LogiHash Documentation

Form and API reference

This page documents the current behavior of the Try platform form and API demo: all supported fields, allowed values, required rules, and practical constraints for production-ready T-Code generation.

LogiHash supports exactly three languages: English (en), German (de), and French (fr). That applies to the console, this documentation, and the EN/DE/FR label-translation fields in forms and APIs—no other locales are offered.

Cryptographic signing keys used for T-Code verification are rotated on a 90-day cycle.

Important creator rule

Creator identity data is account-level and must stay consistent. It is not meant to change for every T-Code. Per-item differences should go into object type, custom fields, validity date, and optional linked document metadata.

Platform security

  • Cryptographic key pairs used in LogiHash are rotated on a 90-day cycle.
  • Passwords must be at least 12 characters and include at least one lowercase letter (a–z), one uppercase letter (A–Z), one digit (0–9), and at least one special character from this set: ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~
  • LogiHash console login requires two-factor authentication (2FA). Browser sessions end after 20 minutes without user interaction; you are signed out if you do not interact with the application during that time.

T-Code form fields (GUI Interface)

Creator NameRequired

Allowed: Non-empty text

Notes: Creator identity for the issuing entity.

Address (Street, House Number, Postal Code, City, Country)Required

Allowed: All non-empty text values

Notes: All five address fields are mandatory.

Object TypeRequired

Allowed: Preset: ID Card, Contract, Invoice, Certificate, Diploma, Permit, Badge, Ticket, Voucher, Warranty, Membership, or custom text

Notes: Custom mode is available via "Other".

T-Code LabelOptional

Allowed: Optional text

Notes: Creator-side helper label, intentionally not encrypted.

Valid UntilRequired

Allowed: YYYY-MM-DD date, minimum today

Default: One year from today (GUI initial date)

Notes: Must be on or after today.

Creator's Logo (optional)Optional

Allowed: Image upload (PNG, JPG/JPEG, WebP, SVG as base64 data URL), max 2 MB

Notes: Click to upload logo (max 2MB).

Linked DocumentOptional

Allowed: Accepted types: PDF, DOC/DOCX, XML, XLS/XLSX, PPT/PPTX, PNG, JPG/JPEG, WebP, SVG (max 10MB)

Notes: Supports optional label and optional EN/DE/FR label translations.

Additional Custom FieldsRequired

Allowed: At least 4 entries, each with non-empty label and value

Notes: Extra rows allowed; translation toggle supports EN/DE/FR per row.

Download FormatRequired

Allowed: PNG | JPG | JPEG | WebP | SVG

Default: PNG (GUI); png (API example)

Notes: Equivalent to API field output_image_format.

T-Code display options in GUI interface

The GUI supports the same visual controls reflected in display_options for API usage. Use this section to keep rendered T-Codes visually consistent across channels.

T-Code colorRequired

Allowed: black, logihash blue, navy, darkGreen, maroon, purple, darkGray, brown

Default: black (maps to #000000 in API)

Notes: These map to fixed hex values used by the API and GUI validator.

T-Code backgroundRequired

Allowed: transparent | white

Default: transparent

Notes: Transparent is ideal for overlay usage; white is print-friendly on noisy backgrounds.

Scan text enabledRequired

Allowed: true | false

Default: true

Notes: Toggles the sentence shown above or below the code.

Scan text contentRequired

Allowed: Default sentence or custom sentence

Default: “Scan to verify with the LogiHash App” (when not using custom text)

Notes: Custom mode uses your own sentence instead of the default.

Scan text positionRequired

Allowed: above | below

Default: below

Notes: Controls where the sentence appears relative to the T-Code.

Scan text alignmentRequired

Allowed: left | center | right

Default: center

Notes: Text alignment inside the generated image block.

Scan text colorRequired

Allowed: Same palette as T-Code color

Default: black

Notes: GUI and API both enforce the same allowed color set.

