Every SaaS company eventually faces the same question: “Can you prove what happened in your system?” Whether it comes from a SOC 2 auditor, a HIPAA compliance officer, or an enterprise customer’s security team, the answer needs to be the same, a comprehensive, tamper-proof audit trail.

The Problem with DIY Audit Logging

Most engineering teams start by appending events to a database table. It works for the first few months. Then reality sets in.

Building a production-grade audit logging system from scratch takes 6 to 12 months of engineering time. You need to handle high-throughput ingestion without blocking your application, design a schema that supports flexible queries across millions of events, implement retention policies that satisfy different compliance frameworks, and build a search interface your compliance team can actually use.

That’s just the initial build. Ongoing maintenance adds up quickly: schema migrations as requirements evolve, storage cost optimization, performance tuning as volume grows, and the constant pressure to keep up with changing compliance standards. Most teams estimate the total cost at $200K to $500K per year when you factor in engineering time, infrastructure, and opportunity cost.

Worse, DIY solutions almost always have compliance gaps. Logs stored in a regular database can be modified or deleted, by a malicious actor, a buggy migration, or even an overzealous cleanup script. When an auditor asks “Can you prove these logs haven’t been tampered with?”, most teams have no good answer.

How AuditRails Solves It

AuditRails is tamper-proof audit logging as a service. You integrate our SDK, call one function to log an event, and we handle everything else: ingestion, hash chaining, immutable storage, search, and the compliance dashboard your auditors need.

Drop-in SDKs

We ship SDKs for the five languages that power most SaaS applications: Node.js, Python, Go, Java, and PHP. Each SDK is designed to be integrated in under 10 minutes. A single function call logs an event with the action, actor, resource, and any metadata you want to attach. The SDK handles batching, retries, and async delivery so your application’s performance is never impacted.

Cryptographic Hash Chaining

Every log event is cryptographically chained to the previous event using SHA-256. The hash of each event includes the previous hash, the event payload, and a millisecond-precision timestamp. This creates an unbreakable chain, if anyone modifies, deletes, or reorders a single event, the chain breaks and the tampering is immediately detectable.

WORM Storage

Beyond hash chaining, every log is written to S3 with Object Lock in compliance mode. This is Write Once, Read Many (WORM) storage, not even an AWS root account can delete or modify the data before the retention period expires. It’s the same technology used by financial institutions for regulatory record-keeping.

Compliance Dashboard

Your compliance team gets a purpose-built dashboard for searching and exporting audit logs. Filter by action, actor, resource, or time range. Verify chain integrity with one click. Export evidence packages for SOC 2, HIPAA, ISO 27001, GDPR, and PCI DSS audits. Role-based access control means auditors see exactly what they need, nothing more, nothing less.

The 5-SDK Approach

We believe audit logging should be a solved problem across the entire backend ecosystem. That’s why we’re launching with SDKs for Node.js, Python, Go, Java, and PHP. Each SDK follows the conventions of its language, promises in Node.js, async/await in Python, goroutines in Go, the builder pattern in Java, and PSR-18 HTTP clients in PHP. You shouldn’t have to learn a new paradigm to add audit logging.

What’s Included in the Free Tier

(As originally published, this section describes the free Developer tier, which no longer exists. The specific numbers below (5,000 events, 90-day retention, $99/month) are historical and do not reflect current pricing. See the pricing page for current plans.)

We want every developer to experience AuditRails without friction. The free Developer tier includes:

Up to 5,000 events per month
Full hash chaining and tamper detection
90-day log retention
Dashboard access with search and export
All five SDKs
Community support

No credit card required. No trial expiration. When you’re ready to scale, paid plans start at €99 per month.

Our Vision

Audit logging is table stakes for modern SaaS, but it shouldn’t consume months of engineering effort. Our vision is to make tamper-proof audit logging as simple as adding a payment provider or an auth library, a single integration that handles the hard parts so you can focus on your product.

We’re just getting started. In the coming months, we’ll be adding webhook alerting, real-time streaming, advanced analytics, and deeper integrations with the compliance-automation platforms teams already use. If you’re building a SaaS product that needs audit logging, we’d love to have you try AuditRails.

Introducing AuditRails