OSV01D
integration & webhook engineering

Your webhook is dropping orders.

Stripe, Shopify and GitHub retry a delivery when an endpoint is slow or answers with an error. If the handler isn't idempotent, one payment becomes two. If the signature isn't verified, anyone who learns the URL can forge a payment. I find which of those is happening and fix it, at a fixed price.

Fixed scope. Flat price in CAD. No retainer you have to remember to cancel.

Get the free endpoint check See pricing
pricing

Four tiers, one price each

Diagnostics are free because a report nobody can argue with is the only honest way to start. Everything after it has a number attached before any work begins, so there is no hourly rate to negotiate and no scope to discover halfway through.

Tier 0 — Health check
Free
report in 24 hours
  • DNS and TLS certificate, including expiry
  • Reachability and acknowledgement latency
  • Server fingerprint and status codes
  • Signature verification, if you authorise the probe
  • A written report, yours to keep either way
No account, no signup. One URL.
Tier 1 — Webhook fix
$250 CAD
48 hours, one endpoint
  • Signature verification against the raw body
  • Idempotency: a redelivery is a no-op
  • Acknowledgement returns before the slow work
  • One test proving duplicates are safe
  • Patch and test are yours, no lock-in
The standard job. Most endpoints need exactly this.
Tier 2 — Monitoring
$75 / month
weekly, ongoing
  • The health check re-run every week
  • A synthetic event in your test suite
  • Alert on certificate expiry or slowing ack
  • Email when a check changes state, silence when it doesn't
Cancel whenever. No minimum term.
Tier 3 — Integration build
$1,500+ CAD
scoped, usually 1–3 weeks
  • A new integration, end to end
  • Payments, inventory, CRM, or ERP
  • Webhook receiver, retries, replay tool
  • Written scope and a fixed price before work starts
Quoted from a 30-minute call and your docs.
the free check

What the check actually does

It is passive by default: one request per check, no payloads, nothing stored on your endpoint. The only active probe sends an unsigned event to see whether you reject it — and that runs only after you say yes, because posting to an endpoint you haven't authorised is not a test. 

$ check https://shop.example/webhooks/stripe

  dns          PASS  shop.example resolves
  transport    PASS  certificate valid, 54 days remaining
  reachability PASS  endpoint answered 200
  latency      FAIL  acknowledgement took 9.10s
  signature    FAIL  accepted a POST with no signature header

  verdict: needs work (40/100)
9.1sack time, retried by the provider
2xevents delivered per order
0signatures verified
1endpoint to fix
software

Built and sold, not just rented out

Some problems are the same for everyone, which makes them a product instead of a project. These are written, tested, and delivered as code you own.

✍ Hand Made by a Human · Served by Intelligence

fixkit — webhook verification kit

The three signature schemes that people get wrong, done correctly: Stripe's t.body HMAC, Shopify's base64 digest, GitHub's sha256= prefix. Plus an idempotency store and the tests that prove a redelivery is a no-op.

Python. No framework required. Drop it into an existing handler.

Hand Made by a Human · Served by Intelligence $149 one-time

Custom software build

A tool that does one job properly: a scraper, a report generator, an internal dashboard, a migration script, a CLI that replaces a spreadsheet. Delivered with tests and a README you can hand to someone else.

Scope and price agreed in writing before any code is written.

Hand Made by a Human · Served by Intelligence from $2,500 CAD

Automation script

One job, one file, one afternoon. Pull data from an API into a spreadsheet. Rename and file a folder of exports. Post a daily summary somewhere useful. Fixed scope, fixed price, no subscription.

If it turns out to be a two-week project, I'll tell you instead.

Hand Made by a Human · Served by Intelligence $350 flat
scope

Written down before you pay

Most of the value of a fixed price is the part it refuses to include. Here is both halves.

Included

  • The endpoint check, written up as a report
  • A patch that verifies signatures and handles duplicates
  • A test proving a redelivery changes nothing
  • One round of questions after delivery
  • Code you own outright, no licence to renew

Not included

  • More than one endpoint on a Tier 1 job
  • Your application logic beyond the handler
  • Hosting, DNS, or infrastructure changes
  • Access to your production, or to any bank account
  • Guarantees about a third party's behaviour

How I work

  • You run the patch. I never deploy to your production.
  • No automated outreach, no scraped mailing lists, no spam.
  • If the check finds nothing wrong, I say so and sell you nothing.
  • If the job is wrong for me, I decline it rather than guess.

Payment

  • Interac e-Transfer, in CAD, after you accept the scope.
  • Tier 1 is paid on delivery of the patch and test.
  • Projects over $1,500 are half on start, half on delivery.
  • No card on file, no subscription, no auto-renewal.
how it goes

From one URL to a fixed endpoint

  1. You send the URL

    One endpoint, and the provider it receives from. Nothing else is needed to start.

  2. You get the report

    Usually within a day. It names what is wrong in plain language, and what each fault costs you.

  3. You decide

    If the report is clean, nothing is for sale and that's the end of it. If it isn't, the price and the scope are already written down.

  4. You get a patch and a test

    Within 48 hours of Tier 1 starting. You run it in your own pipeline, on your own schedule.

start here

Send the endpoint URL.

No form, no account, no discovery call required. If you'd rather talk first, say what's breaking and I'll answer with something specific.

jrchevdog@gmail.com

At a glance

  • Webhook check — free
  • Webhook fix — $250 CAD, 48 hours
  • Monitoring — $75 CAD / month
  • Integration build — from $1,500 CAD
  • Custom software — from $2,500 CAD
  • Automation script — $350 flat