The three agent modes
Build
Default mode. The agent reads and writes files, runs shell commands, executes git operations, and searches your codebase. Use Build for any task where you want the agent to actually implement something — adding features, fixing bugs, refactoring, writing tests, or making multi-file changes.
Plan
The agent analyzes your request and produces a structured todo list of steps before writing any code. It lays out the full plan and waits for your review. Once you’re satisfied, you can switch to Build mode to execute. Use Plan when a change is large enough that you want to understand and approve the approach before committing to it.
Explore
Read-only mode. The agent fans out lightweight sub-agents to read across multiple files and modules cheaply, then synthesizes a coherent answer. No files are modified. Use Explore when you want to understand unfamiliar code, trace a data flow, or answer a structural question without the risk of any changes being made.
Sub-agents
In Explore mode (and during certain Build-mode tasks), Luminy can spin up sub-agents — lightweight agents that each run in their own isolated context. Sub-agents are read-only gatherers: they locate evidence across files, return code snippets and symbol references, and report back to the main agent, which synthesizes the findings. Up to 3 sub-agents run concurrently, allowing the agent to explore multiple independent areas of a codebase in parallel — for example, reading the database layer, the API layer, and the frontend components simultaneously rather than sequentially. Sub-agent activity is shown directly in the chat: each invoke appears as a collapsible tool call with a Compass icon, so you can see exactly what each sub-agent was asked to do and what it returned.Sub-agents operate as read-only gatherers — they locate and return evidence, but all judgments, edits, and final outputs are always produced by the main agent. Sub-agents never write files or run shell commands.
The agentic loop
Every time you send a message, Luminy begins an agentic loop:Reason
The model reads your message and the current conversation history, thinks about what it needs, and decides on a next action.
Act
The agent executes a tool call — reading a file, running a search, writing code, executing a shell command, or invoking a sub-agent.
Observe
The result of the tool call is returned to the model. It evaluates the output and decides what to do next.
