Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add sumup/sumup-skills --skill sumup-debuggit clone --depth 1 https://github.com/sumup/sumup-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/sumup/sumup-skills/sumup-debug)<a href="https://agentmods.dev/skills/sumup/sumup-skills/sumup-debug"><img src="https://agentmods.dev/badge/skills/sumup/sumup-skills/sumup-debug/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/sumup/sumup-skills/sumup-debug"><img src="https://agentmods.dev/badge/skills/sumup/sumup-skills/sumup-debug.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00049 | $0.00869 |
| Opus 5.5 | $0.00020 | $0.00348 |
| Sonnet 5.5 | $0.00010 | $0.00174 |
| Haiku 4.5 | $0.00005 | $0.00087 |
Grade A, and why
sumup-debug scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 179 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SumUp Troubleshooting Playbook
Use this skill for diagnosis and remediation of failing SumUp integrations.
Fast Triage Matrix
- Classify symptom:
- Auth/signature error
- Checkout creation/processing error
- Widget/client-side mount or flow error
- Async mismatch (success in UI, failure in backend state)
- Capture evidence:
- request/response payloads (sanitized), HTTP status, error code/message
- checkout id, merchant code,
checkout_reference - webhook delivery id and signature verdict
- Reproduce in sandbox before changing production behavior.
Common Failures and Fixes
HMAC signature mismatch (x-payload-signature)
Symptoms:
- Webhook verification fails for all events or intermittently.
Likely causes:
- Body parser mutates payload before verification.
- Wrong webhook secret/environment pair.
- Digest computed with non-raw body bytes.
Fix:
- Verify against raw request body bytes.
- Ensure HMAC SHA-256 with exact configured secret.
- Confirm secret belongs to the same merchant/environment.
Verify:
- Signature validation passes for replayed payload and for live sandbox webhook.
Expired checkout/session window
Symptoms:
- Payment attempt fails after delay, stale checkout status, or timeout flow.
Likely causes:
- Checkout left pending beyond validity window.
- Frontend retries with expired checkout id.
Fix:
- Create a new checkout for each retry attempt.
- Add frontend timeout handling that requests a fresh checkout.
Verify:
- Retried flow always uses new checkout id/reference and succeeds in sandbox.
Missing scope activation or auth mismatch
Symptoms:
- 401/403 responses despite valid credentials.
Likely causes:
- Missing
paymentsor other required scope. - API key used where OAuth is required, or vice versa.
Fix:
- Confirm auth model for integration type.
- Request/enable required scopes and re-issue token/key as needed.
Verify:
- Previously failing endpoint succeeds with least-privilege valid credentials.
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 179 lines · 49 tokens per session scan A 473fb06d1af1
sumup-debug is a skill published in the GitHub repository sumup/sumup-skills (5 stars, last pushed today), licensed Apache-2.0. It adds 49 tokens to every session and 869 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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