App buttonsRequired

Allowed: enabled true|false, style filled|outlined, color from palette

Default: enabled false; when enabled: style filled, color black

Notes: Adds in-image app-action buttons for branded visual style.

Generate API request

API base endpoint: https://api.logihash.com

Generate path: /api/v1/tcode/generate — Verify/Retrieve path: /api/v1/tcode/verify-retrieve

creator_nameRequiredstring

Allowed: Non-empty

Notes: Core creator identity.

tcode_labelOptionalstring

Allowed: Any string

Notes: Optional creator-side label.

addressRequiredobject

Allowed: Must include all address subfields as non-empty strings

Notes: street, house_number, postal_code, city, country are required.

object_typeRequiredstring

Allowed: Non-empty

Notes: Usually matches one of form object types.

valid_untilRequiredstring

Allowed: YYYY-MM-DD

Default: One year from creation date

Notes: Expiration date for positive verification.

output_image_formatRequiredstring

Allowed: png | jpg | jpeg | webp | svg

Default: png

Notes: Selects output image format for generated T-Code.

logoOptionalstring

Allowed: data URL only: image/png, image/jpeg, image/webp, image/svg+xml; maximum decoded size 2 MB

Notes: Optional image payload. Use PNG, JPG/JPEG, WebP, or SVG.

custom_fieldsRequiredarray

Allowed: Minimum 4 items; each item needs non-empty label + value

Notes: Rows can also include optional translations.

display_options.tcode_backgroundRequiredstring

Allowed: transparent | white

Default: transparent

Notes: Background style of T-Code.

display_options.tcode_colorRequiredstring

Allowed: #000000, #30acfd, #1e3a5f, #166534, #7f1d1d, #581c87, #374151, #78350f

Default: #000000

Notes: Only these hex values are accepted.

display_options.scan_text.enabledRequiredboolean

Allowed: true | false

Default: true

Notes: Turns the scan sentence on or off in the generated image.

display_options.scan_text.positionRequiredstring

Allowed: above | below

Default: below

Notes: Placement of scan message.

display_options.scan_text.alignmentRequiredstring

Allowed: left | center | right

Default: center

Notes: Horizontal alignment of scan message.

display_options.scan_text.use_customRequiredboolean

Allowed: true | false

Default: false

Notes: When false, the platform default sentence is used (see GUI scan text content).

display_options.scan_text.custom_textRequiredstring | null

Allowed: null or custom text

Default: null

Notes: Set to null when use_custom is false.

display_options.scan_text.colorRequiredstring

Allowed: #000000, #30acfd, #1e3a5f, #166534, #7f1d1d, #581c87, #374151, #78350f

Default: #000000

Notes: Scan line color in the generated image.

display_options.app_buttons.enabledRequiredboolean

Allowed: true | false

Default: false

Notes: Toggles app buttons in the generated image.

display_options.app_buttons.colorRequiredstring

Allowed: #000000, #30acfd, #1e3a5f, #166534, #7f1d1d, #581c87, #374151, #78350f

Default: #000000

Notes: Button color from the fixed palette.

display_options.app_buttons.styleRequiredstring

Allowed: filled | outlined

Default: filled

Notes: Button rendering style in generated image.

linked_documentOptionalobject

Allowed: Object with clearly defined fields. Required: file_name (string, must not be empty), mime_type (string, must be one of: application/pdf; application/msword; application/vnd.openxmlformats-officedocument.wordprocessingml.document; application/xml; text/xml; application/vnd.ms-excel; application/vnd.openxmlformats-officedocument.spreadsheetml.sheet; application/vnd.ms-powerpoint; application/vnd.openxmlformats-officedocument.presentationml.presentation; image/png; image/jpeg; image/webp; image/svg+xml), data_base64 (base64-encoded string). Optional: label (string), enable_label_translations (boolean), label_translations (object). label_translations subfields (all optional): en (string), de (string), fr (string).

Notes: Encrypted attachment metadata and content. Strict validation applies: requests are accepted only when required fields are present, mime_type matches one of the allowed values, and the decoded document payload is at most 10MB.

