All packsWebhook Durability & ReplaySolve
webhook unparseable payload dead letter not dropped
A payload you've already authenticated should never just be discarded
If a signature verifies but the body fails to parse -- a schema change, a truncated body -- the payload is still persisted as a dead row, not thrown away with a 4xx (D5).
This is one of the things Webhook Durability & Replay already handles. Receive webhooks without losing, duplicating or misordering them when the sender retries.
Is this you?
Returning an error status for a payload that verified but doesn't parse trades a permanent loss for a delayed one: the provider retries the identical unparseable bytes, exhausts its retry budget, and the event is gone for good -- with nothing left to replay once the parser is finally fixed.
Why this one is easy to get wrong
A schema the code doesn't recognize looks like exactly the case that should error loudly, so the code fails fast -- which is the right instinct for almost every other kind of input validation, and the wrong one here, because the provider's retry behavior turns "fail loudly" into "lose the event permanently" once the retry budget runs out.
What you get instead
D5 persists the payload anyway, as status='dead' with delivery_id = 'unparsed:' + sha256(raw), and returns 200. The row is visible, replayable the moment the parser ships a fix, and costs exactly one INSERT -- hashing the raw body keeps it idempotent under the provider's own retries of the same bad bytes.
Source: ARCHITECTURE.md D5 — checkable in the pack you receive
How you actually use this
You don’t install a library or wire up an SDK. Your own coding agent builds the code in your project, and you keep it — no runtime dependency on us.
Step 1
Download and unzip
You get a folder: the docs that tell an agent what to build, a starting skeleton, and the test suite that decides when it's done.
Step 2
Open it in Claude Code or Cursor
Point your coding agent at the folder. Nothing to install, no account with us, no API key.
Step 3
Paste one prompt
The pack contains the exact prompt. Paste it as your first message and leave it alone — it works through the build itself, choosing a cheaper or stronger model per task.
Step 4
Run ./verify.sh
One command. It prints a pass or fail for every check. Green means the build is done — the same script we ran to produce the receipt on this page.
Typical build: about 40 minutes of your agent working, mostly unattended. Then you integrate the working module into your app the way you would any code you’d written yourself.
Why you can believe this
3 of 3 runs passedWe ran this pack from an empty folder 3 times and published exactly what happened — every check, the model, the token cost, the wall time. Not a testimonial, and not our opinion: the same verify.sh you run yourself. Read the full receipt →