MCP server for Pascal/Delphi/Lazarus compilation and execution with Claude
Project description
Claude Pascal MCP Server
An MCP (Model Context Protocol) server that lets Claude compile, run, and interact with Pascal/Delphi desktop applications. Supports Free Pascal (fpc), Delphi 32-bit (dcc32), and Delphi 64-bit (dcc64) compilers.
Features
- Compiler Detection — automatically finds Pascal compilers on your system (PATH + known install locations)
- Compile — compile single-file Pascal source or multi-file Delphi projects
- Run — compile and execute console programs, capturing output
- Launch GUI Apps — compile and launch VCL/FMX applications in background (without stealing focus)
- Project Templates — generate proper Delphi project structure (DPR + PAS + DFM) automatically
- Form Parser — read and understand DFM/FMX/LFM form files
- Window Screenshots — capture running desktop app windows (non-intrusive, no focus stealing)
- Windows App Interaction — click, type text, and send keyboard shortcuts to desktop app windows
- Android Device Interaction — full ADB support: screenshots, tap, swipe, type, key events, app management, file transfer
- IDE Observer — capture RAD Studio/Delphi/Lazarus IDE screenshots and read compiler errors
- Preview Bridge — live preview of running Pascal apps through Claude's preview system
- FPC Installer — download and install Free Pascal if no compiler is available
Tools
| Tool | Description |
|---|---|
get_compiler_info |
Detect available compilers and show versions |
compile_pascal |
Compile single-file source code |
compile_delphi_project |
Generate + compile a project from templates — vcl, fmx (cross-platform incl. Android), console, or fpc |
build_dproj |
Build an existing .dproj via MSBuild + rsvars. Auto-resolves PAServer profile, chains Deploy, deep-cleans the dproj's actual output dirs, supports iOS deploy-manifest synthesis. See §build_dproj details below |
run_pascal |
Compile and execute console programs |
launch_app |
Compile and launch GUI app in background |
check_syntax |
Syntax check only (no linking) |
parse_form |
Parse DFM/FMX/LFM form files |
list_remote_profiles |
List PAServer Connection Profiles registered for iOS/macOS/Linux builds |
check_ios_deploy |
Inspect a .dproj for the iOS DeployFile entries required by /t:Deploy |
paserver_info |
Read local info about a PAServer Connection Profile (host/port/sysroot) |
paserver_check_connection |
Two-stage reachability probe: registry validation + TCP socket connect |
paserver_scratch_dir |
Compose PAServer's restricted-mode scratch dir for a profile |
paserver_get |
Pull a file from the PAServer remote host |
paserver_put |
Push a file to the PAServer remote host |
paserver_remove |
Delete a file on the PAServer remote host |
ios_codesign |
Codesign an .app bundle on the remote Mac (paclient -c) |
ios_create_ipa |
Assemble a signed .app into an .ipa (paclient -i) |
ios_install_ipa |
Install an .ipa on an iOS device attached to the Mac (paclient -ii) |
mac_ssh_check |
Probe SSH connectivity + key auth to the remote Mac |
mac_ssh_run |
Run an arbitrary command on the Mac via SSH (xcrun, logging, etc.) |
sim_list |
List iOS simulators known to the Mac (xcrun simctl list) |
sim_boot / sim_shutdown |
Boot or shut down a simulator by UDID |
sim_install / sim_uninstall |
Install / uninstall a .app on a simulator |
sim_launch / sim_terminate |
Launch or terminate an app by bundle ID |
sim_open_url |
Open a URL in the simulator (deep links, web) |
sim_screenshot |
Capture a simulator screenshot as Image (parity with adb_screenshot) |
screenshot_app |
Capture screenshot of a running app window |
list_app_windows |
List visible windows on the desktop |
app_click |
Click on a Windows app window at screenshot pixel coordinates |
app_type |
Type text into a Windows app window |
app_key |
Send key or shortcut (e.g., ctrl+a, enter) to a Windows app |
focus_ide |
