Cometh

Cometh is a French DeFi infrastructure provider building regulated, API-first crypto financial services for European fintechs, asset managers and corporates — custody, staking and yield, digital-asset trading, and payment settlement — on a composable ERC-4337 / Safe smart-account stack inside a MiCA-aligned regulatory perimeter (registered DASP; CASP licence AMF No. A2025-008; ISO 27001:2022). The publicly documented and callable surface today is Cometh Connect, a white-label ERC-4337 smart-wallet SDK with passkey (WebAuthn) signers, ERC-7579 session keys, social recovery and gasless transactions, served by an ERC-4337 Bundler JSON-RPC, a Paymaster JSON-RPC with sponsorship REST routes, and the Connect backend API. Every endpoint is gated at a Kong gateway by a project apikey (query string, front end) or apisecret (header, back end) issued from the app.cometh.io dashboard. The broader "DeFi-as-a-Service" API layer is sales-gated and its documentation is marked coming soon. Cometh was acquired by crypto market-data provider Kaiko, announced December 2025.

Cometh is listed with 3 APIs on the APIs.io network. Tagged areas include Company, Blockchain, Account Abstraction, ERC-4337, and Smart Wallet.

Cometh’s developer surface includes documentation, API reference, getting-started guide, signup flow, YouTube channel, authentication, sandbox, and 17 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

30.1/100 thin ▬ flat Agent 5/100 human only Front door AI 1/6 silent Heartbeat 26/100 dormant saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

3 APIs

Company Blockchain Account Abstraction ERC-4337 Smart Wallet Paymaster Bundler Passkeys WebAuthn Gasless Transactions DeFi Custody Staking Payments JSON-RPC MiCA SAFe Web3

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 30.1/100 · thin

Contract Quality 0.0 / 21

Developer Ergonomics 10.9 / 17

Access Clarity 4.9 / 17

Operational Transparency 1.2 / 11

Contract Governance 1.9 / 10

Discoverability 6.7 / 9

Regulatory Posture 2.9 / 15

Agent readiness — 5/100 · human only

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 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

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Payments regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

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.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

Machine-Readable Contract +18 pts — api_specs includes an OpenAPI document
MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0

11 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 0.0 — up to +25.0 composite points
Access Clarity scores 28.9 — up to +14.2 composite points
Operational Transparency scores 10.5 — up to +11.6 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/cometh/apis.yml: open an issue on github.com/api-evangelist/cometh to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
France Authorised Financial Firms (ACPR REGAFI + AMF white list)	mixed	48.6	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Standards implemented 2

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

JSON RPC

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

WebAuthn

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

APIs 3

Individual APIs this provider publishes, each with its own machine-readable definition.

Cometh Connect Bundler API

ERC-4337 bundler JSON-RPC endpoint. Accepts User Operations into the mempool, estimates UserOp gas, returns a UserOp and its receipt by hash, and lists supported EntryPoint addr...

Cometh Connect Paymaster API

ERC-4337 paymaster JSON-RPC endpoint for transaction sponsorship (pm_sponsorUserOperation, pm_supportedEntryPoints) plus REST routes to read and register the sponsored contract ...

Cometh Connect API

Connect backend API used by the Connect 4337 SDK for wallet lifecycle and recovery — wallet init and import, WebAuthn signer creation and address prediction, project parameters,...

Cometh API pricing

Pricing Plans 1

Published pricing tiers and plan structures.

Cometh Plans Pricing

0 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Cometh Rate Limits

0 limits

RATE LIMITS

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

Cometh

SLA

Security Posture 3

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

Cometh Authentication

apiKey · 2 schemes

SECURITY

Cometh Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Cometh Trust Center

ISO/IEC 27001:2022, MiCA / CASP licence, AMF No. A2025-008 (granted December 2025), Registered DASP (Digital Asset Service Provider)

