loop
Loop XXI

Holding and operating company. We build software, pursue ventures, and grow the balance sheet.

Public Key

npub12yyk7k4nlp42z87kv83yraaa3c8jtcaqu3rt3u48rf4crr25v8gq6k0293

Profile Code

nprofile1qqs9zzt0t2els64prltxrcjp777cure9uwswg34c72n356up342xr5qpz3mhxue69uhhyetvv9ujuerpd46hxtnfduqs6amnwvaz7tmwdaejumr0dsx8e6sy

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relay.damus.io

nos.lol

Author Public Key

npub12yyk7k4nlp42z87kv83yraaa3c8jtcaqu3rt3u48rf4crr25v8gq6k0293

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Last Notes

2026-07-17 01:36:57 UTC

LoopXXI is building software for people and agents with a shared Vault layer. Keep an encrypted, user-controlled copy of the data each app creates, then choose what to export or sell. Notes and AI Chat are live. Sales are simulated. https://loopxxi.com/vault

2026-07-17 00:28:13 UTC

LoopXXI Vault is opening three buyer integration pilot slots.
Starting at $149, AI, research, and data teams get a synthetic encrypted capsule, attestation verification, buyer-local decryption guidance, and an evidence packet.
https://loopxxi.com/vault/pilot

2026-07-16 01:08:01 UTC

Evidence Report 001 is live.
We tested our own L402 route and signed the exact observation: valid 402, 10-sat price, no payment attempted.
A challenge is not settlement.
Read it or check your own route free:
https://loopxxi.com/evidence

2026-07-15 22:36:05 UTC

Three ways to buy from LoopXXI:
Revenue Readiness Audit: $149 for evidence showing where a paid API loses revenue.
AI API credits: from $10.
Agent tools: 10–25 sats per call.
Choose, pay, get the result:
https://loopxxi.com

2026-07-13 15:32:30 UTC

Agent-callable Bitcoin tools now have a machine-readable L402 manifest.
Discover:
https://mcp.loopxxi.com/.well-known/l402-manifest.json
Pay per request:
• BTC price: 10 sats
• send-or-wait decision: 15 sats
• optimal send window: 25 sats
No account. No API key. The 402 response returns a BOLT11 invoice; pay it, then retry with the L402 token + preimage.
Built for autonomous buyers.

2026-07-09 01:52:52 UTC

Use case for loop-mcp: give agents a paid Bitcoin/Lightning toolkit.
Agents can check BTC price, decide send-now vs wait from mempool fees, resolve Lightning addresses, decode txs, and pick cheaper send windows.
Pay per call via L402 or Stripe credits: https://mcp.loopxxi.com

2026-07-09 01:50:39 UTC

loop-mcp is now listed on Smithery.
Point any MCP client at mcp.loopxxi.com/mcp and your agent pays per tool call — 10-25 sats over Lightning (L402), or prepaid fiat credits. No API keys. Payment is the credential.
Five live tools: btc_price, btc_send_decision, lightning_address_resolve, tx_decode_explain, optimal_send_window.
Try the full paid flow in your browser: https://loop-xxi.github.io/loop-mcp/example/playground/
Smithery: https://smithery.ai/server/business-yukr/loop-mcp

2026-07-03 13:02:09 UTC

If the mechanism is real, time becomes part of the work. We favor systems that improve with each pass. https://loopxxi.com

2026-07-02 20:39:36 UTC

Two products live now, both metered by protocol instead of accounts.
Loop Gateway: 300+ AI models through one endpoint.
loop-mcp: any tool call gated by a Lightning invoice.
Pay per request in sats or fiat. No signup. https://loopxxi.com
https://blossom.primal.net/5955bf4814fcbee3b48d020b2ee4edfc589b97dcbfd984843533ca5f11caa366.png

2026-07-01 23:21:14 UTC

New: a plain-HTTP L402 endpoint any agent can hit in one call.
curl https://mcp.loopxxi.com/l402/btc_price
→ 402 + a Lightning invoice. Pay 10 sats, replay with the preimage, get the data.
No API key, no account. 5 Bitcoin/LN tools live.
https://github.com/Loop-XXI/loop-mcp

2026-06-30 13:02:04 UTC

Work that can't survive silence doesn't belong in the foundation. We build for anniversaries. https://loopxxi.com

2026-06-30 01:43:26 UTC

New tool on loop-mcp: optimal_send_window (25 sats).
The insight: raw Bitcoin fee data is free (mempool.space) and commoditized — 8+ L402 providers sell fastestFee/halfHourFee. But the DECISION isn't. No free endpoint tells an agent: wait 90 minutes, fees drop from 18 to 7 sat/vB, 72% confidence, RBF viable.
That synthesis — congestion forecast, recommended send window, fee trajectory with a calibrated confidence score, and RBF viability — is what this tool returns. Built on mempool.space's public API; no node required. Explicitly probabilistic: every forecast carries a confidence score and a reasoning trace, never false certainty.
This is the layer autonomous payment agents will pay for: a timing decision they can't get from free endpoints, at 25 sats a call.
Live at https://mcp.loopxxi.com (L402 Lightning or fiat credits via Stripe). On the MCP Registry: com.loopxxi/loop-mcp. Source: https://github.com/Loop-XXI/loop-mcp
— Loop XXI LLC (business@loopxxi.com)
#bitcoin #lightning #l402 #mcp #agenteconomy

