AI tools show when you sent a message. Chron logs when the AI responded too — and keeps a permanent, queryable, tamper-evident record of the AI work happening across your tools.
Works with Claude Desktop, Claude Code, Cursor, Windsurf, Codex, Gemini CLI, and any MCP-compatible AI tool.
Why
AI tools produce no audit trail by default. You cannot answer:
What did the AI say, and when exactly?
Audit-grade timestamped logs for every AI conversation
2026-11-15
ดาว
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เครื่องมือ
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อัปไทม์
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How long did the AI take to respond?
What was the full conversation that produced this output?
Which tool calls, command results, and code diffs happened during the session?
Did a secret or credential get pasted into an AI prompt?
Has this audit record been edited after the fact?
What did I ask Claude last week about this codebase?
Chron fixes that. Every exchange is logged with a precise local datetime (including timezone offset) to a SQLite file you own. It can hash-chain every event, sign sessions with Ed25519, detect secrets/PII, run deterministic compliance review across four frameworks, and stream metadata-only events to your SIEM. No cloud, no vendor lock-in, no message content leaving your machine.
What Chron captures
Chron stores a local audit trail of:
User and assistant messages
Tool calls and tool results
Code changes with file path, operation, and unified diff
Session start/resume metadata, including parent session and external refs
Secret/PII detections with masked values
Hash-chain integrity data
Optional Ed25519 session signatures
Optional NTP clock attestation metadata
Chron's SIEM integrations send only metadata: session starts, role-only message events, and masked secret detections. Message content and raw secret values stay local.
Need runtime policy enforcement for AI agents? CLAIIM adds agent identity, approval workflows, and ALLOW/DENY gates on top of Chron proof. Try the public preview: https://claiim.io/preview
Fail-closed capture — chron run
Chron's MCP logging depends on the AI client calling a tool. chron run does not.
chron run -- claude
chron run -- codex
The wrapper records each interaction chunk to a local append-only journal and
makes it durable before releasing it. No byte reaches your terminal until the
journal write covering it has been flushed and fsynced. If a journal write
fails, forwarding stops in both directions, the child is terminated, and
whatever was being held is not printed — the command exits 99 rather than
showing you output that was never recorded.
chron run --scope # exactly what this does and does not establish
chron verify --journal # verify the journal chain and see its scope
chron project # replay the journal into the database (idempotent)
What it establishes, and what it does not
chron run records the controlled stdin, stdout and stderr channels before
forwarding or releasing them. That is the whole of the guarantee.
It does not enforce that the wrapper is used — running the client directly
bypasses it, and that requires a control outside Chron, such as a managed
PATH, a restricted shell or an MDM policy. It does not capture every side
effect of the client: files it reads or writes, subprocesses it spawns and
network requests it makes never pass through the wrapper's pipes.
chron run --scope prints the full list, and every run writes that same scope
into its first journal record, so the claim travels with the evidence.
Verified enforcement
A run projected into the database carries a binding to the journal records it
came from. chron verify <session-id> follows that binding — the journal
segments must verify as a chain, the run must still be in it unchanged, and the
projected messages must match the journal field by field — and only then reports
enforced:wrapper. A claim that does not check out is a verification failure,
not a footnote.
A journal chain that verifies establishes that its records are internally
consistent with each other. It does not establish that they were never edited:
the chain is unanchored, so anyone able to rewrite the whole file can recompute
every hash. Chron signs sessions and bundles; it does not yet sign journal heads.
Install
CLI + MCP server:
npm install -g chron-mcp
chron doctor --fix
npx chron-mcp starts the MCP server only — it does not put the chron CLI command in your PATH. You need a global install for the CLI.
chron doctor --fix adds Chron to supported AI clients automatically: Claude Desktop, Claude Code, Cursor, Gemini CLI, Windsurf, and Codex. Restart your AI client after it runs.
First run creates ~/.chron/chron.db automatically. No database setup, no env vars, no migrations.