SECURITY

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal

GettingStarted

SignUp

Sandbox

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt

LLMsTxt

Design & Contract 3

Pagination, idempotency, versioning, errors, and events

Conventions

Conventions

Conformance

Conformance

Lifecycle

Lifecycle

Build 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Packages

Packages

SDKs

SDKs

Access & Security 4

Authentication, authorization, and security posture

DomainSecurity

TrustCenter

Compliance

Authentication

Learn 1

Tutorials, courses, talks, and written guidance

YouTube

YouTube

Operate 2

Status, limits, changes, and where to get help

StatusPage

StatusPage

RateLimits

RateLimits

Commercial 1

Pricing, plans, and the legal terms of use

Plans

Plans

Company 3

The organization behind the API

Website

Website

Twitter

Twitter

LinkedIn

Source (apis.yml)

aid: cometh
name: Cometh
description: Cometh is a French DeFi infrastructure provider building regulated, API-first crypto financial services for European
  fintechs, asset managers and corporates — custody, staking and yield, digital-asset trading, and payment settlement — on
  a composable ERC-4337 / Safe smart-account stack inside a MiCA-aligned regulatory perimeter (registered DASP; CASP licence
  AMF No. A2025-008; ISO 27001:2022). The publicly documented and callable surface today is Cometh Connect, a white-label
  ERC-4337 smart-wallet SDK with passkey (WebAuthn) signers, ERC-7579 session keys, social recovery and gasless transactions,
  served by an ERC-4337 Bundler JSON-RPC, a Paymaster JSON-RPC with sponsorship REST routes, and the Connect backend API.
  Every endpoint is gated at a Kong gateway by a project apikey (query string, front end) or apisecret (header, back end)
  issued from the app.cometh.io dashboard. The broader "DeFi-as-a-Service" API layer is sales-gated and its documentation
  is marked coming soon. Cometh was acquired by crypto market-data provider Kaiko, announced December 2025.
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - rate-limits
  - security
  - sandbox
  generated: '2026-11-06'
  method: derived
image: https://framerusercontent.com/images/Q1Csh4cl9JXyPBmGbxE2xtSPpFE.png
url: https://raw.githubusercontent.com/api-evangelist/cometh/refs/heads/main/apis.yml
x-type: company
x-source: serena-portfolio
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.23'
created: '2026-08-17'
modified: '2026-08-17'
x-docs-platform: gitbook
x-docs-platform-confidence: high
x-docs-platform-checked: 2026-09-24
tags:
- Company
- Blockchain
- Account Abstraction
- ERC-4337
- Smart Wallet
- Paymaster
- Bundler
- Passkeys
- WebAuthn
- Gasless Transactions
- DeFi
- Custody
- Staking
- Payments
- JSON-RPC
- MiCA
- SAFe
- Web3
tags_raw:
- Company
- Blockchain
- account-abstraction
- erc-4337
- smart-wallet
- paymaster
- bundler
- passkeys
- webauthn
- gasless-transactions
- defi
- custody
- staking
- payments
- json-rpc
- mica
- safe
- web3
apis:
- name: Cometh Connect Bundler API
  description: ERC-4337 bundler JSON-RPC endpoint. Accepts User Operations into the mempool, estimates UserOp gas, returns
    a UserOp and its receipt by hash, and lists supported EntryPoint addresses. One endpoint per EVM chain, addressed by chain
    id in the path, authenticated with a project apikey in the query string.
  humanURL: https://docs.cometh.io/bundler/bundler-api
  baseURL: https://bundler.cometh.io/{chainId}
  tags:
  - ERC-4337
  - Bundler
  - Account Abstraction
  - JSON-RPC
  - Blockchain
  tags_raw:
  - erc-4337
  - bundler
  - account-abstraction
  - json-rpc
  - blockchain
  properties:
  - type: Documentation
    url: https://docs.cometh.io/bundler/bundler-api
  - type: APIReference
    url: https://docs.cometh.io/bundler/bundler-api
  - type: Authentication
    url: authentication/cometh-authentication.yml
  - type: Conventions
    url: conventions/cometh-conventions.yml
- name: Cometh Connect Paymaster API
