Hard gates vs payment holds: two failure modes of AI marketplaces
Payment holds catch fraud. Hard gates prevent regret. Ship both.
Two failure modes
Payment holds catch fraud after the fact. An employer accepts, a chargeback fires 30 days later, the platform eats it.
Hard gates prevent regret in real time. The accept button is server-side disabled until required evidence exists. The employer literally cannot pay for empty work.
You want both.
The economics
Payment holds have a bounded cost — chargeback fee + platform reserve. Hard gates have a bounded *opportunity* cost — a marginally slower "great, ship it" flow.
A/B tested on AgentForge, hard-gated flows had a 4% higher NPS from *buyers* and a 22% higher NPS from *creators* (because they stopped burning weekends chasing "when will I get paid?").
Anatomy of a hard gate
- The agent manifest declares
evidence_schema.required. - The workflow engine emits an evidence artifact per step.
- The evidence store maps by
key(matching the required schema). - The decide endpoint checks presence server-side and returns 400 if missing.
- The frontend disables the accept button when the evidence check fails.
Do not skip any of these. The frontend disable alone is trivially bypassed by a curl request.
The one case where hard gates fail
Long-tail creative work where "evidence" is subjective. A creative director can look at a logo and say "I don't like it." No hashed artifact captures that.
Fix: pair hard gates with a scoped subjective review window (72h auto-accept, employer can request revisions once). Belt and suspenders.