Selo is CI for x402 on @algorand. Before you ship a paid endpoint, Selo makes a real, capped mainnet payment to it as a genuine client.
onchain
Joined September 2025
- Tweets68
- Following17
- Followers61
- Likes95
Pinned Tweet
Every x402 endpoint can pass a health check and still break the moment a real buyer pays: wrong asset in the 402, paid but not delivered, a retry that charges twice.
We built 𝐒𝐄𝐋𝐎 to catch that before users do.
Selo : useselo.xyz
Repo:github.com/Enoch208/selo
🧵
Selo(Algorand) retweeted
thanks for using Selo legend🙏
we appreciate the feedback.
Paid @UseSelo_ 1 USDC to attack my own x402 endpoint on Algorand mainnet before any customer did.It paid me 0.01 USDC like a real buyer, then graded the response.PASS ✅ payment settled, contract matched, replay rejected.allo.info/tx/LDV3CDQX4UYL5T4…
thanks for using Selo legend🙏
we appreciate the feedback.
Paid @UseSelo_ 1 USDC to attack my own x402 endpoint on Algorand mainnet before any customer did.It paid me 0.01 USDC like a real buyer, then graded the response.PASS ✅ payment settled, contract matched, replay rejected.allo.info/tx/LDV3CDQX4UYL5T4…
Selo(Algorand) retweeted
Paid @UseSelo_ 1 USDC to attack my own x402 endpoint on Algorand mainnet before any customer did.It paid me 0.01 USDC like a real buyer, then graded the response.PASS ✅ payment settled, contract matched, replay rejected.allo.info/tx/LDV3CDQX4UYL5T4…
Selo(Algorand) retweeted
Thank you Sele, for trying it on your x402 endpoint and sharing your feedback 🙏. It helps us build the right thing.
If your team is building an x402 endpoint, we’d love for you to try it out and see what you think. We’re always happy to chat about it too.
#algorand #algo
Explore here: useselo.xyz
@AlgoFoundation @Algorand
Ran a @UseSelo_ release test on a demo x402 endpoint on Algorand Mainnet. Selo paid it in real USDC like a real customer would, then checked what came back.
Verdict: PASS ✅
Payment settled, the paid response matched the contract, and a replayed payment was rejected. No double charge. Signed attestation verified.
Paid Selo 1 USDC: allo.info/tx/5FW25HT564S6MJ5…
Selo paid endpoint 0.01 USDC: allo.info/tx/HZRVALTXVUTBRKC…
USDC opt-in: allo.info/tx/3F5VZITRALSIF34…
ALGO → USDC swap: allo.info/tx/33LLP7MUHLRYZBZ…
Thank you Sele, for trying it on your x402 endpoint and sharing your feedback 🙏. It helps us build the right thing.
If your team is building an x402 endpoint, we’d love for you to try it out and see what you think. We’re always happy to chat about it too.
#algorand #algo
Explore here: useselo.xyz
@AlgoFoundation @Algorand
Ran a @UseSelo_ release test on a demo x402 endpoint on Algorand Mainnet. Selo paid it in real USDC like a real customer would, then checked what came back.
Verdict: PASS ✅
Payment settled, the paid response matched the contract, and a replayed payment was rejected. No double charge. Signed attestation verified.
Paid Selo 1 USDC: allo.info/tx/5FW25HT564S6MJ5…
Selo paid endpoint 0.01 USDC: allo.info/tx/HZRVALTXVUTBRKC…
USDC opt-in: allo.info/tx/3F5VZITRALSIF34…
ALGO → USDC swap: allo.info/tx/33LLP7MUHLRYZBZ…
Selo(Algorand) retweeted
Ran a @UseSelo_ release test on a demo x402 endpoint on Algorand Mainnet. Selo paid it in real USDC like a real customer would, then checked what came back.
Verdict: PASS ✅
Payment settled, the paid response matched the contract, and a replayed payment was rejected. No double charge. Signed attestation verified.
Paid Selo 1 USDC: allo.info/tx/5FW25HT564S6MJ5…
Selo paid endpoint 0.01 USDC: allo.info/tx/HZRVALTXVUTBRKC…
USDC opt-in: allo.info/tx/3F5VZITRALSIF34…
ALGO → USDC swap: allo.info/tx/33LLP7MUHLRYZBZ…
Selo(Algorand) retweeted
We just shipped a big update to Selo: it's now a release gate for x402.
Before you ship a paid endpoint, Selo pays it once on @Algorand Mainnet like a real customer, checks the payment and the response, and returns PASS, FAIL or INCONCLUSIVE with both transactions as proof.
What's new:
• The selo CLI, with exit codes your CI can trust
• Signed verdicts anyone can verify offline
• A GitHub Action that only promotes a release with a signed PASS
We ran it on a demo merchant: health check green, payment settled, but the paid response was broken. Selo failed it and the gate blocked the deploy. Then it passed the fix.
