Notional Finance

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.

Notional Finance publishes 4 APIs on the APIs.io network. Tagged areas include DeFi, Fixed-Rate Lending, Blockchain, Ethereum, and Arbitrum.

Notional Finance’s developer surface includes documentation, GitHub presence, engineering blog, and 11 more developer resources.

🌐 Visit website 📡 Source on GitHub

23.0/100 emerging ▬ flat Agent 13/100 agent aware self hosted · Apache-2.0 Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

4 APIs

DeFiFixed-Rate LendingBlockchain Ethereum ArbitrumfCashLiquidity PoolsLeveraged VaultsYield Web3

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 23.0/100 · emerging

Contract Quality 8.4 / 23

Developer Ergonomics 3.0 / 18

Access Clarity 0.0 / 18

Operational Transparency 2.5 / 12

Contract Governance 0.0 / 11

Discoverability 6.7 / 9

Open Source Surface 2.5 / 10

Agent readiness — 13/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Open Source Surface applies to this provider. This product is open source and we read its repository directly, so Open Source Surface carries 10 points of the composite. It is scored from what the repository actually publishes — a security policy, a contribution guide, a release history, a code of conduct — read live from the provider rather than inferred from our own catalog pointers. This facet adds; nothing was taken away to make room for it. An open-source project is not excused from the commercial facets, because exemption would strip it of the points it does earn. If we have the wrong repository, or this product is not open source, say so on your provider repo and we will drop the facet rather than have you publish against it.

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 90 points between them, because the conditional facet above carries the other 10. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 90% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/notional: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 4

Individual APIs this provider publishes, each with its own machine-readable definition.

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...

GraphQL 1

GraphQL schemas published by this provider.

Notional Finance GraphQL API

Notional Finance exposes protocol data via GraphQL subgraphs hosted on The Graph protocol. The V2 subgraph covers Ethereum Mainnet fixed-rate lending/borrowing markets, accounts...

GRAPHQL

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Notional Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Resources

Documentation 4

Reference material describing how the API behaves

Documentation

Documentation

V3Documentation

V3Documentation

ABIReference

ABIReference

SubgraphReference

SubgraphReference

Build 1

SDKs, sample code, and the tooling you integrate with

GitHub

GitHub

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 3

Status, limits, changes, and where to get help

IssueTracker

IssueTracker

Releases

Releases

Discord

Discord

Commercial 1

Pricing, plans, and the legal terms of use

License

License

Company 3

The organization behind the API

Website

Website

Blog

Blog

Twitter

Twitter

Other 1

Properties that don't map to a standard resource type

SmartContracts

SmartContracts

Source (apis.yml)

name: Notional Finance
description: '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.

  '
deliveryModel:
  model: self-hosted
  license: Apache-2.0
  open_source: true
  commercial: false
  callable_host: false
  label: Self-hosted open source · you run it yourself
  confidence: high
  source:
  - license
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source: []
  generated: '2026-07-22'
  method: derived
image: https://notional.finance/favicon.ico
tags:
- DeFi
- Fixed-Rate Lending
- Blockchain
- Ethereum
- Arbitrum
- fCash
- Liquidity Pools
- Leveraged Vaults
- Yield
- Web3
created: '2026-06-14'
modified: '2026-06-14'
url: https://raw.githubusercontent.com/api-evangelist/notional/refs/heads/main/apis.yml
specificationVersion: '0.23'
apis:
- name: Notional V2 Subgraph API (Mainnet)
  description: '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, currencies, TVL history, exchange rates, and liquidation events.
    Most numerical values use 8-decimal precision (10^8); interest rates use 9-decimal precision (10^9). Pagination defaults
    to 100 results per page with a maximum of 1000.

    '
  image: https://notional.finance/favicon.ico
  baseURL: https://api.thegraph.com/subgraphs/name/notional-finance/mainnet-v2
  humanURL: https://docs.notional.finance/developer-documentation/off-chain/subgraph-reference
  contact:
  - FN: Notional Finance
    url: https://notional.finance/
  tags:
  - GraphQL
  - Subgraph
  - Ethereum
  - fCash
  - Markets
  - Account
  - Liquidations
  tags_raw:
  - GraphQL
  - Subgraph
  - Ethereum
  - fCash
  - Markets
  - Accounts
  - Liquidations
  properties:
  - type: Documentation
    url: https://docs.notional.finance/developer-documentation/off-chain/subgraph-reference
  - type: GraphQL
    url: https://api.thegraph.com/subgraphs/name/notional-finance/mainnet-v2
  - type: Explorer
    url: https://thegraph.com/hosted-service/subgraph/notional-finance/mainnet-v2
  - url: graphql/notional-schema.graphql
    type: GraphQLSchema
  - url: graphql/notional-graphql.md
    type: GraphQLDocumentation
  apis.json: {}
- name: Notional V3 Subgraph API (Mainnet)
  description: '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, interest rates, and yield analytics for the V3 protocol
    upgrade. Publicly accessible with no authentication required.

