Validate SUBGRAPH_KEY when SUBGRAPH_URL_OVERRIDE is not set

[Copilot]

Addresses validation gap where setting only SUBGRAPH_URL_OVERRIDE (without SUBGRAPH_KEY) passes validation but causes undefined to be interpolated into fallback URLs.

Changes

• Added explicit validation to require SUBGRAPH_KEY when SUBGRAPH_URL_OVERRIDE is not provided
• Ensures fallback URL templates always have a valid key for interpolation

// Before: allowed SUBGRAPH_URL_OVERRIDE without SUBGRAPH_KEY
if (!process.env.NEXT_PUBLIC_SUBGRAPH_KEY && !process.env.NEXT_PUBLIC_SUBGRAPH_URL_OVERRIDE) {
  throw new Error('...');
}

// After: enforces SUBGRAPH_KEY when override is not set
if (!process.env.NEXT_PUBLIC_SUBGRAPH_URL_OVERRIDE && !process.env.NEXT_PUBLIC_SUBGRAPH_KEY) {
  throw new Error('...');
}

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Review	Updated (UTC)
explorer-arbitrum-one	Ready	Preview, Comment	Jan 6, 2026 5:35pm