GET /user/repos: `homepage` field declared as format "uri" but API returns empty string ""

[plengauer]

Description

The repository schema declares the homepage field with format: "uri", but the GitHub API returns an empty string "" for repositories that have no homepage set.

An empty string is not a valid URI per RFC 3986, so MCP servers and other tools that validate API responses against this schema will reject the entire response with a schema validation error.

Error observed

When calling GET /user/repos (or any endpoint returning repository objects), tools that validate against this schema produce:

MCP error -32602: Structured content does not match the tool's output schema: 
data/result/23/homepage must match format "uri"

The offending field is homepage: "" — GitHub returns an empty string when no homepage has been set on a repo, rather than null or omitting the field.

Expected behavior

The schema should either:

• Change homepage to allow null or an empty string alongside valid URIs (e.g. type: ["string", "null"] with the format: "uri" applied only when non-null/non-empty), or
• Document that the API returns "" for unset homepages and update the format constraint accordingly

Steps to reproduce

1. Call GET /user/repos or GET /repos/{owner}/{repo} for any repository that has no homepage URL set in its settings
2. The response will contain "homepage": ""
3. Validating this response against the current OpenAPI schema will fail on the format: "uri" constraint

Notes

• This affects all repository-returning endpoints, not just /user/repos
• The homepage field is likely nullable/optional in practice — the schema should reflect this

[shawnHartsell]

👋 Thanks for submitting this issue! I've routed this to the owning team so they can take a look.

[plengauer]

@shawnHartsell any update?