tool_calls. Rewrite
// every id only when the provider requires generated 9-char ids; otherwise keep
// explicit client ids and fill only missing ones. Overwriting a compacted orphan's
// explicit id by position can make it impersonate a different parallel call.
// Stop at the next assistant so we only link responses belonging to this turn.
if (newIdsInOrder.length > 0) {
let idx = 0;
for (let j = i + 1; j < body.messages.length; j++) {
const later = body.messages[j];
if (later.role === "assistant") break;
if (later.role !== "tool") continue;
if (idx < newIdsInOrder.length) {
if (
use9CharId ||
later.tool_call_id == null ||
String(later.tool_call_id).trim() === ""
) {
later.tool_call_id = newIdsInOrder[idx];
}
idx++;
}
}
}
}
return body;
}
// Get tool_call ids from assistant message (OpenAI format: tool_calls, Claude format: tool_use in content)
export function getToolCallIds(msg: ToolMessage): string[] {
if (msg.role !== "assistant") return [];
const ids: string[] = [];
// OpenAI format: tool_calls array
if (msg.tool_calls && Array.isArray(msg.tool_calls)) {
for (const tc of msg.tool_calls) {
if (tc.id) ids.push(String(tc.id));
}
}
// Claude format: tool_use blocks in content
if (Array.isArray(msg.content)) {
for (const block of msg.content as ToolContentBlock[]) {
if (block.type === "tool_use" && block.id) {
ids.push(String(block.id));
}
}
}
return ids;
}
// Check if user message has tool_result for given ids (OpenAI format: role=tool, Claude format: tool_result in content)
export function hasToolResults(
msg: ToolMessage | null | undefined,
toolCallIds: string[]
): boolean {
if (!msg || !toolCallIds.length) return false;
// OpenAI format: role = "tool" with tool_call_id
if (msg.role === "tool" && msg.tool_call_id) {
return toolCallIds.includes(String(msg.tool_call_id));
}
// Claude format: tool_result blocks in user message content
if (msg.role === "user" && Array.isArray(msg.content)) {
for (const block of msg.content as ToolContentBlock[]) {
if (
block.type === "tool_result" &&
block.tool_use_id &&
toolCallIds.includes(String(block.tool_use_id))
) {
return true;
}
}
}
return false;
}
// Fix missing tool responses - insert empty tool_result if assistant has tool_use but next message has no tool_result.
// Inserts in the same shape as the opening assistant message: OpenAI tool_calls → role:"tool";
// Claude tool_use blocks → role:"user" with tool_result content blocks.
export function fixMissingToolResponses<T extends ToolCallBody>(body: T): T {
if (!body.messages || !Array.isArray(body.messages)) return body;
const newMessages: ToolMessage[] = [];
for (let i = 0; i < body.messages.length; i++) {
const msg = body.messages[i];
const nextMsg = body.messages[i + 1];
newMessages.push(msg);
// Check if this is assistant with tool_calls/tool_use
const toolCallIds = getToolCallIds(msg);
if (toolCallIds.length === 0) continue;
// Check if next message has tool_result
if (nextMsg && !hasToolResults(nextMsg, toolCallIds)) {
const hasOpenAIToolCalls = Array.isArray(msg.tool_calls) && msg.tool_calls.length > 0;
if (hasOpenAIToolCalls) {
for (const id of toolCallIds) {
newMessages.push({
role: "tool",
tool_call_id: id,
content: "",
});
}
} else {
newMessages.push({
role: "user",
content: toolCallIds.map((id) => ({
type: "tool_result",
tool_use_id: id,
content: "",
})),
});
}
}
}
body.messages = newMessages;
return body;
}
// Strip tool-result carriers whose id has no matching tool call anywhere in the
// conversation. Mirrors fixMissingToolResponses on the result side: that helper
// ensures every call has a result; this one ensures every result has a call.
// Client-side history truncation/compaction can drop the assistant turn that
// issued a tool call while leaving its stale tool result behind, which strict
// upstream APIs reject before model execution. Handles both OpenAI-format
// role:"tool" messages and Claude-format tool_result content blocks. Drops a
// user message entirely if stripping empties its content array. Returns the
// same body reference when nothing needs to change (no-op fast path).
export function stripOrphanedToolResults<T extends ToolCallBody>(body: T): T {
if (!body.messages || !Array.isArray(body.messages)) return body;
const knownCallIds = new Set<string>();
for (const msg of body.messages) {
for (const id of getToolCallIds(msg)) {
knownCallIds.add(id);
}
}
let changed = false;
const filteredMessages: ToolMessage[] = [];
for (const msg of body.messages) {
if (msg.role === "tool" && msg.tool_call_id) {
if (knownCallIds.has(String(msg.tool_call_id))) {
filteredMessages.push(msg);
} else {
changed = true;
}
continue;
}
if (Array.isArray(msg.content)) {
const cleanedContent = (msg.content as ToolContentBlock[]).filter((block) => {
if (block?.type !== "tool_result") return true;
return typeof block.tool_use_id === "string" && knownCallIds.has(block.tool_use_id);
});
if (cleanedContent.length !== msg.content.length) {
changed = true;
if (cleanedContent.length === 0) continue;
msg.content = cleanedContent;
}
}
filteredMessages.push(msg);
}
if (!changed) return body;
body.messages = filteredMessages;
return body;
}