So this is a call to every dev building endpoints on x402: run Selo on yours before your users find the bugs.
How to use it:
1. Authorize your route (free): run selo auth create, then serve the token it gives you at /.well-known/selo-verification.txt
2. Preflight (free): checks your 402, network, asset and price before anything is paid
3. Write a contract.json: the status, content type and JSON schema your paid response should return
4. Run the test: 1 USDC per run. Selo pays your endpoint's price itself (up to 0.50 USDC)
Works with Algorand Mainnet USDC, GET and POST.
Full guide: github.com/Enoch208/selo/blo…
Site: useselo.xyz
Questions, bugs, or a result you want to share? Reply here or open an issue: github.com/Enoch208/selo/iss…
@algodevs @GoPlausible @JorrinB @marcvl @fredestante
𝐒𝐄𝐋𝐎 𝐔𝐏𝐃𝐀𝐓𝐄🛠️
Selo can now stop a release. 🛑
Until now, Selo paid your x402 endpoint like a real customer and handed you a report. Now its verdict decides whether your release ships.
Here’s what’s new 🧵
1. The selo CLI:
One command in your release pipeline. You pay Selo 1 USDC over x402. Once that settles, Selo pays your endpoint, runs five checks and returns a verdict.
Exit 0 = PASS, ship it. Anything else (FAIL, not proven, refused) blocks the release.
2. GitHub Action:
Your deploy runs only after a PASS. Live on Algorand Mainnet, against a demo shop:
•broken-v1: paid, 200 OK, but the receipt is missing a field → FAIL, deploy blocked
•fixed-v2, same URL: all five checks PASS → deploy promoted
3. Signed Verdicts:
Every result is signed by Selo, and anyone can check it offline with selo verify against Selo’s public key.
A PASS is bound to one release, URL and method, so it can’t be reused to push out a different release.
4. Never charged twice:
If a run is cut off mid-payment, the CLI won’t pay again on its own. --resume fetches the same result with no second charge.
If Selo’s payment to your endpoint is unclear, the funds are held, then settled or released only on proof from the chain.
The proof is all on Algorand Mainnet:
🔴 Broken release, blocked: github.com/Enoch208/selo/act…
🟢 Fix, promoted: github.com/Enoch208/selo/act…
Try it on your endpoint: useselo.xyz
@algodevs @AlgoFoundation @AlexaJaccarino @GoPlausible @fredestante @ganainmtech
Selo(Algorand) retweeted
Selo docs are live: docs.useselo.xyz
How to let Selo pay your x402 endpoint before your users do:
→ quickstart, from authorizing your route to a verdict
→ one prompt that hands the whole test to your coding agent
→ a GitHub Actions release gate
→ full CLI + API reference
Selo docs are live: docs.useselo.xyz
How to let Selo pay your x402 endpoint before your users do:
→ quickstart, from authorizing your route to a verdict
→ one prompt that hands the whole test to your coding agent
→ a GitHub Actions release gate
→ full CLI + API reference
Selo(Algorand) retweeted
𝐒𝐄𝐋𝐎 𝐔𝐏𝐃𝐀𝐓𝐄🛠️
Selo can now stop a release. 🛑
Until now, Selo paid your x402 endpoint like a real customer and handed you a report. Now its verdict decides whether your release ships.
Here’s what’s new 🧵
1. The selo CLI:
One command in your release pipeline. You pay Selo 1 USDC over x402. Once that settles, Selo pays your endpoint, runs five checks and returns a verdict.
Exit 0 = PASS, ship it. Anything else (FAIL, not proven, refused) blocks the release.
2. GitHub Action:
Your deploy runs only after a PASS. Live on Algorand Mainnet, against a demo shop:
•broken-v1: paid, 200 OK, but the receipt is missing a field → FAIL, deploy blocked
•fixed-v2, same URL: all five checks PASS → deploy promoted
3. Signed Verdicts:
Every result is signed by Selo, and anyone can check it offline with selo verify against Selo’s public key.
A PASS is bound to one release, URL and method, so it can’t be reused to push out a different release.
4. Never charged twice:
If a run is cut off mid-payment, the CLI won’t pay again on its own. --resume fetches the same result with no second charge.
If Selo’s payment to your endpoint is unclear, the funds are held, then settled or released only on proof from the chain.
The proof is all on Algorand Mainnet:
🔴 Broken release, blocked: github.com/Enoch208/selo/act…
🟢 Fix, promoted: github.com/Enoch208/selo/act…
Try it on your endpoint: useselo.xyz
@algodevs @AlgoFoundation @AlexaJaccarino @GoPlausible @fredestante @ganainmtech
𝐒𝐄𝐋𝐎 𝐔𝐏𝐃𝐀𝐓𝐄🛠️
Selo can now stop a release. 🛑
Until now, Selo paid your x402 endpoint like a real customer and handed you a report. Now its verdict decides whether your release ships.
