> ## Documentation Index
> Fetch the complete documentation index at: https://bolt-builder-bolt-cli-5b0aab46-mintlify-541a0110.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Tools: What Bolt Agents Can Actually Do

> The complete list of built-in tools available to Bolt agents, plus how to add your own tools through plugins, MCP servers, or the .opencode/tool directory.

Agents in Bolt do work by calling tools. Every action you see in the TUI (reading a file, running tests, searching the web) is the model choosing a tool and Bolt executing it. Each agent has a declared access level that determines which tools it may call without asking you first (see [Permissions](/concepts/permissions)).

## Built-in tools

| Tool              | What it does                                                                                      |
| ----------------- | ------------------------------------------------------------------------------------------------- |
| `read`            | Read a file from disk.                                                                            |
| `write`           | Create a new file or overwrite an existing one.                                                   |
| `edit`            | Apply a targeted edit (find/replace) to a file.                                                   |
| `apply_patch`     | Apply a unified-diff style patch across one or more files.                                        |
| `glob`            | List files matching a glob pattern.                                                               |
| `grep`            | Search file contents by regex/text.                                                               |
| `bash`            | Run a shell command.                                                                              |
| `task`            | Delegate a subtask to a subagent (`@general`, `@explore`, or a custom subagent).                  |
| `todowrite`       | Maintain the agent's structured task list for multi-step work.                                    |
| `webfetch`        | Fetch a URL and return its contents.                                                              |
| `websearch`       | Search the web.                                                                                   |
| `skill`           | Invoke a named skill (see [Skills](/extending/skills)).                                           |
| `memory_save`     | Persist a fact to [project memory](/concepts/project-memory).                                     |
| `memory_recall`   | Look up a previously-saved memory.                                                                |
| `question`        | Ask you a clarifying question and wait for a reply.                                               |
| `bash_background` | Start a shell command as a managed background process (dev servers, watchers, long builds).       |
| `process_output`  | Read accumulated output and status for a background process, optionally waiting for it to finish. |
| `list_processes`  | List background processes with their id, status, and command.                                     |
| `kill_process`    | Terminate a background process (and its process tree) by id.                                      |
| `test_run`        | Detect and run the project's tests, returning structured pass/fail results and failure details.   |

### Experimental

| Tool      | What it does                                                          |
| --------- | --------------------------------------------------------------------- |
| `lsp`     | Query a language server for definitions, references, and diagnostics. |
| `execute` | Run code in an isolated code-mode sandbox.                            |
| `plan`    | Produce a structured plan before making changes.                      |

Experimental tools may change or be renamed between releases.

## Extending the tool set

Beyond built-ins, Bolt can call tools from three sources:

* **Custom tools** in `.opencode/tool/` (or `.opencode/tools/`) at the project root. See [Custom Tools](/extending/custom-tools).
* **Plugin tools** contributed by any installed [plugin](/extending/plugins).
* **MCP tools** from any [MCP server](/extending/mcp-servers) configured for the project.

All three feel identical from the agent's point of view: they show up in the tool list, honor the agent's access level, and appear in the TUI's tool-call output.

## Related

* [Agents](/concepts/agents) — which agents can call which tools.
* [Permissions](/concepts/permissions) — how tool access is gated per agent.
* [MCP Servers](/extending/mcp-servers) — the most common way to add real-world tools.