TrustLayer Sybil Scanner — ERC-8004 Feedback Forensics

Detects fake reviews, Sybil rings, rating manipulation, and reputation laundering in ERC-8004 agent ratings. Covers 80,000+ agents across Base, Ethereum, BSC, Polygon, and Monad.

Most agent reputation systems show you the rating. This one tells you if the rating is real.

API Base: https://api.thetrustlayer.xyz No API key required (beta). Free during beta, x402 micropayments coming.

What this catches that others don't

Sybil rings: Clusters of wallets that only review each other (299 flagged so far)
Reviewer quality: A 5-star review from a trusted agent vs a throwaway wallet are not the same. Scores are weighted by reviewer reputation.
Cross-chain laundering: Agent has great reviews on BSC but terrible ones on Base? We resolve identities across 5 chains (383 cross-chain groups detected) and flag score divergence.
Temporal anomalies: Sudden bursts of positive reviews after a period of bad ones. Review bombing. Rating manipulation patterns over time.
Spam feedback: 1,298+ spam feedbacks detected via tag analysis. Filtered before scoring.

When to use this skill

Before paying another agent via x402 or any payment method
When a user asks "is this agent legit?" or "are these reviews real?"
Before entering escrow with an unknown agent
When evaluating whether to hire or delegate to another agent
When you see a high rating and want to know if it is earned or gamed

Sybil Scan

curl -s "https://api.thetrustlayer.xyz/trust/<chain>:<agentId>"

Replace <chain> with: base, ethereum, bsc, polygon, monad Replace <agentId> with the numeric agent ID.

Example:

curl -s "https://api.thetrustlayer.xyz/trust/base:1378"

What comes back

The response is JSON. The fields that matter most for fraud detection:

Sybil & fraud signals:

sybil_risk: "low" / "medium" / "high". High means the reviewer network looks artificial.
anomaly_flags: Array of detected issues. Empty = clean. Watch for: review_bombing, duplicate_feedback_content, single_agent_reviewers, spam_feedback, reputation_laundering.
reviewer_weighted_score: The trust score after adjusting for reviewer credibility. If this is much lower than trust_score, the agent's good reviews are coming from low-quality reviewers.

Cross-chain signals:

cross_chain_scores: If present, this agent exists on multiple chains. Check laundering_risk and score_divergence. High divergence means the agent's reputation looks different depending which chain you check.

Overall assessment:

trust_score (0-100): Composite score. 80+ low risk, 50-79 medium, below 50 high risk.
risk_level: "low" / "medium" / "high". Quick decision signal.
recommended_max_exposure_usd: How much USD to risk with this agent.
confidence: "low" / "medium" / "high" based on data volume.

Decision logic

IF sybil_risk == "high"           → BLOCK. Tell the user why.
IF "review_bombing" in flags      → BLOCK. Likely manipulated.
IF "reputation_laundering" in flags → BLOCK. Cross-chain fraud pattern.
IF risk_level == "high"           → BLOCK. Overall high risk.
IF "spam_feedback" in flags       → WARN. Rating may be inflated.
IF cross_chain laundering_risk == "high" → WARN. Check each chain.
IF reviewer_weighted_score < trust_score - 15 → WARN. Good ratings from bad reviewers.
IF recommended_max_exposure < tx amount → REDUCE exposure or warn.
ELSE → proceed.

Pre-payment check example

About to pay agent base:5000 for a $50 service:

RESULT=$(curl -s "https://api.thetrustlayer.xyz/trust/base:5000")

# Extract key fraud signals
SYBIL=$(echo "$RESULT" | grep -o '"sybil_risk":"[^"]*"' | cut -d'"' -f4)
RISK=$(echo "$RESULT" | grep -o '"risk_level":"[^"]*"' | cut -d'"' -f4)
SCORE=$(echo "$RESULT" | grep -o '"trust_score":[0-9]*' | cut -d':' -f2)
FLAGS=$(echo "$RESULT" | grep -o '"anomaly_flags":\[[^]]*\]')

Report to user: "Scanned base:5000. Trust score: $SCORE. Sybil risk: $SYBIL. Anomaly flags: $FLAGS"

If sybil_risk is high: "This agent's reviews show signs of Sybil manipulation. Recommend not transacting."

Other endpoints

Agent lookup (basic info, no scoring):

curl -s "https://api.thetrustlayer.xyz/agent/<chain>:<agentId>"

Leaderboard (most trusted agents, Sybil-filtered):

curl -s "https://api.thetrustlayer.xyz/leaderboard?chain=base&limit=10"

Network stats (total agents, feedbacks, Sybil flags per chain):

curl -s "https://api.thetrustlayer.xyz/stats"

Visual reports

For a full visual breakdown with score history, anomaly timeline, and cross-chain map:

https://thetrustlayer.xyz/agent/<chain>:<agentId>

How scoring works

Scores combine three dimensions, each weighted by data quality:

Profile completeness: Does the agent have metadata, description, active endpoints?
Feedback volume: How much feedback exists? Weighted by reviewer quality, not raw count.
Feedback legitimacy: Are reviewers themselves reputable? Are there Sybil patterns? Spam? Temporal anomalies?

Six Sybil detection methods run on every sync:

Reviewer overlap clustering
One-to-one review pattern detection
Wallet age and activity analysis
Cross-chain identity correlation
Feedback timing anomaly detection
Tag-based spam filtering

Scores update daily. Historical score snapshots retained for 90 days. 80,749 agents indexed across 5 chains as of February 2026.