agentmon/hooks/hermes/handler.js

#!/usr/bin/env node

// handler.ts
import { randomUUID as randomUUID2 } from "node:crypto";
import { mkdirSync, readFileSync, unlinkSync, writeFileSync } from "node:fs";
import { homedir, hostname } from "node:os";
import { join } from "node:path";

// ../shared/lib.ts
import { randomUUID } from "node:crypto";
function isRecord(value) {
  return value !== null && typeof value === "object" && !Array.isArray(value);
}
function pickString(...values) {
  for (const value of values) {
    if (typeof value === "string" && value.trim() !== "") {
      return value;
    }
  }
  return void 0;
}
function pickNumber(...values) {
  for (const value of values) {
    if (typeof value === "number" && Number.isFinite(value)) {
      return value;
    }
  }
  return void 0;
}
function truncate(value, limit) {
  if (value === void 0 || value === null) {
    return void 0;
  }
  const text = typeof value === "string" ? value : safeJSONStringify(value);
  if (!text) {
    return void 0;
  }
  if (text.length <= limit) {
    return text;
  }
  return text.slice(0, limit) + "...";
}
function safeJSONStringify(value) {
  try {
    return JSON.stringify(value);
  } catch {
    return String(value);
  }
}
function buildEnvelope(framework, host, type, sessionKey, opts = {}) {
  const correlation = {};
  if (sessionKey) {
    correlation.session_id = sessionKey;
  }
  if (opts.runId) {
    correlation.run_id = opts.runId;
  }
  if (opts.spanId) {
    correlation.span_id = opts.spanId;
  }
  if (opts.parentSpanId) {
    correlation.parent_span_id = opts.parentSpanId;
  }
  const envelope = {
    schema: { name: "agentmon.event", version: 1 },
    event: {
      id: randomUUID(),
      type,
      ts: (/* @__PURE__ */ new Date()).toISOString(),
      source: {
        framework,
        client_id: host,
        host
      }
    }
  };
  if (Object.keys(correlation).length > 0) {
    envelope.correlation = correlation;
  }
  if (opts.attributes && Object.keys(opts.attributes).length > 0) {
    envelope.attributes = opts.attributes;
  }
  if (opts.payload && Object.keys(opts.payload).length > 0) {
    envelope.payload = opts.payload;
  }
  return envelope;
}
function createTransport(ingestUrl, opts) {
  const batchSize = opts?.batchSize ?? 10;
  const flushMs = opts?.flushMs ?? 2e3;
  const fetchTimeoutMs = opts?.fetchTimeoutMs ?? 500;
  let buffer = [];
  let flushTimer = null;
  let isFlushing = false;
  async function postBatch(batch) {
    const controller = new AbortController();
    const timeout = setTimeout(() => controller.abort(), fetchTimeoutMs);
    try {
      await fetch(`${ingestUrl}/v1/events`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(batch),
        signal: controller.signal
      });
    } finally {
      clearTimeout(timeout);
    }
  }
  function scheduleFlush() {
    if (!flushTimer) {
      flushTimer = setTimeout(() => {
        void flush2();
      }, flushMs);
    }
  }
  async function flush2() {
    if (flushTimer) {
      clearTimeout(flushTimer);
      flushTimer = null;
    }
    if (isFlushing || buffer.length === 0) {
      return;
    }
    isFlushing = true;
    const batch = buffer.splice(0, batchSize);
    try {
      await postBatch(batch);
    } catch {
      console.debug(`[agentmon] failed to flush ${batch.length} events`);
    } finally {
      isFlushing = false;
      if (buffer.length > 0) {
        if (buffer.length >= batchSize) {
          void flush2();
        } else {
          scheduleFlush();
        }
      }
    }
  }
  function enqueue2(event) {
    buffer.push(event);
    if (buffer.length >= batchSize) {
      void flush2();
    } else {
      scheduleFlush();
    }
  }
  return { enqueue: enqueue2, flush: flush2 };
}
async function readStdin() {
  return new Promise((resolve) => {
    let data = "";
    let done = false;
    const timer = setTimeout(() => finish(data), 100);
    const finish = (value) => {
      if (done) return;
      done = true;
      clearTimeout(timer);
      resolve(value);
    };
    process.stdin.on("data", (chunk) => {
      data += chunk;
    });
    process.stdin.on("end", () => finish(data));
    process.stdin.on("error", () => finish(""));
  });
}

// handler.ts
var INGEST_URL = process.env.AGENTMON_INGEST_URL || "http://localhost:8080";
var FRAMEWORK = process.env.AGENTMON_FRAMEWORK || "hermes";
var HOST = process.env.AGENTMON_HOST || hostname();
var { enqueue, flush } = createTransport(INGEST_URL);
var STATE_DIR = join(homedir(), ".agentmon-state", "hermes");
function ensureStateDir() {
  try {
    mkdirSync(STATE_DIR, { recursive: true });
  } catch {
  }
}
function loadState(sessionKey) {
  try {
