Add Hunch prediction-markets plugin (x402 betting on Base)

[rajkaria]

Description

Adds a native Base MCP plugin for Hunch, a prediction market
on Base with a keyless agent layer. An agent discovers/researches markets over Hunch's
public agent API (/api/agent/v1/*) and settles an any-size bet through Base MCP's x402
payment flow (initiate_x402_request → complete_x402_request) — the same Base wallet
that pays is the bet account. Settlement is parimutuel and gasless for the bettor; winners
are paid out automatically on resolution (no claim step). No API key, no separate MCP server.

Authored to the Base MCP Plugin Specification (integration: http-api). Every 402
challenge is pin-checked field-by-field (scheme/network/asset/payTo/resource) against
Hunch's pinned settlement values before any payment, and the authorization is restricted to
EIP-3009 transferWithAuthorization (never approve/permit/blanket allowance).

Type of change

• Base MCP plugin submission
• Update to an existing skill/plugin
• New skill
• Documentation
• Other (please describe):

Affected skill(s)

base-mcp

Plugin checklist

• Plugin spec/manifest is accurate and tested
• (If Applicable) API endpoints and/or external MCP/CLI tested and functional
• Follows Contribution Scope

Notes: the only spec edit is appending prediction-markets + betting to the tag
vocabulary (a genuinely new tag, permitted by Contribution Scope). The SKILL.md plugins
registry, the Integration Types Examples column, and the conformance table are left for
maintainers. The endpoints are Hunch's live production agent API; a drift guard keeps the
plugin's pinned payTo/asset byte-identical to Hunch's hardened x402 registry.

Base MCP Plugin Submission Agreement (when applicable)

By checking the box below, I agree and represent on behalf of the protocol/entity it
references that: I am authorized to submit this plugin on behalf of Hunch; it infringes no
third party's rights; the plugin and Hunch comply with applicable laws and enforce the same
geofencing/eligibility as Hunch's user-facing app; it complies with Hunch's terms; it
accurately describes its behavior with no hidden, deceptive, or malicious instructions and
the Hunch API returns no malicious or unexpected calldata (it returns a standard x402
exact challenge, pin-checked before payment); Hunch is solely responsible for the plugin
and submission is subject to the Base Account and Base App Terms of Service; and Base may
modify, decline to list, or remove the plugin at any time.

• I have read and agree to the Base MCP Plugin Submission Agreement above.

Related issues

N/A

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 1 Sum 2