README

A Laravel Filament plugin for capturing signatures, issuing X.509 certificates, and embedding cryptographically signed stamps into PDF documents.

Supports: Filament v3, v4 and v5 — Laravel 12 — PHP 8.2+

Documentation

Doc	Description
Implementation Plan	Start here. Phase-by-phase plan for integrating the package into your app
Installation	Composer, migrations, plugin registration, admin resource
Configuration	All config keys and env variables
Model Setup	Signable interface and HasSignatures trait
Filament Components	SignaturePad, SignatureColumn, SignatureResource, SignDocumentAction
Signing Workflow	Full lifecycle and SignatureManager API
Ad-hoc Signing	Implement document signing outside a package resource
Certificates	Certificate issuance, CA setup, CFSSL
Signatory Routing	Role-bound slots, signing sessions, consent models, multi-signatory documents, Filament version compatibility
Security	HMAC metadata, machine binding, DB cross-validation, forgery detection

Requirements

PHP 8.2+ with ext-openssl and ext-gd
Laravel 12
Filament 3, 4, or 5

Quick Install

composer require kukux/digital-signature
php artisan vendor:publish --tag=signature-migrations
php artisan vendor:publish --tag=signature-config
php artisan migrate
php artisan filament:assets

filament:assets publishes the plugin's JS bundle (signature pad + picker) so it's reachable from the panel — re-run it after every composer update of this package.

// app/Providers/Filament/AdminPanelProvider.php
use Kukux\DigitalSignature\SignaturePlugin;

->plugins([
    SignaturePlugin::make()
        ->navigationGroup('Documents')   // optional
        ->navigationIcon('heroicon-o-pencil-square')  // optional
        ->navigationSort(10),             // optional
])

This registers:

A floating launcher — a button on every panel page whose slide-over shows what's awaiting the signed-in user, with Sign / Decline on each row
Signatures — a full admin resource for registering reusable signature images and viewing signature records
Sign Document — header actions inside the Signatures resource for signing with a registered signature

The floating launcher

Signing is an interruption, not a destination. Rather than adding sidebar items a signatory has to go looking for, the plugin pins a button to every page of the panel; clicking it slides over the documents waiting on them.

SignaturePlugin::make()                          // launcher on (default)
SignaturePlugin::make()->withoutFloatingLauncher()  // off; sidebar items return

While the launcher is on, the inbox page and the Signatures resource stop claiming navigation items — both stay routable, and the slide-over links to them. Keep the launcher and the sidebar entries with SIGNATURE_LAUNCHER_REPLACES_NAV=false.

It won't land on your own floating button. A plugin doesn't own the corner it's dropped into, so before settling the launcher measures what the host app already has pinned there — a FAB, a chat widget, a cookie bar — and stacks itself clear, re-measuring on resize and when widgets mount late. Sidebars and other full-height layout are floated over rather than stacked above. Where the detector guesses wrong, name the widget in launcher.avoid / launcher.ignore; where you already know the answer, set launcher.offset and turn avoid_overlap off.

Position, icon, label, brand colour, offsets, z-index and badge poll interval are all config; see Configuration.

Preparing a Signable Model

Any model whose PDF can be signed must implement Signable and use HasSignatures.

use Kukux\DigitalSignature\Contracts\Signable;
use Kukux\DigitalSignature\Traits\HasSignatures;

class Contract extends Model implements Signable
{
    use HasSignatures;

    public function getSignableTitle(): string   { return $this->title; }
    public function getSignablePdfPath(): string { return $this->pdf_path; }
    public function getSignableId(): int|string  { return $this->id; }
}

Adding the Sign Action to Your Own Resource

First let the signer register a reusable signature from the built-in Signatures resource. Then add SignDocumentAction to any resource whose model implements Signable.

use Kukux\DigitalSignature\Filament\Actions\SignDocumentAction;
use Kukux\DigitalSignature\Filament\Columns\SignatureColumn;

class ContractResource extends Resource
{
    public static function table(Table $table): Table
    {
        return $table
            ->columns([
                TextColumn::make('title'),
                SignatureColumn::make('signature')->thumbSize(80, 32),
            ])
            ->actions([
                SignDocumentAction::make()
                    ->stampAt(page: 1, x: 100, y: 650, w: 200, h: 80),
            ]);
    }
}

For controller-driven or custom page flows, see Ad-hoc Signing.

