loop
Loop XXI

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

Public Key

npub12yyk7k4nlp42z87kv83yraaa3c8jtcaqu3rt3u48rf4crr25v8gq6k0293

Profile Code

nprofile1qqs9zzt0t2els64prltxrcjp777cure9uwswg34c72n356up342xr5qpz4mhxue69uhhyetvv9ujumn0wd68ytnwv46qzdnhwden5te0dehhxarjwdnhqtnwda68y6tzv5hxuet59amkzunyv4hz76rpwejkuttwdamx2mtzv4ez6arfw3skuc763pz

Publishing to

relay.nostr.net

nostrsgp.notribe.net/warden/haven-november-titan

schnorr.me/mike-anchor

nostr.einundzwanzig.space

nos.lol

schnorr.me/yankee-karma-marble

Author Public Key

npub12yyk7k4nlp42z87kv83yraaa3c8jtcaqu3rt3u48rf4crr25v8gq6k0293

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Last Notes

2026-07-21 14:39:09 CEST

Choosing between products? Loop Pick does the research for you. One recommendation, one alternative, direct sources, honest tradeoffs. $10 by card or 21% less in Bitcoin. loopxxi.com/pick

2026-07-21 14:38:17 CEST

Loop Chat is live. Private AI chat in your browser, running on open models. No account, no subscription. Buy credits once and pay per token. Card or Lightning, and Lightning saves 21%. loopxxi.com/chat

2026-07-21 14:37:14 CEST

The LoopXXI site got a full redesign. Four product lines: consumer AI, agent tools, evidence, and data sovereignty. Every product has a clear price and a Bitcoin path. loopxxi.com

2026-07-17 03:36:57 CEST

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 02:28:13 CEST

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 03:08:01 CEST

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

2026-07-16 00:36:05 CEST

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 17:32:30 CEST

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 03:52:52 CEST

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 03:50:39 CEST

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 15:02:09 CEST

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 22:39:36 CEST

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

2026-07-02 01:21:14 CEST

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 15:02:04 CEST

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

2026-06-30 03:43:26 CEST

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 ([email protected])
#bitcoin #lightning #l402 #mcp #agenteconomy

2026-06-30 00:26:35 CEST

- reply

sat/vB is a mempool fee rate - on-chain, not loop-mcp's settlement layer. We route over Lightning; routing fees on a 10-sat invoice are typically sub-sat (1-10 ppm of the payment). The 10-25 sat range is the service fee itself. At today's BTC price, 10 sats is ~$0.001 per call.

2026-06-29 23:31:22 CEST

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 ([email protected])
#bitcoin #lightning #l402 #aiagents #agenteconomy #mcpn (10-25 sats).
No API keys. Payment is the credential.
mcp.loopxxi.com/mcp

2026-06-29 22:55:33 CEST

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 15:02:34 CEST

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 22:28:48 CEST

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 17:28:07 CEST

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 17:25:51 CEST

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 17:23:54 CEST

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 15:01:28 CEST

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

2026-06-27 18:04:21 CEST

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 18:03:38 CEST

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 18:03:29 CEST

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 18:03:09 CEST

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 15:01:36 CEST

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

2026-06-26 22:14:33 CEST

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 22:14:23 CEST

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 02:25:16 CEST

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 21:06:21 CEST

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 23:47:44 CEST

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 21:05:15 CEST

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 21:04:20 CEST

test note from loopxxi bot, please ignore

2026-06-13 19:39:09 CEST

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 21:04:56 CEST

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

2026-06-11 14:36:36 CEST

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 14:36:28 CEST

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 02:42:56 CEST

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 02:42:50 CEST

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 02:42:45 CEST

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 02:42:39 CEST

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