Restore + foreground the Delphi/Lazarus IDE window |
observe_ide |
Capture IDE screenshot and scan project files |
read_ide_errors |
Read source code around compiler error locations |
list_project_files |
List source files in a Delphi/Lazarus project |
adb_devices |
List connected Android devices with model and version |
adb_device_info |
Get detailed info for a specific Android device |
adb_screenshot |
Capture Android device screen |
adb_tap |
Tap a point on the Android device screen |
adb_swipe |
Swipe on the Android device screen |
adb_type_text |
Type text on the Android device |
adb_key |
Send a key event (home, back, enter, etc.) to Android device |
adb_install |
Install an APK on the Android device |
adb_list_packages |
List installed packages on the Android device |
adb_launch_app |
Launch an app on the Android device |
adb_stop_app |
Force-stop an app on the Android device |
adb_push |
Push a file to the Android device |
adb_pull |
Pull a file from the Android device |
setup_fpc |
Download and install Free Pascal (fallback) |
build_dproj details
build_dproj builds an existing real .dproj (multi-unit, with its own search paths, defines, resources, deployment) via MSBuild + rsvars.bat. It does the things ad-hoc shell calls to MSBuild keep getting wrong:
- Reads the dproj's own output paths. Calls MSBuild against a tiny generated helper
.projthat imports the dproj and emitsDCC_ExeOutput/DCC_DcuOutput/DCC_BplOutputas the dproj's own evaluator sees them. Uses those for deep-clean targeting and artifact lookup — so..\bin\$(Platform)\$(Config)layouts work the same as the default. - Auto-resolves the PAServer Connection Profile for iOS / macOS / Linux builds by reading
HKCU\Software\Embarcadero\BDS\<ver>\RemoteProfiles. When multiple compatible profiles exist (e.g. aPRODUCTIONandSTAGINGLinux profile) it refuses to silently pick — caller has to passremote_profile=<name>explicitly. Stops you accidentally deploying to production. - Chains
/t:Build;Deployautomatically on Android / iOS / macOS / Linux so the build actually produces an APK or.app, not just an intermediatelibProj.soor object file. Passdeploy=Falseto opt out. - Detects + optionally synthesizes iOS DeployFile entries that the IDE writes on first deploy. Without these 4 per-Config-Platform entries (
ProjectiOSEntitlements,ProjectiOSInfoPList,ProjectiOSLaunchScreen,ProjectOutput)/t:Deployships nothing and codesign fails.synthesize_ios_manifest=Truewrites them after a timestamped.bakbackup. - Deep-cleans the platform's actual output dirs before Rebuild/Clean on staging-based platforms (Android / iOS / macOS / Linux). MSBuild's own Clean leaves PAClient / PAServer staging in place, which is the root cause of "I changed the code but the APK didn't update" reports. Filters paths outside the project tree as a safety guard — never wipes the shared system BPL dir.
Working command-line recipe (matches what build_dproj does for you)
rsvars.bat
MSBuild <Proj>.dproj /t:Build /p:Config=<Cfg> /p:Platform=<Plat>
MSBuild <Proj>.dproj /t:Deploy /p:Config=<Cfg> /p:Platform=<Plat> /p:Profile=<ConnectionProfile>
build_dproj collapses this into a single call: build_dproj(dproj_path, platform=<Plat>, config=<Cfg>).
Pre-flight check list
If a build fails, walk through these before assuming the MCP is broken:
- For iOS: did you ever IDE-deploy this project to this Config × Platform? If not, run
check_ios_deploy(dproj_path, config, platform)and setsynthesize_ios_manifest=Trueon the build. - For iOSSimARM64: is the iPhoneSimulator SDK imported in Tools → Manage Platforms? (Importing the iPhoneOS device SDK doesn't satisfy the simulator link —
ld: file not found: /usr/lib/libiconv.dylib.) - For any PAServer platform:
list_remote_profiles()shows what's registered; sidecar.profilefiles must exist at%APPDATA%\Embarcadero\BDS\<ver>\<name>.profilefor/t:Deployto read them. - For Android: is
adbon PATH? Is the device authorized (adb_devices)?
