# Arbitrum

**Canonical:** https://apis.io/providers/arbitrum/  
**Website:** https://arbitrum.io  
**APIs profiled:** 10

Arbitrum is the Ethereum Layer 2 rollup ecosystem from Offchain Labs. It includes Arbitrum One (general-purpose rollup secured by Ethereum), Arbitrum Nova (AnyTrust chain for high-throughput, low-cost apps), Arbitrum Sepolia (testnet), and Arbitrum Orbit (settlement framework for custom L2 / L3 chains). Developers interact via standard Ethereum JSON-RPC, the Stylus SDK for Rust / C / C++ smart contracts, the Arbitrum SDK for cross-chain messaging and bridging, and the Arbitrum Bridge for canonical asset transfer between Ethereum and Arbitrum chains.

## Kin Score — 42.0 / 100 (developing)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 42.0).

| Facet | Score |
|---|---|
| Discoverability | 81.5 |
| Contract Quality | 63.0 |
| Governance | 13.6 |
| Contract Governance | 13.6 |
| Operational Transparency | 42.1 |
| Developer Ergonomics | 26.2 |
| Commercial Clarity | 28.9 |
| Access Clarity | 28.9 |

## Agent readiness — 27.8 (agent-aware)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | no |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | verified |
| Rate Limit Signal | documented |
| Event Surface Described | derived |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Free — onboarding: unknown, pricing: free, trial: no (confidence: medium).

## APIs (10)

- **Arbitrum One JSON-RPC** — Public Ethereum JSON-RPC endpoint for Arbitrum One mainnet (chain ID 42161), the flagship optimistic rollup secured directly by Ethereum L1. Supports standard eth_* methods plus...
- **Arbitrum Nova JSON-RPC** — Public Ethereum JSON-RPC endpoint for Arbitrum Nova (chain ID 42170), an AnyTrust chain with a Data Availability Committee for high-throughput, low-cost transactions suited to g...
- **Arbitrum Sepolia JSON-RPC** — Public Ethereum JSON-RPC endpoint for the Arbitrum Sepolia testnet (chain ID 421614).
- **Arbitrum Bridge** — Canonical cross-chain bridge for transferring ETH and ERC-20 tokens between Ethereum L1, Arbitrum One, Arbitrum Nova, and connected Orbit chains. Bridge operations and underlyin...
- **Arbitrum SDK** — Official TypeScript SDK (@arbitrum/sdk) for cross-chain interactions — building L1-to-L2 and L2-to-L1 messages, deposit and withdrawal flows, retryable tickets, and gas estimati...
- **Stylus SDK (Rust)** — Stylus lets developers write EVM-compatible smart contracts in Rust, C, and C++ that compile to WASM and run alongside Solidity contracts. The Rust SDK provides storage primitiv...
- **Arbitrum Nitro** — Open-source Nitro node implementation that runs Arbitrum One, Nova, and Orbit chains. Includes the sequencer, batch poster, validator, and a fork of go- ethereum patched for Arb...
- **Arbitrum Orbit SDK** — TypeScript SDK and tooling for deploying and operating Orbit chains — custom Arbitrum L2 / L3 chains that settle to Arbitrum One, Nova, or other Orbit chains.
- **Arbiscan Block Explorer** — Etherscan-family block explorer for Arbitrum One, Nova, and Sepolia with a public REST API for contracts, transactions, and addresses.
- **Arbitrum JSON-RPC API** — Ethereum-compatible JSON-RPC 2.0 endpoint

## Agentic access (1)

- **Arbitrum Agentic Access** — 1 operation · 1 acting

## Security (1)

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

## Plans (1)

- **Arbitrum Plans Pricing**

## Tags

Layer 2, Ethereum, Rollup, JSON-RPC, Stylus, Nitro, Orbit, Bridge

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