When you open AI Builder, a yellow banner at the top might say "Heuristic mode active." That means AI Builder couldn't use a real LLM and is falling back to simple pattern matching.
Heuristic mode catches the most common flow shapes (webhook + SMS, email + call), but it's noticeably less helpful than the real AI Builder. Anything beyond basic prompts produces "I didn't quite understand that" responses.
Why it happens
AI Builder uses your tenant's OpenAI API key to call OpenAI's GPT models. If the key isn't set, is invalid, expired, or hit a rate limit, the system silently falls back to heuristic mode rather than failing outright. Better degraded service than no service.
How to fix it
99% of the time, the key just isn't configured for your tenant. To set it:
- Sign in to JAMS IMES.
- Top-right user menu → OpenAI Key (also reachable via /dashboard?open=openai-key).
- Paste your tenant's OpenAI API key (starts with
sk-...). - Save.
- Reload AI Builder. The "Heuristic mode" banner should be gone.
If you don't have an OpenAI key yet:
- Go to platform.openai.com.
- Sign up (uses a separate billing account from your JAMS IMES billing).
- Settings → API Keys → Create new secret key.
- Copy the key (only shown once).
- Paste in JAMS IMES as above.
Cost: AI Builder uses minimal tokens per flow draft (~$0.01–$0.05). Typical JAMS IMES tenants spend under $1/month even with daily flow building. Set an OpenAI usage cap in your OpenAI dashboard if you're worried about runaway costs.
Other reasons for heuristic mode
If the key IS set and you're still seeing the banner:
| Likely cause | What to check |
|---|---|
| Key was revoked or rotated in OpenAI | Open OpenAI dashboard → API Keys → confirm the key listed is the one in JAMS IMES. If you rotated it in OpenAI, paste the new value in JAMS IMES. |
| OpenAI account has no credit | OpenAI requires a payment method on file. Free trial credits expire. Check OpenAI → Billing → make sure you have an active payment method. |
| Rate-limited | First-time OpenAI accounts have low default limits. Usually resolves automatically within 30 days as your account reputation builds. For an immediate workaround, request a limit increase via OpenAI support. |
| Network issue | If your tenant is hosted on a private network blocking outbound HTTPS to api.openai.com, AI Builder can't reach OpenAI. This is rare in JAMS IMES's hosted environment. |
How to verify the key is being used
After saving the key:
- Reload AI Builder.
- Type a simple prompt:
Alert me by SMS when something hits a webhook. - Submit.
- If the response is a thoughtful, multi-line draft → AI is working.
- If the response is a generic "I built a basic webhook flow for you" with no follow-up questions → still heuristic. Re-check the key.
What heuristic mode CAN do
Heuristic mode isn't useless — it just has narrower vocabulary. It correctly handles:
- Webhook trigger + SMS or call to a single recipient
- Email-from-keyword trigger + alert
- Simple escalation timing (1–10 minute interval)
What it CAN'T do without real AI:
- Complex multi-step prompts ("monitor X and if it happens twice in 5 minutes alert Y")
- Inferring missing details (recipients, channel preferences) from context
- Plain-English variations beyond a handful of templates
If you're stuck in heuristic mode but need a complex flow, use the manual flow builder instead — it has the same expressiveness as AI Builder, just clickier.
What's next
- Using AI Builder — once the key is set, see the prompts that work best
- Getting Started if this is your first flow