  description: ERC-4337 paymaster JSON-RPC endpoint for transaction sponsorship (pm_sponsorUserOperation, pm_supportedEntryPoints)
    plus REST routes to read and register the sponsored contract addresses and sponsored chains of a project. Chain id in
    the path; reads use a project apikey in the query string, writes use an apisecret from the back end.
  humanURL: https://docs.cometh.io/paymaster/paymaster-api
  baseURL: https://paymaster.cometh.io/{chainId}
  tags:
  - ERC-4337
  - Paymaster
  - Gasless Transactions
  - JSON-RPC
  - Blockchain
  tags_raw:
  - erc-4337
  - paymaster
  - gasless-transactions
  - json-rpc
  - blockchain
  properties:
  - type: Documentation
    url: https://docs.cometh.io/paymaster/paymaster-api
  - type: APIReference
    url: https://docs.cometh.io/paymaster/paymaster-api
  - type: Authentication
    url: authentication/cometh-authentication.yml
- name: Cometh Connect API
  description: Connect backend API used by the Connect 4337 SDK for wallet lifecycle and recovery — wallet init and import,
    WebAuthn signer creation and address prediction, project parameters, relayed transaction status, and the social recovery
    flow (start, start-with-shared, finalize). Recovery routes are apisecret-protected and documented as server-to-server
    calls.
  humanURL: https://docs.cometh.io/advanced/social-recovery
  baseURL: https://api.4337.cometh.io
  tags:
  - Smart Wallet
  - Account Abstraction
  - Passkeys
  - WebAuthn
  - social-recovery
  tags_raw:
  - smart-wallet
  - account-abstraction
  - passkeys
  - webauthn
  - social-recovery
  properties:
  - type: Documentation
    url: https://docs.cometh.io/advanced/social-recovery
  - type: Authentication
    url: authentication/cometh-authentication.yml
  - type: Sandbox
    url: sandbox/cometh-sandbox.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: DomainSecurity
  url: security/cometh-domain-security.yml
- type: Website
  url: https://www.cometh.io/
- type: Documentation
  url: https://docs.cometh.io/
- type: DeveloperPortal
  url: https://app.cometh.io/
- type: APIReference
  url: https://docs.cometh.io/bundler/bundler-api
- type: GettingStarted
  url: https://docs.cometh.io/quick-start/getting-started
- type: SignUp
  url: https://app.cometh.io/register?product=connect
- type: GitHubOrganization
  url: https://github.com/cometh-hq
- type: StatusPage
  url: https://status.cometh.io/
- type: TrustCenter
  url: https://security.cometh.io/
- type: Compliance
  url: https://security.cometh.io/
- type: Twitter
  url: https://x.com/Cometh
- type: LinkedIn
  url: https://www.linkedin.com/company/comethstudio
- type: YouTube
  url: https://www.youtube.com/@comethio
- type: LLMsTxt
  url: llms/cometh-llms.txt
- type: Packages
  url: packages/cometh-packages.yml
- type: SDKs
  url: packages/cometh-packages.yml
- type: Authentication
  url: authentication/cometh-authentication.yml
- type: Conventions
  url: conventions/cometh-conventions.yml
- type: Conformance
  url: conformance/cometh-conformance.yml
- type: Lifecycle
  url: lifecycle/cometh-lifecycle.yml
- type: Sandbox
  url: sandbox/cometh-sandbox.yml
- type: Plans
  url: plans/cometh-plans-pricing.yml
- type: RateLimits
  url: rate-limits/cometh-rate-limits.yml
x-enrichment:
  date: '2026-08-17'
  status: enriched
  artifacts_added: 13
  pass: local-v1

Cometh API — frequently asked questions

Does Cometh have an API?

Yes. APIs.io lists 3 APIs from Cometh, including Cometh Connect Bundler API, Cometh Connect Paymaster API and Cometh Connect API.

How do I authenticate with the Cometh API?

Cometh uses bearer-token authentication (apiKey · 2 schemes). The details are profiled on APIs.io as Cometh Authentication.

Is the Cometh API ready for AI agents?

Cometh has a Kin Score of 30.1 out of 100 (thin) and an Agent Readiness score of 5.0 (human-only), scored by API Evangelist on 2026-11-06.

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