ESP Workspace MCP Server For Hermes

A full autonomous embedded firmware workspace server — the MCP (Model Context Protocol) infrastructure layer for AI agents working with ESP-IDF projects.

What it does

ESP-Workspace MCP turns an AI coding assistant into an autonomous firmware engineer. It provides tools for:

• Filesystem operations — read, write, list, glob with path sandboxing
• Shell execution — run commands with timeout, background jobs, output capture
• ESP-IDF build system — build, flash, clean, reconfigure via eim run with WISH_PRODUCT support
• Security — Bearer token auth, path traversal prevention, configurable filesystem roots

Quick Start

Prerequisites

• Python 3.10+
• Espressif Install Manager (eim — handles ESP-IDF installation and environment setup

Installation

pip install esp-workspace-mcp

Or from source:

git clone https://github.com/AIRcableLLC/esp-workspace-mcp.git
cd esp-workspace-mcp
python -m venv .venv
source .venv/bin/activate
pip install -e ".[dev]"

Configuration

Create a .env file:

MCP_API_TOKEN=your-secret-token-here
MCP_HOST=0.0.0.0
MCP_PORT=8765
MCP_ALLOWED_ROOTS=/home/user/projects
MCP_WISH_PRODUCT=TargetS3
MCP_EIM_PATH=eim

Or set environment variables directly.

Run the server

# SSE mode (default, for network access)
python run_server.py

# Stdio mode (for local MCP clients)
python run_server.py --stdio

The server exposes:

• GET /sse — SSE connection endpoint (requires Bearer token)
• POST /messages — MCP message endpoint
• GET /health — health check (no auth required)

MCP Tools

Filesystem Tools

Tool	Description
read_file(path, offset, limit)	Read text file with pagination
write_file(path, content)	Write content to a file
append_file(path, content)	Append to an existing file
list_dir(path)	List directory entries
create_dir(path)	Create directory recursively
delete_path(path)	Delete file or empty directory
file_stat(path)	Get file/directory metadata
glob_search(pattern, path)	Find files by glob pattern

Shell Tools

Tool	Description
run_command(cmd, cwd, timeout)	Execute command and wait
start_process(cmd, cwd)	Start background job
get_job_output(job_id, offset)	Read job output
kill_job(job_id)	Terminate background job
list_jobs()	List all jobs

ESP-IDF Tools

All ESP-IDF operations are invoked through eim run "WISH_PRODUCT=<product> idf.py ..." which handles environment setup automatically.

Tool	Description
eim_run(commands, project_dir, wish_product)	Run any idf.py command via eim
build_project(project_dir, wish_product, reconfigure)	Build an ESP-IDF project
set_target(project_dir, target, wish_product)	Set target chip (esp32, esp32s3, etc.)
flash_project(project_dir, port, wish_product)	Flash firmware to device
clean_project(project_dir)	Clean build artifacts
fullclean_project(project_dir)	Remove entire build directory
reconfigure_project(project_dir, wish_product)	Regenerate sdkconfig + CMake cache

Build Step Decision Tree

Is sdkconfig missing or have defaults changed?
├── YES → eim_run("reconfigure build", project_dir, wish_product)
└── NO  → eim_run("build", project_dir, wish_product)

Security

Control	Implementation
Filesystem sandbox	All paths validated against MCP_ALLOWED_ROOTS
Path traversal prevention	Symlink-resolved, .. escapes rejected
Shell timeout	Configurable, default 30s, max 300s
Output truncation	50 KB max per response
Authentication	Bearer token on every request
Credential safety	Tokens in env vars only, never logged

Integration with AI Agents

Hermes

hermes mcp add esp-workspace \
  --url http://host:port/sse \
  --header "Authorization: Bearer your-token"

Generic MCP Client

Any MCP-compatible client can connect to the SSE endpoint. The server implements the standard MCP protocol over SSE/HTTP transport.

Architecture

esp_workspace_mcp/
├── config.py          # Settings from env, fail-fast validation
├── server.py          # FastMCP server, tool registration
├── auth.py            # Bearer token middleware
├── tools/
│   ├── filesystem.py  # 8 path-validated file operations
│   ├── shell.py       # Command execution + background jobs
│   └── esp_idf.py     # eim-run wrapper, build/flash/clean
├── utils/
│   ├── security.py    # Path sandboxing, symlink resolution
│   └── process.py     # Subprocess management, JobManager
└── resources/
    └── project.py     # MCP resources (project status, etc.)

License

Apache-2.0