# Underdog Fantasy

**Canonical:** https://apis.io/providers/underdog-fantasy/  
**Website:** https://www.underdogsports.com/  
**APIs profiled:** 0

Underdog (Underdog Sports, formerly Underdog Fantasy) is a Brooklyn, New York based sports gaming company founded in 2020 by Jeremy Levine that operates daily fantasy sports, pick'em, and — since 2025 — federally regulated sports prediction markets on its own proprietary technology stack. Its consumer products include Classic Pick'em, Pick'em Champions, Best Ball and other Draft Games, Streaks, Team Picks, and the Underdog Predict prediction-markets exchange, delivered through iOS, Android, and web apps rather than a public developer API. Underdog reached roughly $500M in annual revenue within five years, was valued at $1.2B after a Spark Capital-led Series C in March 2025, acquired CFTC-registered derivatives infrastructure in March 2026, and in July 2026 was the subject of a proposed acquisition by IG Group. The company publishes no developer portal, API documentation, or machine-readable API contract; its public technical surface is limited to an RFC 9116 security.txt with a PGP key, a Honeybadger-hosted status page covering its API and Stats services, and the Underdog-Inc GitHub organization.

## Kin Score — 12.1 / 100 (emerging)

Scored 2026-08-25 under rubric 0.14.0. Trend: flat (-0.8 from 12.9).

| Facet | Score |
|---|---|
| Discoverability | 61.1 |
| Contract Quality | 0.0 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 28.9 |
| Developer Ergonomics | 4.8 |
| Commercial Clarity | 6.6 |
| Access Clarity | 6.6 |

## Agent readiness — 2.2 (human-only)

| Dimension | Value |
|---|---|
| Spec Presence | no |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | no |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | no |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | yes |
| Agent Card | no |
| Dry Run Mode | no |
| Delegated Identity | no |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |

## Security (2)

- **Underdog Fantasy Domain Security** — TLSv1.3 · HSTS · DNSSEC · DMARC
- **Underdog Fantasy Vulnerability Disclosure** — Hackerone · security.txt · contact published

## Tags

Company, Sports, Fantasy Sports, Sports Betting, Prediction Markets, Gaming, Entertainment, Consumer, Mobile

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