// CRITICALimport { randomUUID } from "node:crypto";import type { AppContext } from "../../types/context";import { badRequest, notFound, serviceUnavailable } from "../../core/errors";import { fetchInference } from "../../services/inference/inference-client";import { COMPACTION_SYSTEM_PROMPT, COMPACTION_USER_PROMPT } from "./configs"; type MessageRecord = Record<string, unknown>; export interface ChatCompactionOptions { model?: string; systemPrompt?: string; title?: string; preserveFirst?: boolean; preserveLast?: boolean;} export interface ChatCompactionResult { session: Record<string, unknown>; summary: string;} const getString = (value: unknown): string | undefined => typeof value === "string" ? value : undefined; const getNumber = (value: unknown): number | undefined => typeof value === "number" && !Number.isNaN(value) ? value : undefined; const formatToolCalls = (toolCalls: unknown[]): string => { const formatted = toolCalls .map((call) => { if (!call || typeof call !== "object") return null; const record = call as Record<string, unknown>; const function_ = record["function"] as Record<string, unknown> | undefined; const name = getString(function_?.["name"]) ?? "tool"; const args = getString(function_?.["arguments"]); const callLabel = args ? `${name}(${args})` : `${name}()`; const rawResult = record["result"]; if (rawResult === undefined || rawResult === null) { return callLabel; } let resultText = ""; let isError = false; if (typeof rawResult === "string") { resultText = rawResult; } else if (typeof rawResult === "object") { const resultRecord = rawResult as Record<string, unknown>; const content = getString(resultRecord["content"]); if (content) { resultText = content; } else { try { resultText = JSON.stringify(rawResult); } catch { resultText = String(rawResult); } } isError = resultRecord["isError"] === true; } else { resultText = String(rawResult); } if (!resultText) { return callLabel; } const errorSuffix = isError ? " (error)" : ""; return `${callLabel} => ${resultText}${errorSuffix}`; }) .filter((value): value is string => Boolean(value)); return formatted.length > 0 ? `\n\n[Tool calls]: ${formatted.join("; ")}` : "";}; const buildSummaryMessages = ( messages: MessageRecord[]): Array<{ role: string; content: string }> => { return messages .map((message) => { const role = getString(message["role"]) ?? "assistant"; const content = getString(message["content"]) ?? ""; const toolCalls = Array.isArray(message["tool_calls"]) ? message["tool_calls"] : []; const toolSuffix = toolCalls.length > 0 ? formatToolCalls(toolCalls) : ""; const combined = `${content}${toolSuffix}`.trim(); if (!combined) return null; return { role, content: combined }; }) .filter((value): value is { role: string; content: string } => Boolean(value));}; const buildSystemPrompt = (systemPrompt?: string): string => { if (systemPrompt && systemPrompt.trim()) { return `${COMPACTION_SYSTEM_PROMPT}\n\nOriginal system prompt:\n${systemPrompt.trim()}`; } return COMPACTION_SYSTEM_PROMPT;}; const resolveModel = ( options: ChatCompactionOptions, session: MessageRecord, fallbackModel?: string): string => { return options.model || getString(session["model"]) || fallbackModel || "default";}; const requestSummary = async ( context: AppContext, model: string, systemPrompt: string, messages: Array<{ role: string; content: string }>): Promise<string> => { const response = await fetchInference(context, "/v1/chat/completions", { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ model, messages: [ { role: "system", content: systemPrompt }, ...messages, { role: "user", content: COMPACTION_USER_PROMPT }, ], temperature: 0.3, stream: false, }), }); if (!response.ok) { throw serviceUnavailable(`Compaction summary failed (${response.status})`); } const data = (await response.json()) as { choices?: Array<{ message?: { content?: string } }>; }; const summary = data.choices?.[0]?.message?.content?.trim() ?? ""; if (!summary) { throw badRequest("Compaction summary returned empty content"); } return summary;}; const createSummaryMessage = (summary: string, model?: string): MessageRecord => { const content = [ `[Context compacted on ${new Date().toLocaleString()}]`, "", "The following is a summary of the prior conversation. All tasks described as completed have already been done — do NOT redo them.", "", summary, ].join("\n"); return { role: "assistant", content, model: model ?? null, parts: [{ type: "text", text: content }], };}; const pickFirstUserMessage = (messages: MessageRecord[]): MessageRecord | null => messages.find((message) => getString(message["role"]) === "user") ?? null; /** * Pick the last user/assistant exchange to preserve after the summary. * Returns a pair so the compacted session always ends with valid alternation. * If the conversation ends with an assistant message, return the preceding user + that assistant. * If it ends with a user message (no response yet), return only that user message. * Never returns a standalone assistant message (would create assistant→assistant after summary). */const pickLastExchange = ( messages: MessageRecord[], firstUser: MessageRecord | null,): { lastUser: MessageRecord | null; lastAssistant: MessageRecord | null } => { if (messages.length === 0) return { lastUser: null, lastAssistant: null }; const last = messages[messages.length - 1]; if (!last) return { lastUser: null, lastAssistant: null }; const lastRole = getString(last["role"]); if (lastRole === "assistant") { // Find the preceding user message for this assistant response let precedingUser: MessageRecord | null = null; for (let i = messages.length - 2; i >= 0; i--) { if (getString(messages[i]!