Open source affiliate software in 2026

What "open source affiliate software" actually means

The phrase is doing a lot of work. To most teams searching for it, it means three related but distinct things:

• An open-source license you can read and modify. MIT, Apache, AGPL — the actual source of the attribution engine, the click router, and the payout ledger is in a public repository you can fork.
• A self-hosting path. You can run the system on your own infrastructure, on your own database, behind your own domain. Nothing about the core product requires phoning home to a vendor.
• Data portability. Your clicks, identities, events, attributions, and commission ledger export cleanly and re-import elsewhere — including back into a self-hosted copy of the same software.

A tool that has only one of those properties isn't really what those teams are looking for. A "source-available" license that bans commercial use, a self-host option that costs more than the hosted plan, or an "export" that produces a lossy CSV you can't re-import — those are vendor lock-in dressed in friendlier language.

Why open source matters for partner programs specifically

Affiliate and partner programs are unusually bad places to be locked in. Three reasons.

1. Attribution history compounds

A two-year-old click that converts today is worth real money, and the only way to attribute that conversion correctly is to still have the click. Every month you run a program, your attribution log gets more valuable — and harder to migrate. A vendor who knows that has every incentive to make the export shape just lossy enough that switching means starting over.

2. The partner side has to trust the books

Partners are paid from a ledger they didn't generate. If the merchant changes platforms and partners suddenly see a different commission history, that's a trust problem. Open source plus immutable raw-event tables means the math is auditable from outside the platform — anyone holding the raw export can re-derive the numbers, and a brand can show a partner exactly which events earned what.

3. Pricing leverage flips when the source is open

A hosted-only platform priced at 5% of partner-driven GMV has nothing stopping it from raising the rate. A hosted platform built on an MIT core that you can self-host for free at any time has a natural ceiling on what it can charge. The vendor still earns its hosted price; it just earns it from convenience, not lock-in.

The current open-source affiliate landscape

Here is the honest state of what's actually available in 2026.

Tool	License	Status	Best fit
OpenPartner	MIT	Active — built for modern SaaS	SaaS / B2C teams that want Stripe-native attribution, marketplace, optional self-host
Post Affiliate Pro	Proprietary	Active, cloud-only for new customers: no standalone licenses sold since June 2022	Programs already on its hosted plans
Reflio	GPL-3.0 or AGPL-3.0, depending on the copy	Unavailable: original repository and website gone (October 2026)	None for new programs
Raider	MPL-2.0	Small and stable: Rust, last release September 2023	Teams that want a self-hosted affiliate dashboard fed by their own backend
AffiliateWP	GPL v2+ (paid plugin; the license key covers updates and support)	Active	WordPress-only programs
Roll your own	Yours	Always available	Teams that enjoy maintaining attribution code more than building their actual product

A quick tour of what's out there

Reflio (unavailable)

Reflio was the obvious early answer — open source, built on Next.js and Supabase, focused on Stripe. As of October 2026 its GitHub repository returns a 404 and reflio.com no longer serves a site, so all that's left are other people's copies of the code. Those copies stop in early January 2023, and their stated license varies: a mid-2022 copy says GPL-3.0, a later one says AGPLv3 with a paid commercial license option. If you fork one, you start from code last touched in January 2023, built around Supabase, with no upstream to send fixes to.

Raider (niche)

Raider is a small, self-hosted affiliate dashboard written in Rust and licensed MPL-2.0, and used by Crisp. Affiliates sign up, create tracking links, see their balance and request payouts; your backend reports each referred payment to its API, and you pay affiliates yourself. Its last release was in September 2023. If that's all you need, it's a reasonable building block. It's an affiliate dashboard rather than a partner platform: the billing integration is yours to write. Different shape of problem.

Post Affiliate Pro (proprietary, cloud-only for new customers)

Post Affiliate Pro is the elder statesman, sold by Quality Unit, a company founded in 2004. It used to be the usual pick for affiliate software you could install on your own server, but it was never open source. Quality Unit ended sales of new standalone licenses in 2020 and switched off purchases on June 1, 2022. The last standalone release, and support for it, ended on December 31, 2022, so existing self-hosted installs get no more updates. New customers can only buy it hosted, from $89/month on monthly billing ($79 billed annually) as of October 2026. It works and it's still actively maintained. It also looks its age, has a feature surface designed for the affiliate networks of that era, and lists its Recurring commissions feature only on its Ultimate plan ($269/month, or $249 billed annually) and up. It earns its place for programs already running on it; few new programs should start there, and it isn't an option if you want to self-host.

