GitLab 18.4: AI-native development with automation and insight

What this post added

Introduced the GitLab Duo AI Catalog for creating and sharing custom agents. Enhanced Agentic Chat with custom agent interaction, user model selection, improved formatting, and session management. Launched the GitLab Knowledge Graph (Beta) for codebase navigation and understanding. Introduced the Fix Failed Pipelines Flow for automated, business-aware pipeline maintenance. Made GitLab Duo Model Selection generally available and added GPT OSS and GPT-5 support for self-hosted deployments. Introduced GitLab Duo Context Exclusion for granular data protection. Added new tools to the GitLab MCP server.