PAServer & PAClient
Cross-platform Embarcadero builds (iOS, macOS, Linux) compile through PAServer on a remote Mac or Linux host, driven by paclient.exe on Windows. This MCP wraps both ends:
build_dprojfor iOS/macOS/Linux auto-resolves a Connection Profile, chains/t:Deploy, and synthesizes the iOS manifest if needed (see §build_dproj details).paserver_*tools cover the direct file/transfer/diagnostic surface that MSBuild doesn't reach.ios_*tools wrap the iOS-bundle pipeline (codesign → IPA → device install) for cases where you want surgical control instead of a full Deploy.
Connection Profiles
PAServer profiles live in HKCU\Software\Embarcadero\BDS\<ver>\RemoteProfiles\ (registry) with a sidecar at %APPDATA%\Embarcadero\BDS\<ver>\<name>.profile. Configure them via RAD Studio → Tools → Options → Environment Options → Connection Profile Manager.
# What's registered:
list_remote_profiles()
# Verify a specific one's reachable:
paserver_check_connection("MACBOOK", timeout=3.0)
Restricted mode
By default PAServer rejects any file op outside its per-profile scratch dir:
/Users/<remote_user>/PAServer/scratch-dir/<windows_user>-<PROFILE>/
Targeting /tmp or /Users/anything-else returns Error: E0006 ... PAServer is running in restricted mode. Either point your transfer at the scratch dir (paserver_scratch_dir composes the path) or have the host operator start PAServer with -restricted=false.
iOS Simulator via SSH
xcrun simctl runs on the Mac and PAClient doesn't expose arbitrary command execution, so simulator control goes through SSH. One-time setup on the Windows side:
# Enable Remote Login on the Mac: System Settings → General → Sharing → Remote Login.
# Then install your public key (asks for the Mac password once):
ssh-copy-id <mac_user>@<mac_host>
Once that's done, the sim_* tools have parity with adb_* — same verbs, same return shape:
mac_ssh_check("192.168.88.79", "andrevanzuydam") # pre-flight
sim_list(host, user, booted_only=True) # what's running?
sim_boot(host, user, "<UDID>")
sim_install(host, user, "/Users/.../scratch-dir/...-MACBOOK/MyApp.app")
sim_launch(host, user, "com.embarcadero.MyApp")
sim_screenshot(host, user) # returns an Image
Full iOS deploy recipe
# 1. Build the iOS app — Deploy chain leaves a .app in the scratch dir
build_dproj(
r"D:\src\App.dproj",
config="Release",
platform="iOSDevice64",
synthesize_ios_manifest=True, # if this is the first iOS deploy
)
# 2. Codesign it (or skip with "-" for ad-hoc dev signing)
ios_codesign(
"MACBOOK",
"/Users/macuser/PAServer/scratch-dir/winuser-MACBOOK/App.app",
"iPhone Developer: Jane Doe (ABCDE12345)",
entitlement="/Users/macuser/Provisioning/App.entitlements",
)
# 3. Package as IPA
ios_create_ipa(
"MACBOOK",
app_path="/Users/.../App.app",
out_path="/Users/.../App.ipa",
certificate="iPhone Developer: ...",
provisioning_profile="/Users/.../App.mobileprovision",
ipa_type=1, # ad-hoc; 2 for App Store
)
# 4. Install on attached device (find UDID via xcrun devicectl)
ios_install_ipa("MACBOOK", "/Users/.../App.ipa", "00008101-001234567890123A")
Preview Bridge
The preview bridge lets Claude see and interact with running Pascal desktop applications through its web-based preview system. It serves live screenshots of desktop app windows as a web page.
