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APIs · head to head

curl vs Unit

curl logo

curl

APIs

Command-line tool for transferring data using URLs with wide protocol support

From
Free
Rated
-
Full reviewWebsite
Unit logo

Unit

APIs

Banking as a service platform for embedding deposit accounts, cards and payments, with a sponsor bank behind it

From
On request
Rated
-
Full reviewWebsite

The short version

  • Only curl has a free tier, so it costs nothing to try first.
  • Each has a real cost: curl open-source with no vendor pricing: curl is free and open-source under GPL 3.0; no subscription or licensing costs apply; Unit your product depends on a sponsor bank you do not contract with directly, and 2024 showed what that means: Thread Bank received an FDIC enforcement action naming its banking as a service programmes and Blue Ridge Bank went under an OCC consent order and offboarded fintech partners.
  • They diverge on capability: curl covers HTTP/HTTPS, Unit covers Deposit accounts.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which curl and Unit actually diverge.

Attributes where curl and Unit differ
AttributecurlUnit
Starting priceFreeOn request
Pricing modelopen-sourcequote
Free tierYesNo
PlatformsLinux, MacOS, Windows, Unix, MobileWeb, iOS, Android
Founded1997Unknown

Identical on both: user rating (Not yet rated), category (APIs).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in curl

  • HTTP/HTTPS
  • FTP
  • Multiple protocols
  • Universal compatibility
  • Scripting tools
  • Linux support
  • MacOS support
  • Windows support

Only in Unit

  • Deposit accounts
  • Card issuing
  • Payments
  • White label components
  • Compliance operations
  • Lending
  • Programme reporting
  • Sandbox

What people use each for

The jobs each tool is most often brought in to do.

curl

  • API Developmentnot Unit
  • API Gatewaynot Unit
  • API Testingnot Unit
  • API Documentationnot Unit
  • Microservicesnot Unit

Unit

  • A vertical SaaS platform for contractors that wants to hold customer funds and issue expense cards without pursuing a charternot curl
  • A payroll or benefits platform embedding accounts so employees can be paid ahead of schedulenot curl
  • A marketplace that wants seller balances to sit in real accounts under its own brand rather than as ledger entries at a processornot curl
  • A company that needs interchange revenue from a card programme to make the unit economics of its core product worknot curl

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

curl

  • Open-source with no vendor pricing: curl is free and open-source under GPL 3.0; no subscription or licensing costs apply
  • Commercial support costs hidden: site references 'commercial support available' but pricing is not detailed or accessible from homepage
  • No SaaS model: curl is a command-line tool and library; costs are limited to optional commercial support contracts (pricing unknown)
  • Self-support burden: free software means customers rely on community forums or undisclosed commercial support pricing

Unit

  • Your product depends on a sponsor bank you do not contract with directly, and 2024 showed what that means: Thread Bank received an FDIC enforcement action naming its banking as a service programmes and Blue Ridge Bank went under an OCC consent order and offboarded fintech partners.
  • Programme approval by the bank is a separate gate from signing with Unit, and it can add months and impose product restrictions that were not visible during the commercial conversation.
  • Compliance obligations are shared but the operational load lands on you, and platforms consistently underestimate the staffing needed for disputes, escalations and the bank ongoing oversight requests.
  • Pricing is unpublished and blends platform fees, per-account and per-transaction charges and interchange sharing, which makes it hard to model unit economics before you have volume and easy to be surprised by the minimum.
  • Migrating a live deposit programme to a different provider or bank is extremely disruptive because it involves moving customer accounts and card credentials, so switching costs are far higher than for ordinary software.

Pricing, plan by plan

curl

Free
  • Open SourceFree
    • Full curl functionality
    • Community support

Unit

On request
  • Unit Banking as a Service$undefined/year
    • Platform fee plus per-account and per-transaction charges, quoted
    • Interchange sharing arrangements negotiated per programme
    • Minimum commitment typical

Which should you pick?

Choose curl if

  • You need http/https.
  • You want to start without paying.
  • You work on Linux, MacOS, Windows, Unix, Mobile.
  • You also want ftp.
curl review

Choose Unit if

  • You need deposit accounts.
  • You work on Web, iOS, Android.
  • You also want card issuing.
Unit review

Questions people ask

Is curl or Unit better?
Neither clearly leads. curl starts at Free and Unit at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, curl or Unit?
curl has a free tier; the other does not. Paid plans start at Free for curl and On request for Unit.
Does curl or Unit run on more platforms?
curl runs on Linux, MacOS, Windows, Unix, Mobile. Unit runs on Web, iOS, Android.
Can I use curl for free?
Yes. curl has a free tier, so you can try it without paying. Unit starts at On request.
What is curl best used for?
curl is most often used for api development, api gateway, api testing, api documentation. Of those, api development and api gateway are not what Unit is typically brought in for.
What can curl do that Unit cannot?
curl covers HTTP/HTTPS, FTP, Multiple protocols, Universal compatibility. Unit covers Deposit accounts, Card issuing, Payments, White label components.

Answered from the vendors’ own pages

curl: How much does curl cost?

curl is free and open-source software under the GPL 3.0 license. There is no cost to download, use, or modify the software.

Source
Unit: Who actually holds the money?

A chartered partner bank, not Unit. Deposits sit at the sponsor bank and FDIC insurance flows from that bank, so its condition is your condition.

curl: Is commercial support available for curl?

Yes. The curl website references 'commercial support available,' but pricing and details are not disclosed on the homepage and require visiting the support page.

Source
Unit: What happened with Unit sponsor banks in 2024?

Thread Bank received an FDIC enforcement action that explicitly named its banking as a service and lending as a service programmes, and Blue Ridge Bank was under an OCC consent order from January 2024 and offboarded fintech partners. Blue Ridge exited the order in late 2025.

curl: Can I sponsor curl financially?

Yes. The curl website offers an option to 'Sponsor curl financially.' Visitors can donate to support curl development, but the donation link must be accessed through the site's support section.

Source
Unit: What does Unit cost?

Not published. Expect a platform fee, per-account and per-transaction charges, an interchange share and a minimum commitment.

Unit: Do we need our own compliance team?

Yes. Unit supplies tooling and the bank sets the rules, but disputes, escalations and evidence for bank oversight require named people on your side.

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