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Launch your own branded stablecoin, backed 1:1 by USDC reserves on Coinbase, with instant onchain liquidity. This documentation is for technical partners integrating with Custom Stablecoins. You can swap tokens directly onchain via the Stableswapper program, or use the Prime API for centralized conversions and withdrawals through Coinbase Prime.

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Use cases

Branded payment tokens

Launch your own stablecoin for in-app payments and rewards while maintaining USDC liquidity

Loyalty and rewards

Issue branded tokens as rewards that users can seamlessly convert to USDC

Gaming economies

Create in-game currencies backed by USDC with instant redemption

DeFi protocols

Integrate custom stablecoins into DeFi applications with guaranteed USDC liquidity

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Key features

  • 1:1 USDC backing: Fully backed by USDC reserves on Coinbase
  • Instant swaps: Single-transaction settlement
  • Predictable pricing: Fixed 1:1 ratio with no slippage surprises
  • Multi-chain support: Available on Solana and Base (EVM)
  • Flexible integration: Use via Cross-Program Invocation (Solana) or direct smart contract calls (EVM)
  • Multi-decimal support: Automatic normalization between tokens with different decimal precision
  • Prime API support: Convert and withdraw custom stablecoins programmatically via Coinbase Prime

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Supported networks

NetworkUse caseContract type
Solana DevnetTesting and developmentAnchor program
Solana MainnetProduction useAnchor program
Base SepoliaTesting and developmentEVM smart contract
Base MainnetProduction useEVM smart contract

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Onchain conversions

Stableswapper is the onchain liquidity program that powers instant swaps between USDC and any Custom Stablecoin issued through the program. It is deployed on both Solana and Base, providing the settlement layer partners need to let their users move freely between custom tokens and USDC. Learn how to integrate swaps into your application.

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How it works

The Stableswapper program maintains a liquidity pool with reserves for each supported token.
1

User initiates swap

The input token is transferred to the contract
2

Validation

The program checks the allowlist (if enabled), validates slippage protection, and applies any configured fee
3

Settlement

The equivalent amount of the output token is sent to the destination address
Swaps settle atomically in a single transaction at a 1:1 ratio before fees, with automatic decimal normalization between tokens with different precision.

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Concepts

ConceptDescription
PDA (Program Derived Address)Deterministic on-chain account owned by the program — used for the pool, vaults, and whitelist
VaultA PDA that acts as the logical owner for a token’s reserves within the pool
Vault Token AccountThe SPL token account that actually holds the token reserves for a given vault
ATA (Associated Token Account)A user’s standard token account for a given mint, derived deterministically from their wallet
WhitelistAn optional on-chain list of authorized wallet addresses. When enabled, only listed addresses can execute swaps
SlippageThe minimum acceptable output amount (min_amount_out). Protects against fee changes between transaction construction and execution

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Prime conversions

Partners with Coinbase Prime accounts can convert between USDC and custom stablecoins using the Prime Conversion API, and withdraw converted tokens to onchain wallets. This path is ideal for institutional workflows and Prime-custodied assets. Learn more in the Prime Conversions guide.

Quickstart

Get up and running with your first swap in 10 minutes

Reference

Swap instruction parameters and accounts

Production Readiness

Helper functions, error handling, and best practices

Key Addresses

Program IDs, contract addresses, and token mints

Prime API

Convert and withdraw custom stablecoins via Coinbase Prime