Files
agentmon/hooks/claude-code/handler.ts
T
2026-04-29 09:41:07 -07:00

519 lines
16 KiB
JavaScript

#!/usr/bin/env node
import { randomUUID } from 'node:crypto';
import { hostname, homedir } from 'node:os';
import { readFileSync, writeFileSync, mkdirSync, unlinkSync } from 'node:fs';
import { join } from 'node:path';
import {
type Dict,
isRecord,
pickString,
pickNumber,
truncate,
buildEnvelope,
createTransport,
readStdin,
} from '../shared/lib';
const INGEST_URL = process.env.AGENTMON_INGEST_URL || 'http://localhost:8080';
const FRAMEWORK = process.env.AGENTMON_FRAMEWORK || 'claude-code';
const HOST = process.env.AGENTMON_HOST || hostname();
const { enqueue, flush } = createTransport(INGEST_URL);
// ── Persisted state (survives between hook subprocess invocations) ──────────
interface SessionState {
runId?: string;
spans: { [key: string]: string }; // key = sessionKey:toolName, value = spanId
spanStartTimes?: { [spanId: string]: number }; // spanId -> epoch ms
subagent?: { name: string; spanId: string };
compactSpanId?: string;
}
const STATE_DIR = join(homedir(), '.agentmon-state');
function ensureStateDir() {
try { mkdirSync(STATE_DIR, { recursive: true }); } catch { /* ignore */ }
}
function loadState(sessionKey: string): SessionState {
try {
const raw = readFileSync(join(STATE_DIR, sessionKey + '.json'), 'utf8');
return JSON.parse(raw) as SessionState;
} catch {
return { spans: {} };
}
}
function saveState(sessionKey: string, state: SessionState) {
ensureStateDir();
try {
writeFileSync(join(STATE_DIR, sessionKey + '.json'), JSON.stringify(state), 'utf8');
} catch { /* ignore */ }
}
function clearState(sessionKey: string) {
try { unlinkSync(join(STATE_DIR, sessionKey + '.json')); } catch { /* ignore */ }
}
// ─────────────────────────────────────────────────────────────────────────────
const activeRuns = new Map<string, string>();
const activeSpans = new Map<string, string>();
const activeSubagents = new Map<string, { name: string; spanId: string }>();
function getSessionKey(input: Dict): string | undefined {
return pickString(
input.sessionId,
input.session_id,
input.conversationId,
input.conversation_id,
);
}
function getUsage(input: Dict): Dict | undefined {
const usage = isRecord(input.usage) ? input.usage :
isRecord(input.llm) ? input.llm :
undefined;
if (!usage) return undefined;
const result: Dict = {};
if (usage.input_tokens !== undefined) result.input_tokens = usage.input_tokens;
if (usage.output_tokens !== undefined) result.output_tokens = usage.output_tokens;
if (usage.cache_creation_tokens !== undefined) result.cache_creation_tokens = usage.cache_creation_tokens;
if (usage.cache_read_tokens !== undefined) result.cache_read_tokens = usage.cache_read_tokens;
if (usage.thinking_tokens !== undefined) result.thinking_tokens = usage.thinking_tokens;
if (usage.total_tokens !== undefined) result.total_tokens = usage.total_tokens;
if (usage.total_cost !== undefined) result.total_cost = usage.total_cost;
return Object.keys(result).length > 0 ? result : undefined;
}
function getContextWindow(input: Dict): Dict | undefined {
const stats = isRecord(input.context_stats) ? input.context_stats :
isRecord(input.stats) ? input.stats : undefined;
if (!stats) return undefined;
const result: Dict = {};
if (stats.input_tokens !== undefined) result.input_tokens = stats.input_tokens;
if (stats.output_tokens !== undefined) result.output_tokens = stats.output_tokens;
if (stats.used_tokens !== undefined) result.used_tokens = stats.used_tokens;
if (stats.max_tokens !== undefined) result.max_tokens = stats.max_tokens;
if (stats.tokens_remaining !== undefined) result.tokens_remaining = stats.tokens_remaining;
return Object.keys(result).length > 0 ? result : undefined;
}
