Code Mode

Code Mode is a built-in tool in Hawa Code that lets the model call configured MCP server capabilities through a snippet of JavaScript code, and return the execution result to the model for further processing.

In short, Code Mode turns MCP server tools into a programmable JavaScript API. You can combine multiple MCP tool calls like ordinary JS code to accomplish more complex tasks such as searching, querying, computing, and writing.

Supports tens of thousands of MCP tools, discovered progressively on demand through Search, without taking up context window space.
Chains multiple MCP tool calls through code, reducing back-and-forth transfer of tool call results and saving token usage.
Common code logic can be saved and automatically reused, enabling self-evolving business functionality.

Code Mode UI

Quick Start

1. Configuration File

Code Mode uses .codemode.json to configure MCP servers, with the same format as .mcp.json.

The configuration supports two levels:

Global config: ~/.hcode/.codemode.json
Project config: {project-directory}/.codemode.json

The project config overrides the global config.

Example .codemode.json:

{
  "mcpServers": {
    "supabase": {
      "type": "http",
      "url": "https://mcp.supabase.com/mcp",
      "headers": {
        "Authorization": "Bearer your-token"
      }
    },
    "github": {
      "type": "http",
      "url": "https://api.githubcopilot.com/mcp/",
      "headers": {
        "Authorization": "Bearer your-token"
      }
    }
  }
}

Tip: If .codemode.json is not configured separately, Code Mode will also reuse Hawa Code’s existing MCP configuration (global config, project config, .mcp.json).

2. Usage

In a conversation, ask Hawa Code to enter Code Mode, and the model will automatically generate and execute JavaScript code. No manual plugin installation or extra commands are required.

Typical use cases:

Call an MCP tool to query data
Combine multiple MCP tools to complete multi-step tasks
Search for available tools and discover capabilities automatically

Code Format

Code Mode receives an asynchronous JavaScript arrow function and executes it.

You can write the full arrow function body:

async () => {
  const result = await codemode.supabase.list_tables();
  return result;
}

Or you can write only the function body, and the system will wrap it automatically:

const result = await codemode.supabase.list_tables();
return result;

Calling MCP Tools

Configured MCP servers are exposed as JavaScript functions in the form codemode.<server>.<tool>.

For example, if you configured a server named supabase with a tool called list_tables, you can call it like this:

async () => {
  const tables = await codemode.supabase.list_tables();
  return tables;
}

If the server or tool name contains special characters, it will be converted into a valid JavaScript identifier automatically. For example, my-server becomes codemode.my_server.

Discovering Available Tools

Searching Tools

If you are unsure where a capability is, use codemode.search():

async () => {
  const matches = await codemode.search("list tables");
  return matches;
}

The result includes tool path, server, method name, description, and match score, helping you quickly locate the tool you need.

Viewing Tool Details

Use codemode.describe() to view a tool’s type definition and parameter description:

async () => {
  const docs = await codemode.describe("supabase.list_tables");
  return docs;
}

You can also describe the entire server:

async () => {
  const docs = await codemode.describe("supabase");
  return docs;
}

Saving and Reusing Code Snippets

You can save frequently used code as snippets for later reuse:

async () => {
  await codemode.saveSnippet(
    "list-supabase-tables",
    "const tables = await codemode.supabase.list_tables(); return tables;",
    "List all tables in supabase"
  );
  return "saved";
}

Snippets are saved in the .codemode-snippets.json file in the project directory, and like MCP tools, can be found with codemode.search() and codemode.describe().

Combining Multiple Tools

The real value of Code Mode lies in combining multiple MCP tools to complete complex tasks.

For example:

async () => {
  const tables = await codemode.supabase.list_tables();
  const details = [];
  for (const table of tables.slice(0, 5)) {
    const schema = await codemode.supabase.describe_table({ table });
    details.push({ table, schema });
  }
  return details;
}

Execution Environment Notes

Code Mode runs code in an isolated Node child process and communicates with Hawa Code via IPC.
The execution environment does not include Node.js APIs such as fs, require, or process. All I/O must go through configured MCP tools.
The default timeout for a single execution is 60 seconds, after which it will be terminated automatically.
Standard JavaScript syntax is supported, but TypeScript type annotations are not supported.

Permissions and Confirmation

Code Mode is a tool that requires user confirmation. Before execution, you will be asked whether to allow it; the code runs only after confirmation. If auto-permission mode is enabled, you may not need to confirm every time when conditions are met.

Common Scenarios

Scenario	Example
Query database	`codemode.supabase.query({ sql: "SELECT * FROM users" })`
Query GitHub info	`codemode.github.search_issues({ query: "repo:owner/repo is:open" })`
Combine tools	List tables first, then query each table’s schema
Reuse logic	Save common queries as snippets

Troubleshooting

Execution Timeout

If code execution exceeds 60 seconds, a timeout error is returned. Consider splitting it into multiple steps or reducing the amount of data processed in a single run.

Tool Not Found

Check whether .codemode.json is configured correctly.
Use codemode.search("keyword") to confirm the tool is loaded.
Use codemode.describe("server.tool") to verify the tool name.

Result Too Long

Code Mode automatically truncates overly long results to avoid consuming too much context. If the result is truncated, try using more precise query conditions or fetching data in batches.

Summary

Code Mode turns MCP server capabilities into executable JavaScript code, allowing the model to:

Discover tools automatically
Combine multiple tools
Reuse common code snippets
Execute in a secure sandbox environment

With Code Mode, you can let Hawa Code handle more complex and flexible multi-step tasks.

Hexo

code mode