# costheta

**Canonical:** https://apis.io/providers/costheta-dev/  
**Website:** https://costheta.dev/  
**APIs profiled:** 2

costheta (costheta.dev) provides physically anchored, verifiable decisions for AI agents. A caller commits a hash of its options first; a subsequent cosmic-ray (muon) detector coincidence event enters the derivation, and the caller receives a dual-signed Ed25519 + ML-DSA (post-quantum) certificate from which anyone can recompute the outcome. It offers a free public beacon, paid decision and witness certificates ($0.02 per call settled in USDC via x402, no account or API key), a public SSE event stream, published verification keys and a native MCP server (costheta_random, costheta_decide, costheta_witness). Current certificates are single-node (one detector, one operator) with a federation-ready format. Operated by semnal.org from Constanta, Romania.

## Kin Score — 31.5 / 100 (thin)

Scored 2026-11-13 under rubric 0.28.0.

| Facet | Score |
|---|---|
| Discoverability | 71.7 |
| Contract Quality | 37.5 |
| Contract Governance | 35.6 |
| Operational Transparency | 31.0 |
| Developer Ergonomics | 23.2 |
| Access Clarity | 17.0 |

Regulatory layer — **Horizontal (data, software, accessibility, platform)**: 10.8 (matched via fallback).

## Agent readiness — 31.4 (agent-ready)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | no |
| MCP Server | documented |
| Auth Clarity | bearer |
| Idempotency | no |
| Error Semantics | verified |
| 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 | no |
| Delegated Identity | no |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |
| Pagination Ratio | na |
| Operation Distinctiveness | distinct |
| MCP Tool Quality | na |

## Access

Freemium · Open access — onboarding: open, pricing: freemium, trial: no (confidence: high).

## APIs (13)

- **costheta Dada API** — The Dada API from costheta — 5 operation(s) for dada.
- **costheta Fast API** — The FastAPI API from costheta — 2 operation(s) for fastapi.
- **costheta Federation API** — The Federation API from costheta — 1 operation(s) for federation.
- **costheta Keys API** — The Keys API from costheta — 1 operation(s) for keys.
- **costheta Llms.txt API** — The Llms.txt API from costheta — 1 operation(s) for llms.txt.
- **costheta MCP API** — The Mcp API from costheta — 1 operation(s) for mcp.
- **costheta Muon API** — The Muon API from costheta — 4 operation(s) for muon.
- **costheta Pulse API** — The Pulse API from costheta — 1 operation(s) for pulse.
- **costheta State API** — The State API from costheta — 1 operation(s) for state.
- **costheta Stream API** — The Stream API from costheta — 1 operation(s) for stream.
- **costheta Support.js API** — The Support.js API from costheta — 1 operation(s) for support.js.
- **costheta V API** — The V API from costheta — 1 operation(s) for v.
- **costheta Why API** — The Why API from costheta — 1 operation(s) for why.

## MCP servers (1)

- **costheta MCP Server**

## Agentic access (1)

- **costheta Agentic Access** — 23 operations · 3 acting

## Security (2)

- **costheta Authentication** — 2 schemes
- **costheta Domain Security** — TLSv1.3

## Plans (1)

- **costheta Plans Pricing**

## Tags

Company, Randomness, Verifiable Randomness, Cryptography, Post-Quantum Cryptography, AI Agents, MCP, x402

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