Overview

Arenas exposes its credit protocol as a developer platform, so you can embed lending, launch markets, and fund them without writing Solidity. This section covers the API, SDK, CLI, and MCP surfaces.

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The surfaces

Surface	Use it for
REST API	Read markets, pools, requests, financings and intents; build any UI or backend. Curated JSON with normalized amounts and millisecond timestamps.
SDKs & Tooling	Typed helpers for calldata, unit conversion, and contract reads on top of the API and ABIs.
CLI	Script and automate the same flows from a terminal or CI.
MCP	Agent-native access at mcp.atomica.org — skills, primitives and integration bundles for AI-assisted builds. See SDKs & Tooling.

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Authentication

Every read call is scoped to an arena by an arenaKey. Pass it as a query parameter or a header:

# query param
curl "$ARENAS_API/lending/markets?arenaKey=$ARENA_KEY"

# or header
curl -H "X-Arena-Key: $ARENA_KEY" "$ARENAS_API/lending/markets"

Write actions are on-chain transactions signed by the user’s wallet — the API and SDK give you the calldata and ABIs, your app sends the transaction.

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Pick your journey

Arenas has three builder journeys, mapped to the three sides of a market:

You are…	You want to…	Start here
Borrower / Builder	Embed credit in your product	Embed Credit
Supplier / Originator	Launch a white-label market	Launch a Market
Liquidity Provider	Fund markets and earn yield	Fund Markets

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How reads and writes fit together

Reads come from the curated API; writes are wallet transactions against the Atomica contracts. After a write, poll the indexer (/provisioning-sync/last-synced-blocks) before refetching so lists reflect the new state.