2026-06-29 21:31:22 UTC

loop-mcp is live: an MCP server where AI agents pay per tool call in sats over Lightning.
4 L402-paid tools: btc_price, lightning_address_resolve, btc_send_decision, tx_decode_explailoop-mcp: an MCP server where AI agents pay per tool call in sats over Lightning. Live now.
The agent economy needs a payment rail that isn't credit cards and signup forms. L402 (Lightning HTTP 402) is that rail — proof of payment IS the auth credential, verified statelessly, no session, no database.
How it works:
1. Agent calls a tool with no auth → server returns 402 + a BOLT11 invoice (10-25 sats).
2. Agent pays over Lightning, gets the preimage.
3. Agent retries with Authorization: L402 <token>:<preimage> → server verifies and serves the result.
No accounts. No API keys. Agents pay exactly what they use, per call.
4 paid tools live:
• btc_price — 10 sats
• lightning_address_resolve — 10 sats
• btc_send_decision — 15 sats
• tx_decode_explain — 25 sats
Live: https://mcp.loopxxi.com/mcp
Source: https://github.com/Loop-XXI/loop-mcp
On the official MCP Registry: com.loopxxi/loop-mcp
Try it with one curl call — you'll get a 402 with an invoice. The whole handshake is ~3 HTTP requests and costs less than a third of a cent.
— Loop XXI LLC (business@loopxxi.com)
#bitcoin #lightning #l402 #aiagents #agenteconomy #mcpn (10-25 sats).
No API keys. Payment is the credential.
mcp.loopxxi.com/mcp

2026-06-29 20:55:33 UTC

loop-mcp has four paid tools live on the MCP Registry. btc_price: 10 sats. btc_send_decision: 15 sats. lightning_address_resolve: 10 sats. tx_decode_explain: 25 sats. Agents pay per call in Lightning. https://api.loopxxi.com

2026-06-29 13:02:34 UTC

Sign and broadcast a Nostr note without leaving your browser. Local signing with Alby. The nsec never leaves you. https://sign.loopxxi.com

2026-06-28 20:28:48 UTC

loop-mcp is now on the official MCP Registry.
AI agents can discover it, call it, and pay 10 sats per request via Lightning. First L402-native MCP server on the registry.
registry.modelcontextprotocol.io/v0/servers?search=loop-mcp

2026-06-28 15:28:07 UTC

21% off for paying in Bitcoin.
Not a coupon code. A different model.
Sats-settled AI inference, one API key, 300+ models.
api.loopxxi.com
https://blossom.primal.net/0e74b1c5b473c3151a87a66c624c50f8f5a760598f904c86a241fedaa9bb56c6.png

2026-06-28 15:25:51 UTC

The loop returns with more than it left with.
Or it doesn't survive.
There's no middle case worth building for.
loopxxi.com
https://blossom.primal.net/605be0d0c544d6137ba247112a0ac020fc08f467ac517d1236a7652f9c37bc0a.png

2026-06-28 15:23:54 UTC

Agents don't have bank accounts. They have wallets.
L402 settles machine-to-machine in sats — no account, no human, no card on file.
That's a different kind of infrastructure.
api.loopxxi.com

2026-06-28 13:01:28 UTC

Most platforms are built for humans. We build for what comes next: systems that act, verify, and transact autonomously. loopxxi.com

2026-06-27 16:04:21 UTC

Three things shipped to Loop Gateway this week: a sats pricing endpoint, operator console, and security hardening. The loop keeps tightening. api.loopxxi.com

2026-06-27 16:03:38 UTC

Three things shipped to Loop Gateway this week: a sats pricing endpoint, operator console, and security hardening. The loop keeps tightening. api.loopxxi.com

2026-06-27 16:03:29 UTC

Moved our operational crons off LLM-agents onto deterministic Python. Zero AI on the paths that count things. That's not a downgrade — that's how you trust your numbers.

2026-06-27 16:03:09 UTC

Loop Gateway now returns a real-time sats quote for any AI credit purchase. Pay in Bitcoin and get 21% off the fiat rate — priced per token, settled per use. api.loopxxi.com

2026-06-27 13:01:36 UTC

Loop XXI is infrastructure for the agent economy. We build the rails others build on. loopxxi.com

2026-06-26 20:14:33 UTC

Loop Gateway: one API key, 300+ AI models, no accounts. Pay in sats or fiat, use what you need. https://api.loopxxi.com

2026-06-26 20:14:23 UTC

LoopXXI is a holding company for durable systems. We measure compounding, not hype. The first product is already live. https://loopxxi.com

2026-06-15 00:25:16 UTC

Built a small open index: sats earned per dollar of AI credits spent.
Question I kept asking myself while running an L402-paid AI proxy was simple. Is anyone in this category actually earning sats yet, or are we all just shipping pricing pages?
So I started logging it. Public, attested, no paid placements, null where revenue isn't public. Right now the table covers Routstr, SmartSat (mine, pre-revenue, honest about it), Fewsats, IdeaFactoryLab, and Lightning Labs.
Most cells are still null. That's the actual finding.
If you run a Lightning-native AI service and you have real revenue you'd let me publish, send the row.
Index: https://roi.loopxxi.com
Github: https://github.com/Loop-XXI/ai-bitcoin-roi
Tip jar on the page is a reusable BOLT12 from my phoenixd node. If a row saved you research time, settle it directly.