How it works
Claude Preview Tools (preview_start, preview_screenshot, preview_click)
| HTTP
v
Preview Bridge Server (Python/Starlette)
/ -> HTML page with live screenshot viewer
/api/screenshot -> PNG of target window
/api/controls -> enumerate child controls with positions
/api/click -> click at coordinates or by control hwnd
/api/type -> send keystrokes to target window
/api/move -> move window to screen position
/api/resize -> resize window
| Win32 PrintWindow API
v
Running Pascal Desktop Application
API Endpoints
| Route | Method | Description |
|---|---|---|
/ |
GET | HTML page with auto-refreshing screenshot viewer |
/api/screenshot |
GET | PNG screenshot of target window |
/api/windows |
GET | List visible windows |
/api/target |
POST | Set target window by title |
/api/controls |
GET | Enumerate child controls (buttons, inputs, etc.) |
/api/click |
POST | Click by coordinates or direct control hwnd |
/api/type |
POST | Send text or key combos (e.g., ctrl+a, enter) |
/api/drag |
POST | Drag from one point to another |
/api/move |
POST | Move target window |
/api/resize |
POST | Resize target window |
/api/window-info |
GET | Window position, size, and client area offset |
/api/console |
GET | Console output from launched apps |
/api/launch |
POST | Launch an executable |
Click Methods
The click endpoint supports three modes, from most to least reliable:
- Direct control click (
{"hwnd": "12345"}) — sendsBM_CLICKdirectly to a control handle. Works regardless of DPI, monitors, or foreground state. Get hwnds from/api/controls. - Client-area coordinates (
{"x": 200, "y": 142, "client": true}) — uses Win32ClientToScreenfor proper DPI handling. - Window-relative coordinates (
{"x": 312, "y": 261}) — raw coordinates in the screenshot image space.
Windows App Interaction
The app_click, app_type, and app_key tools let Claude interact with running Windows desktop applications.
Workflow
- Take a screenshot with
screenshot_appto see the current UI - Identify pixel coordinates of the target element (button, text field, etc.)
- Use
app_clickwith those coordinates to click - Use
app_typeto enter text into a focused field - Use
app_keyto send keyboard shortcuts (enter,ctrl+a,alt+f4, etc.)
Clicks use PostMessage with automatic child window targeting, so they reach the correct control. Typing and key events use SendInput for full Unicode and modifier support.
Android Device Interaction (ADB)
Full Android device interaction via ADB. All tools accept an optional device serial number — auto-selects when only one device is connected.
Device Management
adb_devices— list connected devices with model, Android version, screen sizeadb_device_info— detailed info for a specific device
Screenshots and UI Automation
adb_screenshot— capture the device screenadb_tap/adb_swipe— touch interaction at pixel coordinatesadb_type_text— type text (auto-escapes for adb shell)adb_key— send key events with aliases:home,back,enter,menu,power,volume_up,volume_down,tab,delete,space,escape,app_switch
App Management
adb_install— install APK filesadb_list_packages— list installed packages (with optional filter)adb_launch_app— launch an app by package nameadb_stop_app— force-stop an app
File Transfer
adb_push— push files from PC to deviceadb_pull— pull files from device to PC
Project Templates
The compile_delphi_project tool generates proper Delphi project structure automatically. You specify components and events, and it creates the correct DPR, PAS, and DFM files.
Templates automatically handle:
- Modern Delphi (RAD Studio): namespaced units (
Vcl.Forms,System.SysUtils) - Legacy Delphi (Delphi 7): non-namespaced units (
Forms,SysUtils) - Form definitions (DFM) with proper component declarations
- Event handler wiring between DFM and PAS files
Example
compile_delphi_project(
project_name="HelloWorld",
form_caption="My App",
components='[{"type": "TButton", "name": "btnHello", "caption": "Click Me",
"left": 100, "top": 100, "width": 120, "height": 35,
"event": "btnHelloClick"}]',
events='[{"name": "btnHelloClick", "body": "ShowMessage(\'Hello!\');"}]',
compiler="C:\\Path\\To\\dcc64.exe"
)
This generates:
HelloWorld.dpr— project file with proper uses clauseuMain.pas— unit with form class, component declarations, event handlersuMain.dfm— form definition with component properties
Installation
Prerequisites
- Python 3.11+
- uv package manager
- A Pascal compiler (Free Pascal, Delphi, or RAD Studio)
Option 1 — Run from PyPI (recommended)
Once a release is published to PyPI, no clone is needed:
uvx --from claude-pascal-mcp pascal-mcp
Option 2 — Run straight from GitHub (no PyPI required)
uvx --from git+https://github.com/tina4stack/claude-pascal-mcp pascal-mcp
Pin to a tag for reproducibility: git+https://github.com/tina4stack/claude-pascal-mcp@v0.1.0.