After npm install -g chron-mcp, the chron command is available globally:
Usage: chron <command> [options]
Commands:
run Run a command with fail-closed capture — output is withheld until recorded
project Replay the capture journal into the database (idempotent)
reconcile Read-only: what your client records that Chron cannot account for
history List sessions or show full log for a session
report Aggregate audit stats across sessions
export Export a session as markdown
secrets List detected secrets across sessions
settings View current configuration
connect Connect to a SIEM or AI tool (codex, cursor, gemini, crowdstrike, sentinel, splunk)
summary Structured summary of a session (timeline, mutations, secrets)
sign Sign a session with its Ed25519 key — produces a .chron.sig file
verify Verify a session's hash chain and Ed25519 signature
prune Delete sessions older than a retention cutoff
doctor Check your Chron setup — Node version, DB, MCP configs, SIEM
import Import conversations from external AI tools into Chron
review Review AI sessions against compliance control criteria
update Update chron to the latest version
Options (history):
--limit=<n> Max sessions to show (default: 20)
--search=<query> Full-text search across all sessions (FTS5: phrases, boolean, prefix*)
--ref=<value> Filter by external_ref prefix (e.g. --ref=jira:ENG-123)
<id-prefix> Show full log for the session with this ID prefix
Options (report):
--since=<range> Filter by date: 7d, 30d, or YYYY-MM-DD (default: all time)
--format=soc2 Generate SOC 2 HTML evidence package
--output=<file> Output file for --format=soc2
Options (export):
<id-prefix> Markdown export for a single session
--signed Tamper-evident bundle (JSONL + manifest + Ed25519 sig)
--session=<id> Filter bundle to a single session
--since=<range> Filter bundle by date: 7d, 30d, or YYYY-MM-DD
--output=<file> Output path (default: bundle.chron.tar.gz)
Options (reconcile):
--json Machine-readable JSON output, including the compared message indices
Options (verify):
<id-prefix> Verify a session's hash chain + Ed25519 signature
--bundle=<file> Verify a signed bundle offline (no DB needed)
Options (prune):
--older-than=<n>d Cutoff in days (falls back to retention_days in config)
--dry-run Show what would be deleted without deleting
--confirm Required flag to actually delete
Options (doctor):
--json Machine-readable JSON output
Options (import):
chatgpt <file> Import from ChatGPT export (.zip or conversations.json)
Options (review):
--framework=<name> Framework to review against: soc2, iso27001, euaiact, nist-ai-rmf
--since=<range> Limit to sessions since: 7d, 30d, or YYYY-MM-DD
--all Include accepted, dismissed, and resolved findings
--output=<file> Write HTML report to file (printable to PDF from browser)
accept <id> Mark a finding as accepted; supports --note=<text>
dismiss <id> Mark a finding as dismissed; supports --note=<text>
resolve <id> Mark a finding as resolved; supports --note=<text>
Reconciliation — chron reconcile
Your AI client keeps its own transcripts. Chron keeps evidence. chron reconcile
reads both and reports what the client recorded that Chron cannot account for.
chron reconcile # human-readable
chron reconcile --json # includes the compared message indices
It is read-only. It opens the database through a copy, never writes a row, and
touches neither the capture journal nor the transcripts it reads.
What it establishes, and what it does not
Three outcomes, kept apart on purpose:
Recorded identity — an imported session is bound to a transcript by
external_ref. That says which session an import created. It does not say
that the session's messages correspond to the transcript's, so content is
reported separately and in its own terms.
Candidate association — the messages correspond, but nothing binds them.
It needs confirmation; it is not a conclusion.
No association found — within the search that was actually performed.
A transcript with no match does not establish that a session was bypassed.
Chron cannot see what it did not record, so an absence is a statement about the
search, not about the user. Every absence carries the scope that produced it: the
sources inspected, the time, how many messages were compared out of how many
were comparable, and — in --json — the exact transcript ordinals compared, so
a sampled result can be reproduced rather than taken on trust.
The limits, stated separately
There is no transcript size limit: transcripts are streamed, and a 480MB
file is inspected completely. Each transcript is compared at up to 200 of its
messages, evenly spaced. These are independent — more files are inspectable
than before, and none is compared more deeply.