["role"]) === "user") { precedingUser = messages[i]!; break; } } // Skip if the preceding user is the same as firstUser (already preserved) if (precedingUser && firstUser && precedingUser["id"] === firstUser["id"]) { precedingUser = null; } return { lastUser: precedingUser, lastAssistant: last }; } if (lastRole === "user") { // Last message is user with no response — skip if same as firstUser if (firstUser && last["id"] === firstUser["id"]) { return { lastUser: null, lastAssistant: null }; } return { lastUser: last, lastAssistant: null }; } // tool/system/other — skip return { lastUser: null, lastAssistant: null };}; const cloneMessageToSession = ( context: AppContext, sessionId: string, message: MessageRecord): void => { const role = getString(message["role"]) ?? "assistant"; const content = getString(message["content"]) ?? undefined; const model = getString(message["model"]) ?? undefined; const toolCalls = Array.isArray(message["tool_calls"]) ? message["tool_calls"] : undefined; const toolCallId = getString(message["tool_call_id"]) ?? undefined; const toolName = getString(message["name"]) ?? undefined; const parts = Array.isArray(message["parts"]) ? message["parts"] : undefined; const metadata = Object.prototype.hasOwnProperty.call(message, "metadata") ? message["metadata"] : undefined; const promptTokens = getNumber(message["request_prompt_tokens"]); const toolsTokens = getNumber(message["request_tools_tokens"]); const totalInputTokens = getNumber(message["request_total_input_tokens"]); const completionTokens = getNumber(message["request_completion_tokens"]); context.stores.chatStore.addMessage( sessionId, randomUUID(), role, content, model, toolCalls, promptTokens, toolsTokens, totalInputTokens, completionTokens, parts, metadata, toolCallId, toolName );}; export const compactChatSession = async ( context: AppContext, sessionId: string, options: ChatCompactionOptions = {}): Promise<ChatCompactionResult> => { const session = context.stores.chatStore.getSession(sessionId); if (!session) { throw notFound("Session not found"); } const current = await context.processManager.findInferenceProcess(context.config.inference_port); if (!current) { throw serviceUnavailable("No model running"); } const messages = Array.isArray(session["messages"]) ? (session["messages"] as MessageRecord[]) : []; if (messages.length === 0) { throw badRequest("Session has no messages to compact"); } const summaryMessages = buildSummaryMessages(messages); if (summaryMessages.length === 0) { throw badRequest("Session messages are empty"); } const systemPrompt = buildSystemPrompt(options.systemPrompt); const model = resolveModel(options, session, current.served_model_name ?? undefined); const summaryText = await requestSummary(context, model, systemPrompt, summaryMessages); const firstUser = options.preserveFirst === false ? null : pickFirstUserMessage(messages); const { lastUser, lastAssistant } = options.preserveLast === false ? { lastUser: null, lastAssistant: null } : pickLastExchange(messages, firstUser); const titleBase = getString(session["title"]) ?? "Chat"; const newTitle = options.title ?? `${titleBase} (Compacted)`; const newSessionId = randomUUID(); const agentState = Object.prototype.hasOwnProperty.call(session, "agent_state") ? session["agent_state"] : undefined; const newSession = context.stores.chatStore.createSession( newSessionId, newTitle, model, sessionId, agentState ); // Build a valid alternating message sequence: // [firstUser] → summary(assistant) → [lastUser → lastAssistant] if (firstUser) { cloneMessageToSession(context, newSessionId, firstUser); } const summaryMessage = createSummaryMessage(summaryText, model); cloneMessageToSession(context, newSessionId, summaryMessage); if (lastUser) { cloneMessageToSession(context, newSessionId, lastUser); } if (lastAssistant) { cloneMessageToSession(context, newSessionId, lastAssistant); } const hydrated = context.stores.chatStore.getSession(newSessionId) ?? newSession; return { session: hydrated, summary: summaryText, };};
// CRITICAL
import { randomUUID } from "node:crypto";
import type { AppContext } from "../../types/context";
import { badRequest, notFound, serviceUnavailable } from "../../core/errors";