Built-in Signatures Admin Resource

When the plugin is registered, a Signatures resource appears in the sidebar automatically.

Register SignaturePlugin::make() on every Filament panel that should use the package. If a panel discovers or registers SignatureResource without the plugin, Filament can report Plugin [signature] is not registered for panel [admin].

List page — table of all signature records with thumbnail, signer, status, and method.
View page — full infolist showing the large signature image, signer details, security metadata.

Both pages include a Sign Document header action.

Customize appearance:

SignaturePlugin::make()
    ->navigationGroup('Documents')
    ->navigationIcon('heroicon-o-pencil-square')
    ->navigationSort(10)
    ->navigationLabel('Document Signatures')

// Disable the resource entirely (bring your own):
SignaturePlugin::make()->withoutResource()

Multi-Signatory Documents

When a document is signed by roles rather than by whoever opens it — an Accomplishment Report with Prepared by, Attested by and Noted by — declare the roles on the template and let the plugin find the people:

// config/signature.php
'templates' => [
    'accomplishment-report' => [
        'view'     => 'pdf.accomplishment-report',
        'signable' => \App\Models\AccomplishmentReport::class,
        'slots'    => [
            'prepared_by' => ['label' => 'Prepared by', 'signatory' => 'preparedBy', 'order' => 1, 'required' => true],
            'attested_by' => ['label' => 'Attested by', 'signatory' => 'attestedBy', 'order' => 2, 'required' => true],
            'noted_by'    => ['label' => 'Noted by',    'signatory' => 'notedBy',    'order' => 3, 'required' => true],
        ],
    ],
],

class AccomplishmentReport extends Model implements Signable
{
    use HasPdfTemplate, HasSignatories;

    protected string $signaturePdfTemplate = 'accomplishment-report';

    public function preparedBy(): BelongsTo { return $this->belongsTo(User::class, 'prepared_by_id'); }
    public function attestedBy(): BelongsTo { return $this->belongsTo(User::class, 'attested_by_id'); }
    public function notedBy(): BelongsTo    { return $this->belongsTo(User::class, 'noted_by_id'); }
}

// In your resource
SignatoryPanel::make('signatories');       // who signs, and where they're up to
RequestSignaturesAction::make();            // freeze the PDF and ask them

Each person registers their signature once in their own panel. Being tagged on a record is then enough for the document to reach them — the plugin resolves the person, finds their signature, pre-fills the placement, and lists the document in their Awaiting my signature inbox.

On consent. By default the plugin never signs for anyone: the signature is always produced in the signatory's own authenticated request, with their own certificate. Truly hands-off signing requires that person to grant a scoped, expiring, revocable authorisation from their own account — and every use of it is audited and notified. See Signatory Routing.

Security Highlights

Feature	Default
PKCS#7 cryptographic signature embedded in PDF	Always on
DocMDP P=2 — post-signing modification detection	Always on
HMAC-signed PNG metadata (tEXt + XMP)	Always on
XMP metadata visible in macOS Preview & Windows Explorer	Always on
Signer identity (name + email) embedded in PNG	Always on
Forgery / screenshot upload rejection	Always on
Document integrity hashes (before + after)	Always on
Machine binding — DB cross-validation on re-upload	Always on
Signature chain hashes across multi-signatory documents	Always on
Audit row for every auto-affixed signature	Always on
Auto-signing on someone's behalf	Off — requires their explicit grant
Machine lock — reject re-upload from different device	`SIGNATURE_MACHINE_LOCK=true`
CRL certificate revocation check	`SIGNATURE_CRL_ENABLED=true`
RFC 3161 trusted timestamp via TSA	`SIGNATURE_TSA_URL=https://...`

For full details see docs/security.md.

Queue

Signing runs asynchronously. Start a queue worker:

php artisan queue:work

To sign synchronously (no queue required):

SignDocumentAction::make()   // default is now synchronous

The action calls embedAndFinalize() directly unless you opt in to queued signing:

SignDocumentAction::make()->queued()

kukux / digital-signature

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