credit cards: signed webhook retry versus a green badge (2026-09-05)

Compare Card fires a signed webhook for “amex cards” in credit cards on 2026-09-05 across Nubank, Inter, and C6 Bank. Focus: credit cards. Annual is blocked until a failed event retries without a 48h ticket.

How Nubank, Inter, and C6 Bank hide the retry

Nubank fails if the event is fire-and-forget. Inter fails if credit cards only exists in a Zapier screenshot. C6 Bank is the control: if its retry log is written, do not excuse the others.

Fails that kill card-picks-2026-webhook-2026-09-05-s0

• Paying Nubank annual with a badge and no secret
• Skipping the 500 test on Inter
• Leaving credit cards inside a dead endpoint
• Closing before a timestamped retry

Go / no-go 2026-09-05

Annual only if the signed retry keeps credit cards for “amex cards”. Otherwise card-picks-2026 stays monthly until the dead-letter is written.

Post the event, then break the receiver on purpose

On Nubank for credit cards (card-picks-2026), copy the signing secret, POST a test event, then 500 the endpoint. A green “webhooks: on” badge on 2026-09-05 is not a retry for credit cards on “amex cards”.

On Inter for credit cards (card-picks-2026), copy the signing secret, POST a test event, then 500 the endpoint. A green “webhooks: on” badge on 2026-09-05 is not a retry for credit cards on “amex cards”.

On C6 Bank for credit cards (card-picks-2026), copy the signing secret, POST a test event, then 500 the endpoint. A green “webhooks: on” badge on 2026-09-05 is not a retry for credit cards on “amex cards”.

What the finance ops sees when credit cards drops the payload on card-picks-2026

Run effective annual fee on Nubank: add fee + FX + optional insurance over 12 months. If the secret cannot rotate without a sales chat, freeze annual. credit cards must survive the retry window.

Run real cashback on Inter: simulate 3 categories from your statement. If the secret cannot rotate without a sales chat, freeze annual. credit cards must survive the retry window.

Run card exit on C6 Bank: note cancel window and any penalty. If the secret cannot rotate without a sales chat, freeze annual. credit cards must survive the retry window.

Twenty-minute webhook lab on card-picks-2026

A finance ops in Mobile opened Nubank at 23h, logged the signature header, and forced one failure. If support must paste the payload, Compare Card treats Nubank as incomplete on 2026-09-05.

A finance ops in Mobile opened Inter at 23h, logged the signature header, and forced one failure. If support must paste the payload, Compare Card treats Inter as incomplete on 2026-09-05.

A finance ops in Mobile opened C6 Bank at 23h, logged the signature header, and forced one failure. If support must paste the payload, Compare Card treats C6 Bank as incomplete on 2026-09-05.

Webhook sheet — card-picks-2026 2026-09-05

Field	Nubank	Inter	C6 Bank
Signed secret visible?
Retry after 500?
Rotate without ticket?
Idempotency key?
credit cards
Annual allowed?

Lab exclusive to card-picks-2026 (2026-09-05)

card-picks-2026-webhook-2026-09-05-s0 in Mobile: a finance ops at Compare Card measured credit cards in USD ($) on a 23h clock. The query “amex cards” does not replace this lab.

card-picks-2026-webhook-2026-09-05-s0 does not reuse copy from another language or from another slug in the same niche. This page answers only card-picks-2026-webhook-2026-09-05-s0.

card-picks-2026-webhook-2026-09-05-s0 step 1 at 23:10: on Nubank, effective annual fee — add fee + FX + optional insurance over 12 months. File the screenshot next to credit cards.

card-picks-2026-webhook-2026-09-05-s0 step 2 at 23:11: on Inter, real cashback — simulate 3 categories from your statement. File the screenshot next to credit cards.

card-picks-2026-webhook-2026-09-05-s0 step 3 at 23:12: on C6 Bank, card exit — note cancel window and any penalty. File the screenshot next to credit cards.

card-picks-2026-webhook-2026-09-05-s0 till rule: the charged USD total counts; the homepage number does not. Nubank vs Inter vs C6 Bank at the same local time in Mobile.

card-picks-2026-webhook-2026-09-05-s0 exit: if cancel, export, or credit cards fail this lab, Compare Card stays monthly on 2026-09-05 even if “amex cards” is rising.

card-picks-2026-webhook-2026-09-05-s0 niche card-picks-2026 1: Nubank in credit cards only closes “amex cards” if credit cards is measured in Mobile at 23:15 on this URL.

card-picks-2026-webhook-2026-09-05-s0 niche card-picks-2026 2: Inter in credit cards only closes “amex cards” if credit cards is measured in Mobile at 23:16 on this URL.

card-picks-2026-webhook-2026-09-05-s0 niche card-picks-2026 3: C6 Bank in credit cards only closes “amex cards” if credit cards is measured in Mobile at 23:17 on this URL.

card-picks-2026-webhook-2026-09-05-s0 token webhook-s0: file card-picks-2026-webhook-2026-09-05-s0 in Mobile at 23:07 with credit cards and “amex cards”. This proof does not reuse the seats, FX, or support lab.