BCID interoperability

How Building Culture Identity works alongside ENS, .culture, EAS, World ID, and ERC-8004 — without breaking existing production systems.

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Principles

1. No breaking changes — .culture mint, credentials, and Culture Reputation stay live
2. Opt-in bridge — users choose when to mint Human BCID
3. Credential portability — earned credentials map 1:1 where categories align
4. Complement, don't compete — cite partner standards in all external docs
5. Single wallet owner — bridge requires the same EVM address owns both tokens

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Identity mapping

Live (Culture ID)	BCID v1 equivalent
.culture NFT (transferable)	Human BCID (soulbound) — linked, not replaced
CultureIdentity Postgres row	BcidIdentity + BcidBridgeLink
UserCredential (6 types)	BcidCredential (extended catalog)
computeCultureScore()	computeBcidReputation() (4 scores)
Member.farcasterFid	BcidLinkedAccount platform=farcaster

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ENS

• ENS name stored as linked account + optional resolver text record bcid=<did>
• BCID does not replace .eth — link for human-readable resolution
• Reverse resolution pattern for profile discovery

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EAS (Ethereum Attestation Service)

• BCID credentials map to EAS-compatible schemas on Base
• High-trust credentials can anchor easAttestationUid on BcidCredential
• Third-party issuers use published schema UIDs — see EAS schema pack
• EAS handles attestations; BCID handles identity namespace + dynamic reputation

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World ID / Gitcoin Passport

• Optional linked proof for sybil resistance — not required for mint
• Verification Score incorporates human-proof signals at configurable weight
• No Orb or stamp data stored on-chain in v1

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ERC-8004 (agent registry)

• Agent BCID binds wallet + reputation + revenue split
• Agent card links did:bcid:agent:* for discoverability
• BUILDCHAIN Agent ID on 0G Chain interoperates via agent-card metadata

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Bridge flow (.culture → BCID)

User → POST /api/bcid/bridge/culture (SIWE)
     → Verify wallet owns cultureTokenId
     → Mint Human BCID (or link existing)
     → Copy eligible UserCredentials → BcidCredential
     → Seed Contribution Score from Culture history

Response example:

{
  "ok": true,
  "did": "did:bcid:human:abc123",
  "cultureHandle": "alice.culture",
  "credentialsMigrated": 3,
  "contributionScoreSeed": 12.5
}

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Credential mapping

Culture credential	BCID credential	Auto-migrate
builder	bcid-builder	Yes
contributor	bcid-contributor	Yes
community-leader	bcid-community-leader	Yes
verified-human	bcid-verified-human	Yes
verified-project	bcid-verified-project	Yes

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Dual-identity period

During the parallel rollout, Culture Reputation events feed BCID scores at reduced weight:

Culture dimension	BCID score	Weight
Credentials	Trust Score	0.5×
Contributions	Contribution Score	0.5×
Social trust	Excluded	0×
Human verification	Verification Score	1.0×

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APIs

Endpoint	Purpose
GET /api/bcid/resolve?did=	Resolve DID to public profile
GET /api/bcid/by-culture?handle=	Lookup BCID by .culture handle
POST /api/bcid/bridge/culture	Bridge .culture → Human BCID
GET /api/bcid/catalog	Credential type catalog
GET /api/bcid/scores?did=	Reputation scores

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For DAO integrators

Use BCID as applicant identity in grant forms and Snapshot/Guild gates:

1. Require did:bcid:human:* or bcid-builder credential
2. Verify via /api/bcid/resolve — no custom indexer required for v1
3. Issue dao-member credential back to contributors (pilot)

Partnership: hello@buildingcultureid.space · DAO brief