import { fetchInference } from "../../services/inference/inference-client";
import { COMPACTION_SYSTEM_PROMPT, COMPACTION_USER_PROMPT } from "./configs";
type MessageRecord = Record<string, unknown>;
export interface ChatCompactionOptions {
model?: string;
systemPrompt?: string;
title?: string;
preserveFirst?: boolean;
preserveLast?: boolean;
}
export interface ChatCompactionResult {
session: Record<string, unknown>;
summary: string;
}
const getString = (value: unknown): string | undefined =>
typeof value === "string" ? value : undefined;
const getNumber = (value: unknown): number | undefined =>
typeof value === "number" && !Number.isNaN(value) ? value : undefined;
const formatToolCalls = (toolCalls: unknown[]): string => {
const formatted = toolCalls
.map((call) => {
if (!call || typeof call !== "object") return null;
const record = call as Record<string, unknown>;
const function_ = record["function"] as Record<string, unknown> | undefined;
const name = getString(function_?.["name"]) ?? "tool";
const args = getString(function_?.["arguments"]);
const callLabel = args ? `${name}(${args})` : `${name}()`;
const rawResult = record["result"];
if (rawResult === undefined || rawResult === null) {
return callLabel;
}
let resultText = "";
let isError = false;
if (typeof rawResult === "string") {
resultText = rawResult;
} else if (typeof rawResult === "object") {
const resultRecord = rawResult as Record<string, unknown>;
const content = getString(resultRecord["content"]);
if (content) {
resultText = content;
} else {
try {
resultText = JSON.stringify(rawResult);
} catch {
resultText = String(rawResult);
}
}
isError = resultRecord["isError"] === true;
} else {
resultText = String(rawResult);
}
if (!resultText) {
return callLabel;
}
const errorSuffix = isError ? " (error)" : "";
return `${callLabel} => ${resultText}${errorSuffix}`;
})
.filter((value): value is string => Boolean(value));
return formatted.length > 0 ? `\n\n[Tool calls]: ${formatted.join("; ")}` : "";
};
const buildSummaryMessages = (
messages: MessageRecord[]
): Array<{ role: string; content: string }> => {
return messages
.map((message) => {
const role = getString(message["role"]) ?? "assistant";
const content = getString(message["content"]) ?? "";
const toolCalls = Array.isArray(message["tool_calls"]) ? message["tool_calls"] : [];
const toolSuffix = toolCalls.length > 0 ? formatToolCalls(toolCalls) : "";
const combined = `${content}${toolSuffix}`.trim();
if (!combined) return null;
return { role, content: combined };
})
.filter((value): value is { role: string; content: string } => Boolean(value));
};
const buildSystemPrompt = (systemPrompt?: string): string => {
if (systemPrompt && systemPrompt.trim()) {
return `${COMPACTION_SYSTEM_PROMPT}\n\nOriginal system prompt:\n${systemPrompt.trim()}`;
}
return COMPACTION_SYSTEM_PROMPT;
};
const resolveModel = (
options: ChatCompactionOptions,
session: MessageRecord,
fallbackModel?: string
): string => {
return options.model || getString(session["model"]) || fallbackModel || "default";
};
const requestSummary = async (
context: AppContext,
model: string,
systemPrompt: string,
messages: Array<{ role: string; content: string }>
): Promise<string> => {
const response = await fetchInference(context, "/v1/chat/completions", {
method: "POST",
headers: { "Content-Type": "application/json" },
body: JSON.stringify({
model,
messages: [
{ role: "system", content: systemPrompt },
...messages,
{ role: "user", content: COMPACTION_USER_PROMPT },
],
temperature: 0.3,
stream: false,
}),
});
if (!response.ok) {
throw serviceUnavailable(`Compaction summary failed (${response.status})`);
}
const data = (await response.json()) as {
choices?: Array<{ message?: { content?: string } }>;
};
const summary = data.choices?.[0]?.message?.content?.trim() ?? "";
if (!summary) {
throw badRequest("Compaction summary returned empty content");
}
return summary;
};
const createSummaryMessage = (summary: string, model?: string): MessageRecord => {
const content = [
`[Context compacted on ${new Date().toLocaleString()}]`,
"",
"The following is a summary of the prior conversation. All tasks described as completed have already been done — do NOT redo them.",
"",
summary,
].join("\n");
return {
role: "assistant",
content,
model: model ?? null,
parts: [{ type: "text", text: content }],
};
};
const pickFirstUserMessage = (messages: MessageRecord[]): MessageRecord | null =>
messages.find((message) => getString(message["role"]) === "user") ?? null;
/**
* Pick the last user/assistant exchange to preserve after the summary.
* Returns a pair so the compacted session always ends with valid alternation.
* If the conversation ends with an assistant message, return the preceding user + that assistant.
* If it ends with a user message (no response yet), return only that user message.
* Never returns a standalone assistant message (would create assistant→assistant after summary).
