Losbeto MCP Server

Losbeto — point-in-time Brazilian market data for AI agents

The problem: the IPCA number you fetch from the Banco Central API today is not the number that was published back then. Official Brazilian series are revised. Any backtest built on the current series silently contains look-ahead bias.

The US has ALFRED for this. Brazil has nothing public.

What this is: a node that has been recording Brazilian official statistics as they were published, timestamping every reading, and signing each day with Ed25519 — continuously, since deploy. That archive cannot be scraped retroactively by anyone, including us. It only exists because the node was running.

Paid per call over x402 — USDC on Base, Solana or Algorand. No signup, no API key, no invoice.

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Quick start

# free — see the whole archive and how to verify it
curl https://api.losbeto.xyz/br-pit-proof

# free — what the paid endpoints actually cost and why
curl https://api.losbeto.xyz/why-buy

# free — the buying criterion, published: what is worth paying for here and what is not
curl https://api.losbeto.xyz/what-agents-buy

# paid — IPCA as it was known on 5 Aug 2026 (not as revised since)
curl https://api.losbeto.xyz/br-asof?series=ipca_12m_pct&date=2026-08-05
# -> HTTP 402 with the payment challenge; pay and repeat

With an x402 client

import { wrapFetchWithPayment } from "x402-fetch";

const fetchWithPay = wrapFetchWithPayment(fetch, wallet);
const r = await fetchWithPay(
  "https://api.losbeto.xyz/br-asof?series=selic_meta_pct&date=2026-06-30"
);
console.log(await r.json());

As an MCP server (Claude Desktop, Cursor, Claude Code)

{
  "mcpServers": {
    "losbeto": {
      "url": "https://api.losbeto.xyz/mcp",
      "headers": { "Authorization": "Bearer <credit-key>" }
    }
  }
}

Get a credit key with one on-chain payment: POST https://api.losbeto.xyz/buy-credits.

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The archive products (the moat)

Series tracked: selic_meta_pct, cdi_daily_pct, ipca_12m_pct, igpm_month_pct, usd_brl_ptax, eur_brl.

The Brazilian primitives (zero upstream, sub-millisecond)

Pure computation over Brazilian specifications — no external API in the request path, no rate limit, no provider outage, priced for loops:

The spec-level traps these absorb: CRC16-CCITT/FALSE (poly 0x1021, seed 0xFFFF), Carnaval/Corpus Christi moving with Easter, and Consciência Negra becoming a national holiday only in 2024. Getting any of them wrong silently corrupts a rate calculation or makes a QR refused at the register. Verifiable from outside: GET /zero-upstream.json declares which routes never touch the network.

The node also exposes ~80 other endpoints (crypto, FX, commodities, equities). Those are convenience wrappers over public sources — see /what-agents-buy, where we publish the formula and tell you plainly which ones you should not pay for.

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Verify anything, offline

Every observation is a Merkle leaf:

leaf = sha256("<series>|<ref_date>|<value>|<seq>|<observed_ts>")

Leaves are sorted and hashed into a daily Merkle root (sha256; an odd level duplicates its last leaf). The root is signed:

Ed25519( "losbeto-pit|<day>|<root>" )   # pubkey published at /br-pit-proof

import base64, nacl.signing
pub = nacl.signing.VerifyKey(base58_decode(signer))
pub.verify(f"losbeto-pit|{day}|{root}".encode(), base64.b64decode(signature))

Daily roots are optionally anchored on Algorand as a zero-value note transaction, so the timestamp does not depend on trusting us.

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For agents: start at the manifest

GET /agents.json (also at /.well-known/agents.json) — the agents.json manifest: outcome-based flows with exact parameters, payment networks, the free tier, and pointers to the OpenAPI contract, the x402 manifest, the scorecard and the fidelity recipes. CORS open, cached 1h.

For indexers and QoS scorers

If you are ScoutScore, EntRoute, x402scan, x402-list, BlockRun or any other service that probes and ranks x402 nodes, these are for you:

Free probes never charge. A paid route that hits an unexpected internal error degrades to a 402 rather than a 500 — the resource is still for sale. The OpenAPI and Swagger specs carry a stable ETag and answer 304 — no need to re-download 130 KB between probes.

Revenue transparency

GET /.well-known/honest-revenue.json — signed, and it separates:

• organic — paid by a wallet the operator does not control
• operator-test — the operator's own declared wallets
• self-sweep — one wallet settling many distinct endpoints in a short window

Operator-funded traffic is labelled, not hidden. If the organic number is small, it says so.

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Run it yourself

pip install -r requirements.txt
export SOLANA_WALLET_ADDRESS=...      # where payments land
export BASE_PAYTO_EVM=0x...           # optional
export ALGORAND_WALLET_ADDRESS=...    # optional
export BUYER_WALLETS=...              # your own test-buyer wallets, comma separated
gunicorn --workers 2 --threads 8 --preload --bind 0.0.0.0:$PORT nexus_omega:app

Useful env vars: AI_WARMER=1 (re-enable AI preview warming), LLM_DAILY_BUDGET, LLM_PAID_RESERVE, PIT_INTERVAL_S, ALGO_ANCHOR_MNEMONIC (+ pip install py-algorand-sdk).

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Contact

Roberto Martins — roberto.martins622@gmail.com

Missing a series or a market you need? Open an issue. New endpoints get built on request.

MIT licensed.