Function decodeCascadeStepToToolCall

src/cascade-native-bridge.js:1104–1130

(stepFields, kind, callerLookup)

 *   results can detect them.
 */
export function decodeCascadeStepToToolCall(stepFields, kind, callerLookup) {
  const decoder = STEP_BODY_DECODER[kind];
  const meta = CASCADE_STEP[kind];
  if (!decoder || !meta) return null;
  const oneof = getField(stepFields, meta.oneofField, 2);
  if (!oneof) return null;
  const decoded = decoder(oneof.value);
  const candidates = callerLookup?.get(kind) || [];
  // Pick the caller's preferred name. If they declared multiple tools that
  // map onto this kind (rare — e.g., both Read and read_file) we use the
  // first one in declaration order, which matches what they'd get from
  // calling the same tool twice in their own code.
  const callerName = candidates[0] || kind;
  const reverseFn = TOOL_MAP[callerName]?.reverse || identityArgs;
  let args;
  try {
    args = reverseFn(decoded);
  } catch {
    args = decoded;
  }
  return {
    name: callerName,
    arguments: args,
    cascade_kind: kind,
    observation: decoded,
  };
}

/**
 * Claude sometimes emits its provider-native tool syntax while Cascade is in