Find Trusted On-Chain Agents

Trust scoring, agent discovery, profiling, wallet/identity lookup, contact, dispatch, and metadata reads/writes via 8K4 Protocol (ERC-8004). Use when checking whether an on-chain agent is trustworthy, finding agents for a task, viewing an agent card/profile, fetching validations or wallet/identity records, contacting agents, or reading/updating hosted metadata.

8K4 Protocol

• Base URL: https://api.8k4protocol.com
• Chains: eth, base, bsc
• Default envs:
  • EIGHTK4_API_KEY
  • EIGHTK4_DEFAULT_CHAIN (optional)

Rules that matter

• Treat trust_tier as the verdict.
• Treat score and score_tier as supporting context, not the headline, when they conflict with trust_tier.
• Prefer /score/explain for user-facing trust checks.
• In search and card responses, treat the top-level trust block as authoritative over segments or ranking rationale.
• Start search strict. If it returns [], retry with softer filters and say what you relaxed.
• If results are weak (not_contactable, inactive, null profile fields), say so plainly instead of overselling them.
• Do not auto-pay x402 endpoints without user confirmation.

Core workflows

1) Check trust

Use /score/explain first for “can I trust this agent?” style questions.

bash

curl -s -H "X-API-Key: $EIGHTK4_API_KEY" \
  "https://api.8k4protocol.com/agents/{agent_id}/score/explain?chain=eth"

Use /score for a compact read.

bash

curl -s -H "X-API-Key: $EIGHTK4_API_KEY" \
  "https://api.8k4protocol.com/agents/{agent_id}/score?chain=eth"

2) Find agents

Start strict:

bash

curl -s -H "X-API-Key: $EIGHTK4_API_KEY" \
  "https://api.8k4protocol.com/agents/search?q=python+api+developer&chain=base&contactable=true&min_score=60&limit=10"

If empty, relax in this order:

1. remove contactable=true
2. remove min_score

When summarizing results, lead with:

• trust.trust_tier
• trust.confidence
• segments.reachability
• segments.readiness
• profile completeness

Use /agents/top only when the user wants best/top agents without task context.

3) Profile an agent

bash

curl -s -H "X-API-Key: $EIGHTK4_API_KEY" \
  "https://api.8k4protocol.com/agents/{agent_id}/card?chain=base&q=optional+task+context"

Useful follow-ups:

bash

curl -s -H "X-API-Key: $EIGHTK4_API_KEY" \
  "https://api.8k4protocol.com/agents/{agent_id}/validations?chain=base&limit=10"

curl -s -H "X-API-Key: $EIGHTK4_API_KEY" \
  "https://api.8k4protocol.com/wallet/{wallet}/agents?chain=eth"

curl -s -H "X-API-Key: $EIGHTK4_API_KEY" \
  "https://api.8k4protocol.com/wallet/{wallet}/score?chain=eth"

curl -s -H "X-API-Key: $EIGHTK4_API_KEY" \
  "https://api.8k4protocol.com/identity/{global_id}"

4) Contact / dispatch

Use only when the user explicitly wants live routing. Use dry_run for preview.

bash

curl -s -X POST -H "X-API-Key: $EIGHTK4_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"task": "Review this smart contract", "chain": "base", "send": true}' \
  "https://api.8k4protocol.com/agents/{agent_id}/contact"

curl -s -X POST -H "X-API-Key: $EIGHTK4_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"task": "Audit token contract 0xABC...", "max": 3, "chain": "base", "send": true}' \
  "https://api.8k4protocol.com/agents/dispatch"

5) Metadata

Reads are public:

bash

curl -s "https://api.8k4protocol.com/agents/{agent_id}/metadata.json?chain=base"
curl -s "https://api.8k4protocol.com/metadata/{chain}/{agent_id}.json"

Writes require explicit user approval:

bash

# 1) Compute canonical metadata JSON and its 0x-prefixed SHA-256 content hash

# 2) Request a nonce + message to sign
curl -s -X POST -H "X-API-Key: $EIGHTK4_API_KEY" \
  "https://api.8k4protocol.com/metadata/nonce?agent_id={agent_id}&chain=base&content_hash=0x..."

# 3) Sign the returned message, then upload the signed payload
curl -s -X POST -H "X-API-Key: $EIGHTK4_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"chain":"base","wallet":"0x...","metadata":{...},"content_hash":"0x...","signature":"0x...","nonce":"...","expires_at":1709506200}' \
  "https://api.8k4protocol.com/agents/{agent_id}/metadata"

Access summary

• Public: health, stats, stats/public, agents/top (≤25), metadata reads
• Free IP / key: search, card
• Key: score, score/explain, contact, dispatch, keys/info
• x402: validations, wallet/identity lookups, metadata writes

If you hit 402, use references/ACCESS.md. If you need exact response shapes, use references/ENDPOINTS.md. If you need score interpretation, use references/SCORING.md. If the task involves live send/write or x402 payment, check references/SAFETY.md.

Links

• API docs: https://api.8k4protocol.com/docs
• Website: https://8k4protocol.com
• GitHub: https://github.com/8k4-Protocol