CodeStory is a YC S23-backed startup (London, two-person team) that builds Aide, an open-source AI-native code editor. Aide is a fork of VS Code that integrates AI agents directly into the editing workflow rather than bolting them on as extensions. The product is positioned as a privacy-first alternative to tools like Cursor, running AI inference locally or via the user's own API keys so no code is sent to CodeStory's servers by default. Aide's core differentiator is its agentic multi-file editing capability. Unlike single-file AI completions, Aide's agents can iterate across multiple files simultaneously, using the Language Server Protocol for go-to-definition and go-to-references lookups to pull in relevant context automatically. Proactive agents also watch for linter errors and propose fixes without the developer having to ask. The editor combines a chat interface with an inline edit widget (Cmd/Ctrl+K), allowing developers to brainstorm in chat and then jump directly into edits across the codebase. Tab-autocomplete uses Tree-sitter to parse code into syntactically meaningful chunks, improving the accuracy of suggestions beyond line-by-line token prediction. CodeStory raised $500K from Y Combinator (S23 batch) and was still actively developing and maintaining the Aide repository on GitHub as of mid-2026, with open job listings posted through YC. The project is open source under the codestoryai GitHub organization, making community contributions possible. Key features: - Open-source VS Code fork with native AI agent integration - Agentic multi-file editing using LSP go-to-definition and go-to-references for context - Proactive agents that detect and fix linter errors without explicit prompting - Inline edit widget (Cmd/Ctrl+K) for in-flow code modifications - Chat + edit combined flow for brainstorming and iterating across files - Tree-sitter-based tab-autocomplete for syntactically correct suggestions - Privacy-first: runs locally or uses user-supplied API keys (no code sent to CodeStory) - Support for Anthropic Claude models (Opus, Sonnet, Haiku) for completion and chat
Free and open source; users supply their own model API keys or use CodeStory's provider (usage counted toward monthly quota; specific paid tier details not publicly listed as of mid-2026)