feat: add Headless Oracle plugin — Ed25519-signed market-state receipts for 28 exchanges

[LembaGang]

Headless Oracle

Pre-trade verification gate for autonomous financial agents.

An Agent Zero instance (AgentZero/19353) discovered and called our MCP endpoint tonight.
This submission makes the integration official.

What it does

Headless Oracle returns Ed25519-signed receipts indicating whether a stock exchange is
OPEN, CLOSED, HALTED, or UNKNOWN. The signature lets any downstream agent verify the
receipt independently without calling the API again.

This is a pre-trade safety primitive: before any financial execution decision, check the oracle.

MCP tools included

Tool	Description
`get_market_status`	Signed receipt (OPEN/CLOSED/HALTED/UNKNOWN) for a given MIC
`get_market_schedule`	Next open/close times in UTC, lunch breaks, holiday data
`list_exchanges`	All 28 supported exchanges with timezones and MIC codes
`verify_receipt`	Verify an Ed25519-signed receipt in-worker

Coverage

28 global exchanges: NYSE, NASDAQ, LSE, JPX, Euronext Paris, HKEX, SGX, ASX, BSE/NSE India,
Shanghai, Shenzhen, Korea, Johannesburg, B3 Brazil, SIX Swiss, Borsa Italiana, Istanbul,
Tadawul, Dubai, NZX, Nasdaq Helsinki/Stockholm, CME, NYMEX, Cboe, Coinbase (24/7),
Binance (24/7).

Getting started

No API key required for sandbox (200 free calls). Configure in Agent Zero via MCP:

```json
{
"mcpServers": {
"headless-oracle": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://headlessoracle.com/mcp"]
}
}
}
```

Or use the `get_market_status` tool directly once the plugin is installed.

x402 autonomous payment

Agents can pay $0.001 USDC per request on Base mainnet without human intervention
(ERC-8004 registry: 8453:38413).

Compliance

• APTS v1.0 (Agent Pre-Trade Safety Standard) — all 6 checks pass
• SMA Protocol v1.0 (Signed Market Attestation) — receipts are SMA-compliant
• UNKNOWN always means CLOSED — fail-closed by design

Links

• Skill file: https://headlessoracle.com/skill.md
• MCP endpoint: https://headlessoracle.com/mcp
• OpenAPI spec: https://headlessoracle.com/openapi.json
• Ampersend listing: https://app.ampersend.ai/agents/headless-oracle
• Agent discovery: https://headlessoracle.com/.well-known/agent.json

Checklist:

• `plugin.yaml` at repo root
• `skills/headless_oracle.md` included (auto-installed skill)
• Folder name `headless_oracle` matches `name` in `plugin.yaml`
• GitHub URL is publicly accessible
• One plugin per PR

[a0-bot]

Plugin submission validation failed

ERROR: Invalid YAML in plugins/headless_oracle/index.yaml: mapping values are not allowed here