clockworklabs/SpacetimeDB · error

Unknown index algorithm {:?}

Error message

Unknown index algorithm {:?}

What it means

generate_index_name (crates/schema/src/def/validate/v9.rs:1462) maps each index algorithm to a name label: btree, direct, or hash. RawIndexAlgorithm is #[non_exhaustive] with exactly those three variants (crates/lib/src/db/raw_def/v9.rs:309), so an unrecognized variant reaching this function triggers unimplemented!() — meaning the module binary carried an algorithm this host build does not know.

Source

Thrown at crates/schema/src/def/validate/v9.rs:1462

/// Concatenate a list of column names.
fn concat_column_names(table_type: &ProductType, selected: &ColList) -> String {
    selected.iter().map(|col| column_name(table_type, col)).join("_")
}

/// All indexes have this name format.
///
/// Generated name should not go through case conversion.
pub fn generate_index_name(
    table_name: &Identifier,
    table_type: &ProductType,
    algorithm: &RawIndexAlgorithm,
) -> RawIdentifier {
    let (label, columns) = match algorithm {
        RawIndexAlgorithm::BTree { columns } => ("btree", columns),
        RawIndexAlgorithm::Direct { column } => ("direct", &col_list![*column]),
        RawIndexAlgorithm::Hash { columns } => ("hash", columns),
        _ => unimplemented!("Unknown index algorithm {:?}", algorithm),
    };
    let column_names = concat_column_names(table_type, columns);
    RawIdentifier::new(format!("{table_name}_{column_names}_idx_{label}"))
}

/// All sequences have this name format.
///
/// Generated name should not go through case conversion.
pub fn generate_sequence_name(table_name: &Identifier, table_type: &ProductType, column: ColId) -> RawIdentifier {
    let column_name = column_name(table_type, column);
    RawIdentifier::new(format!("{table_name}_{column_name}_seq"))
}

/// All schedules have this name format.
///
/// Generated name should not go through case conversion.
pub fn generate_schedule_name(table_name: &Identifier) -> RawIdentifier {
    RawIdentifier::new(format!("{table_name}_sched"))

View on GitHub (pinned to 524b4487d9)

Solutions

1. Update the SpacetimeDB host/CLI to a version at or above the SDK used to build the module, then republish
2. Or downgrade the SDK in the module to the host's supported ABI version
3. Stick to #[index(btree)] / #[index(hash)] / direct indexes on unique columns, which all current hosts accept

Example fix

# before
spacetime publish --server mainnet my-module # module built with newer SDK

# after
spacetime update   # or reinstall CLI; then rebuild and republish
spacetime publish --server mainnet my-module

# Match toolchain before publish:
spacetime version                     # host/CLI version
cargo tree -p spacetimedb --depth 0   # SDK version used by the module
# If SDK > host, downgrade SDK or update host before building

When it happens

Trigger: Publishing a module compiled against a newer SDK that introduces an additional index algorithm variant to an older host; synthesizing a module ABI with an out-of-range index algorithm tag.

Common situations: cargo update bumping the spacetimedb SDK ahead of the running server; preview toolchains publishing to a stable cluster; module .wasm built on a different machine with a newer toolchain.

Related errors

• Unknown constraint type
• unknown misc export
• Index '${indexLabel}' on table '${tableLabel}' must define a
• Index '${idx.sourceName ?? '<unknown>'}' on table '${tableDe
• never types are not yet supported in C# output

AI-assisted analysis of clockworklabs/SpacetimeDB@524b4487d9 (2026-08-16). Data as JSON: /api/errors/1395b9bd98d39829. Report an issue: GitHub.