# Retroactive public goods funding: how retro funding works

> Retroactive public goods funding pays for impact already shown. How Optimism, FIL-RetroPGF, Ronin and Algorand xGov measure it, who votes, and how to prepare.

Last reviewed 2026-10-31. Dates are UTC.

Retroactive public goods funding pays projects for impact they have already delivered, instead of paying for a plan. A round sets an impact window, measures what each project did in it through voters, metrics or a formula, and splits a pool accordingly. As of October 31, 2026, 4 of the 99 programs in web3grant's directory work this way, and the two largest are paused.

## Key takeaways

- The idea rests on one claim, in Vitalik Buterin's framing: "it's easier to agree on what was useful than what will be useful."
- Four programs in web3grant's directory are retro: Optimism Retro Funding, FIL-RetroPGF, Ronin Proof of Distribution and Algorand xGov.
- Optimism Retro Funding has been paused since January 2026 for at least 12 months, and FIL-RetroPGF is paused in 2026 with no date for its next round.
- Rounds measure impact in three ways: human voters (FIL-RetroPGF badgeholders, the xGov committee), metrics algorithms (Optimism's 2025 missions) or an automatic on-chain score (Ronin).
- You are paid only for impact you can prove, so you carry the cost and risk of building first.

## What is retroactive public goods funding?

Retroactive public goods funding (often shortened to retro funding or RetroPGF) is a grant model that rewards results after they happen. A public good is something many people benefit from without paying for it, such as an open-source library, a block explorer or documentation. A normal grant pays for a proposal before the work exists. A retro round pays after the work has shipped and been used.

The case for it is that judging the past is easier than predicting the future. Optimism's governance forum, in a November 2024 review of two years of rounds, quotes Vitalik Buterin's framing: "it's easier to agree on what was useful than what will be useful." The same [review on the Optimism forum](https://gov.optimism.io/t/lessons-learned-from-two-years-of-retroactive-public-goods-funding/9239) is candid about the evidence: "we don't (yet) have the data to show that retroactive funding produces superior outcomes."

Retro funding sits alongside rolling grants, rounds and [quadratic funding](https://www.web3grant.com/guides/quadratic-funding-explained) as one of the four funding models in our directory. For the wider picture, see [what Web3 grants are](https://www.web3grant.com/guides/what-are-web3-grants).

## How retro funding works, step by step

Most retro programs follow the same four steps, with different machinery at each one:

1. **The funder sets a pool and an impact window.** FIL-RetroPGF Round 3 had a 585,000 FIL pool and counted impact from November 2024 to September 2025.
2. **Projects register and show evidence.** Optimism used project profiles on OP Atlas. FIL-RetroPGF asked for a public showcase on GitHub, then a full application on Drips. Ronin asks you to register your contracts and prove you control them.
3. **Impact is measured.** Voters, an algorithm or a formula decide how much each project contributed.
4. **The pool is split and paid.** Optimism paid OP monthly, FIL-RetroPGF paid FIL through Drips, and Ronin pays RON after each 30-day season.

## Who decides: voters, metrics or a formula

The biggest difference between retro programs is who, or what, judges impact. The table compares the four retro programs in our directory as of October 31, 2026.

| Program | Who decides | What counts as impact | Paid in | Status |
| --- | --- | --- | --- | --- |
| [Optimism Retro Funding](https://www.web3grant.com/grants/optimism-retro-funding) | Open Source Observer algorithms, monthly (2025) | Dependency graphs, developer connections, contract activity, gas fees, users | OP | Paused since January 2026 |
| [FIL-RetroPGF](https://www.web3grant.com/grants/fil-retropgf) | Badgeholder votes | Measurable on-chain results on Filecoin | FIL | Paused in 2026 |
| [Ronin Proof of Distribution](https://www.web3grant.com/grants/ronin-proof-of-distribution) | Automatic Builder Score, then an anti-sybil review | On-chain activity on your registered contracts | RON | Running, monthly seasons |
| [Algorand xGov](https://www.web3grant.com/grants/algorand-xgov) | xGov committee vote, then a Council check | A built, working open-source tool | ALGO | Taking proposals; payouts on hold |

### Human voters

FIL-RetroPGF uses badgeholders, a group of voters who review every eligible project and allocate the pool by impact. In Round 3 they were asked to favor measurable on-chain results such as paid storage deals, retrievability and on-chain economic activity, and a project needed at least 4 ballots and at least 500 FIL of support to count.