function emitError(sessionKey: string | undefined, runId: string | undefined, spanId: string | undefined, errorValue: unknown) {
if (errorValue === undefined || errorValue === null || errorValue === false) {
return;
}
const errorRecord = isRecord(errorValue) ? errorValue : {};
const message = pickString(errorRecord.message, errorRecord.error, errorValue) || 'unknown';
const errType = pickString(errorRecord.type, errorRecord.code) || FRAMEWORK;
enqueue(buildEnvelope(FRAMEWORK, HOST, 'error', sessionKey, {
runId,
spanId,
payload: {
error: {
type: errType,
message,
},
},
}));
}
async function handleSessionStart(input: Dict) {
const sessionKey = getSessionKey(input);
if (!sessionKey) {
console.error('[agentmon] ignoring claude-code session.start without session_id');
return;
}
const hookEventName = pickString(input.hook_event_name);
if (hookEventName && hookEventName !== 'SessionStart') {
console.error(`[agentmon] ignoring claude-code session.start with hook_event_name=${hookEventName}`);
return;
}
const runId = randomUUID();
activeRuns.set(sessionKey, runId);
saveState(sessionKey, { runId, spans: {} });
const contextWindow = getContextWindow(input);
enqueue(buildEnvelope(FRAMEWORK, HOST, 'session.start', sessionKey, {
attributes: contextWindow ? { context_window: contextWindow } : undefined,
}));
enqueue(buildEnvelope(FRAMEWORK, HOST, 'run.start', sessionKey, {
runId,
attributes: {
trigger: pickString(input.trigger_type, input.trigger),
},
payload: {
prompt_preview: truncate(input.prompt, 200),
},
}));
await flush();
}
async function handleSessionEnd(input: Dict) {
const sessionKey = getSessionKey(input);
const state = sessionKey ? loadState(sessionKey) : { spans: {} };
const runId = sessionKey ? (activeRuns.get(sessionKey) || state.runId) : undefined;
const usage = getUsage(input);
const contextWindow = getContextWindow(input);
const duration = pickNumber(input.duration_ms, input.elapsed_ms);
if (runId) {
enqueue(buildEnvelope(FRAMEWORK, HOST, 'run.end', sessionKey, {
runId,
payload: {
status: 'success',
duration_ms: duration,
model: pickString(input.model),
...(usage && { usage }),
...(contextWindow && { context_window: contextWindow }),
},
}));
}
enqueue(buildEnvelope(FRAMEWORK, HOST, 'session.end', sessionKey, {
payload: {
...(usage && { usage }),
...(contextWindow && { context_window: contextWindow }),
},
}));
activeRuns.delete(sessionKey || '');
activeSpans.clear();
activeSubagents.clear();
if (sessionKey) clearState(sessionKey);
await flush();
}
async function handlePromptSubmit(input: Dict) {
const sessionKey = getSessionKey(input);
const state = sessionKey ? loadState(sessionKey) : { spans: {} };
const runId = sessionKey ? (activeRuns.get(sessionKey) || state.runId) : undefined;
const prompt = pickString(input.prompt, input.text, input.message);
if (runId && prompt) {
enqueue(buildEnvelope(FRAMEWORK, HOST, 'run.end', sessionKey, {
runId,
payload: {
status: 'success',
duration_ms: pickNumber(input.elapsed_ms, input.duration_ms),
},
}));
}
const newRunId = randomUUID();
if (sessionKey) {
activeRuns.set(sessionKey, newRunId);
saveState(sessionKey, { runId: newRunId, spans: {} });
}
enqueue(buildEnvelope(FRAMEWORK, HOST, 'run.start', sessionKey, {
runId: newRunId,
attributes: {
type: 'user_prompt',
},
payload: {
prompt_preview: truncate(prompt, 200),
},
}));
await flush();
}
async function handleToolStart(input: Dict) {
const sessionKey = getSessionKey(input);
const state = sessionKey ? loadState(sessionKey) : { spans: {} };
const runId = sessionKey ? (activeRuns.get(sessionKey) || state.runId) : undefined;
const toolName = pickString(input.tool, input.tool_name, input.name) || 'unknown';
const toolInput = isRecord(input.input) ? input.input : {};
const spanId = randomUUID();
const spanKey = sessionKey ? sessionKey + ':' + toolName : undefined;
if (spanKey) {
