# CTlogs.io

**Canonical:** https://apis.io/providers/ctlogs-io/  
**Website:** https://ctlogs.io/  
**APIs profiled:** 1

CTlogs.io is a Certificate Transparency search service operated by Lyalpha GmbH (Düsseldorf, Germany; HRB 106435, Amtsgericht Düsseldorf). It indexes publicly-trusted TLS certificates from major CT logs and offers structured search by exact hostname or SHA-256 fingerprint (issuer, validity window, names on the certificate), a live check of the certificate a host serves right now, and CA certificate lookups. It provides a subscription REST API at https://api.ctlogs.io authenticated with an X-API-Key header, an MCP server at https://mcp.ctlogs.io/mcp, and free single-purpose web tools. It comes from the same team as DomainKits.

## Kin Score — 52.7 / 100 (developing)

Scored 2026-11-13 under rubric 0.28.0.

| Facet | Score |
|---|---|
| Discoverability | 65.0 |
| Contract Quality | 59.8 |
| Contract Governance | 22.0 |
| Operational Transparency | 33.3 |
| Developer Ergonomics | 42.3 |
| Access Clarity | 76.6 |

Regulatory layer — **Horizontal (data, software, accessibility, platform)**: 18.6 (matched via fallback).

## Agent readiness — 52.0 (agent-native)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | na |
| MCP Server | documented |
| Auth Clarity | served |
| Idempotency | na |
| Error Semantics | documented |
| OpenAPI Examples | no |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | derived |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | na |
| Delegated Identity | served |
| Protected Resource Metadata | verified |
| Dynamic Client Registration | yes |
| Agentic Commerce | no |
| Pagination Ratio | paginated |
| Operation Distinctiveness | na |
| MCP Tool Quality | na |

## Access

Paid — onboarding: unknown, pricing: paid, trial: no (confidence: high).

## APIs (6)

- **CTlogs.io MCP Connector** — Remote MCP connector exposing read-only Certificate Transparency lookup tools to AI assistants, as advertised on ctlogs.io.
- **CTlogs.io Certs API** — The Certs API from CTlogs.io — 1 operation(s) for certs.
- **CTlogs.io Me API** — The Me API from CTlogs.io — 1 operation(s) for me.
- **CTlogs.io Search API** — The Search API from CTlogs.io — 1 operation(s) for search.
- **CTlogs.io Stats API** — The Stats API from CTlogs.io — 1 operation(s) for stats.
- **CTlogs.io Subdomains API** — The Subdomains API from CTlogs.io — 1 operation(s) for subdomains.

## MCP servers (1)

- **CTlogs.io MCP Connector** — Official remote MCP connector from CTlogs.io (Lyalpha GmbH) giving AI assistants read-only Certificate Transparency lookups over the same index as the CTlogs.io site and API. St...

## Agentic access (1)

- **CTlogs.io Agentic Access** — 5 operations

## Security (2)

- **CTlogs.io Authentication** — apiKey · 2 schemes
- **CTlogs.io Domain Security** — TLSv1.3 · HSTS · DMARC

## Plans (1)

- **CTlogs.io Plans Pricing**

## Tags

Company, Certificate Transparency, TLS Certificates, SSL, Security, PKI, Domains, MCP

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/ctlogs-io/). Scores are computed from the provider's own public artifacts under a published rubric.