AffiliateWP (WordPress-only)

The plugin is GPL-licensed (v2 or later), but it's sold as a paid plugin: the yearly license key covers updates and support, and once it lapses and a grace period ends, the admin screens lock while the front end keeps running (as of October 2026). Mentioned because it shows up in the same searches. If your store and your site both live inside WordPress and WooCommerce, it can be the right answer. Outside that world, it doesn't extend.

Rolling your own

Always an option. We've watched several teams do it. The first version takes a weekend; the production-quality version takes six months and never quite ships, because the work that looks small from the outside — Safari ITP, cross-device stitching, recurring-revenue commission math, fraud heuristics, payout rails — is most of the actual product.

OpenPartner: the modern open-source answer

We built OpenPartner because the alternatives above were either abandoned, niche, or dated. The thesis is short:

• MIT-licensed core. The click router, the API, the attribution engine, the partner portal — all in the public repository at github.com/getcoherence/openpartner. No "community edition" with the good parts hidden behind an enterprise tier.
• Three deployment shapes, one codebase. Self-host on your own infrastructure, run on Revshare with no monthly fee, or run on Flex for $49/month. On Revshare each partner sale costs 3% of the sale, or 10% of the commission if that's higher; on Flex it's 1.5% or 5%. The same `main` branch ships all three.
• Raw data is immutable, attribution is derived. Clicks, identities, and events are append-only. Every attribution is computed from them and points back to the click it came from, and the raw layers export alongside the attributions, so anyone with the export can re-derive the numbers outside the platform. You can change a program's model (last-click, first-click, linear, position-based) at any time. The new model applies to conversions from then on; past attributions and commissions aren't recomputed.
• Export-as-import. Your program data (partners, programs, the raw clicks, identities and events, and the commission and payout ledger) exports as a JSON bundle or a SQL dump, and either one restores into a self-hosted instance. Any single table also exports as CSV for spreadsheets, though CSV doesn't restore. Moving off the hosted tier doesn't require a rebuild; the portability docs list what you set up again.
• Marketplace optional. The Network — our partner marketplace — is a separate surface you opt into. It's included in hosted plans; on self-host, Network access is $29/month plus 3% of what you pay partners you found through it. The core software works without it.

What self-hosted affiliate tracking looks like in practice

For OpenPartner, the single-box deploy is the repo's production Compose file: point DNS at the box, fill in the environment, run docker compose -f docker-compose.prod.yml up -d, and finish the install wizard. The stack:

• Postgres — the source of truth for clicks, identities, events, attributions, commissions
• Router — the redirect endpoint at /r/:slug that records the click and sets the first-party cookie
• API — SDK ingestion, admin actions, attribution engine, payouts
• Portal — the admin and partner web UIs

Two CPU cores and 4GB of RAM handle a few hundred thousand clicks a day. The parts that need attention as volume grows — Postgres tuning, router caching, attribution job throughput — are the predictable ones, and they're documented. We wrote a longer piece on what scales when if you want the operational view.

When open-source partner program software is the right answer

Open source isn't always the right call. It's the right call when:

• You expect your program to compound over years and don't want to be locked into a vendor's renewal cycle
• Your partners are technical enough to care about how attribution actually works
• You have a compliance or data-residency story that makes "the data lives in their cloud" a hard no
• You want the option to start hosted and migrate to self-hosted later — or vice versa — without rebuilding
• You'd rather pay for your own servers and upkeep than a percentage of partner revenue

It's the wrong call when you want hands-on help from the vendor. PartnerStack's Enterprise plan includes a designated customer success manager and partner-recruitment support; impact.com includes a dedicated CSM on its Enterprise plan. They sell that well.

Where to go from here

If open source is the shape you want, the practical paths:

• Self-host OpenPartner on your own infrastructure — free, MIT-licensed, one documented Docker Compose deploy
• Start on Revshare with no monthly fee if you want the hosted convenience without the lock-in story
• Read the comparisons against the incumbents: Rewardful, Dub Partners, Tapfiliate, PartnerStack, Post Affiliate Pro

The category looks empty for now. That's the opportunity.