fix(gemini): strip deprecated keyword from tool schemas sent to Gemini API

[n24q02m]

Summary

Gemini API rejects function declarations containing the JSON Schema deprecated keyword with INVALID_ARGUMENT (400). Claude Code and other clients include this field in their tool definitions, causing errors on Antigravity/Gemini routes.

Changes

Add "deprecated" to the unsupported keywords list in removeUnsupportedKeywords() (internal/util/gemini_schema.go) so it is stripped before forwarding to Gemini.

Reproduction

1. Use Claude Code (or any client that emits "deprecated": true in tool schemas) with an Antigravity account
2. Observe INVALID_ARGUMENT / 400 error from Gemini API:

   Unknown name "deprecated" at 'request.tools[0].function_declarations[X].parameters.properties[Y].value'
   

3. After this fix, the field is stripped and requests succeed.

Related

• Same class of bug as x-google-* vendor extension fields that were already being stripped
• Mirror PR on standard repo: fix(gemini): strip deprecated keyword from tool schemas sent to Gemini API CLIProxyAPI#1839
• One-line change, no new dependencies

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses a critical compatibility issue with the Gemini API, where tool declarations containing the deprecated JSON Schema keyword were being rejected. By proactively removing this unsupported keyword from the outgoing schemas, the change ensures that clients can successfully interact with the Gemini API without encountering INVALID_ARGUMENT errors, thereby improving the robustness and interoperability of the system.

Highlights

• Gemini API Compatibility: Resolved an INVALID_ARGUMENT error (400) from the Gemini API when tool schemas containing the JSON Schema deprecated keyword were sent, which was affecting clients like Claude Code.
• Schema Keyword Stripping: The deprecated keyword is now explicitly stripped from tool schemas before being forwarded to the Gemini API, preventing rejection.

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Changelog

• internal/util/gemini_schema.go
  • Added "deprecated" to the list of unsupported JSON Schema keywords that are stripped before sending to the Gemini API.

Activity

• No human activity (comments, reviews) has been recorded on this pull request yet.

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[gemini-code-assist]

Code Review

This pull request addresses an issue where the Gemini API rejects schemas containing the deprecated keyword. The fix is to add deprecated to the list of unsupported keywords that are stripped from the schema before sending it to Gemini. The change is simple and correct. I've suggested adding a test case to verify this behavior and prevent regressions.

[gemini-code-assist]

This change correctly adds deprecated to the list of unsupported keywords. To ensure this fix is robust and prevent future regressions, it would be great to add a test case that verifies the deprecated keyword is stripped.

You could add the following test to internal/util/gemini_schema_test.go:

func TestCleanJSONSchemaForGemini_RemovesDeprecatedField(t *testing.T) {
	input := `{
		"type": "object",
		"properties": {
			"old_field": {
				"type": "string",
				"deprecated": true
			}
		}
	}`

	expected := `{
		"type": "object",
		"properties": {
			"old_field": {
				"type": "string"
			}
		}
	}`

	result := CleanJSONSchemaForGemini(input)
	compareJSON(t, expected, result)
}