ERC-8004 agent trust score lookup via x402 micropayment on Base
What it does
This endpoint returns the trust score for a specific ERC-8004 registered AI agent (agent ID 21480) from the 8k4 Protocol Trust API ("The Oracle"). It is a read-only GET endpoint that accepts an agent ID as a path parameter and an optional chain query parameter (bsc, base, or eth; defaults to bsc). The response is a `ScorePublicResponse` object containing the agent's numeric score, score tier, trust tier, confidence level, adjustment flags, validator count bucket, and a timestamp.
The 8k4 Protocol API is a comprehensive agent trust and identity system built around the ERC-8004 standard. Beyond individual score lookups, the broader API offers score explanations, agent search, agent cards, validation history, wallet-level scores, metadata management, identity resolution across chains, and dispatch capabilities. Most paid endpoints cost $0.001 per call, settled via the x402 protocol on Base (eip155:8453) through the Coinbase CDP facilitator. Payments are sent to address 0xb273616670037C0870E9835B3FFBE68f58de68B0.
The specific `/agents/21480/score` endpoint returned HTTP 200 on GET during probing (rather than 402), which may indicate this particular agent ID returns data freely or that the x402 payment gate was not triggered during the probe. The OpenAPI spec documents this endpoint as requiring x402 payment at $0.001 per call. The API supports chains including BSC, Base, and Ethereum. API version is 1.2.0.
Capabilities
Use cases
- —Look up the trust score of an ERC-8004 registered AI agent before delegating a task
- —Filter candidate agents by trust tier and confidence level in multi-agent orchestration
- —Audit an agent's trust history and validator feedback before integration
- —Resolve agent identity across BSC, Base, and Ethereum chains
Fit
Best for
- —AI agent orchestration systems that need trust verification
- —Multi-agent frameworks requiring reputation-based agent selection
- —On-chain agent registries needing cross-chain identity resolution
- —Automated pipelines that gate task delegation on trust thresholds
Not for
- —General-purpose web reputation or human identity verification
- —Agents not registered under the ERC-8004 standard
- —Use cases requiring free unlimited queries (paid per call)
Quick start
curl https://api.8k4protocol.com/agents/21480/score?chain=bscExample
Response
{
"as_of": "2025-01-15T12:00:00Z",
"chain": "bsc",
"score": 0.75,
"adjusted": false,
"agent_id": 21480,
"global_id": "8k4:bsc:21480",
"confidence": "medium",
"disclaimer": "Score is informational only.",
"score_tier": "good",
"trust_tier": "trusted",
"score_version": 1,
"adjustment_reasons": [],
"validator_count_bucket": "5-10"
}Endpoint
Quality
Full OpenAPI 3.1 schema with detailed component definitions and clear x-payment-info annotations. The endpoint returned 200 on GET probe rather than the expected 402, which is slightly ambiguous but the spec clearly documents x402 payment. No external documentation was crawlable beyond the API root JSON. Example response values are inferred from the schema, not from an actual captured response.
Warnings
- —Probe returned HTTP 200 on GET instead of expected 402; the x402 payment gate may not have been active for this agent ID or the endpoint may serve some data freely
- —No external documentation site was reachable (https://8k4protocol.com/docs/ referenced but not crawled)
- —Example response field values are synthetic, inferred from the ScorePublicResponse schema
Citations
- —API is titled 'ERC-8004 Trust API' version 1.2.0 described as 'The Oracle - Read-only API for agent trust scores'https://api.8k4protocol.com
- —Score endpoint price is $0.001 via x402 on Base (eip155:8453) with facilitator https://api.cdp.coinbase.com/platform/v2/x402https://api.8k4protocol.com
- —Payment address is 0xb273616670037C0870E9835B3FFBE68f58de68B0https://api.8k4protocol.com
- —Supported chains include bsc, base, and ethhttps://api.8k4protocol.com
- —ScorePublicResponse schema includes agent_id, chain, global_id, score_version, score, score_tier, trust_tier, confidence, adjusted, adjustment_reasons, validator_count_bucket, as_of, disclaimerhttps://api.8k4protocol.com