API3 website screenshot

API3

API3 is a first-party blockchain oracle network that connects real-world APIs directly to smart contracts without intermediary nodes. Its core technology is Airnode, a serverless oracle node that API providers operate themselves, cryptographically signing data before serving it on-chain. The API3 Market enables dApp developers to subscribe to managed decentralized APIs (dAPIs) — aggregated, multi-source data feeds covering 150+ price pairs across 40+ EVM chains — without speaking to a sales rep or signing a contract. API3's OEV (Oracle Extractable Value) mechanism captures MEV that traditionally leaks to bots around oracle updates and redistributes 80% of that revenue to the dApps reading the feeds, creating a net-positive oracle revenue model. The DAO governs the network via staked API3 tokens.

API3 publishes 3 APIs on the APIs.io network: Airnodes API, Signed Data API, and Status API. Tagged areas include Blockchain, Oracle, Decentralized, Data Feeds, and Price Feeds.

The API3 catalog on APIs.io includes 1 JSON-LD context.

API3’s developer surface includes authentication, documentation, engineering blog, and 15 more developer resources.

41.5/100 thin ▬ flat Agent 37/100 agent ready Full breakdown ↓
scored 2026-07-28 · rubric v0.6
AccessPaidSelf serve
6 APIs
BlockchainOracleDecentralizedData FeedsPrice FeedsWeb3DeFiSmart ContractsOEVdAPI

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6
Composite quality — 41.5/100 · thin
Contract Quality 17.0 / 25
Developer Ergonomics 4.3 / 20
Commercial Clarity 7.9 / 20
Operational Transparency 4.8 / 13
Governance 0.0 / 12
Discoverability 7.4 / 10
Agent readiness — 37/100 · agent ready
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 7 / 7
Rate-Limit Signaling 7 / 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
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/api3: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 6

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

API3 dAPI Data Feeds

Managed decentralized API (dAPI) data feeds sourced directly from first-party oracle nodes operated by the data providers themselves. Each feed aggregates signed data from multi...

API3 OEV Rewards

Oracle Extractable Value (OEV) Rewards is API3's revenue-sharing mechanism for dApps that integrate OEV-enabled Api3ReaderProxyV1 proxy contracts. When liquidation or arbitrage ...

API3 Airnode HTTP Gateway

The Airnode HTTP gateway exposes a REST endpoint that allows authorized callers to query an Airnode operator's API data off-chain without sending a blockchain transaction. API p...

API3 Airnodes API

Airnode address discovery

API3 Signed Data API

Reading and writing cryptographically signed oracle data

API3 Status API

Health and deployment information

Pricing Plans 1

Published pricing tiers and plan structures.

Api3 Plans

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Api3 Rate Limits

3 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Api3 Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Api3 Context

6 classes · 8 properties

JSON-LD

Security Posture 2

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

Api3 Authentication

http · 1 scheme

SECURITY

Api3 Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Api3 Agentic Access

4 operations · 1 acting

4 operations · 1 acting

AGENTIC

Resources

Documentation 2

Reference material describing how the API behaves

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

Build 1

SDKs, sample code, and the tooling you integrate with

Access & Security 2

Authentication, authorization, and security posture

Operate 3

Status, limits, changes, and where to get help

Commercial 2

Pricing, plans, and the legal terms of use

Company 3

The organization behind the API

Other 3

Properties that don't map to a standard resource type

Source (apis.yml)

