Explore OpenRPC as alternative to OpenAPI for JSON-RPC documentation

[r-near]

Summary

We should explore using OpenRPC for documenting NEAR's JSON-RPC API.

Background

NEAR added OpenAPI spec generation in May 2025. However, OpenAPI was designed for REST APIs and doesn't map cleanly to JSON-RPC, resulting in:

• 21k+ lines of generated spec with 343 schemas for ~40 RPC methods
• Fake REST paths (/block, /chunk) when JSON-RPC is really just POST /
• Significant per-method wrapper type duplication

At the time, OpenRPC appeared unmaintained so we went with OpenAPI.

OpenRPC Status Update

OpenRPC has since become active again:

• Received Optimism RetroPGF funding in 2025
• Ethereum officially uses it for the Execution API specification
• Active development resumed (v2.1.1 released Oct 2025)

Proposal

Evaluate whether OpenRPC would be a better fit for NEAR's JSON-RPC API documentation.

Resources

• OpenRPC spec: https://github.com/open-rpc/spec
• OpenRPC generator: https://github.com/open-rpc/generator
• Current NEAR OpenAPI: chain/jsonrpc/openapi/