Draft changelog: Sep 25, 2026 weekly update

[mintlify]

Summary

Adds a Sep 25, 2026 changelog entry covering product changes merged since the Sep 21 entry.

Changes

• New features: X Activity API subscription expires_at; OAuth 2.0 client secret webhook signing (X-Twitter-Webhooks-Signature-OAuth2)
• Updates: is_moderator in broadcast.chat; broadcast scopes in OAuth 1.0a token exchange; Livestream API allowlist access form

Context

Based on #441, #443, #445, #448, #454. Docs-only fixes (#451, #459) and the source field doc cleanup (#450) are excluded. The published OpenAPI spec still lists source.

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Project	Status	Preview	Updated
x-corp	🟢 Ready	View Preview	Sep 25, 2026, 11:08 PM

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