Here’s what’s new 🧵
1. The selo CLI:
One command in your release pipeline. You pay Selo 1 USDC over x402. Once that settles, Selo pays your endpoint, runs five checks and returns a verdict.
Exit 0 = PASS, ship it. Anything else (FAIL, not proven, refused) blocks the release.
2. GitHub Action:
Your deploy runs only after a PASS. Live on Algorand Mainnet, against a demo shop:
•broken-v1: paid, 200 OK, but the receipt is missing a field → FAIL, deploy blocked
•fixed-v2, same URL: all five checks PASS → deploy promoted
3. Signed Verdicts:
Every result is signed by Selo, and anyone can check it offline with selo verify against Selo’s public key.
A PASS is bound to one release, URL and method, so it can’t be reused to push out a different release.
4. Never charged twice:
If a run is cut off mid-payment, the CLI won’t pay again on its own. --resume fetches the same result with no second charge.
If Selo’s payment to your endpoint is unclear, the funds are held, then settled or released only on proof from the chain.
The proof is all on Algorand Mainnet:
🔴 Broken release, blocked: github.com/Enoch208/selo/act…
🟢 Fix, promoted: github.com/Enoch208/selo/act…
Try it on your endpoint: useselo.xyz
@algodevs @AlgoFoundation @AlexaJaccarino @GoPlausible @fredestante @ganainmtech
Selo(Algorand) retweeted
10 finalists. 100K USD on the line.
🗓️ Save the date + join us October 30 for the Global x402 Challenge live pitch competition and watch the final teams compete for a share of the prize pool.
Selo(Algorand) retweeted
The Top 10 finalists in the Global x402 Challenge have been revealed! They'll each get a chance to pitch their project to compete for 5 remaining prizes out of a 100K USDC prize pool.
Selo(Algorand) retweeted
You can’t build the future of finance on cryptography quantum computers could break.
As tokenization scales, post-quantum security needs to be a core infrastructure decision.
My latest: algorand.co/blog/you-cant-bu…
Selo(Algorand) retweeted
The Global x402 Challenge results are in! 🏆
115 teams shipped live x402 endpoints on Algorand mainnet.
🏅 20 projects sharing 500,000 ALGO
🚀 10 finalists competing for $100,000 USDC on October 30
Congrats to all the teams who built and participated!
Meet the winners 👇
algorand.co/blog/the-global-…
Selo(Algorand) retweeted
Selo made the top 20 on the leaderboard at the @Algorand Global x402 Challenge🎉🎉 .
Grateful for the recognition, and thank you to everyone who supported the build, but there is still work to be done.
We are heading back to the kitchen😁👨🍳, updates are on the way.. keep an eye out👀
@ganainmtech @AlgoFoundation @Camohe90
Selo made the top 20 on the leaderboard at the @Algorand Global x402 Challenge🎉🎉 .
Grateful for the recognition, and thank you to everyone who supported the build, but there is still work to be done.
We are heading back to the kitchen😁👨🍳, updates are on the way.. keep an eye out👀
@ganainmtech @AlgoFoundation @Camohe90
Selo(Algorand) retweeted
Unplanned downtime costs the world's 2,000 largest companies $600 billion a year, according to Splunk.
On Algorand, you can protect your business from quantum threats on a network that hasn't gone down once since 2019.
Even our post-quantum upgrade shipped with zero downtime.
Selo(Algorand) retweeted
guess what I woke up to guys??.. yet again another win🥹, makes it no 18
excited to share that Selo was chosen as one of the winners of @Algorand global x402 hackathon, with a $1200 prize. building in the agentic payment has been an exciting challenge and this recognition means a lot.
thanks to the @algodevs team for the opportunity, this is just day 1.. let’s do more 🙂↕️🙏
We’ve been working on @UseSelo_ since the beginning of this month, and it’s finally live 😁
We originally built Selo for the @algodevs Global x402 hackathon, what we’ve shipped today is only V1. there is more updates and improvements coming over the next few days.
Huge thanks to the @Algorand team for putting the challenge together, and a special shoutout to @ganainmtech, @Camohe90 and the rest of the team for the guidance throughout the challenge AMA
I’m excited to see where we take Selo from here.
We built this for devs,teams , agent builders who sell an API or resource behind x402, these includes paid APIs,data feeds, and AI/agent tools charging per request in USDC.
Test it before your users do :
1. useselo.xyz → Test an endpoint
2. Verify you own it (one small file on your domain)
3. Free preflight shows the exact cost
4. Pay 1 USDC with the script we give you → Selo pays your endpoint for real and returns PASS/FAIL with on-chain proof
Agents: api.useselo.xyz/llms.txt
@JorrinB @SilentRhetoric
Selo(Algorand) retweeted
A 1-cent API call.
At standard published card rates, the processing fee is about 30 cents.
Cards were never designed for software to buy one response at a time. x402 on Algorand is.
New guide 👇
algorand.co/learn/why-api-ke…
