Guides / culpa vs respan
Culpa vs Respan
Respan, the platform formerly called Keywords AI, is a gateway and observability product that sets budgets per key, per customer or org-wide and blocks requests before spend runs away. Culpa, a local-first LLM cost, margin, and forecast ledger, prices those calls against what each customer pays you and forecasts next month with a range.
Why this happens
Respan gets closer to Culpa's question than anything else in this cluster, and the gap that remains is exact. It sets budgets and rate limits per key, per customer or org-wide, warns as you approach them and blocks requests past them. Its feature table lists cost and usage tracking, user analytics and custom properties on every tier including the free one. So per-customer cost attribution is there, and per-customer enforcement is there, which is more than most of this category ships. Two things aren't. A budget is a number you chose, so it tells you what you'll allow rather than what you'll spend, and the tool holds no revenue, so the spend it attributes to a customer has nothing to sit against. Note also that keywordsai.co now resolves here and the footer still reads Keywords AI, Inc, so the rename is recent enough that older references point at the old name.
What this usually looks like
- You can cap a customer's spend and can't say whether that customer is profitable.
- A budget got raised because a customer complained, and nobody checked what they pay you.
- Per-customer cost exists and per-customer revenue lives in the billing system nobody joins to it.
- You know which key overspent and not which ones are worth the money.
- Your forecast is last month's number with a percentage added.
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Run the free Cost Leak Scan
It shows your most expensive conversation before you install anything.
Mistakes that cost the most
| Mistake | Why it hurts | Do instead |
|---|---|---|
| Reading a per-customer budget as per-customer economics. | A budget is a ceiling you set. Economics needs the revenue that customer pays, which no observability tool holds. | Join attributed spend to your billing system, or use a ledger that already carries revenue. |
| Treating a warning threshold as a forecast. | A threshold fires when you get there. A forecast tells you beforehand, with a range. | Keep the threshold for safety and project the month from your own history. |
| Assuming old Keywords AI links and docs still describe today's product. | The product renamed to Respan and older material may not match the current feature set. | Verify against respan.ai directly rather than cached references to the old name. |
Run this check tonight
- Pick your largest customer by spend and write down what they pay you.
- Divide one by the other, and see whether any tool did that for you.
- Ask what next month costs, with a range rather than a point.
- Check whether your budget thresholds were derived from anything or just chosen.
A budget cap and a margin, on the same customer
Respan can cap a customer at a monthly figure and block requests past it. Take a customer capped at $300 a month of model spend who pays you $250 a month, priced on Claude Haiku 4.5 at real rates of $1.00 and $5.00 per million from the price book, effective 2026-07-02. Their usage is modelled and the rates are real.
The cap did its job and the customer is still unprofitable, because the cap was never told what they pay. A ceiling set above your revenue is a ceiling that protects nothing, and no tool without revenue can tell you where to set it.
Every number, with its confidence and source
| Figure | What it means | Confidence | Source |
|---|---|---|---|
| $199 per month | Respan's published Team plan price, billed yearly | provider-reported | respan.ai/pricing, read 2026-08-03. Team includes 100k logs and 10k scores with unlimited datasets, evaluators and prompts, additional logs at $8 per 100k and additional scores at $1 per 1k. Free is $0 with 100k logs, 1k scores, 5 datasets, 2 evaluators and 5 prompts. Enterprise is custom. |
| -$50.00 per month | modelled margin on a customer capped at $300 of spend who pays $250 | calculated | 150M input tokens at $1.00 per million plus 30M output tokens at $5.00 per million on Claude Haiku 4.5 = $150.00 + $150.00 = $300.00 of model spend, against $250.00 of revenue, giving -$50.00. Rates are real, from the price book effective 2026-07-02. Token volumes, the cap and the revenue figure are modelled. |
What a generic answer can’t know
Respan is the closest thing in this set to what Culpa does, so the honest comparison is narrow rather than sweeping. It attributes cost per customer, it enforces budgets at that granularity, and it does both on the free tier. Everything up to the join is covered. What it doesn't hold is the revenue side, and that single missing column is the difference between attribution and economics: a customer costing $300 is a fact, and whether that's good depends entirely on what they pay you. Culpa carries that figure, so it reports margin per customer rather than spend per customer, prices every call from a versioned price book in exact decimal so the totals reconcile, and forecasts next month from your own history with a range rather than a threshold you picked.
Questions founders ask next
Is Respan the same as Keywords AI?
It's the same company under a new name. keywordsai.co now resolves to respan.ai, and the footer on that site reads Keywords AI, Inc with Respan as a registered trademark, read 2026-08-03. Older documentation and links under the previous name may not match the current product.
Does Respan track cost per customer?
Yes, and this page says so plainly. Its published feature table lists cost and usage tracking, user analytics and custom properties on every tier including the free one, and it sets budgets per key, per customer or org-wide. Cost attribution isn't the gap.
So what does Culpa add over Respan?
The revenue each customer pays you, which turns cost per customer into margin per customer, and a forecast of next month from your own history rather than a threshold you chose. Neither appears in Respan's published feature set as read on 2026-08-03.
What does Respan cost?
Free is $0 with the full platform, 100k logs, 1k scores, 5 datasets, 2 evaluators and 5 prompts. Team is $199 a month billed yearly with unlimited datasets, evaluators and prompts. Additional logs are $8 per 100k and additional scores $1 per 1k. Enterprise is custom. Read 2026-08-03.
On your infrastructure
Culpa runs on your infrastructure. Your prompts and responses never leave it. Culpa counts calls to run your plan, and it fails open, so if it ever breaks your app keeps running.
How Culpa works
Find the culprit. Not just the total.
Your dashboard shows what you spent. It stops short of who spent it. Culpa shows the conversation, the user and the feature behind it.
Your prompts stay local.
Culpa runs on your own infrastructure. What you send to a model reaches us at no point.
Every dollar has a name.
Follow any charge to the conversation, the user, the feature and the customer behind it.
See the bill before it lands.
Cost your next feature before you ship it. You get the likely bill and the worst case, at best, median, p90 and p99.
Three steps to your first answer.
Change one base URL.
Or drop in the Python or TypeScript library.
Find your most expensive conversation.
In the first session, not the first week.
Cost your next feature before you ship it.
Why the bill went up
Example dashboardCalls traced
418,209
across 3 projects
Spend this week
$378.41
+ $182 vs last week
Failed calls
312
74% retried, and you paid for all of them
+ $182 this week traced to one culprit
Spend over 14 days
Most expensive users
Next week forecast
Graded against reality. Accuracy shown as results land.
Free, no card, no account
Run the free Cost Leak Scan
It shows your most expensive conversation before you install anything.
Keep reading
Sources: Respan, Respan pricing. Last reviewed 2026-08-03. Plain text version.