NanoGPT

Pay-per-prompt multi-model LLM gateway with no subscription, fund-your-wallet model, and the only mainstream privacy-respecting API in this directory that price-anchors on Nano (XNO) at sub-cent inference. Listed at Grade A because the no-account anonymous tier + crypto-only funding + multi-frontier-model proxy + persistent low-friction privacy posture (no email at signup, no retention contract beyond the API call) make NanoGPT the canonical fit for users who want OpenAI/Claude/Gemini quality without an OpenAI/Anthropic/Google account for crypto users — and the Nano integration is uniquely positioned for the smallest-unit micropayments the rest of the AI economy hasn't figured out.

Background. NanoGPT was built by the Nano (XNO) community starting in 2023 as a proof point that feeless, instant cryptocurrency can power per-prompt LLM inference in a way that the legacy subscription model can't — pay $0.0003 per GPT-4o call, $0.0008 per Claude Sonnet, etc., with the actual rate set by upstream API costs plus a thin margin. The site at nano-gpt.com runs a balance-based account where you top up via crypto (Nano confirms in ~0.5s, BTC/XMR/ETH/USDC available too), and every prompt deducts from balance in real time. No subscription, no minimum, no "pro tier" upsell — just credits.

The operator is publicly identified as Milan Korst (Milan W. on X / @milan_w_), an active Nano community contributor running the service as a self-funded project — no VC, no token, no separate company structure beyond a single LLC for legal contracting. NanoGPT is profitable on the margin between wholesale API cost and end-user inference price.

What you trust.

• Anonymous signup at the free tier. You can use NanoGPT through the web UI without providing an email — there's a guest/no-account browse mode for small sessions. For larger sessions or API key access, you create an account by signing up — but email is the only required field, no name, no verification, no government ID, no phone.
• Crypto-only funding path that includes XMR. Top up in XNO, BTC, XMR, ETH, or USDC. Nano is the headline because of feeless instant settlement (the entire roundtrip — generate invoice, send payment, confirm, credit balance — finishes in under 2 seconds), but XMR is the privacy-coin path that breaks the on-chain trail before NanoGPT even sees the value.
• Multi-frontier model proxy. GPT-4 / GPT-4o / o1 / o3-mini (OpenAI), Claude Opus / Sonnet / Haiku (Anthropic), Gemini Pro / Flash (Google), DeepSeek, Mistral, Llama, Grok, Qwen — all routed through a single API endpoint and a single web UI. You pay per call; NanoGPT's margin replaces the per-vendor account hurdle.
• API key + OpenAI-compatible endpoint for programmatic use. Drop the OPENAI_API_BASE override + your NanoGPT API key into any OpenAI-SDK consumer (LangChain, Continue.dev, Cursor, Aider, the official `openai` Python SDK) and it works without code changes — you get all the upstream models under one key, billed against your NanoGPT balance.
• Stated no-logging posture for inference content. NanoGPT's privacy policy commits to not retaining prompt or completion text beyond the time required to forward to the upstream provider — they keep usage metadata (tokens consumed, model, timestamp) for billing reconciliation, but not the content. You're still trusting the upstream provider (OpenAI sees your prompt if you call OpenAI), but NanoGPT itself isn't logging a parallel copy.
• Open-source frontend. The web UI is open-source under MIT on GitHub (github.com/Lurkin-prog/NanoGPT) — you can self-audit the client behavior, run a local copy, or fork. The backend (billing, proxy routing) is closed-source because it talks to operator API keys and payment processors.

Operational specs.

• Pricing: pay-per-token, denominated in dollars, with the per-model rate posted publicly at nano-gpt.com/pricing. As of mid-2025: GPT-4o ≈ $0.005/1k input + $0.015/1k output, Claude Sonnet ≈ $0.003/1k input + $0.015/1k output, DeepSeek Chat ≈ $0.0001/1k input + $0.0002/1k output, Llama 3 70B ≈ $0.0006/1k input. NanoGPT's markup is in the 5-15% range over upstream wholesale.
• Wallet top-up minimum: $5 equivalent in any supported crypto. No balance expiry; credit sits indefinitely until you spend it.
• Models exposed: 40+ at last count, including all OpenAI, Anthropic, Google, DeepSeek, Mistral, Meta (Llama), xAI (Grok), Qwen, and several open-weight images/video generators (Stable Diffusion XL, Flux, AnimateDiff). Image and video generation billed per-image with the same wallet model.
• API endpoint: `https://nano-gpt.com/api/v1` (OpenAI-compatible). API key auth via `Authorization: Bearer ngpt_...`. Rate limit is generous (10 req/sec free tier) and can be lifted on request for legitimate high-throughput use cases.
• Streaming + JSON-mode + function-calling: all OpenAI-compatible endpoints expose the same features the upstream model supports, including SSE streaming, JSON-strict-mode, tool/function calling, and vision (where the upstream supports it).
• No Tor mirror advertised — clearnet-only at nano-gpt.com. Pricing pages and the API endpoint work fine through Tor Browser exit nodes, but there's no `.onion` for the service itself.
• Support: Discord (active developer presence — Milan answers in-channel), email at support@nano-gpt.com, X at @nanogpt_ai. Response times within hours during weekdays.

