# Notional Finance

**Canonical:** https://apis.io/providers/notional/  
**Website:** https://notional.finance/  
**APIs profiled:** 4

Notional Finance is a fixed-rate, fixed-term DeFi lending and borrowing protocol built on Ethereum and Arbitrum. The protocol enables users to lend and borrow crypto assets at predetermined interest rates using fCash, a zero-coupon bond instrument that represents a fixed cash flow at maturity. Notional V3 introduced leveraged vaults and expanded yield strategies, making it DeFi's leading fixed-rate lending platform with tenors ranging from three months to twenty years.

## Kin Score — 23.2 / 100 (emerging)

Scored 2026-08-21 under rubric 0.12.0. Trend: flat (+0.0 from 23.2).

| Facet | Score |
|---|---|
| Discoverability | 74.1 |
| Contract Quality | 38.9 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 21.1 |
| Developer Ergonomics | 16.7 |
| Commercial Clarity | 0.0 |
| Access Clarity | 0.0 |

## Agent readiness — 15.4 (agent-aware)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| 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 | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Unknown — onboarding: unknown, pricing: unknown, trial: no (confidence: low).

## APIs (4)

- **Notional V2 Subgraph API (Mainnet)** — GraphQL subgraph API for querying Notional V2 on-chain data on Ethereum Mainnet via The Graph protocol. Provides access to accounts, trades, markets, nTokens, cash groups, curre...
- **Notional V3 Subgraph API (Mainnet)** — GraphQL subgraph API for querying Notional V3 on-chain data on Ethereum Mainnet via The Graph Studio. Supports queries for accounts, leveraged vault positions, fCash markets, in...
- **Notional V3 Subgraph API (Arbitrum)** — GraphQL subgraph API for querying Notional V3 on-chain data on Arbitrum One via The Graph Studio. Notional V3 launched primarily on Arbitrum and this endpoint provides the most ...
- **Notional Typescript SDK** — Client-side Typescript SDK for interacting with Notional Finance smart contracts. Provides helper methods for computing fixed-rate trade values including getCashAmountGivenfCash...

## Security (1)

- **Notional Domain Security** — TLSv1.3 · HSTS · DNSSEC · DMARC

## Tags

DeFi, Fixed-Rate Lending, Blockchain, Ethereum, Arbitrum, fCash, Liquidity Pools, Leveraged Vaults, Yield, Web3

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