Does this solve indexing of codebases like Cursor does, or do you still need tools / plugins like Lumen (https://github.com/ory/lumen) for that in order to work in larger codebases without wasting tens of thousands of tokens on tool calls and brute force guessing with grep?
how does lumen differ from serena? https://github.com/oraios/serena curious about it seems promising
ctx sits around the agent harness, not in place of it.
So Claude Code, Codex, OpenCode, etc keep their normal tools/capabilities rather than being reimplemented inside a new proprietary agent. If a harness has its own indexing/code-search story, you still get that; if it doesn’t, ctx doesn’t provide additional tools like codebase indexing.
The only additional tools we do provide are orchestration-related: - local merge queue for agents (submit your diff and make sure it lands cleanly on others) - agnostic subagents (for example, a Claude Code primary agent can invoke a Codex subagent)