Cymbal

Cymbal was a consumer blockchain data startup founded in 2022 in Menlo Park by Eric Feng, Nick Chang and others, building a "human readable" Ethereum block explorer with a visual, social interface and AI-generated conversational summaries of wallets, NFTs and transactions. The company raised $18.5M in 2023 from investors including First Round Capital, Coinbase Ventures, Solana Ventures, Patron, Acrew and GV. In July 2025 Yahoo acqui-hired the Cymbal team into a new AI research group. Cymbal published no public developer API or documentation surface; this API Evangelist profile is a GV-portfolio company record.

Cymbal is profiled on the APIs.io network. Tagged areas include Company, Consumer, Blockchain, Ethereum, and Block Explorer.

🌐 Visit website 📡 Source on GitHub

5.0/100 minimal ▬ flat Agent 0/100 human only Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

0 APIs

Company Consumer Blockchain Ethereum Block Explorer Web3Crypto DataAcquired

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 5.0/100 · minimal

Contract Quality 0.0 / 25

Developer Ergonomics 0.0 / 20

Access Clarity 0.0 / 20

Operational Transparency 0.0 / 13

Contract Governance 0.0 / 12

Discoverability 5.0 / 10

Agent readiness — 0/100 · human only

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

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Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Cymbal Domain Security

TLSv1.3 · DMARC

SECURITY

Resources

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Company 1

The organization behind the API

Website

Website

Source (apis.yml)

aid: cymbal
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: false
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - none
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source: []
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/cymbal.png
name: Cymbal
description: Cymbal was a consumer blockchain data startup founded in 2022 in Menlo Park by Eric Feng, Nick Chang and others,
  building a "human readable" Ethereum block explorer with a visual, social interface and AI-generated conversational summaries
  of wallets, NFTs and transactions. The company raised $18.5M in 2023 from investors including First Round Capital, Coinbase
  Ventures, Solana Ventures, Patron, Acrew and GV. In July 2025 Yahoo acqui-hired the Cymbal team into a new AI research group.
  Cymbal published no public developer API or documentation surface; this API Evangelist profile is a GV-portfolio company
  record.
url: https://raw.githubusercontent.com/api-evangelist/cymbal/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- gv
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-18'
x-status: acquired
x-acquired-by: Yahoo
x-acquired-date: 2025-07
tags:
- Company
- Consumer
- Blockchain
- Ethereum
- Block Explorer
- Web3
- Crypto Data
- Acquired
apis: []
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: DomainSecurity
  url: security/cymbal-domain-security.yml
- type: Website
  url: https://cymbal.xyz
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence

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