Coding Tools

The coding server provides tools for reading and writing files, running shell commands, searching codebases, fetching web content, and using LSP-backed code intelligence. See Tools for settings.

Configuration

.aether/mcp.json

{
  "servers": {
    "coding": {
      "type": "in-memory",
      "args": ["--rules-dir", ".aether/skills"]
    }
  }
}

Supported args:

Arg	Description
--root-dir <path>	Workspace root. Users don’t need to set this as Aether sets this automatically.
--rules-dir <path>	Directory to load Rules from. Repeatable.
--permission-mode always-allow|auto|always-ask	Approval behavior for destructive tools. Default is always-allow.
--disable-lsp	Run without LSP integration. The lsp_* tools remain listed but fail when invoked.

Permission modes:

Mode	Behavior
always-allow	Tool calls execute without eliciting approval. This is the default.
auto	File writes auto-execute; destructive bash commands ask for approval.
always-ask	Every destructive tool — write_file, edit_file, bash, and lsp_rename — asks for approval; read-only tools are ungated.

File operations

Tool	Description
read_file	Read a file with optional line range.
write_file	Write content to a file, creating or overwriting it.
edit_file	Exact string replacement within a file.

Bash

Use shell commands through bash for text search, file discovery, structural search, and directory listings.

Tool	Description
bash	Execute a shell command. Pass timeout to cap execution time (max 600000 ms), or run_in_background to run it as a background MCP task that returns its complete output at completion.

Because bash spawns real subprocesses, it composes with deferred (proxied) tools from other MCP servers via the aether mcp CLI — pipelines, redirects, and command substitution all work.

Web

Tool	Description
web_fetch	Fetch a URL, extract main article content, and convert it to Markdown.
web_search	Search the web via Brave Search API. Requires BRAVE_SEARCH_API_KEY.

LSP tools inside coding

Unless --disable-lsp is set, Aether wires LSP-backed tools into the coding server. With --disable-lsp, the lsp_* tools are still advertised but every call returns an “LSP not configured” error.

Tool	Description
lsp_symbol	Definition, references, and hover for a symbol.
lsp_check_errors	Compiler diagnostics without running a full build command.
lsp_rename	Rename a symbol across the workspace.