[Feature Request]: Nano (XNO) payment wrapper for embedding API usage

[dhyabi2]

Describe the problem

OpenAI's embedding API (text-embedding-3-small at $0.02/M tokens, text-embedding-3-large at $0.13/M tokens) is the most widely used embedding service in AI agent pipelines. Agents that call the embeddings endpoint at high frequency accumulate micropayments — but paying for them requires USD or USDC, which means per-transaction fees that make sub-cent micropayments uneconomical.

For autonomous agents that need per-operation payment authority (each embedding request paid for by the agent itself), the absence of a fee-free micropayment rail means agents either bypass payment entirely or pay more in fees than the request is worth.

Describe the proposed solution

Add a Nano (XNO) payment wrapper for the OpenAI Python SDK that allows agents to pay for embedding API usage in fee-free, instant XNO via the x402 protocol.

Concretely:

1. A NanoPaymentClient wrapper around openai.OpenAI that intercepts embedding requests, derives a per-request Nano payment via x402 (using the existing feeless402 library — github.com/michardnicolas/feeless402), and submits the payment alongside the API call. The wrapper would be a drop-in replacement: client = NanoPaymentClient(api_key=...) instead of client = OpenAI(api_key=...).

2. Usage tracking: the wrapper reports tokens used per request, enabling agents to track their embedding spend in Nano. At $0.02/M tokens (text-embedding-3-small), a 100K-token batch costs ~$0.002 — a micropayment that is economic in Nano but uneconomical in USDC after gas.

3. For OpenAI: accept Nano as a billing currency for the embeddings API. Agents that already hold XNO (e.g. via the OpenAI Agents SDK's Nano x402 payer — github.com/dhyabi2/openai-agents-nano-x402) can pay for embedding usage without converting to USD, avoiding fee erosion.

Alternatives considered

• USDC on Base via x402: the existing agent-payments rail, but each transaction carries a gas fee. For sub-cent embedding micropayments, the gas fee exceeds the payment value.
• Credit card billing: aggregated monthly, which works for humans but not for autonomous agents that need per-operation payment authority.
• Do nothing: agents embed for free until the bill comes due, which works for low-volume use but doesn't give agents payment authority.

Importance

• would make my life easier — for high-frequency embedding workloads where each request should be paid for in real time by the agent itself, the absence of a fee-free micropayment rail forces a choice between unmonetized usage or uneconomical per-transaction fees.

Additional context

• The existing feeless402 library (MIT license) provides fee-free x402 micropayments in Nano — github.com/michardnicolas/feeless402.
• A working Nano x402 adapter for the OpenAI Agents SDK already exists — github.com/dhyabi2/openai-agents-nano-x402 — proving the pattern works for OpenAI's agent ecosystem.
• Nano settles in under 1 second (>99.9% in <1s), has no per-transaction fee, and is self-custodied (no issuer, no freeze).