This glossary keeps the Stellar- and PayFi-specific terms used in the repo in one place. The term links point to the canonical source for each definition, either Stellar docs/specs or this codebase.
| Term | Definition |
|---|---|
| Claimable balance | A ledger entry that reserves an asset until one of its claimants satisfies the predicate and claims it later. |
| Circuit breaker | An opossum-backed guard around RPC calls that opens after repeated failures and short-circuits new calls until recovery. |
| Horizon | Stellar's HTTP API for account, transaction, and ledger data, plus transaction submission. |
| nonce | A one-time x402 challenge value used to prevent replay and to correlate the settled payment back to the original request. |
| PayFi | Payment-finance flows where value transfer is part of automated application logic, not just a manual user action. |
| SAC | Stellar Asset Contract, the built-in contract interface for Stellar assets and trustline balances used by Soroban contracts. |
| SEP-0001 | Stellar Info File, the stellar.toml metadata file anchors and apps use to discover endpoints, assets, and signing info. |
| SEP-0010 | Stellar Authentication, the challenge-response web auth standard used to establish an authenticated session with an anchor. |
| SEP-0031 | Cross-Border Payments, the standard for anchor-to-anchor and wallet-mediated cross-border payment flows. |
| SEP-0038 | Quote, the standard for requesting indicative or firm exchange quotes between Stellar and off-chain assets. |
| Soroban | Stellar's smart-contract platform and runtime for on-chain logic compiled to Wasm. |
| trustline | An opt-in ledger relationship that lets an account hold or send a non-XLM asset issued by another account. |
| WASM | WebAssembly, the portable binary format used to compile Soroban contracts for on-chain execution. |
| x402 | An HTTP 402-based payment standard for machine-to-machine payment of gated resources. |
| XDR | External Data Representation, Stellar's binary serialization format for transactions, ledger data, and smart-contract metadata. |