How do I install the Payment Offer Preflight skill?

Run npx skillmds@latest add epistemedeus/payment-offer-preflight in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Payment Offer Preflight safe to use?

This skill has not completed SkillMD's automated safety review yet. Independent scanners report: SkillSpector: PASS, Skill Scanner: PASS. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Payment Offer Preflight?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Payment Offer Preflight free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Payment Offer Preflight?

epistemedeus (@epistemedeus) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Payment Offer Preflight by epistemedeus

Name: Payment Offer Preflight
Author: epistemedeus

Payment Offer Preflight

Compare x402 and MPP payment challenges for one exact public HTTPS GET URL before buyer authorization. Use to normalize live payment terms, verify URL and realm binding, detect expiry or cross-protocol economic drift, and decide whether an offer is parseable or needs review. The target inspection uses no credential, signs nothing, sends no payment, follows no redirects, and reads no response body.

epistemedeus Updated Sep 21, 2026

File contents

Preflight a machine-payment offer

Call:

GET https://agents.samedaydesk.com/commerce/payment-offer-preflight?url=<exact-https-get-url>

Supply the complete public HTTPS URL, including every required query parameter. Do not supply a URL containing credentials, authorization material, session tokens, private-network hosts, or unresolved route parameters.

Read the current operation, response contract, and price from https://agents.samedaydesk.com/openapi.json. Send X-SameDayDesk-Agent-Source: agent-skills-v1 on the initial request and replay.

On HTTP 402, verify the complete SameDayDesk resource, amount, Base network, canonical Base USDC asset, and recipient. Pay only with caller authorization through x402 v2 or MPP evm/charge. Preserve the source header and reconcile the protocol receipt.

Use decision, normalized offers, parity, findings, URL and realm binding, and expiry fields to decide whether the target offer can enter a separate buyer authorization policy. Treat parseable_offer as evidence that the challenge was well formed, not permission to pay the target. Route review_required to policy review and treat no_parseable_offer as a failed preflight.

Verify the returned boundary states that the target inspection used no credentials, signed and sent no target payment, read no response body, and followed no redirect. Keep the result point-in-time. Re-run immediately before any separately authorized target purchase because prices, recipients, expiry, and network state can change.

The target-offer inspection is unpaid; the hosted SameDayDesk preflight itself may have a price in the live catalog. Any authorized purchase of that hosted record belongs to a separate payment executor. A preflight result never authorizes payment to the inspected target.

---name: payment-offer-preflightdescription: Compare x402 and MPP payment challenges for one exact public HTTPS GET URL before buyer authorization. Use to normalize live payment terms, verify URL and realm binding, detect expiry or cross-protocol economic drift, and decide whether an offer is parseable or needs review. The target inspection uses no credential, signs nothing, sends no payment, follows no redirects, and reads no response body.---# Preflight a machine-payment offerCall:`GET https://agents.samedaydesk.com/commerce/payment-offer-preflight?url=<exact-https-get-url>`Supply the complete public HTTPS URL, including every required query parameter.Do not supply a URL containing credentials, authorization material, sessiontokens, private-network hosts, or unresolved route parameters.Read the current operation, response contract, and price from`https://agents.samedaydesk.com/openapi.json`. Send`X-SameDayDesk-Agent-Source: agent-skills-v1` on the initial request and replay.On HTTP 402, verify the complete SameDayDesk resource, amount, Base network,canonical Base USDC asset, and recipient. Pay only with caller authorizationthrough x402 v2 or MPP `evm/charge`. Preserve the source header and reconcilethe protocol receipt.Use `decision`, normalized `offers`, `parity`, `findings`, URL and realm binding,and expiry fields to decide whether the target offer can enter a separate buyerauthorization policy. Treat `parseable_offer` as evidence that the challengewas well formed, not permission to pay the target. Route `review_required` topolicy review and treat `no_parseable_offer` as a failed preflight.Verify the returned boundary states that the target inspection used nocredentials, signed and sent no target payment, read no response body, andfollowed no redirect. Keep the result point-in-time. Re-run immediately beforeany separately authorized target purchase because prices, recipients, expiry,and network state can change.The target-offer inspection is unpaid; the hosted SameDayDesk preflight itself may have a price in the live catalog. Any authorized purchase of that hosted record belongs to a separate payment executor. A preflight result never authorizes payment to the inspected target.

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