25.3.1

What's Changed

New Features

• MuxedAddress now implements ScVal conversion traits and SorobanArbitrary, allowing it to be used as a field in #[contracttype] structs. (#1782)

Improvements

• Compiler error for reserved type names in contract types: #[contracttype] definitions whose names collide with SDK built-in type names (e.g. Address, Bytes, Symbol) now produce a clear compile-time error instead of silently mapping to the built-in type in the contract spec. (#1788)
• Using #[contractevent(data_format = "single-value")] with more than one data field now produces a clear compile-time error. (#1794)
• #[contractimpl] macro now correctly resolves associated types in function return values (not just inputs), and emits clear compiler errors when it cannot resolve an associated type. (#1780)
• LedgerSnapshot::write_file now writes to a temporary file before atomically replacing the destination, preventing corrupted snapshot files if serialization fails. (#1796)
• Replaces regular subtraction with saturating_sub when computing max_ttl to guard against potential underflow from misconfiguration. (#1792)

Bug Fixes

• Generated try_ client methods were always calling mock_all_auths() and ignoring the allow_non_root_auth flag, causing non-root auth to silently fail. They now correctly call mock_all_auths_allowing_non_root_auth() when the flag is set. (#1761)
• Doc comment truncation could split multi-byte UTF-8 codepoints, producing invalid UTF-8 in the contract's spec XDR. Truncation now always occurs at a valid character boundary. (#1769)
• The build.rs target check was evaluating against the host target instead of the compilation target, so the Rust version check never fired during cross-compilation. This could silently produce Wasm binaries with unsupported features. The error message now also recommends wasm32v1-none as the preferred target. (#1771)
• Added checks in register_contract_with_source and register_stellar_asset_contract_v2 to prevent potential auth manager overrides. (#1803)

Documentation

• Added documentation for the ToXdr and FromXdr traits. (#1767)
• Improved documentation for Val conversion behavior in SDK collection types. (#1774)
• Added documentation for the SHA-256 hash verification options available in contractimport! and contractfile! macros. (#1790)
• Documented how #[contractimpl] determines the exported function names in the contract spec. (#1809)
• Updated the Pausable trait doc examples to include access control patterns. (#1764)
• Expanded documentation on how to use mock auth in test scenarios. (#1798)
• Improved documentation for Poseidon hash functions. (#1816)

All Changes

• Add comment for future EnvTestConfig API privatization by @leighmcculloch in #1752
• Fix try_ client ignoring allow_non_root_auth flag by @leighmcculloch in #1761
• Add access control to Pausable trait examples by @leighmcculloch in #1764
• Document ToXdr and FromXdr traits by @leighmcculloch in #1767
• Fix rust and wasm target check for sdk by @leighmcculloch in #1771
• Improve docs around Val conversion in collections by @mootz12 in #1774
• Add ScVal conversion and SorobanArbitrary impls for MuxedAddress by @mootz12 in #1782
• Improve parsing for associated type usage and add better errors for unsupported patterns by @mootz12 in #1780
• Fix docs_from_attrs truncating mid-UTF-8 codepoint by @leighmcculloch in #1769
• chore: use saturating sub with max_ttl computation by @mootz12 in #1792
• Add compiler error when single value event used with multiple data entries by @mootz12 in #1794
• Expand docs for mock auth usage in tests by @mootz12 in #1798
• Write to a temp file first during snapshot write_file by @mootz12 in #1796
• Add compiler error when reserved type names are used as contract types by @mootz12 in #1788
• Document contractimport! and contractfile! SHA-256 verification options by @mootz12 in #1790
• Fix panic safety in register_contract_with_source and register_stellar_asset_contract_v2 by @mootz12 in #1803
• Fix misc typos and doc links by @mootz12 in #1804
• Document #[contractimpl] export name behaviour by @leighmcculloch in #1809
• Skip privacy-pools in soroban-examples CI by @leighmcculloch in #1811
• improve poseidon, poseidon2_permutation docs by @jayz22 in #1816
• Bump version to 25.3.1 by @github-actions[bot] in #1821

Full Changelog: v25.3.0...v25.3.1