apis.yml Raw ↑
aid: api3
url: https://raw.githubusercontent.com/api-evangelist/api3/refs/heads/main/apis.yml
name: API3
kind: company
description: API3 is a first-party blockchain oracle network that connects real-world APIs directly to smart contracts without
  intermediary nodes. Its core technology is Airnode, a serverless oracle node that API providers operate themselves, cryptographically
  signing data before serving it on-chain. The API3 Market enables dApp developers to subscribe to managed decentralized APIs
  (dAPIs) — aggregated, multi-source data feeds covering 150+ price pairs across 40+ EVM chains — without speaking to a sales
  rep or signing a contract. API3's OEV (Oracle Extractable Value) mechanism captures MEV that traditionally leaks to bots
  around oracle updates and redistributes 80% of that revenue to the dApps reading the feeds, creating a net-positive oracle
  revenue model. The DAO governs the network via staked API3 tokens.
accessModel:
  pricing: paid
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Paid · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/api3.png
tags:
- Blockchain
- Oracle
- Decentralized
- Data Feeds
- Price Feeds
- Web3
- DeFi
- Smart Contracts
- OEV
- dAPI
type: Index
access: 3rd-Party
position: Consumer
created: '2026-06-13'
modified: '2026-06-13'
specificationVersion: '0.19'
apis:
- aid: api3:dapi-data-feeds
  name: API3 dAPI Data Feeds
  description: Managed decentralized API (dAPI) data feeds sourced directly from first-party oracle nodes operated by the
    data providers themselves. Each feed aggregates signed data from multiple Airnode operators and is updated on-chain based
    on deviation thresholds (0.25%, 0.5%, 1%, 2.5%, or 5%) and a 24-hour heartbeat. Smart contracts read feeds via the IProxy/AggregatorV2V3Interface-compatible
    Api3ReaderProxyV1 contract. Over 150 asset pairs — crypto, forex, equities, and commodities — are available across 40+
    EVM networks. Subscriptions are purchased through the API3 Market; testnet plans are 7-day trials and mainnet plans are
    3-month subscriptions.
  humanURL: https://market.api3.org/
  baseURL: https://market.api3.org
  tags:
  - Data Feeds
  - Price Feeds
  - dAPI
  - Oracle
  - DeFi
  - EVM
  properties:
  - type: Documentation
    url: https://docs.api3.org/dapps/
  - type: Integrations
    url: https://docs.api3.org/dapps/integration/
  - type: GettingStarted
    url: https://docs.api3.org/dapps/
  x-features:
  - 150+ price pairs (crypto, forex, equities, commodities)
  - Configurable deviation thresholds (0.25% – 5%)
  - 24-hour heartbeat interval
  - AggregatorV2V3Interface-compatible proxy contracts
  - 40+ EVM chains including Ethereum, Arbitrum, Base, BNB Chain, Polygon, Avalanche
  - No minimum commitment; pay-as-you-go subscription
  x-use-cases:
  - DeFi lending protocols needing reliable collateral price feeds
  - Derivatives and perpetuals platforms requiring low-latency mark prices
  - Stablecoin systems referencing external price anchors
  - Prediction markets and options protocols reading settlement prices
- aid: api3:oev-rewards
  name: API3 OEV Rewards
  description: Oracle Extractable Value (OEV) Rewards is API3's revenue-sharing mechanism for dApps that integrate OEV-enabled
    Api3ReaderProxyV1 proxy contracts. When liquidation or arbitrage opportunities arise around oracle updates, API3 runs
    an auction on the OEV Network and captures the resulting MEV. 80% of auction proceeds are paid monthly in the native gas
    token of the dApp's deployed chain to the wallet the dApp designates. Integration requires deploying a custom proxy (free
    via the API3 Market) rather than the generic shared proxy, and registering a recipient wallet address with an API3 representative.
  humanURL: https://docs.api3.org/dapps/oev-rewards/
  baseURL: https://market.api3.org
  tags:
  - OEV
  - MEV
  - Revenue Sharing
  - DeFi
  - Oracle
  properties:
  - type: Documentation
    url: https://docs.api3.org/dapps/oev-rewards/
  - type: GettingStarted
    url: https://docs.api3.org/dapps/oev-rewards/
  x-features:
  - 80% of OEV auction proceeds returned to dApp
  - Monthly payouts in native chain gas token
  - No code changes to smart contracts required
  - Custom proxy deployment via API3 Market
  - Supported on all 40+ API3 chain deployments
  x-use-cases:
  - Lending protocols (Compound, Morpho, Moonwell) offsetting oracle costs
  - Any DeFi application using API3 dAPI feeds to generate passive revenue
  - Treasury diversification via oracle MEV redistribution
- aid: api3:airnode-http-gateway
  name: API3 Airnode HTTP Gateway
  description: The Airnode HTTP gateway exposes a REST endpoint that allows authorized callers to query an Airnode operator's
    API data off-chain without sending a blockchain transaction. API providers configure the gateway in their Airnode's nodeSettings,
    protecting it with an API key. Responses contain the same cryptographically signed data that is eventually posted on-chain,
    enabling off-chain verification, testing, and direct signed-data consumption by third-party data push relayers. The OEV
    Gateway variant is used by auction searchers to retrieve Airnode-signed price updates that can only be used by the winning
    OEV auction bidder.
  humanURL: https://old-docs.api3.org/airnode/pre-alpha/
  baseURL: https://airnode.api3.org
  tags:
  - Airnode
  - HTTP Gateway
  - Signed Data
  - OEV
  - REST
  properties:
  - type: Documentation
    url: https://old-docs.api3.org/airnode/pre-alpha/
  x-features:
  - API-key-protected REST endpoint per Airnode deployment
  - Returns cryptographically signed data from the source API provider
  - Enables off-chain data consumption without on-chain transactions
  - OEV Gateway variant restricts signed data to winning auction bidder
  x-use-cases:
  - Off-chain testing of Airnode data before on-chain integration
  - Third-party push relayers submitting signed data to chain
  - OEV searchers fetching price updates to submit winning auction bids
- aid: api3:api3-airnodes-api
  name: API3 Airnodes API
  description: Airnode address discovery
  humanURL: https://market.api3.org/
  baseURL: https://market.api3.org
  tags:
  - Airnodes
  properties:
  - type: OpenAPI
    url: openapi/api3-airnodes-api-openapi.yml
- aid: api3:api3-signed-data-api
  name: API3 Signed Data API
  description: Reading and writing cryptographically signed oracle data
  humanURL: https://market.api3.org/
  baseURL: https://market.api3.org
  tags:
  - Signed Data
  properties:
  - type: OpenAPI
    url: openapi/api3-signed-data-api-openapi.yml
- aid: api3:api3-status-api
  name: API3 Status API
  description: Health and deployment information
  humanURL: https://market.api3.org/
  baseURL: https://market.api3.org
  tags:
  - Status
  properties:
  - type: OpenAPI
    url: openapi/api3-status-api-openapi.yml
common:
- type: AgenticAccess
  url: agentic-access/api3-agentic-access.yml
- type: DomainSecurity
  url: security/api3-domain-security.yml
- type: Authentication
  url: authentication/api3-authentication.yml
- type: Website
  url: https://api3.org/
- type: Documentation
  url: https://docs.api3.org/
- type: Blog
  url: https://blog.api3.org/
- type: GitHubOrganization
  url: https://github.com/api3dao
- type: Discord
  url: https://discord.gg/qnRrcfnm5W
- type: Twitter
  url: https://twitter.com/API3DAO
- type: Telegram
  url: https://t.me/API3DAO
- type: Forums
  url: https://forum.api3.org/
- type: Staking
  url: https://stake.api3.org/
- type: Market
  url: https://market.api3.org/
- type: OpenAPI
  url: openapi/api3-signed-api-openapi.yml
- type: JSONLD
  url: json-ld/api3-context.jsonld
- type: Plans
  url: plans/api3-plans.yml
- type: RateLimits
  url: rate-limits/api3-rate-limits.yml
- type: FinOps
  url: finops/api3-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com