activeSpans.set(spanKey, spanId);
state.spans[spanKey] = spanId;
state.spanStartTimes = state.spanStartTimes || {};
state.spanStartTimes[spanId] = Date.now();
if (runId) state.runId = runId;
if (sessionKey) saveState(sessionKey, state);
}
enqueue(buildEnvelope(FRAMEWORK, HOST, 'span.start', sessionKey, {
runId,
spanId,
attributes: {
span_kind: 'tool',
name: toolName,
},
payload: {
input: truncate(toolInput, 200),
},
}));
await flush();
}
async function handleToolEnd(input: Dict) {
const sessionKey = getSessionKey(input);
const state = sessionKey ? loadState(sessionKey) : { spans: {} };
const runId = sessionKey ? (activeRuns.get(sessionKey) || state.runId) : undefined;
const toolName = pickString(input.tool, input.tool_name, input.name) || 'unknown';
const spanKey = sessionKey ? sessionKey + ':' + toolName : undefined;
const spanId = spanKey ? (activeSpans.get(spanKey) || state.spans[spanKey]) : undefined;
const result = isRecord(input.result) ? input.result : isRecord(input.output) ? input.output : {};
const success = !result.error;
const startTime = spanId ? state.spanStartTimes?.[spanId] : undefined;
const duration = pickNumber(input.duration_ms, input.elapsed_ms) ?? (startTime ? Date.now() - startTime : undefined);
if (spanId && state.spanStartTimes) {
delete state.spanStartTimes[spanId];
if (sessionKey) saveState(sessionKey, state);
}
enqueue(buildEnvelope(FRAMEWORK, HOST, 'span.end', sessionKey, {
runId,
spanId,
attributes: {
span_kind: 'tool',
name: toolName,
},
payload: {
status: success ? 'success' : 'error',
result_preview: truncate(result.output ?? result.error ?? result, 500),
duration_ms: duration,
},
}));
if (!success) {
emitError(sessionKey, runId, spanId, result.error);
}
activeSpans.delete(spanKey || '');
await flush();
}
async function handleSubagentStart(input: Dict) {
const sessionKey = getSessionKey(input);
const state = sessionKey ? loadState(sessionKey) : { spans: {} };
const runId = sessionKey ? (activeRuns.get(sessionKey) || state.runId) : undefined;
const agentName = pickString(input.agent, input.agent_name, input.name) || 'unknown';
const spanId = randomUUID();
if (sessionKey) {
activeSubagents.set(sessionKey, { name: agentName, spanId });
state.subagent = { name: agentName, spanId };
state.spanStartTimes = state.spanStartTimes || {};
state.spanStartTimes[spanId] = Date.now();
if (runId) state.runId = runId;
saveState(sessionKey, state);
}
enqueue(buildEnvelope(FRAMEWORK, HOST, 'span.start', sessionKey, {
runId,
spanId,
attributes: {
span_kind: 'agent',
name: agentName,
type: 'subagent',
},
payload: {
prompt_preview: truncate(input.prompt, 200),
},
}));
await flush();
}
async function handleSubagentStop(input: Dict) {
const sessionKey = getSessionKey(input);
const state = sessionKey ? loadState(sessionKey) : { spans: {} };
const runId = sessionKey ? (activeRuns.get(sessionKey) || state.runId) : undefined;
const subagent = sessionKey ? (activeSubagents.get(sessionKey) || state.subagent) : undefined;
const spanId = subagent?.spanId;
const agentName = subagent?.name || pickString(input.agent, input.agent_name) || 'unknown';
const startTime = spanId ? state.spanStartTimes?.[spanId] : undefined;
const duration = pickNumber(input.duration_ms, input.elapsed_ms) ?? (startTime ? Date.now() - startTime : undefined);
const usage = getUsage(input);
if (spanId && state.spanStartTimes) {
delete state.spanStartTimes[spanId];
if (sessionKey) saveState(sessionKey, state);
}
enqueue(buildEnvelope(FRAMEWORK, HOST, 'span.end', sessionKey, {
runId,
spanId,
attributes: {
span_kind: 'agent',
name: agentName,
type: 'subagent',
},
payload: {
status: 'success',
duration_ms: duration,
...(usage && { usage }),
},
}));
activeSubagents.delete(sessionKey || '');
await flush();
}
async function handleCompactStart(input: Dict) {
