# auth.sigmaidentity.com

> Probe-verified (tier 2 of 3). Last checked 2026-08-23. 2 of 5 capability checks passed.

- host: auth.sigmaidentity.com
- url: https://auth.sigmaidentity.com/
- category: oauth 2.1 provider
- type: saas
- language: en

## Probe-verified · tier 2 of 3

Probed live on 2026-08-23 against rubric v1. 2 of 5 checks passed.

- PASS — Markdown negotiation
- fail — Markdown twin at a predictable URL
- fail — llms.txt
- PASS — API catalog
- fail — MCP server answers

## Unverified actions

Read from the page's own content, with the wording each was drawn from. Inference is kept separate from tested facts; an agent completing the action is tier 3.

- **query_api** — "OpenAPI schema" → `https://auth.sigmaidentity.com/api/auth/open-api/generate-schema`
- **register** — "POST https://auth.sigmaidentity.com/api/auth/oauth2/register to create a client programmatically" → `https://auth.sigmaidentity.com/api/auth/oauth2/register`

## Summary

Sigma Identity provides an OAuth 2.1 and OpenID Connect authorization server using Bitcoin identity keys for user authentication.

## Context

2006 sites in this index share the type "saas"; 1410 are transactional.

## How we grade

- tier 1 — **Declared**: The site says agents are welcome in its robots.txt. A permission, not a capability.
- tier 2 — **Probe-verified** (this site): We fetched the site and tested each signal ourselves. Dated, repeatable, re-checked on a schedule.
- tier 3 — **Behaviourally verified**: An agent completed the action end to end — booked, bought, submitted — and it worked.

## About this record

Known-Good probes sites live and publishes what was tested and when.
Method: https://knowngood.sh/about.md · Rubric: https://knowngood.sh/benchmark