    const raw = readFileSync(join(STATE_DIR, sessionKey + ".json"), "utf8");
    const state = JSON.parse(raw);
    return { spans: {}, ...state };
  } catch {
    return { spans: {} };
  }
}
function saveState(sessionKey, state) {
  if (!sessionKey) {
    return;
  }
  ensureStateDir();
  try {
    writeFileSync(join(STATE_DIR, sessionKey + ".json"), JSON.stringify(state), "utf8");
  } catch {
  }
}
function clearState(sessionKey) {
  if (!sessionKey) {
    return;
  }
  try {
    unlinkSync(join(STATE_DIR, sessionKey + ".json"));
  } catch {
  }
}
function getExtra(input) {
  return isRecord(input.extra) ? input.extra : {};
}
function getSessionKey(input) {
  const extra = getExtra(input);
  return pickString(
    input.session_id,
    input.sessionId,
    input.sessionID,
    input.session,
    extra.session_id,
    extra.sessionId,
    extra.sessionID,
    extra.parent_session_id,
    extra.task_id
  );
}
function getToolCallId(input) {
  const extra = getExtra(input);
  return pickString(input.tool_call_id, extra.tool_call_id, extra.call_id, extra.id);
}
function getToolName(input) {
  const extra = getExtra(input);
  return pickString(input.tool_name, input.tool, input.name, extra.tool_name, extra.tool, extra.name) || "unknown";
}
function getUsage(input) {
  const extra = getExtra(input);
  const usage = isRecord(input.usage) ? input.usage : isRecord(extra.usage) ? extra.usage : void 0;
  if (!usage) return void 0;
  const result = {};
  if (usage.input_tokens !== void 0) result.input_tokens = usage.input_tokens;
  if (usage.prompt_tokens !== void 0) result.input_tokens = usage.prompt_tokens;
  if (usage.output_tokens !== void 0) result.output_tokens = usage.output_tokens;
  if (usage.completion_tokens !== void 0) result.output_tokens = usage.completion_tokens;
  if (usage.cache_read_tokens !== void 0) result.cache_read_tokens = usage.cache_read_tokens;
  if (usage.cache_write_tokens !== void 0) result.cache_write_tokens = usage.cache_write_tokens;
  if (usage.cache_creation_tokens !== void 0) result.cache_write_tokens = usage.cache_creation_tokens;
  if (usage.reasoning_tokens !== void 0) result.reasoning_tokens = usage.reasoning_tokens;
  if (usage.total_tokens !== void 0) result.total_tokens = usage.total_tokens;
  if (usage.total_cost !== void 0) result.total_cost = usage.total_cost;
  if (usage.cost !== void 0) result.total_cost = usage.cost;
  return Object.keys(result).length > 0 ? result : void 0;
}
function getModel(input) {
  const extra = getExtra(input);
  return pickString(input.model, extra.model, extra.response_model);
}
function getPlatform(input) {
  const extra = getExtra(input);
  return pickString(input.platform, extra.platform);
}
function getDuration(input) {
  const extra = getExtra(input);
  return pickNumber(input.duration_ms, input.elapsed_ms, extra.duration_ms, extra.api_duration, extra.elapsed_ms);
}
function ensureSessionStarted(sessionKey, input, state) {
  if (!sessionKey || state.sessionStarted) {
    return;
  }
  enqueue(buildEnvelope(FRAMEWORK, HOST, "session.start", sessionKey, {
    attributes: {
      synthetic: true,
      recovered_from: "hermes-hook",
      cwd: pickString(input.cwd),
      platform: getPlatform(input),
      model: getModel(input)
    }
  }));
  state.sessionStarted = true;
  saveState(sessionKey, state);
}
async function handleSessionStart(input) {
  const sessionKey = getSessionKey(input) || randomUUID2();
  const state = loadState(sessionKey);
  if (!state.sessionStarted) {
    enqueue(buildEnvelope(FRAMEWORK, HOST, "session.start", sessionKey, {
      attributes: {
        cwd: pickString(input.cwd),
        platform: getPlatform(input),
        model: getModel(input)
      }
    }));
    state.sessionStarted = true;
    saveState(sessionKey, state);
  }
  await flush();
}
async function handleRunStart(input) {
  const sessionKey = getSessionKey(input) || randomUUID2();
  const state = loadState(sessionKey);
  ensureSessionStarted(sessionKey, input, state);
  if (state.runId) {
    enqueue(buildEnvelope(FRAMEWORK, HOST, "run.end", sessionKey, {
      runId: state.runId,
      payload: { status: "success" }
    }));
  }
  const runId = randomUUID2();
  state.runId = runId;
  saveState(sessionKey, state);
  const extra = getExtra(input);
  enqueue(buildEnvelope(FRAMEWORK, HOST, "run.start", sessionKey, {
    runId,
    attributes: {
      is_first_turn: extra.is_first_turn,
      platform: getPlatform(input),
      model: getModel(input)
    },
    payload: {
      prompt_preview: truncate(extra.user_message ?? input.user_message, 200)
    }
  }));
  await flush();
}
async function handleRunEnd(input) {
  const sessionKey = getSessionKey(input);
