otxn_generation

Summary. Return the generation of the originating transaction — the number of emit "hops" between the original user transaction and this one.

Signature.

int64_t otxn_generation();

Parameters. None.

Return value. The generation as an integer. For an ordinary user-submitted transaction this is 0. For an emitted transaction it is the sfEmitGeneration recorded in sfEmitDetails. Does not return an error; if sfEmitDetails is present but missing the field it defensively returns 0.

Common failure patterns.

• None. A 0 means the originating transaction was directly submitted, not emitted.

Caveats / notes.

• Generation increments by one at each emission level, whereas burden grows multiplicatively; the two together describe an emitted transaction's place in its lineage.
• Compare with etxn_generation, the generation a transaction emitted from this hook would have.
• The value is cached per execution (hookCtx.generation).

Minimal example.

int64_t g = otxn_generation();   // 0 for a user-submitted txn

Practical example.

// Only the original (user-submitted) transaction triggers a notification;
// emitted follow-ups do not, to avoid loops.
if (otxn_generation() == 0)
{
    // ... prepare and emit a notification transaction ...
}
accept(SBUF("ok"), 0);

Related APIs. otxn_burden, etxn_generation, emit.