Option 3 — Local development clone
git clone https://github.com/tina4stack/claude-pascal-mcp.git
cd claude-pascal-mcp
# Install dependencies
uv sync
# Run the MCP server (stdio mode)
uv run pascal-mcp
# Run the preview bridge (HTTP mode)
uv run pascal-preview
Register with Claude Code
PyPI install:
claude mcp add --transport stdio pascal-dev -- uvx --from claude-pascal-mcp pascal-mcp
Git install:
claude mcp add --transport stdio pascal-dev -- uvx --from git+https://github.com/tina4stack/claude-pascal-mcp pascal-mcp
Local clone:
claude mcp add --transport stdio pascal-dev -- uv run --directory /path/to/claude-pascal-mcp pascal-mcp
Or add to your project's .mcp.json — pick the form that matches how you installed:
{
"mcpServers": {
"pascal-dev": {
"command": "uvx",
"args": ["--from", "claude-pascal-mcp", "pascal-mcp"]
}
}
}
{
"mcpServers": {
"pascal-dev": {
"command": "uvx",
"args": ["--from", "git+https://github.com/tina4stack/claude-pascal-mcp", "pascal-mcp"]
}
}
}
{
"mcpServers": {
"pascal-dev": {
"command": "uv",
"args": ["run", "--directory", "/path/to/claude-pascal-mcp", "pascal-mcp"]
}
}
}
Register with Claude Desktop
Add to your claude_desktop_config.json (pick the form matching your install):
{
"mcpServers": {
"pascal-dev": {
"command": "uvx",
"args": ["--from", "claude-pascal-mcp", "pascal-mcp"]
}
}
}
{
"mcpServers": {
"pascal-dev": {
"command": "uv",
"args": ["run", "--directory", "C:/path/to/claude-pascal-mcp", "pascal-mcp"]
}
}
}
Releasing
Maintainer notes — cutting a new release publishes to PyPI automatically.
- Bump
versioninpyproject.toml. - Commit and tag:
git tag v0.1.0 && git push origin v0.1.0. - GitHub Actions (
.github/workflows/publish.yml) builds the sdist + wheel, publishes to PyPI via Trusted Publishing, and attaches the artifacts to a GitHub Release.
One-time PyPI Trusted Publisher setup (required before the first release):
- Create the project on pypi.org (or reserve it via a first manual
uv publish). - Under Project → Publishing → Add a new publisher, configure GitHub Actions:
- Owner:
tina4stack - Repository:
claude-pascal-mcp - Workflow:
publish.yml - Environment:
pypi
- Owner:
- In the GitHub repo, create an environment named
pypi(Settings → Environments).
No API tokens needed — OIDC handles auth.
Preview Bridge Setup
Add to .claude/launch.json in your project root:
{
"version": "0.0.1",
"configurations": [
{
"name": "pascal-preview",
"runtimeExecutable": "/path/to/claude-pascal-mcp/.venv/Scripts/pythonw.exe",
"runtimeArgs": ["-m", "pascal_mcp.preview_bridge"],
"port": 18080,
"autoPort": true
}
]
}
Then in Claude Code, use preview_start("pascal-preview") to open the preview panel.
Supported Compilers
The server automatically detects compilers in this priority order:
- Free Pascal (fpc) — open source, cross-platform
- Delphi 64-bit (dcc64) — RAD Studio command-line compiler
- Delphi 32-bit (dcc32) — RAD Studio / Delphi 7 command-line compiler
You can also specify a full path to any compiler executable:
compile_pascal(source, compiler="C:\\Program Files (x86)\\Embarcadero\\Studio\\37.0\\bin\\dcc64.exe")
Detection checks the system PATH first, then known installation directories:
C:\FPC\*\bin\*\fpc.exeC:\Lazarus\fpc\*\bin\*\fpc.exeC:\Program Files (x86)\Embarcadero\Studio\*\bin\dcc*.exe
License
MIT
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