Algorand xGov uses a committee of xGovs, Algorand accounts that take part in consensus. A proposal is discussed on the Algorand forum for at least two weeks, then goes to a two-week vote with a quorum that rises with the amount requested. If it passes, the xGov Council checks it against the terms before the treasury pays.

### Metrics and algorithms

In 2025 Optimism ran Retro Funding as two missions: Dev Tooling, for open-source compilers, libraries and debuggers used by Superchain builders, and Onchain Builders, for apps deployed on OP Chains. You registered once on OP Atlas, then Open Source Observer's open-source algorithms scored each project every month. Season 8 paid about 3.33M OP in total, and Season 8 excluded apps with more than $100M in monthly Superchain TVL.

Optimism's 2024 review found that voters scored more easily from metrics than from long lists of projects, but that metrics alone missed qualities such as momentum, which experts could judge.

### Automatic formulas

Ronin Proof of Distribution has no application at all. You register your game or app and its contracts, and each 30-day season you earn a share of a 410,958 RON pool (about $26,800 at late-September 2026 prices) based on a Builder Score. The score weighs NFT volume, DEX volume, gas spend, contract volume, paying users and new paying users, and since September 10, 2026 it includes a RON Conviction multiplier that favors projects whose communities hold RON. The Ronin team reviews each season for botting, sybil activity and wash trading before paying out.

## How payouts are set

Retro payouts are set in one of three ways, and the amounts are usually modest:

- **A share of a fixed pool.** FIL-RetroPGF and Optimism divided a pool by votes or scores. Three FIL-RetroPGF rounds between 2024 and 2025 distributed about 1M FIL across 284 grants. In our data, past awards ranged from about $520 to $21,540 for FIL-RetroPGF and from about $55 to $32,500 for Optimism Retro Funding, at late-September 2026 prices.
- **A fixed amount you ask for.** xGov pays a set amount you request, from 5,000 to 400,000 ALGO (about $634 to $50,700), paid in full if approved. You lock a refundable deposit of 3% of the request.
- **A formula.** Ronin pays each project its share of the season's pool by score. In Season 1, Axie Infinity earned over 97K RON.

Some regular programs also pay retroactively. The [Rocket Pool GMC](https://www.web3grant.com/grants/rocket-pool-gmc-grants) makes retrospective awards for completed Rocket Pool work, and they can be submitted on behalf of others, though its notice says funds are tight. [MoonDAO Projects](https://www.web3grant.com/grants/moondao-project-grants) fund work upfront, then let finished projects file a final report and earn retroactive rewards by community vote.

## Retro funding as of October 2026

Two of the four retro programs in our directory are paused, and a third is taking proposals it can't yet pay.

- [Optimism Retro Funding](https://www.web3grant.com/grants/optimism-retro-funding): Optimism Foundation. Grant size: $55–$32.5K (USD equivalent). Closed: the latest round ran 2025-08-01 to 2025-12-31; next round not announced. Note: Paused since January 2026 for at least 12 months. No Retro Funding missions are planned for Seasons 9 or 10.
- [FIL-RetroPGF](https://www.web3grant.com/grants/fil-retropgf): Blueshift Foundation. Grant size: $520–$21.5K (USD equivalent). Closed: the latest round ran 2025-09-22 to 2025-10-27; next round not announced. Note: Paused in 2026. The stewards expect to bring retro funding back in late 2026 under a new framework, with no dates yet.
- [Ronin Proof of Distribution](https://www.web3grant.com/grants/ronin-proof-of-distribution): Ronin Network. Grant size: Not published. Always open: no deadline, applications reviewed as they arrive.
- [xGov](https://www.web3grant.com/grants/algorand-xgov): Algorand Foundation. Grant size: $634–$50.7K (USD equivalent). Always open: no deadline, applications reviewed as they arrive. Note: Proposals are still accepted, but payouts wait on a Foundation top-up of the xGov treasury and a newly elected Council.

