[HAYDEN-OAI]

Summary

• Handle Zod v3 z.literal(null) before JavaScript's typeof null === 'object' fallback, producing the same { type: 'null', const: null } JSON Schema as Zod v4.
• Preserve existing OpenAPI 3 compatibility by delegating null literals to the existing parseNullDef implementation.
• Add focused coverage for all five public Zod helpers, strict and Realtime schemas, local parsing, nested/described/optional/nullable fields, mixed and optimized unions, arrays, defaults, shared definitions, plain null, existing primitive literals, and Zod v4 behavior.

Why

The current converter emits { type: 'object' } for Zod v3 null literals. Consequently, the model-visible schema rejects actual null while the local Zod validator rejects every object accepted by that schema. This affects zodResponseFormat, zodTextFormat, zodFunction, zodResponsesFunction, and zodRealtimeFunction.

The regression-first run on unmodified main produced 10 failing / 6 passing dedicated tests, including independent failures for all five helpers.

Verification

• ./node_modules/.bin/vitest run --config vitest.config.mts tests/helpers/zod.test.ts tests/helpers/zod-null-literal.test.ts — 58 passed.
• pnpm test:unit — 2,106 passed across 71 handwritten test files.
• pnpm lint and targeted oxfmt --check — passed.
• pnpm exec tsc — passed.
• pnpm build — passed for CommonJS and ESM.
• ./node_modules/typescript-4-9/bin/tsc --project dist/src/tsconfig.json --noEmit — passed.
• ./node_modules/typescript/bin/tsc --project dist/src/tsconfig.json --noEmit — passed.
• node --experimental-strip-types scripts/test-packed-package.ts — packed CommonJS/ESM artifact and both TypeScript generations passed across 1,200 source maps.
• Direct built-package smoke verified all five CommonJS helpers, four local parsers, OpenAPI 3 null compatibility, and the ESM helper.

[openai-sdks]

OkTest Summary

✅ 237/237 SDK tests passed in 10.386s for Node SDK PR #2355.

Test results — 42 files

Test	Result	Time
tests/chat-completions-complex-body.test.ts	✅ Passed	168ms
tests/chat-completions-create.test.ts	✅ Passed	195ms
tests/chat-completions-stream.test.ts	✅ Passed	194ms
tests/files-content-binary.test.ts	✅ Passed	153ms
tests/files-create-multipart.test.ts	✅ Passed	134ms
tests/files-list-pagination.test.ts	✅ Passed	146ms
tests/initialize-config.test.ts	✅ Passed	172ms
tests/instance-isolation.test.ts	✅ Passed	128ms
tests/models-list.test.ts	✅ Passed	139ms
tests/responses-background-lifecycle.test.ts	✅ Passed	238ms
tests/responses-body-method-errors.test.ts	✅ Passed	282ms
tests/responses-cancel-timeout.test.ts	✅ Passed	189ms
tests/responses-cancel.test.ts	✅ Passed	264ms
tests/responses-compact-retries.test.ts	✅ Passed	228ms
tests/responses-compact.test.ts	✅ Passed	262ms
tests/responses-create-advanced-stream.test.ts	✅ Passed	134ms
tests/responses-create-advanced.test.ts	✅ Passed	202ms
tests/responses-create-disconnect.test.ts	✅ Passed	1.098s
tests/responses-create-errors.test.ts	✅ Passed	198ms
tests/responses-create-malformed-api-responses.test.ts	✅ Passed	181ms
tests/responses-create-retries.test.ts	✅ Passed	272ms
tests/responses-create-stream-failures.test.ts	✅ Passed	213ms
tests/responses-create-stream-timeout.test.ts	✅ Passed	2.16s
tests/responses-create-stream-wire.test.ts	✅ Passed	2.628s
tests/responses-create-stream.test.ts	✅ Passed	79ms
tests/responses-create-terminal-states.test.ts	✅ Passed	264ms
tests/responses-create-timeout.test.ts	✅ Passed	197ms
tests/responses-create.test.ts	✅ Passed	142ms
tests/responses-delete.test.ts	✅ Passed	180ms
tests/responses-input-items-errors.test.ts	✅ Passed	191ms
tests/responses-input-items-list.test.ts	✅ Passed	186ms
tests/responses-input-items-options.test.ts	✅ Passed	107ms
tests/responses-input-tokens-count-timeout.test.ts	✅ Passed	242ms
tests/responses-input-tokens-count.test.ts	✅ Passed	219ms
tests/responses-malformed-inputs.test.ts	✅ Passed	2.219s
tests/responses-not-found-errors.test.ts	✅ Passed	285ms
tests/responses-parse.test.ts	✅ Passed	189ms
tests/responses-retrieve-retries.test.ts	✅ Passed	235ms
tests/responses-retrieve.test.ts	✅ Passed	255ms
tests/responses-stored-method-errors.test.ts	✅ Passed	537ms
tests/retry-behavior.test.ts	✅ Passed	3.138s
tests/sdk-error-shape.test.ts	✅ Passed	279ms

View OkTest run #31850915668

_{SDK merge (cc0016653878) · head (4b6e5b539185) · base (a3deafb5f91d) · OkTest (a845fa206fa4)}

[jbeckwith-oai]

Reviewed the full exact-head diff in two passes. The null-literal guard is placed at the canonical Zod v3 parser boundary, preserves the other literal branches, reuses the existing OpenAPI null parser, and is covered across all public helpers plus nested/reference/target and Zod v4 compatibility paths. Strict thermo and test-policy review are clean, and all applicable exact-head CI is green. No findings.