Halliday

• Name: Halliday
• URL: https://halliday.xyz/
• Category: payment orchestration / deposit routing / cross-chain onboarding middleware
• Summary: Halliday is a route broker for getting funds into apps. It hides ramps, exchange-funded deposits, swaps, bridge selection, and recovery behind one vendor surface. Useful when the question is who owns quote ordering, retry rights, and fallback behavior. Less interesting as a rail in its own right.
• What it does:
  • Provides a widget and REST API for adding onramp, bridge, swap, and deposit flows to apps and chains
  • Combines fiat on/offramp providers, cross-chain routing, and centralized-exchange connectivity behind one integration surface
  • Uses a one-time wallet (OTW) / deposit address per payment that is controlled by the specified owner wallet address
  • Exposes APIs for supported assets and chains, payment quotes, payment confirmation, payment status, wallet balances, and recovery/withdrawal flows
  • Positions a broader Halliday Workflow Protocol as infrastructure for automating onchain workflows without custom smart-contract development
• Key claims:
  • Homepage positions Halliday as a “Unified crypto payments” layer for onramps, bridges, cross-chain swaps, and deposits
  • Official docs say users can acquire any token on any chain with minimal effort and that Halliday Payments is fully self-custodial
  • Homepage says developers can set up a deposit UI with seven lines of code or use a more flexible API
  • March 2025 company blog says Halliday Payments is used by 35+ clients and that Halliday has been running production partner flows since 2023
  • Ecosystem materials show integrations or relationships across chains, infra vendors, wallets, and payment providers including Story, MoonPay, Stripe, Coinbase, Privy, Dynamic, and Alchemy
• Whitepaper: No classic whitepaper or litepaper was found during this pass. Primary-source snapshots were saved in ../whitepapers/halliday-primary-sources-2026-04-22.md.
• Sources:
  • https://halliday.xyz/
  • https://docs.halliday.xyz/
  • https://halliday.xyz/ecosystem
  • https://blog.halliday.xyz/halliday-raises-20m-series-a-led-by-a16z-crypto-to-ensure-developers-never-write-a-smart-contract-again/

Internal linkages

• Strongest upward reads: bridge-xyz and coinflow.

Control surface

• The leverage sits in provider admission, quote generation, route ranking, exchange connectivity, retry rights, and recovery handling.

• Read it as route-and-deposit middleware, not as a canonical bridge or settlement rail.

• Keep the note in the comparison set, but not at the center of it.

• Last reviewed: 2026-06-03 UTC