- **Optimism Retro Funding** has been paused since January 2026 for at least 12 months, and no missions are planned for Seasons 9 or 10. About 777.6M OP of the Retro Funding allocation remains unspent, and the Optimism Foundation has said it may propose reallocating it.
- **FIL-RetroPGF** is paused in 2026 while Filecoin's public goods funding moves to three tracks: Kernel, Revenue Development and R&D. The stewards expect retro funding to return in late 2026 under a new framework, with no dates yet. See [Filecoin grants](https://www.web3grant.com/ecosystems/filecoin) for what is open.
- **Ronin Proof of Distribution** is running, with monthly seasons, for any game, dApp or DeFi protocol with a contract on Ronin.
- **Algorand xGov** accepts proposals, but payouts wait on a Foundation top-up of the xGov treasury and a newly elected Council.

## Retro funding vs a regular grant

The two models put risk in different places, so choose by where your project is:

| | Regular grant | Retro funding |
| --- | --- | --- |
| When you are paid | Before or during the work | After the work is used |
| What you show | A plan, budget and team | Evidence of impact |
| Who carries the risk | The funder | You |
| Predictability | Amount agreed upfront | Unknown until results |
| Best for | New work you can't self-fund | Work already shipped |

Retro funding suits projects that already ship and have users. If you need money to start, a proactive grant is the better fit, and our guide on [how to apply for Web3 grants](https://www.web3grant.com/guides/how-to-apply-for-web3-grants) covers that route.

## How to position your work for retro funding

Retro rounds reward what you can prove, so the preparation is evidence you collect while you build:

- **Work in public.** Keep the repository open and the license clear. Optimism's Dev Tooling mission required an open-source repository or package, and xGov asks for open-source code listed with Electric Capital.
- **Register early.** Profiles such as OP Atlas or Ronin's Builders Portal link your contracts and repositories to your project, and only registered contracts count on Ronin.
- **Keep an impact log.** Rounds use impact windows, so record dates: releases, integrations, user counts and who adopted your work.
- **Track the metrics funders use.** Downstream dependents for libraries; transactions, gas and paying users for apps. Our guide to [grant impact metrics](https://www.web3grant.com/guides/grant-impact-metrics) covers how to measure and present them.
- **Don't game the numbers.** Ronin reviews every season for botting and wash trading, and inflated activity can cost you the payout.
- **Don't plan your runway on it.** With the two largest programs paused, treat retro rewards as a bonus. Our guide to [sustainable funding for open source crypto projects](https://www.web3grant.com/guides/funding-after-the-grant-ends) covers steadier sources.

## FAQ

### Is retroactive public goods funding the same as a prize?

Retroactive public goods funding is close to a prize, but not the same. A prize usually sets a target in advance and pays the winner who reaches it. A retro round looks back over an impact window and splits a pool among many projects according to how much each contributed, judged by voters, metrics or a formula. Most retro rounds pay many projects modest amounts rather than one winner.

### Can I get retro funding for work a grant already paid for?

Retro funding for work a grant already paid for depends on the round's rules, so read them before you apply. Many programs ask you to disclose other funding for the same work, and voters may weigh it when they decide how much your impact is worth. When in doubt, disclose the earlier grant in your application.

### When will Optimism Retro Funding come back?

Optimism Retro Funding has been paused since January 2026 for at least 12 months, according to the Optimism Foundation, and no Retro Funding missions are planned for Seasons 9 or 10. As of October 2026 there is no restart date. About 777.6M OP of the allocation remains unspent, and the Foundation has said it may propose reallocating it.

### Does retro funding only pay open-source public goods?

Retro funding does not only pay open-source public goods. FIL-RetroPGF, Optimism's Dev Tooling mission and Algorand xGov focus on open-source work, but Ronin Proof of Distribution pays commercial games and apps by on-chain activity, and Optimism's Onchain Builders mission rewarded deployed apps. What every retro program shares is that it pays for results already delivered.

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From web3grant: https://www.web3grant.com/guides/retroactive-public-goods-funding. Program details change often: confirm on each program's official site before applying.