Payments and messaging

Used here, in this category

• Resendserves
  Sends the single-use CV link. The only outbound mail this site sends.
  Evidence: functions/_lib/cv-email.ts

All 29

Alphabetical. Checked on 2026-09-04; anything that did not answer says so.

• Ably
  Hosted realtime messaging with delivery guarantees and presence, sold on what happens when connections drop.
  Sells the reconnection, not the websocket.
• Anymail finder
  Finds work email addresses from a name and a domain, and charges only for the ones it can verify.
  Prices itself on the deliverable, not the lookup.
• Applozic the certificate does not validate
  Chat and messaging SDKs. The site presents an expired or misconfigured certificate and would not load.
  Unreachable: the certificate does not validate.
• Braintree
  PayPal's payment platform for merchants who need cards, wallets and PayPal behind one integration.
  PayPal's answer to being only PayPal.
• EasyPost
  One API across many carriers for rates, labels and tracking.
  Abstracts the carriers, who all disagree.
• FormSpree
  A form backend for static sites, so an HTML form can submit without any server behind it.
  The one server a static site still needed.
• Heybounce
  Email validation before sending, protecting sender reputation from hard bounces.
  Cheaper than the reputation damage.
• Hunter.io
  Finds and verifies professional email addresses from a domain, one of the older tools in this category.
  The incumbent everyone else is compared to.
• Imitate Email
  Captures outbound mail in development so a test run cannot reach a real inbox.
  Stops the staging environment emailing your customers.
• Increase
  An API-first bank for technology companies, giving direct access to payment rails rather than a wrapper over one.
  A bank with an API, not an API over a bank.
• Knock
  Notification infrastructure: templates, preferences, batching and delivery across channels.
  The notification system nobody wants to build twice.
• LemonSqueezy
  Sells digital products as merchant of record, taking on sales tax and VAT compliance.
  Sells you out of the tax problem.
• Lob
  Physical mail as an API, with a print and delivery network behind it.
  An API call that arrives in an envelope.
• Loops
  Marketing, lifecycle and transactional email in one product, aimed at software teams rather than marketing departments.
  One sender for both kinds of email.
• MagicBell
  Notification infrastructure across email, push, Slack and SMS, with user preferences handled.
  The preference centre nobody wants to build.
• Mailgun
  Transactional email APIs with deliverability tooling, one of the long-standing options for programmatic sending.
  Sells deliverability, which is the part that is hard.
• Novu
  Open-source notification infrastructure across in-app, email and SMS, self-hostable.
  The notification layer, without a vendor holding it.
• OpenMeter
  Usage metering and entitlements for consumption pricing, open source, now part of Kong.
  The meter behind usage-based billing.
• Paddle
  Merchant of record for software, handling tax, fraud and payments so a small team can sell globally.
  Takes the compliance, not just the payment.
• Pingram
  One API for email, SMS, voice and WhatsApp, with the telecom registration handled.
  Four channels, one integration, and the paperwork done.
• Plaid
  Connects applications to bank accounts for balances, transactions and payments. The layer most fintech is built on.
  The plumbing under most financial products you have used.
• Resend
  Transactional email for developers, with templates written in React and a deliverability-first pitch.
  Made sending email feel like a modern API again.
  Used here: functions/_lib/cv-email.ts
• Sendgrid
  Long-standing transactional and marketing email at large volume. Now part of Twilio.
  The one that carried a lot of the internet's email.
• Stigg
  Pricing, entitlements and usage metering as infrastructure, so a pricing change is not a code change.
  Pricing that product can edit without a deploy.
• Stream
  Activity feeds, chat and video as APIs on an edge network, so social features do not require building the hard parts.
  The feed and the chat, both already solved.
• Stripe Payments
  The payments API that made accepting money a library call. Documentation quality alone reset expectations for the industry.
  Changed what developers expect from any API.
• Twilio
  SMS, voice, video and messaging APIs. The company that made telecoms something you call from code.
  Turned the phone network into an API.
• Vonage
  Voice, messaging and video APIs alongside unified communications, from a carrier-scale business.
  Communications APIs with a telecom behind them.
• Zyntra
  Unlimited disposable inboxes with API access, for testing email flows and QA.
  An inbox per test run.

Other shelves