Relay: cross-chain payments API (quote, execute, status)

Relay (relay.link) is multichain onchain payments infrastructure: you define an intent (bridge, swap, or call), and Relay’s network quotes and executes the route. Builder docs: docs.relay.link (llms.txt).

GitHub org: github.com/relayprotocol. App for humans: same domain; integrations use the REST API and optional RelayKit UI kit.

What you integrate for

Core API loop

Base URL: https://api.relay.link. Provision an API key in the Relay dashboard (keys & rate limits). Typical flow from the quickstart:

1. Get Quote — POST executable quote (swap / bridge / call)
2. Execute steps — wallet signs/submits returned steps; some paths use Submit Permit
3. Get Status — poll intent status (v3)
4. Optional: Get Requests, websockets, webhooks for lower latency

# Docs + keys
open https://docs.relay.link/references/api/quickstart
open https://docs.relay.link/references/api/api-keys

# Base
export RELAY_API=https://api.relay.link
export RELAY_API_KEY=***   # dashboard key — header per current docs

# Sketch: quote then poll status (paths from API reference)
# POST $RELAY_API/.../quote   body: origin/destination chain, tokens, amount, user
# GET  $RELAY_API/.../intents/.../status   # v3 status lifecycle

Drive step execution carefully: see step execution, wallet detection / explicitDeposit, and error guides for quote vs execution failures.

Feature flags builders care about

• App fees — take a fee on routes, collect in stablecoins
• Fee sponsorship — sponsor user fees
• Deposit addresses — bridge without connect/sign (CEX-like UX)
• Gas top-up — include destination native gas in the fill
• Gasless execution / gasless swaps — reduce gas friction
• Fast fill — accelerate destination fill
• Price stabilization — consistent stablecoin pricing across chains

Chain coverage notes

Docs advertise 69+ networks and dedicated guides for:

• Solana deposit/withdraw vs EVM
• Bitcoin, Hyperliquid, Lighter
• Testnets, smart accounts (ERC-4337 / EIP-7702)

Always resolve live support via Get Chains / supported routes, not a hardcoded list in your app.

Integration surfaces

Safety

• Compliance + unsupported exchanges lists in docs
• MEV protection notes; bug bounty program
• Contract audits under protocol references
• Support: support.relay.link

Links

• relay.link
• Docs
• API quickstart
• github.com/relayprotocol

Summary

Relay turns cross-chain payment intents into executable quotes and tracked fills. Start at api.relay.link with a dashboard key, implement quote → steps → status, then layer app fees, deposit addresses, or Solana/BTC guides as your product needs. Prefer live chain/route endpoints over static allowlists.