No credit card · No account · No usage limits

Free.
Forever.
No asterisk.

LangSight is Apache 2.0 open source. Self-host the entire platform — CLI, SDK, API, dashboard, and every feature — at no cost. Not “open core”. Not a free tier. Just free.

$pip install langsight && langsight init

Self-hosted

Open Source

Free forever
$0forever · Apache 2.0
Get started →
✓Unlimited agents, sessions, tool calls
✓Unlimited team members
✓Unlimited projects with RBAC
✓All CLI commands
✓Full REST API + dashboard
✓PostgreSQL + ClickHouse (dual-backend)
✓MCP health monitoring
✓Prevention guardrails (loop detection, budget limits, circuit breaker)
✓Per-agent override config from dashboard
✓Security scanning (OWASP + CVE)
✓Cost attribution + model pricing
✓Anomaly detection + SLO tracking
✓AI root cause analysis (bring your key)
✓Self-hosted — your data, your infra
✓Apache 2.0 — fork, modify, sell freely

Managed cloud

Cloud

Coming soon
TBDusage-based pricing
○Everything in Open Source
○No infrastructure to manage
○Automatic backups + upgrades
○99.9% uptime SLA
○Enterprise SSO (SAML/OIDC)
○Priority support + SLA
○Dedicated Slack channel
○Custom data retention
○Usage-based — pay only for what you use

Get notified when cloud launches

Leave a GitHub star and we'll announce via releases.Star on GitHub →

Everything included

No feature gating. Ever.

Every capability listed below is available in the free open-source version. We will never move an existing feature to a paid tier.

Agent Runtime Reliability

✓Full session traces — every tool call
✓Multi-agent call tree reconstruction
✓Payload capture (input args + output)
✓LLM reasoning traces (llm_input / llm_output)
✓Anomaly detection (z-score vs 7-day baseline)
✓Agent SLO tracking (success_rate, latency_p99)

MCP Health Monitoring

✓Continuous proactive health checks
✓Schema drift detection
✓Latency tracking and p99 trends
✓Slack + webhook alerts on DOWN/recovery
✓Multi-transport: stdio, SSE, StreamableHTTP

MCP Security Scanning

✓CVE detection against public database
✓5 of 10 OWASP MCP checks (more coming)
✓Tool poisoning detection (injection, unicode, base64)
✓Auth gap analysis
✓CI/CD integration with --ci flag
✓JSON output for SIEM integration

Cost Attribution

✓Token-based pricing for LLM calls
✓Per-tool call-based pricing rules
✓Cost per session / per agent / per tool
✓Model pricing table (admin-managed)
✓Historical cost trends

Infrastructure

✓PostgreSQL for metadata
✓ClickHouse for analytics
✓Dual-storage architecture
✓Docker Compose deployment
✓Alembic migrations

Teams & Access

✓Multi-user with invite-based signup
✓Project-level RBAC (owner / member / viewer)
✓API key auth with role scopes
✓Global admin + per-project roles
✓Audit trail for auth events

Cost comparison

$0 vs $2,000+/month

What you needLangSightDatadog APMNew Relic
Monthly cost (10 services)$0~$2,400/mo~$1,800/mo
Agent action traces✓ Free✓ Paid✓ Paid
MCP health monitoring✓ Free✗✗
Security scanning✓ Free✗✗
Data leaves your networkNeverAlwaysAlways
Vendor lock-inNone (Apache 2.0)HighHigh
Custom retentionUnlimitedPay per GBPay per GB

FAQ

Common questions

Start now. It's free.

30 seconds to install. Two lines to instrument. No account required.