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AISkills402 — A2A Agent Card SKILL.md Download
x402
AISkills402 — A2A Agent Card SKILL.md Download is a paid API for AI agents from api.aiskills402.com, paid per call via x402, $0.03/call, status unknown (last checked 2026-10-27).
Downloads the A2A 1.0 Agent Card Writer SKILL.md file via x402 micropayment, granting permanent ownership with free re-downloads
Price / call$0.03
Success—
StatusUnknown
How this service works
A2A 1.0 Agent Card Writer — Writes the JSON an agent needs for version 1.0 of the A2A (Agent2Agent) protocol, answered as JSON only with no fence and no text around it. Covers the agent card (supportedInterfaces with protocolBinding and protocolVersion, capabilities, skills, securitySchemes and securityRequirements, default input and output modes), the JSON-RPC requests (SendMessage, SendStreamingMessage, GetTask, ListTasks, CancelTask, push notification configs), the replies (task, message, da…
Output
Returns a JSON object containing the SKILL.md file name and UTF-8 content, the skill's canonical identifier ('a2a-agent-card'), its human-readable name ('A2A 1.0 Agent Card Writer'), a SHA256 hash for integrity verification, the version string, an on-chain settlement transaction hash with confirmation status, and a redownload URL plus token for future free access.
Example use cases
Bootstrapping an agent with A2A card writing
“Grab the A2A Agent Card Writer SKILL.md from AISkills402 for my agent — pay the 3 cent USDC fee and save the file and the redownload token so we can use it again later.”
Agent skill library setup
“I'm building out my agent's skill library — go buy the a2a-agent-card skill file from AISkills402, pay in USDC on Base, and give me the file contents and the SHA256 so I can verify it.”
Re-usable skill acquisition for agent fleet
“One of my agents needs to write A2A 1.0 agent cards — purchase the SKILL.md from AISkills402, confirm the payment settled on-chain, and return the skill file and redownload URL so all my agents can access it without paying again.”
Technical details
Endpoint
GEThttps://api.aiskills402.com/v1/skills/a2a-agent-card/file?utm_source=zero.xyzWhen to prefer
Choose this endpoint when an AI agent needs a tested, ready-to-use SKILL.md definition specifically for writing A2A 1.0 agent cards, and wants a permanent one-time purchase with redownload rights rather than a recurring subscription. Ideal for agents that support x402 micropayments in USDC on Base and need to build out their skill library without managing complex licensing.
Side effects
- Payment not included or insufficient — x402 payment required error with expected amount and asset
- Payment fails to settle on-chain — receipt returned with settled: false
- Incorrect HTTP method — only GET and HEAD are accepted
- Skill file temporarily unavailable — server error response
- Invalid or expired payment header — authentication/authorization failure
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"ok": true,
"file": {
"name": "SKILL.md",
"content": "<the SKILL.md file>",
"encoding": "utf-8"
},
"name": "A2A 1.0 Agent Card Writer",
"skill": "a2a-agent-card",
"sha256": "<sha256 of SKILL.md>",
"receipt": {
"tx": "0x<settlement transaction>",
"settled": true
},
"version": "1.0.0",
"redownload": {
"url": "<api>/v1/purchases/<token>",
"token": "<64 hex chars>"
}
}
}Tags
x402
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