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 open source affiliate software. 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 — partners can re-derive their numbers from the same events the merchant has.

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 (source-available)	Active but dated — built ~2004	Legacy programs that already run it
Reflio	MIT	Effectively abandoned (2022)	Read-only reference
Raider	MIT	Niche Laravel package	PHP/Laravel shops that want a tracker, not a platform
AffiliateWP	Proprietary (WordPress plugin)	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 (abandoned)

Reflio was the obvious early answer — MIT-licensed, Next.js, Stripe-focused, built around 2021. It worked. It also stopped getting maintained shortly after, and the repo hasn't seen a real commit in years. If you fork it today you inherit unmaintained dependencies, no migration path off Supabase, and a product surface that never finished. Useful as a reference; not safe to deploy in production.

Raider (niche)

Raider is a Laravel package, not a platform — it gives a PHP/Laravel app the ability to track referrals. If you're already deep in Laravel and want a tracker rather than a tool, it's a reasonable building block. It isn't a partner portal, a payout system, or a marketplace. Different shape of problem.

Post Affiliate Pro (dated, mostly proprietary)

Post Affiliate Pro is the elder statesman — built around 2004, sold by Quality Unit with a source-available license model that includes a self-host SKU. It works. It also looks like 2004, has a feature surface designed for the affiliate networks of that era, and treats SaaS recurring revenue as a bolt-on rather than a first-class concept. It earns its place for legacy programs that already run on it; few new programs should start there.

AffiliateWP (WordPress-only)

Not open source in the usual sense — it's a paid WordPress plugin — but 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 our hosted Flex plan ($49/month + 1.5% of partner GMV), or run on Revshare with no monthly fee and a 3% platform cut. The same `main` branch ships all three.
• Raw data is immutable, attribution is derived. Clicks, identities, and events are append-only. Attribution is a view computed over them — which means you can change the attribution model (last-click 60d, first-touch, linear, position-based) and re-run history without re-collecting data.
• Export-as-import. Every table exports to CSV, JSON, and SQL dump. The self-hosted version accepts exports from the hosted version directly. Moving off the hosted tier doesn't require a rebuild.
• Marketplace optional. The Network — our partner marketplace — is a separate surface you opt into. The core software works without it.

What self-hosted affiliate tracking looks like in practice

For OpenPartner, the single-box deploy is one docker compose up -d against the template in the repo. 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're price-sensitive on per-GMV fees and a one-time infrastructure cost looks better than 3–5% forever

It's the wrong call when you need a managed partner-success team, a CSM running recruiting for you, and a six-figure enterprise contract is the budget. That's what PartnerStack and Impact.com sell, and they sell it 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, two commands to start
• Start on Revshare with no monthly fee if you want the hosted convenience without the lock-in story
• Read the comparisons against the closed-source incumbents: Rewardful, Dub Partners, Tapfiliate, PartnerStack, Post Affiliate Pro

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