  if (!sessionKey) {
    await flush();
    return;
  }
  const state = loadState(sessionKey);
  ensureSessionStarted(sessionKey, input, state);
  if (state.runId) {
    enqueue(buildEnvelope(FRAMEWORK, HOST, "run.end", sessionKey, {
      runId: state.runId,
      payload: {
        status: "success",
        duration_ms: getDuration(input),
        model: getModel(input),
        response_preview: truncate(getExtra(input).assistant_response, 500)
      }
    }));
    state.runId = void 0;
    saveState(sessionKey, state);
  }
  await flush();
}
async function handleToolStart(input) {
  const sessionKey = getSessionKey(input);
  const state = sessionKey ? loadState(sessionKey) : { spans: {} };
  ensureSessionStarted(sessionKey, input, state);
  const toolName = getToolName(input);
  const toolCallId = getToolCallId(input);
  const spanKey = toolCallId || toolName;
  const spanId = randomUUID2();
  state.spans[spanKey] = spanId;
  saveState(sessionKey, state);
  enqueue(buildEnvelope(FRAMEWORK, HOST, "span.start", sessionKey, {
    runId: state.runId,
    spanId,
    attributes: {
      span_kind: "tool",
      name: toolName,
      tool_call_id: toolCallId
    },
    payload: {
      input: truncate(input.tool_input ?? getExtra(input).args, 500)
    }
  }));
  await flush();
}
async function handleToolEnd(input) {
  const sessionKey = getSessionKey(input);
  const state = sessionKey ? loadState(sessionKey) : { spans: {} };
  const toolName = getToolName(input);
  const toolCallId = getToolCallId(input);
  const spanKey = toolCallId || toolName;
  const spanId = state.spans[spanKey];
  const extra = getExtra(input);
  const result = extra.result ?? input.result;
  const resultRecord = isRecord(result) ? result : {};
  const success = extra.error === void 0 && resultRecord.error === void 0;
  enqueue(buildEnvelope(FRAMEWORK, HOST, "span.end", sessionKey, {
    runId: state.runId,
    spanId,
    attributes: {
      span_kind: "tool",
      name: toolName,
      tool_call_id: toolCallId
    },
    payload: {
      status: success ? "success" : "error",
      result_preview: truncate(resultRecord.output ?? resultRecord.error ?? extra.error ?? result, 500),
      duration_ms: getDuration(input)
    }
  }));
  delete state.spans[spanKey];
  saveState(sessionKey, state);
  await flush();
}
async function handleAPIResult(input) {
  const sessionKey = getSessionKey(input);
  const state = sessionKey ? loadState(sessionKey) : { spans: {} };
  const usage = getUsage(input);
  if (!usage) {
    await flush();
    return;
  }
  enqueue(buildEnvelope(FRAMEWORK, HOST, "metric.snapshot", sessionKey, {
    runId: state.runId,
    payload: {
      metrics: {
        usage,
        model: getModel(input),
        provider: pickString(getExtra(input).provider),
        duration_ms: getDuration(input)
      }
    }
  }));
  await flush();
}
async function handleSessionEnd(input) {
  const sessionKey = getSessionKey(input);
  const state = sessionKey ? loadState(sessionKey) : { spans: {} };
  if (state.runId) {
    enqueue(buildEnvelope(FRAMEWORK, HOST, "run.end", sessionKey, {
      runId: state.runId,
      payload: {
        status: input.interrupted || getExtra(input).interrupted ? "interrupted" : "success",
        model: getModel(input)
      }
    }));
  }
  enqueue(buildEnvelope(FRAMEWORK, HOST, "session.end", sessionKey, {
    payload: {
      model: getModel(input),
      completed: getExtra(input).completed,
      interrupted: getExtra(input).interrupted
    }
  }));
  clearState(sessionKey);
  await flush();
}
var handler = async () => {
  const hookType = process.argv[2] || "unknown";
  let input = {};
  try {
    const stdin = await readStdin();
    if (stdin) {
      input = JSON.parse(stdin);
    }
  } catch {
    input = {};
  }
  try {
    switch (hookType) {
      case "session-start":
      case "start":
        await handleSessionStart(input);
        break;
      case "run-start":
      case "pre-llm":
        await handleRunStart(input);
        break;
      case "run-end":
      case "post-llm":
        await handleRunEnd(input);
        break;
      case "tool-start":
        await handleToolStart(input);
        break;
      case "tool-end":
        await handleToolEnd(input);
        break;
      case "api-result":
      case "post-api":
        await handleAPIResult(input);
        break;
      case "session-end":
      case "stop":
        await handleSessionEnd(input);
        break;
      default:
        console.debug(`[agentmon] unknown hermes hook type: ${hookType}`);
    }
  } catch (err) {
    console.debug("[agentmon] hermes handler error:", err);
  }
};
handler();