Operator philosophy. Milan's framing in interviews and X threads is "the subscription model is broken for AI" — paying $20/mo for ChatGPT Plus when you only use it twice a week is a tax on irregular users, and signing up for separate Claude / OpenAI / Gemini / Mistral accounts to comparison-test models is overhead nobody wants. NanoGPT's pitch is "one wallet, every model, pay only for what you use, and we don't care who you are." The Nano integration is the proof-of-concept that micropayments at the sub-cent level are technically feasible — XNO settles in 0.5s with no fees, which is what makes $0.0003 inference economically reasonable at the transaction level. The MIT-licensed frontend reinforces that this isn't a walled garden: the operator wants the model to be copyable by anyone who wants to run a competing instance.

Grade rationale. Grade A reflects: the anonymous-signup posture (no email required for browse, optional for accounts, no other PII), the privacy-coin funding path (XMR + XNO + BTC + ETH + USDC), the no-logging commitment on inference content, the OpenAI-compatible API surface (drop-in for any existing tool), the open-source frontend (auditable), the multi-frontier-model proxy (one account = OpenAI + Anthropic + Google + DeepSeek + …), the named-operator accountability (Milan Korst publicly identified, contactable, active in community), the kycnot.me corroboration of the no-KYC claim, and no major support / billing / data-leak threads in r/Nano / r/privacy / r/LocalLLaMA in the last 12 months. Pricing transparency (per-model rate posted publicly, no hidden markup beyond stated 5-15%) closes the editorial gap that would otherwise hold it at B. Last verified 2026-05-26.

Useful when:

• You want OpenAI / Claude / Gemini / DeepSeek quality without creating an account at any of those vendors.
• You want to comparison-test multiple frontier models without managing separate API keys + invoices.
• You're a developer using Continue.dev / Cursor / Aider / LangChain and want a single OpenAI-compatible endpoint that exposes every major model.
• You want crypto-paid inference (XMR / Nano / BTC) and the rest of the AI economy still demands a credit card.
• You're a low-volume user who doesn't justify a $20/mo subscription and prefers pay-per-prompt economics.
• You're running batch jobs or experimentation where total spend is a few dollars and the convenience of one wallet across models is worth the small markup.

Caveats:

• Upstream providers still see your prompt. When you call GPT-4o through NanoGPT, OpenAI sees the prompt — NanoGPT is a proxy, not a TEE. If you need the upstream not to see the prompt either, use Venice.ai's TEE/E2EE modes (listed separately) or run open-weight models locally via Ollama / llama.cpp.
• NanoGPT is a single-operator dependency. Milan running the service alone is great for accountability and a single-operator continuity risk — if he stops, the service stops. There's no DAO, no multi-sig operator, no clear succession.
• Closed-source backend. The billing + proxy-routing layer is closed; you can't independently verify that NanoGPT doesn't log your prompts beyond the privacy-policy commitment. This is a "trust the operator" relationship, not a cryptographically verified one.
• Pricing is dollar-denominated but settled in crypto — XNO's USD value moves, so the same $5 top-up might give you fewer or more credits over time depending on Nano's exchange rate (NanoGPT freezes the USD equivalent at top-up time, so you're not exposed to volatility after deposit, but you ARE exposed at the moment you fund).
• No Tor mirror — clearnet-only at nano-gpt.com. Tor Browser exit nodes work fine, but there's no `.onion` for the service itself. Flag as a privacy gap if you want network-layer anonymity alongside the no-KYC posture.
• Markup is real but small (5-15% over upstream wholesale). If you're at high volume and direct OpenAI / Anthropic accounts make economic sense, you'll save by going direct — NanoGPT's value is convenience + anonymity + multi-vendor unification, not lowest-cost raw inference.
• Support is single-operator — Milan answers in Discord within hours during weekdays, but there's no 24/7 SLA or enterprise support contract. For mission-critical workloads, this is a limitation worth pricing in.