*/
const pickLastExchange = (
messages: MessageRecord[],
firstUser: MessageRecord | null,
): { lastUser: MessageRecord | null; lastAssistant: MessageRecord | null } => {
if (messages.length === 0) return { lastUser: null, lastAssistant: null };
const last = messages[messages.length - 1];
if (!last) return { lastUser: null, lastAssistant: null };
const lastRole = getString(last["role"]);
if (lastRole === "assistant") {
// Find the preceding user message for this assistant response
let precedingUser: MessageRecord | null = null;
for (let i = messages.length - 2; i >= 0; i--) {
if (getString(messages[i]!["role"]) === "user") {
precedingUser = messages[i]!;
break;
}
}
// Skip if the preceding user is the same as firstUser (already preserved)
if (precedingUser && firstUser && precedingUser["id"] === firstUser["id"]) {
precedingUser = null;
}
return { lastUser: precedingUser, lastAssistant: last };
}
if (lastRole === "user") {
// Last message is user with no response — skip if same as firstUser
if (firstUser && last["id"] === firstUser["id"]) {
return { lastUser: null, lastAssistant: null };
}
return { lastUser: last, lastAssistant: null };
}
// tool/system/other — skip
return { lastUser: null, lastAssistant: null };
};
const cloneMessageToSession = (
context: AppContext,
sessionId: string,
message: MessageRecord
): void => {
const role = getString(message["role"]) ?? "assistant";
const content = getString(message["content"]) ?? undefined;
const model = getString(message["model"]) ?? undefined;
const toolCalls = Array.isArray(message["tool_calls"]) ? message["tool_calls"] : undefined;
const toolCallId = getString(message["tool_call_id"]) ?? undefined;
const toolName = getString(message["name"]) ?? undefined;
const parts = Array.isArray(message["parts"]) ? message["parts"] : undefined;
const metadata = Object.prototype.hasOwnProperty.call(message, "metadata")
? message["metadata"]
: undefined;
const promptTokens = getNumber(message["request_prompt_tokens"]);
const toolsTokens = getNumber(message["request_tools_tokens"]);
const totalInputTokens = getNumber(message["request_total_input_tokens"]);
const completionTokens = getNumber(message["request_completion_tokens"]);
context.stores.chatStore.addMessage(
sessionId,
randomUUID(),
role,
content,
model,
toolCalls,
promptTokens,
toolsTokens,
totalInputTokens,
completionTokens,
parts,
metadata,
toolCallId,
toolName
);
};
export const compactChatSession = async (
context: AppContext,
sessionId: string,
options: ChatCompactionOptions = {}
): Promise<ChatCompactionResult> => {
const session = context.stores.chatStore.getSession(sessionId);
if (!session) {
throw notFound("Session not found");
}
const current = await context.processManager.findInferenceProcess(context.config.inference_port);
if (!current) {
throw serviceUnavailable("No model running");
}
const messages = Array.isArray(session["messages"])
? (session["messages"] as MessageRecord[])
: [];
if (messages.length === 0) {
throw badRequest("Session has no messages to compact");
}
const summaryMessages = buildSummaryMessages(messages);
if (summaryMessages.length === 0) {
throw badRequest("Session messages are empty");
}
const systemPrompt = buildSystemPrompt(options.systemPrompt);
const model = resolveModel(options, session, current.served_model_name ?? undefined);
const summaryText = await requestSummary(context, model, systemPrompt, summaryMessages);
const firstUser = options.preserveFirst === false ? null : pickFirstUserMessage(messages);
const { lastUser, lastAssistant } =
options.preserveLast === false
? { lastUser: null, lastAssistant: null }
: pickLastExchange(messages, firstUser);
const titleBase = getString(session["title"]) ?? "Chat";
const newTitle = options.title ?? `${titleBase} (Compacted)`;
const newSessionId = randomUUID();
const agentState = Object.prototype.hasOwnProperty.call(session, "agent_state")
? session["agent_state"]
: undefined;
const newSession = context.stores.chatStore.createSession(
newSessionId,
newTitle,
model,
sessionId,
agentState
);
// Build a valid alternating message sequence:
// [firstUser] → summary(assistant) → [lastUser → lastAssistant]
if (firstUser) {
cloneMessageToSession(context, newSessionId, firstUser);
}
const summaryMessage = createSummaryMessage(summaryText, model);
cloneMessageToSession(context, newSessionId, summaryMessage);
if (lastUser) {
cloneMessageToSession(context, newSessionId, lastUser);
}
if (lastAssistant) {
cloneMessageToSession(context, newSessionId, lastAssistant);
}
const hydrated = context.stores.chatStore.getSession(newSessionId) ?? newSession;
return {
session: hydrated,
summary: summaryText,
};
};