Messages shorter than 24 characters once normalised are not compared, because a
match on "ok" means little and a false correspondence is worse than a missed
one. Lines past 4MB are skipped and reported. Timestamps are not compared at
all: clock tolerance is null, so no finding rests on two clocks agreeing.
A transcript that is only partly readable says so, and its completeness travels
with every finding about it — including whether the file changed while it was
being read, in which case its digest is the digest of the bytes read and not of
a settled file.
Claude Code only, for now. Codex and Cursor reuse the same contract once their
formats are validated against real samples.
Chron Intelligence — compliance review
chron review scans your session history and flags findings against a compliance framework. No model inference. No API calls. Pure deterministic pattern matching on structured events Chron already captured.
Add --since=30d to scope to recent sessions, and --output=report.html to generate a printable HTML evidence report.
Four frameworks supported:
Framework
Rules
Controls covered
SOC 2
5
CC6.1, CC6.6, CC6.7, CC7.2, CC8.1
ISO 27001:2022
6
A.8.2, A.8.3, A.8.12, A.8.20, A.8.24, A.8.31
EU AI Act
6
Art. 9, Art. 10, Art. 12, Art. 13, Art. 14
NIST AI RMF 1.0
7
GOVERN, MAP, MEASURE, MANAGE
Finding workflow:
Every finding has a stable SHA-256 ID. Act on findings as you review:
chron review accept <id> --note="approved by security team, PR #512"
chron review dismiss <id> --note="test fixture, not production code"
chron review resolve <id> --note="credential rotated, no commit exposure"
chron review --framework=soc2 --all # show accepted/dismissed/resolved too
Reviewed findings do not reappear as noise on the next run. New findings — from sessions since your last review — surface cleanly.
Important: Chron covers the subset of controls evaluable from AI coding session evidence. A full framework assessment requires policy documentation, board records, and auditor judgement that session logs cannot replace. Each HTML report includes a framework-specific disclaimer on the cover page.
chron otel receipts
Every export writes a receipt: where the evidence went, how much of it, and what came back.
A receipt is an append-only, hash-chained record: the destination, scope and content posture are bound into the chain, and each batch records what was about to be sent before it was sent. A process killed mid-export therefore reads as delivery unknown rather than claiming nothing was sent.
Receipts are verified on every read. One that does not verify shows the reason and no delivery state — a record that does not hold up is not evidence of anything — and the command exits non-zero so automation notices without parsing each row.
Wording matters here. "Accepted" means the collector returned success for the payload. Whether it retained the data is something only that platform can show, and Chron does not claim it. Credentials never enter a receipt: userinfo, query parameters and unrecognised path segments are all stripped before the destination is recorded, and collector error bodies are reduced to a category rather than stored.
chron doctor
chron doctor validates the pieces that make Chron useful in real life:
Node.js version (v18+ required)
Local Chron version vs npm latest
The exact MCP launcher written into client configs
DB directory and key directory write access
Claude Desktop, Claude Code, Cursor, Gemini CLI, Windsurf, and Codex MCP config presence
Whether Chron is configured in each MCP client
Optional HTTP mode health check on /health
Splunk, Sentinel, and LogScale configuration via env vars or ~/.chron/config.json
Run chron doctor --fix to add the Chron MCP server to supported clients automatically. Warnings for optional integrations do not fail the command. Real failures exit with code 1.
What it logs
Every exchange is recorded with precise local timestamps — user message when received, assistant response when sent:
[user: 2026-05-08 14:32:11 +02:00 | assistant: 2026-05-08 14:32:43 +02:00]
The main risks of deploying this contract are...
The gap between user and assistant timestamps is real generation time. Both are stored in your local SQLite DB with full timezone offset.