2026-06-14 19:06:21 UTC

One thing that moved LoopXXI forward this week: fewer moving parts, sharper defaults. The best systems don't feel clever; they feel inevitable.

2026-06-13 21:47:44 UTC

Shout out to the builders keeping Bitcoin + AI sovereign: nostr-sdk, Cashu, Lightning, and the infra glue. Real leverage is composable rails + agents that can verify, route, and settle without permission. LoopXXI is building for that edge.

2026-06-13 19:05:15 UTC

Shoutout to the rust-nostr / nostr-sdk crew: one clean FFI stack, three relays, signed notes, and bots in Python. That’s the kind of boring infrastructure that makes sovereign automation real.

2026-06-13 19:04:20 UTC

test note from loopxxi bot, please ignore

2026-06-13 17:39:09 UTC

Just shipped a redesign of loopxxi.com — dark atmospheric hero section in the Fable 5 style. Animated tech ring, orbital particles, full-bleed background. Technology that compounds.
https://loopxxi.com

2026-06-12 19:04:56 UTC

Friday Signal: LoopXXI is building sovereign agent infrastructure that turns Bitcoin-native workflows into reliable systems people can actually run.

2026-06-11 12:36:36 UTC

Three patterns that show up in every "AI agent that earns sats" project I've looked at:
**1. A reusable sat sink, not an invoice generator**
The fragile version: every time the agent needs to receive sats, it generates a fresh BOLT11 invoice, races expiry, and rotates again. Works until the agent crashes mid-flow and you can't reconcile.
The pattern that holds: a single reusable BOLT12 offer wired as the agent's address-of-record. The agent never generates invoices — it publishes the offer once, lets the payer initiate. Reconciliation becomes "did sats land in the sink during the window we care about." Much smaller attack surface.
**2. The ledger is the source of truth, not the wallet**
Every wallet lies a little — pending HTLCs, rebalances, fee bumps. If the agent treats wallet's "received" event as the moment revenue exists, you'll spend weeks chasing ghosts.
The pattern: a separate append-only ledger (JSONL file is enough) where each earning event is logged with preimage/txid, source mechanism, and timestamp. The wallet is custody. The ledger is accounting. When they disagree, the ledger wins.
**3. The agent allocates effort by sats-per-credit**
You log credits-burned per task alongside sats-earned per task. The agent prefers tasks whose ratio is improving, deprioritizes ones that are flat. Over time the compute budget drifts toward what's actually working, without anyone writing a new rule. RL with a sat-denominated reward signal and a fiat-denominated cost signal.
The trap is reading the ratio too early. Need dozens of completed tasks per category before the signal stabilizes. Run a deliberate exploration policy first.
---
If one of these three patterns isn't in place, fix it before adding capability. The capability will work for a week and break in a way that takes a month to debug.
#bitcoin #lightning #ai #agents

2026-06-11 12:36:28 UTC

Just migrated SmartSat to the Loop XXI stack. It's been running quietly for a while — thought it was time to give it a proper home.
SmartSat is a Bitcoin-native AI API proxy. 300+ models via OpenRouter. Pay per prompt in sats. No account, no email, no KYC.
Setup takes about 30 seconds:
1. POST to /v1/topup with an amount_sats
2. Pay the Lightning invoice
3. Use the bearer token as your API key in any OpenAI-compatible client
Standard rates — 15% markup over OpenRouter cost, priced in real-time sats.
Live at https://smartsat.loopxxi.com
API: https://api.smartsat.loopxxi.com
#bitcoin #lightning #ai #nostr

2026-06-11 00:42:56 UTC

Building in public on nostr.
Products, decisions, lessons — we'll share them here. If you're building too, follow along. We'd rather grow alongside people who ship than people who talk about shipping.
loopxxi.com
#nostr #buildinpublic

2026-06-11 00:42:50 UTC

We believe the balance sheet is the scoreboard.
Every product we ship is built to contribute to it — lean operations, no waste, systems that work while we sleep.
LoopXXI is the vehicle.
loopxxi.com

2026-06-11 00:42:45 UTC

What we do at LoopXXI:
— Build software tools that run lean and scale fast
— Operate AI-first from day one
— Pursue ventures that compound
Early stage. High conviction. Moving fast.
loopxxi.com

2026-06-11 00:42:39 UTC

LoopXXI is on nostr.
We're a holding and operating company — building software products and pursuing ventures.
This is our home base for updates. Follow along.
loopxxi.com