Add OpenChainBench API

[Flotapponnier]

New API Submission

API: OpenChainBench
Base URL: https://openchainbench.com
Docs: https://openchainbench.com/api/openapi.json

Description

OpenChainBench publishes daily open benchmarks for crypto infrastructure: RPC providers, oracles, bridges, L1 finality, prediction markets, and Hyperliquid builders. Data is reproducible, methodology is public, and citable Parquet snapshots are mirrored on HuggingFace with a Zenodo DOI.

Endpoints exposed:

• /api/citable — flat index of all benchmarks
• /api/stat/{slug} — single benchmark with rankings, sparkline, citation
• /api/og/{slug} — OG image for a benchmark

No authentication. CORS enabled (access-control-allow-origin: *).

Maintainer

Mobula / OpenChainBench (contact@openchainbench.com)
Source and methodology: https://github.com/ChainBench/OpenChainBench

[gemini-code-assist]

Code Review

This pull request introduces the OpenAPI 3.1.0 specification for the OpenChainBench API, defining endpoints for listing benchmarks, retrieving individual benchmark statistics, and fetching open graph images. The review feedback highlights compatibility issues with OpenAPI 3.1.0, specifically the use of the deprecated nullable keyword which should be replaced with multi-type arrays, and a missing items definition for the rankings array property.

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[gemini-code-assist]

In OpenAPI 3.1.0, the nullable keyword is no longer supported because OpenAPI 3.1.0 aligns with JSON Schema Draft 2020-12. To define a nullable field, you should use a multi-type array (e.g., type: [number, "null"]) instead.

          type:
            - "number"
            - "null"

[gemini-code-assist]

In OpenAPI 3.1.0, the nullable keyword is no longer supported because OpenAPI 3.1.0 aligns with JSON Schema Draft 2020-12. To define a nullable field, you should use a multi-type array (e.g., type: [number, "null"]) instead.

          type:
            - "number"
            - "null"

[gemini-code-assist]

The rankings property is defined as type: array but is missing the items keyword. In OpenAPI/JSON Schema, array types should specify the schema of their items. If the items can be of any type, you can use an empty object items: {}.

        rankings:
          type: array
          items: {}

[Flotapponnier]

Thanks for the review. Pushed a follow-up commit (baf47ad) addressing all three findings:

• CitableRow.value and Stat.value: { type: number, nullable: true } → type: [number, "null"] (OpenAPI 3.1 / JSON Schema 2020-12).
• Stat.rankings: added a Ranking schema as items (the spec didn't have one before; the schema now mirrors what /api/stat/{slug} actually returns — name, slug, ms.{p50,p90,p99,mean}, successRate, plus optional sampleSize / sampleHealth / dataConfidence).

The upstream source (https://openchainbench.com/api/openapi.json) is also updated in ChainBench/OpenChainBench#691 so any future re-pull stays consistent.