FuelLabs/fuels-ts · error · FuelError

ABI_MAIN_METHOD_MISSING

ABI_MAIN_METHOD_MISSING

Error message

ABI doesn't have a 'main()' method.

What it means

The predicate template requires the ABI to declare a `main` function (the predicate entrypoint). abi.functions.find(f => f.name === 'main') returning undefined means the ABI cannot be turned into a predicate, since the predicate's configurable inputs are derived from main's parameters.

Source

Thrown at packages/abi-typegen/src/templates/predicate/main.ts:30

export function renderMainTemplate(params: { abi: Abi; versions: BinaryVersions }) {
  const { abi, versions } = params;

  const { types, configurables } = abi;

  const {
    rawContents,
    capitalizedName,
    hexlifiedBinContents: hexlifiedBinString,
    commonTypesInUse,
  } = params.abi;

  const abiJsonString = JSON.stringify(rawContents, null, 2);

  const func = abi.functions.find((f) => f.name === 'main');

  if (!func) {
    throw new FuelError(ErrorCode.ABI_MAIN_METHOD_MISSING, `ABI doesn't have a 'main()' method.`);
  }

  const { enums } = formatEnums({ types });
  const { structs } = formatStructs({ types });
  const { imports } = formatImports({
    types,
    baseMembers: [
      'Predicate as __Predicate',
      'Provider',
      'InputValue',
      'PredicateParams',
      'decompressBytecode',
    ],
  });

  const { prefixedInputs: inputs, output } = func.attributes;

  const text = renderHbsTemplate({

View on GitHub (pinned to b3f37c91ac)

Solutions

1. Verify the ABI is a predicate ABI and contains a function named exactly 'main'.
2. Recompile the Sway predicate with `forc build` (predicates emit a main function) and regenerate the ABI.
3. Ensure programType passed to typegen matches the actual ABI kind.

function assertPredicateMain(abi: JsonAbi) {
  if (!abi.functions.some(f => f.name === 'main')) {
    throw new Error('predicate ABI must declare a main() function');
  }
}

function isPredicateAbi(abi: JsonAbi): boolean {
  return abi.functions.some(f => f.name === 'main');
}

When it happens

Trigger: Running typegen with programType=PREDICATE against an ABI whose functions array has no entry named exactly 'main'; using a contract ABI by mistake for predicate generation.

Common situations: Wrong programType for the supplied ABI (contract ABI used as predicate); Sway predicate whose entrypoint was renamed away from `main`; ABI for an older predicate that used a different entrypoint name.

Related errors

• ABI_MAIN_METHOD_MISSING
• JSON_ABI_ERROR
• TYPE_ID_NOT_FOUND
• INVALID_COMPONENT
• INVALID_COMPONENT

AI-assisted analysis of FuelLabs/fuels-ts@b3f37c91ac (2026-08-12). Data as JSON: /api/errors/73969a8a7fa356fa. Report an issue: GitHub.