const sessionKey = getSessionKey(input);
const state = sessionKey ? loadState(sessionKey) : { spans: {} };
const runId = sessionKey ? (activeRuns.get(sessionKey) || state.runId) : undefined;
const spanId = randomUUID();
if (sessionKey) {
activeSpans.set(sessionKey + ':compact', spanId);
state.compactSpanId = spanId;
state.spanStartTimes = state.spanStartTimes || {};
state.spanStartTimes[spanId] = Date.now();
if (runId) state.runId = runId;
saveState(sessionKey, state);
}
enqueue(buildEnvelope(FRAMEWORK, HOST, 'span.start', sessionKey, {
runId,
spanId,
attributes: {
span_kind: 'internal',
name: 'context_compaction',
},
}));
await flush();
}
async function handleCompactEnd(input: Dict) {
const sessionKey = getSessionKey(input);
const state = sessionKey ? loadState(sessionKey) : { spans: {} };
const runId = sessionKey ? (activeRuns.get(sessionKey) || state.runId) : undefined;
const spanKey = sessionKey ? sessionKey + ':compact' : undefined;
const spanId = spanKey ? (activeSpans.get(spanKey) || state.compactSpanId) : undefined;
const startTime = spanId ? state.spanStartTimes?.[spanId] : undefined;
const duration = pickNumber(input.duration_ms, input.elapsed_ms) ?? (startTime ? Date.now() - startTime : undefined);
const contextWindow = getContextWindow(input);
if (spanId && state.spanStartTimes) {
delete state.spanStartTimes[spanId];
if (sessionKey) saveState(sessionKey, state);
}
enqueue(buildEnvelope(FRAMEWORK, HOST, 'span.end', sessionKey, {
runId,
spanId,
attributes: {
span_kind: 'internal',
name: 'context_compaction',
},
payload: {
status: 'success',
duration_ms: duration,
...(contextWindow && { context_window: contextWindow }),
},
}));
activeSpans.delete(spanKey || '');
await flush();
}
async function handleNotification(input: Dict) {
const sessionKey = getSessionKey(input);
const notificationType = pickString(input.notification_type, input.type);
const usage = getUsage(input);
const contextWindow = getContextWindow(input);
const duration = pickNumber(input.duration_ms, input.elapsed_ms);
if (notificationType === 'Done' || notificationType === 'success') {
const state = sessionKey ? loadState(sessionKey) : { spans: {} };
const runId = sessionKey ? (activeRuns.get(sessionKey) || state.runId) : undefined;
if (runId) {
enqueue(buildEnvelope(FRAMEWORK, HOST, 'run.end', sessionKey, {
runId,
payload: {
status: 'success',
duration_ms: duration,
model: pickString(input.model),
...(usage && { usage }),
...(contextWindow && { context_window: contextWindow }),
},
}));
}
// Do NOT emit session.end or clear state here — "Done" means Claude
// finished a turn, not the session. State must persist so tool calls
// between turns still have a runId. The actual session.end is emitted
// by handleSessionEnd when the Stop hook fires.
}
await flush();
}
const handler = async () => {
const args = process.argv.slice(2);
const hookType = args[0] || 'unknown';
let input: Dict = {};
try {
const stdin = await readStdin();
if (stdin) {
input = JSON.parse(stdin);
}
} catch {
input = {};
}
try {
switch (hookType) {
case 'start':
await handleSessionStart(input);
break;
case 'stop':
await handleSessionEnd(input);
break;
case 'prompt':
await handlePromptSubmit(input);
break;
case 'tool-start':
await handleToolStart(input);
break;
case 'tool-end':
await handleToolEnd(input);
break;
case 'subagent-start':
await handleSubagentStart(input);
break;
case 'subagent-stop':
await handleSubagentStop(input);
break;
case 'compact-start':
await handleCompactStart(input);
break;
case 'compact-end':
await handleCompactEnd(input);
break;
case 'notification':
await handleNotification(input);
break;
default:
console.debug(`[agentmon] unknown hook type: ${hookType}`);
}
} catch (err) {
console.debug('[agentmon] handler error:', err);
}
};
handler();