The accountability engine for AI Agents
AI agents ship to production with zero security telemetry. They execute processes, read files, make network calls, hold credentials — and nobody is watching. Quint changes that.This page tells the full story in one scroll. Each section links to the detailed reference page if you want to go deeper.
1. The Problem
Every major AI coding agent — Claude Code, Cursor, Copilot, Windsurf, Cline — runs with the same privileges as the developer using it. Full filesystem. Full network. Full process execution. No audit trail. Traditional security tools don’t see agent actions. EDR sees processes but can’t attribute them to an agent session. CASB sees network traffic but can’t tie it to a tool call. SIEM gets logs but has no concept of an agent’s declared intent versus its actual behavior. The result: shadow AI agents proliferate with zero visibility, and the enterprise has no answer to the question “what are our AI agents actually doing?“2. The Insight: Intent vs. Truth
Quint sits in two data paths simultaneously on the same machine:Intent Stream
The Forward Proxy intercepts every LLM API response and extracts
tool_use blocks — what the agent says it will do. 7 protocol parsers: Anthropic, OpenAI Chat, OpenAI Responses, Gemini, Bedrock, Azure, generic.Truth Stream
Endpoint Security observes the kernel — every process spawn, file read/write, and network connection the OS actually performs. Filtered to the agent’s process tree.
The six divergence types
Products that only see intent can’t detect truth-without-intent. Products that only see truth can’t detect target mismatch. Quint sees both.
Go Deeper: Intent vs. Truth
The full specification: both streams, the join algorithm, all six divergence types with examples, and why the two-stream architecture is defensible.
3. Follow One Tool Call
A user types a prompt in Claude Code. Here’s what happens:1
Agent sends request
Claude Code sends a streaming POST to
bedrock-runtime.us-east-1.amazonaws.com.2
Interception
The macOS Network Extension recognizes the Bedrock hostname and relays the flow to the daemon. On other OSes,
HTTPS_PROXY routes it through the forward proxy.3
MITM TLS + parse
The daemon presents a leaf cert signed by the local Quint CA.
llmparse detects Bedrock eventstream format, extracts the model, tools, and messages.4
Session stamped
The daemon looks up the source PID in
unisession.Tracker. Every audit row gets session_id = "{rootPID}-{startUnixMs}".5
Tool call extracted
When the response produces a
tool_use block (e.g., Bash({"command":"ls"})), the parser extracts it and fires OnToolCall.6
Local audit
The tool call is persisted to the signed audit log (
quint.db). Each row is Ed25519-signed and chained via prev_hash.7
Cloud forward
A structured
QuintEvent is enqueued in the cloud forwarder (batched 500 events / 1s flush, retries 5x with backoff, overflows to disk).8
Ingest + scoring
api.quintai.dev/v1/ingest stamps org_id, publishes to SNS FIFO, fans out to SQS. The scoring service runs the 4-gate behavioral pipeline.9
Dashboard
The score lands in Postgres, SSE pushes it to the Sessions view. If a rule triggered
block, the next identical action is rejected at the edge.Go Deeper: End-to-End Flow
The full 12-step trace with architecture diagrams, design principles, and data flow details.
4. How Detection Works
The Agent Fingerprint (~3.1KB)
Every agent builds a probabilistic behavioral fingerprint — a fixed-size statistical summary that captures what the agent normally does without storing raw history.
Memory: ~3,100 bytes per agent. 40K concurrent agents in 128MB. Update is O(1), ~186ns per action.
The 4-Gate Pipeline
A fast-rejection architecture — each gate is cheaper than the next, and 95% of actions exit at Gate 1.
The noise budget: 95% of actions produce zero output — not a low score, literally nothing. Operators only see the <0.5% that reach ANOMALOUS.
Confidence Bands
The behavioral engine does not produce per-action risk scores. It classifies every action into one of three bands:
Three bands solve alert fatigue. Operators only see Band 3 sessions.
Flow Matrices + Threat Signatures
The fingerprint tracks capability-to-capability transitions as a 12x12 flow matrix. Threat signatures are structural shapes matched via Jensen-Shannon Divergence — not hardcoded tool combinations. A signature is NOT “ifread_file then curl = exfiltration.” A signature IS “the flow matrix has 80%+ mass in the read→outbound quadrant.” This catches any tool combination that produces that shape.
5 built-in signatures: Exfiltration, Credential Relay, Staging + Execution, Reconnaissance, Cover Tracks.
Envelope Lifecycle
Fingerprints are alive — they evolve as agent behavior changes:5. The Detection Ladder
Quint’s detection architecture is a five-stage ladder. Each stage depends on data the previous stage produced. Skipping rungs produces detection that either fires on everything or misses real attacks.This ladder describes the pre-pivot behavioral progression and is superseded by Intent-Scoped Security; the earlier per-action flow-matrix/GNN closed loop is retired. The re-aimed GNN (Stage 4) is a global-tier, offline model — unjustified activity is a subgraph with no path to a goal node — not an edge scorer, and it never makes an enforcement decision. See ML Ladder for the full, superseded detail.
Go Deeper: Detection Ladder
Stage-by-stage justification with academic references (Grinsztajn NeurIPS 2022, TGN, E-GraphSAGE), data threshold analysis, and advancement triggers.
6. Three-Tier Architecture
Design principles
- Local-first capture, cloud-first scoring. Raw bodies stay on the machine. Normalized events flow to the cloud.
- Lossy at the edge, durable in the cloud. Under backpressure, the edge drops events rather than block user traffic.
- Zero client changes. Forward proxy + NE means no SDK integration, no new endpoints.
- Session-centric model. Everything anchors to sessions, not raw events.
- Code signing first. Agent detection uses macOS code signing as the highest-confidence signal.
- Tenant isolation at every layer. Deploy tokens scoped to orgs. Postgres RLS. FIFO queues keyed by session.
What stays on the machine vs. goes to cloud
Go Deeper: System Design
Full deployment topology, security properties, resource footprints.
Go Deeper: Edge Architecture
How the daemon, proxy, ES, and NE fit together on one machine.
7. Platform Coverage
Quint is one behavioral intelligence engine fed by platform-specific collectors that all produce the sameQuintEvent envelope. Adding a platform means adding a collector, not rebuilding the product.
The architectural constraint that makes this possible: no top-level
QuintEvent field is platform-specific. Detection logic, model training data, and dashboard views are identical across every collector. Data compounds across platforms because the schema is one schema.
Go Deeper: Platform Coverage
The source-agnostic architecture, all five deployment categories (desktop, browser, cloud, CI/CD, SaaS), and the decision framework for new platforms.
8. What’s Real
The honest one-paragraph description
Quint is a working edge daemon for macOS that intercepts AI agent LLM traffic, observes agent behavior through Endpoint Security and Network Extension, compiles each turn’s stated intent into an enforceable scope and checks every tool call against it deterministically in microseconds (with a per-agent behavioral layer running in shadow), and streams events to a cloud pipeline with proper multi-tenant isolation. The two layers that make the pitch most compelling — intent-vs-truth divergence detection and the fleet-trained intent model (QIM) — are specified, designed, and partially implemented, with the architectural foundations proven. What’s built is genuinely well-engineered. What’s ahead is a data problem, not an architecture problem.Tech Stack
Interactive Architecture Demo
Animated, interactive visualization of the full architecture — flow matrices, behavioral envelopes, scoring pipeline particles, intent-vs-truth correlation, and threat signature matching. Built for live walkthroughs.