    '
  image: https://notional.finance/favicon.ico
  baseURL: https://api.studio.thegraph.com/query/60626/notional-v3-mainnet/v0.0.9
  humanURL: https://docs.notional.finance/v3-technical-docs/subgraph-guides/notional-v3-subgraphs
  contact:
  - FN: Notional Finance
    url: https://notional.finance/
  tags:
  - GraphQL
  - Subgraph
  - Ethereum
  - v3
  - Leveraged Vaults
  - fCash
  - Fixed Rate
  tags_raw:
  - GraphQL
  - Subgraph
  - Ethereum
  - V3
  - Leveraged Vaults
  - fCash
  - Fixed-Rate
  properties:
  - type: Documentation
    url: https://docs.notional.finance/v3-technical-docs/subgraph-guides/notional-v3-subgraphs
  - type: GraphQL
    url: https://api.studio.thegraph.com/query/60626/notional-v3-mainnet/v0.0.9
  - type: Explorer
    url: https://thegraph.com/explorer/subgraphs/2t4T7bts8ZQCpGcVq9VSzDyPVCQc5Y7TFwZKfmXKeSVx?view=Query&chain=arbitrum-one
  apis.json: {}
- name: Notional V3 Subgraph API (Arbitrum)
  description: '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 comprehensive V3 dataset including leveraged vault
    positions, fixed-rate lending pools, fCash positions, nToken portfolio holdings, and interest rate analytics. No authentication
    required.

    '
  image: https://notional.finance/favicon.ico
  baseURL: https://api.studio.thegraph.com/query/60626/notional-v3-arbitrum/version/latest
  humanURL: https://docs.notional.finance/v3-technical-docs/subgraph-guides/notional-v3-subgraphs
  contact:
  - FN: Notional Finance
    url: https://notional.finance/
  tags:
  - GraphQL
  - Subgraph
  - Arbitrum
  - v3
  - Leveraged Vaults
  - fCash
  - Fixed Rate
  - Yield
  tags_raw:
  - GraphQL
  - Subgraph
  - Arbitrum
  - V3
  - Leveraged Vaults
  - fCash
  - Fixed-Rate
  - Yield
  properties:
  - type: Documentation
    url: https://docs.notional.finance/v3-technical-docs/subgraph-guides/notional-v3-subgraphs
  - type: GraphQL
    url: https://api.studio.thegraph.com/query/60626/notional-v3-arbitrum/version/latest
  - type: Explorer
    url: https://thegraph.com/explorer/subgraphs/4oVxkMtN4cFepbiYrSKz1u6HWnJym435k5DQRAFt2vHW?view=About&chain=arbitrum-one
  apis.json: {}
- name: Notional Typescript SDK
  description: 'Client-side Typescript SDK for interacting with Notional Finance smart contracts. Provides helper methods
    for computing fixed-rate trade values including getCashAmountGivenfCashAmount, getfCashAmountGivenCashAmount, and getSlippageRate.
    Enables developers to build applications that integrate with Notional''s fixed-rate lending and borrowing markets without
    directly encoding ABI calls.

    '
  image: https://notional.finance/favicon.ico
  baseURL: https://github.com/notional-finance/sdk-v2
  humanURL: https://github.com/notional-finance/sdk-v2
  contact:
  - FN: Notional Finance
    url: https://github.com/notional-finance
  tags:
  - SDK
  - TypeScript
  - Client Library
  - fCash
  - Fixed Rate
  - Ethereum
  tags_raw:
  - SDK
  - TypeScript
  - Client Library
  - fCash
  - Fixed-Rate
  - Ethereum
  properties:
  - type: Documentation
    url: https://docs.notional.finance/developer-documentation/
  - type: GitHubRepository
    url: https://github.com/notional-finance/sdk-v2
  apis.json: {}
common:
- type: IssueTracker
  url: https://github.com/notional-finance/sdk-v2/issues
- type: Releases
  url: https://github.com/notional-finance/sdk-v2/releases
- type: License
  name: Apache-2.0
  url: https://github.com/notional-finance/sdk-v2/blob/master/LICENSE
- type: DomainSecurity
  url: security/notional-domain-security.yml
- type: Website
  url: https://notional.finance/
- type: Documentation
  url: https://docs.notional.finance/developer-documentation/
- type: V3Documentation
  url: https://docs.notional.finance/v3-technical-docs
- type: GitHub
  url: https://github.com/notional-finance
- type: Blog
  url: https://blog.notional.finance/
- type: Discord
  url: https://discord.com/invite/notional
- type: Twitter
  url: https://twitter.com/NotionalFinance
- type: SmartContracts
  url: https://docs.notional.finance/developer-documentation/on-chain/notional-proxy
- type: ABIReference
  url: https://docs.notional.finance/developer-documentation/on-chain/notional-abi-reference.md
- type: SubgraphReference
  url: https://docs.notional.finance/developer-documentation/off-chain/subgraph-reference
maintainers:
- FN: API Evangelist
  email: info@apievangelist.com

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