Config by tool
Claude Desktop
Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):
chron connect cursor
chron doctor --verify-logging cursor
This writes the global MCP config and a project workspace rule:
~/.cursor/mcp.json
.cursor/mcp.json
.cursor/rules/chron.mdc
Chron also advertises the logging contract through the MCP server's initialization instructions, so Cursor receives it outside project workspaces. Cursor must be restarted after setup. Use Cursor Agent mode, then run the verify command above to confirm a real Chron session appears in the local database.
Chron ships with skills/chron.skill.md — a plain-text instruction file that tells the AI how to use the MCP tools automatically. Load it into your AI tool once. After that, the AI:
Creates or resumes a named session at the start of every conversation
Logs your message before it starts responding (captures the real user timestamp)
Logs its response after composing it (captures the real assistant timestamp)
Shows [user: YYYY-MM-DD HH:MM:SS ±HH:MM | assistant: YYYY-MM-DD HH:MM:SS ±HH:MM] at the top of every response
Retrieves prior session history so context is never lost across conversations
MCP Tools
Tool
Description
init_session
Initialize or resume a session — returns session_id, message count, and recent messages in one call
start_session
Create a new named audit session (legacy — prefer init_session)
log_message
Record a single message with the current local datetime
log_tool_call
Record an AI tool invocation as an audit event
log_tool_result
Record tool output and link it to a tool call
log_code_change
Record a file edit with operation and unified diff
log_exchange
Log a user/assistant pair atomically (for batch imports)
list_sessions
List all sessions ordered by most recently active
get_session_history
Retrieve the full timestamped log for a session
verify_session
Verify the tamper-evident hash chain — detects any post-log edits
scan_prompt
Scan text for secrets (API keys, credentials) before logging — returns masked detections
rehydrate_response
Restore redacted placeholders in an assistant response back to their original values
delete_session
Delete a session and cascade its messages/secrets
summarize_session
Return a timeline summary with latency, mutations, secrets, and prod references
Integrity and signing
Every new audit event is linked to the previous one via a SHA-256 chain:
valid: true — no messages were modified after logging
valid: false, first_break: <id> — exact row ID of the first tampered message
This turns your local log into a verifiable audit artifact. Any edit to a stored message — content, timestamp, or role — breaks the chain and is detected immediately.
Chron also generates an Ed25519 keypair per new session when possible. The private key stays under ~/.chron/keys. Use:
MCP tools can also call scan_prompt before sending content to an AI tool. Redaction uses $CHRON_* placeholders and rehydrate_response can restore values from the returned token map.
--signed covers one session, because a manifest carries one signature and the
signing key belongs to that session. It fails rather than producing an unsigned
bundle: a flag that names a guarantee and exits successfully without it would
hand someone an artefact they had no reason to distrust. chron verify --bundle
likewise exits non-zero on a bundle with no signature — matching files against
their own manifest establishes internal consistency, not origin.
The SOC 2 report and signed bundles are designed for audit review, legal hold, and incident reconstruction without sending conversation content to Chron infrastructure.
CrowdStrike LogScale integration
Stream AI session telemetry directly from developer machines into your CrowdStrike LogScale repository. No relay service — events go straight to your own LogScale instance.
What gets sent: session starts, message counts (role only), and masked credential detections. Message content never leaves the machine.
Setup
1. Create a LogScale repository and ingest token
In Falcon console → Log Management → Repositories → New repository (name it ChronAIEvents).
Then Settings → API Tokens → Add token → select Ingest permission → copy the token.
npm install -g chron-mcp
chron connect crowdstrike
# Paste your ingest URL and token when prompted
# The wizard sends a test event and confirms before saving
3. Add env vars to your MCP client config
The wizard prints the exact block to paste. For Claude Code, add to the chron entry in ~/.claude.json:
Splunk HEC base URL, e.g. https://localhost:8088 or https://your-host:8088
CHRON_SPLUNK_TOKEN
HEC ingest token
CHRON_SPLUNK_INSECURE
Set to 1 to skip TLS verification (local Docker with self-signed cert)
CHRON_SPLUNK_URL and CHRON_SPLUNK_TOKEN must both be set for events to flow.
