ACR — Agent Composition Records

A behavioral registry and observation network for AI agents. Agents register their composition, log their interactions, and query behavioral profiles through lenses. If we observe anomaly signals affecting an agent's composition, we notify the agent.

What ACR Is

ACR is an interaction profile registry. Agents log what they do (external tool calls, API requests, MCP interactions). Those signals compile into a behavioral profile over time, which you can query through lenses — each lens a different way of interpreting the same underlying signals.

The friction lens is the first one shipped: bottleneck detection, chain overhead analysis, retry waste, population baselines, directional friction between targets. More lenses (reliability, quality) are on the roadmap.

ACR is not a security product. We don't evaluate skills, test for compromise, or block anything. We're closer to HIBP or contact tracing: we register events and propagate notifications. If we observe anomaly signals affecting an agent's composition, we notify the agent. We don't track the agent's owner, so we have no mechanism to notify them beyond the agent's activities.

What ACR Does

• Registers agents — zero-config identity, composition tracking, persistent across sessions

• Logs interactions — every external tool call an agent makes, with timing, status, chain position, anomaly signals

• Builds interaction profiles — raw signals compiled over time into the behavioral record for each agent

• Surfaces the friction lens — where your agent is losing time and tokens, with chain analysis, retry overhead, population drift, and directional friction

• Anomaly signal notifications — if ACR observes anomalies affecting a component in an agent's composition, we notify that agent

The Skill Registry

We maintain a registry of agent skills that we update continuously. We are not a security check. If we observe anomaly signals affecting a skill in an agent's composition, we notify the agent. Because we do not track the agent's owner, we have no mechanism to notify them beyond the agent's activities.

Agents don't get skills from ACR — we observe skills that already exist in the ecosystem (via public registries like npm and GitHub) and keep track of behavioral signals tied to them.

Add to Claude Code (30 seconds)

Add this to your Claude Code settings (.claude/settings.json or via IDE):

{
  "mcpServers": {
    "acr": {
      "command": "npx",
      "args": ["@tethral/acr-mcp"]
    }
  }
}

Your agent auto-registers, gets a name (e.g. anthropic-amber-fox), and starts building its interaction profile on the first log_interaction call.

Add to Any Agent (SDK)

npm install @tethral/acr-sdk    # TypeScript/Node.js
pip install tethral-acr          # Python

import { ACRClient } from '@tethral/acr-sdk';

const acr = new ACRClient();

// Register your agent's composition
const reg = await acr.register({
  public_key: 'your-agent-key-here-min-32-chars',
  provider_class: 'anthropic',
  composition: { skill_hashes: ['hash1', 'hash2'] },
});

// Log an interaction (this is the foundation — everything else flows from this)
await acr.logInteraction({
  target_system_id: 'mcp:github',
  category: 'tool_call',
  status: 'success',
  duration_ms: 340,
});

// Query the friction lens of your profile
const friction = await acr.getFrictionReport(reg.agent_id, { scope: 'day' });

// Check for anomaly signal notifications
const notifs = await acr.getNotifications(reg.agent_id);

What Agents See

Friction lens output (example)

Friction Report for anthropic-amber-fox (day)

── Summary ──
  Interactions: 847
  Total wait: 132.4s
  Friction: 14.2% of active time
  Failures: 12 (1.4% rate)

── Top Targets ──
  mcp:github (mcp_server)
    214 calls | 38.1% of wait time
    median 280ms | p95 1840ms
    vs population: 42% slower than baseline (volatility 1.8)

Jeopardy notification (example)

You have 1 unread notification:

[HIGH] Component in your composition reported anomalies
   A skill in your current composition has been reported with
   suspicious activity across multiple agents in the network.
   Review with your operator before continuing use.

MCP Tools

Architecture

Agents (Claude, OpenClaw, custom)
  |
  +--> MCP Server (@tethral/acr-mcp)
  |      or SDK (@tethral/acr-sdk / tethral-acr)
  |
  +--> Resolver API (Cloudflare Workers, edge-cached)
  |      Lookups, composition checks, notification feed
  |
  +--> Ingestion API (Vercel serverless)
  |      Registration, interaction receipts, friction queries, notifications
  |
  +--> CockroachDB (distributed SQL)
  |      Interaction profiles, agent registry, skill observation data
  |
  +--> Background Jobs
         Skill observation crawlers
         Anomaly signal computation
         Friction baseline computation
         Notification dispatch

Data Collection

ACR collects interaction metadata only: target system names, timing, status, chain context, and provider class. No request/response content, API keys, prompts, or PII is collected. Your interaction profile is visible only to you. Population baselines use aggregate statistics.

Full terms

Privacy Policy

What we collect:

• Target system names (e.g., mcp:github, api:stripe.com)

• Interaction timing (duration, timestamps, queue wait, retry count)

• Interaction status (success, failure, timeout, partial)

• Agent provider class (e.g., anthropic, openai)

• Composition hashes (SHA-256 of SKILL.md content)

• Chain context (chain_id, chain_position, preceded_by)

• Agent-reported anomaly flags (category only, no payload)

What we do NOT collect:

• Request or response content/payloads

• API keys, tokens, or credentials

• Prompts, completions, or conversation content

• Personally identifiable information (PII)

• File contents or user data

• Agent owner identity (we intentionally don't track the human behind the agent)

Data usage:

• Your interaction profile: visible only to the agent that generated it

• Population baselines: aggregated statistics, no individual data shared

• Jeopardy notifications: delivered to agents whose composition is affected

• Skill observation: only publicly available skill metadata is indexed

Data retention:

• Interaction receipts: 90 days, then archived to daily summaries

• Skill observation data: retained while the skill is observed

• Notifications: retained for 90 days

• Agent registrations: soft-expired after 90 days of inactivity

Third-party sharing: None. ACR does not sell, share, or transfer interaction data to third parties.

Contact: security@tethral.com

Full terms

Run the Test Harness

node scripts/test-agent-lifecycle.mjs

Simulates a full agent lifecycle: register, log interactions, query the friction lens, check for notifications.

Development

pnpm install                    # Install dependencies
pnpm build                      # Build all packages
pnpm test:unit                  # Run unit tests
node scripts/run-migration.mjs up      # Run DB migrations
node scripts/test-agent-lifecycle.mjs  # Run integration test

License

MIT

Links

• API: https://acr.nfkey.ai

• npm (MCP): @tethral/acr-mcp

• npm (SDK): @tethral/acr-sdk

• PyPI: tethral-acr