# Verify PDF signatures: web app, CLI, MCP and C#  
## What it does  
Checks digital signatures embedded in a PDF file. The verification confirms whether each signature is valid and reports the signing identity.  

## Inputs and limits  
* Input file: a signed PDF document (maximum 32 MB per request on the web app).  

## Web app  
The page asks for a PDF file. After uploading the signed PDF, press **Verify**. The service returns a JSON result indicating whether the signatures are valid and lists their names.  

## Command line (CLI)  
The CLI verifies signatures in a PDF placed in a task folder. Run the plugin with a task identifier, and it produces a `verify_result.json` file containing the verification status.  

```bash
# Linux / macOS (needs the .NET 10 runtime and documentize.lic next to the DLL)
export PLUGIN_INPUT_DIR=./work/input
export PLUGIN_OUTPUT_DIR=./work/output
mkdir -p "$PLUGIN_INPUT_DIR/job1"
cp Sign_test.pdf "$PLUGIN_INPUT_DIR/job1/"
dotnet Documentize.VerifyESign.dll --task-id job1
ls "$PLUGIN_OUTPUT_DIR/job1"
```

```powershell
# Windows PowerShell
$env:PLUGIN_INPUT_DIR  = "$PWD\work\input"
$env:PLUGIN_OUTPUT_DIR = "$PWD\work\output"
New-Item -ItemType Directory -Force "$env:PLUGIN_INPUT_DIR\job1" | Out-Null
Copy-Item Sign_test.pdf "$env:PLUGIN_INPUT_DIR\job1\"
dotnet Documentize.VerifyESign.dll --task-id job1
Get-ChildItem "$env:PLUGIN_OUTPUT_DIR\job1"
```

## Verified

Every code sample on this page was run on 2026-11-03 and its result was checked:

- Verify signatures via CLI with result check (CLI plugin): passed in 2 s