Microsoft Sentinel integration
Stream AI session telemetry into your Microsoft Sentinel workspace via the Azure Monitor Logs Ingestion API. Events go directly from developer machines to your own Log Analytics workspace — no relay service.
What gets sent: session starts, message counts (role only), and masked credential detections. Message content never leaves the machine.
Setup
1. Register an Azure App
Azure Portal → Azure Active Directory → App registrations → New registration → name it chron-ingest.
Note the Application (client) ID and Directory (tenant) ID.
Go to Certificates & secrets → New client secret → copy the value immediately.
2. Create a custom table in Log Analytics
Open your Log Analytics workspace → Tables → Create → New custom log (DCR-based) → name it ChronEvents_CL.
Add these columns (in addition to the auto-added TimeGenerated):
Column
Type
EventType
string
SessionIdPrefix
string
AiTool
string
OS
string
ChronVersion
string
Computer
string
Role
string
DetectionType
string
MaskedValue
string
The wizard creates a Data Collection Endpoint (DCE) and Data Collection Rule (DCR) — note both.
3. Grant the App ingest permission
Open the DCR → Access control (IAM) → Add role assignment → Role: Monitoring Metrics Publisher → Member: the chron-ingest app.
4. Get the DCR Immutable ID
Open the DCR → Overview → JSON view → copy the immutableId field (starts with dcr-).
5. Install the CLI and run the onboarding wizard
npm install -g chron-mcp
chron connect sentinel
# Enter tenant ID, client ID, client secret, DCE URL, DCR immutable ID, and stream name
# The wizard authenticates with Azure AD and sends a test event before saving
6. Add env vars to your MCP client config
The wizard prints the exact block to paste. For Claude Code, add to ~/.claude.json:
Bring your existing ChatGPT history into Chron's tamper-evident audit trail.
# From a ChatGPT data export ZIP
chron import chatgpt ~/Downloads/chatgpt-export.zip
# Or from an extracted conversations.json
chron import chatgpt ~/Downloads/conversations.json
How to get your ChatGPT export:
ChatGPT → Settings → Data Controls → Export data → wait for email → download the ZIP.
What gets imported:
One Chron session per conversation, with ai_tool=chatgpt
Original message timestamps from the export
external_ref=chatgpt:<conversation_id> on every session (visible in chron history)
Full SHA-256 hash chain across all imported messages
Secret detection runs on all user messages
Re-running is safe — already-imported conversations are skipped by external_ref match.
After import, sessions appear in chron history and chron verify works on them the same as any natively-logged session.
Your data
Your audit log lives at ~/.chron/chron.db — a single SQLite file on your machine. Query it directly with any SQLite tool:
sqlite3 ~/.chron/chron.db \
"SELECT s.title, m.role, m.content, m.created_at
FROM messages m JOIN sessions s ON s.id = m.session_id
ORDER BY m.created_at"
No cloud, no analytics, and no vendor-held copy of your log. Change the location with CHRON_DB_PATH.
What leaves your machine
Chron sends no usage data — there is no analytics endpoint, no account, and no
phone-home. Two kinds of packet can leave, and this is the whole list:
What
When
Contains
Switch it off
NTP clock check
automatically, when a session is created
a 48-byte NTP request to pool.ntp.org. No session data, no identifier.
CHRON_DISABLE_NTP=1, or redirect it with CHRON_NTP_SERVER=your.ntp.host
SIEM / OTLP export
only after you configure a destination
the events you configured, to the endpoint you chose
nothing to switch off — it is inert until you run chron connect
The clock check is what lets chron verify tell you whether a session's
timestamps were taken against a synchronised clock. It is the only packet Chron
sends without being asked, which is why it is listed first and why it has a
switch. Turn it off and chron verify says so, rather than reporting a clock it
never checked:
Clock attestation
! Clock attestation is disabled by configuration — none was requested.
License
Copyright (c) 2026 Nivaya. All rights reserved.
Source code is public for transparency only. Cloning, forking, modification, and redistribution are not permitted without explicit written permission. See LICENSE for full terms.