T-Code display options in API interface

This is the dedicated display_options object used in API requests.

display_options.tcode_backgroundRequiredstring

Allowed: transparent | white

Default: transparent

Notes: Background style of generated T-Code.

display_options.tcode_colorRequiredstring

Allowed: #000000, #30acfd, #1e3a5f, #166534, #7f1d1d, #581c87, #374151, #78350f

Default: #000000

Notes: Only this fixed color set is accepted.

display_options.scan_text.enabledRequiredboolean

Allowed: true | false

Default: true

Notes: Turns scan sentence on or off.

display_options.scan_text.positionRequiredstring

Allowed: above | below

Default: below

Notes: Placement of scan text relative to T-Code.

display_options.scan_text.alignmentRequiredstring

Allowed: left | center | right

Default: center

Notes: Text alignment within the image block.

display_options.scan_text.use_customRequiredboolean

Allowed: true | false

Default: false

Notes: Enables custom sentence mode.

display_options.scan_text.custom_textRequiredstring | null

Allowed: null or custom text

Default: null

Notes: When custom mode is off, use null.

display_options.scan_text.colorRequiredstring

Allowed: #000000, #30acfd, #1e3a5f, #166534, #7f1d1d, #581c87, #374151, #78350f

Default: #000000

Notes: Uses the same fixed color palette.

display_options.app_buttons.enabledRequiredboolean

Allowed: true | false

Default: false

Notes: Toggles app buttons in generated image.

display_options.app_buttons.colorRequiredstring

Allowed: #000000, #30acfd, #1e3a5f, #166534, #7f1d1d, #581c87, #374151, #78350f

Default: #000000

Notes: Button color from fixed palette.

display_options.app_buttons.styleRequiredstring

Allowed: filled | outlined

Default: filled

Notes: Rendering style for app buttons.

How to place T-Code on a document

Option 1: API-driven workflow

  • Send a generate request with metadata, custom fields, and display options.
  • Receive the generated T-Code value and image format output.
  • Embed the returned code/image into your own document pipeline.
  • Use your own rendering rules for page position and size in your backend or DMS.

Option 2: GUI document upload workflow

  • Upload your document in the GUI interface.
  • Select T-Code position (preset corner/center or custom coordinates where available).
  • Set size and opacity/visibility style for the placed code.
  • Choose page scope: all pages, selected pages, range, odd/even, first/last (mode dependent).
  • Generate and download the final document with T-Code already embedded.

Valid API request examples

Use these payloads as copy-ready templates for integration testing. Replace IDs, dates, and sample values with your own creator data.

Generate: /api/v1/tcode/generate

1) Minimal valid generate request (defaults)

{
  "creator_name": "LogiHash GmbH",
  "tcode_label": "INV-2026-0001",
  "address": {
    "street": "Bahnhofstrasse",
    "house_number": "1A",
    "postal_code": "8001",
    "city": "Zurich",
    "country": "CH"
  },
  "object_type": "Invoice",
  "valid_until": "2027-04-09",
  "output_image_format": "png",
  "custom_fields": [
    {
      "label": "Invoice No",
      "value": "INV-2026-0001"
    },
    {
      "label": "Customer",
      "value": "ACME Europe"
    },
    {
      "label": "Amount",
      "value": "CHF 4,250.00"
    },
    {
      "label": "Currency",
      "value": "CHF"
    }
  ],
  "display_options": {
    "tcode_background": "transparent",
    "tcode_color": "#000000",
    "scan_text": {
      "enabled": true,
      "position": "below",
      "alignment": "center",
      "use_custom": false,
      "custom_text": null,
      "color": "#000000"
    },
    "app_buttons": {
      "enabled": false,
      "color": "#000000",
      "style": "filled"
    }
  }
}

2) Generate request with custom scan text and app buttons

{
  "creator_name": "LogiHash GmbH",
  "address": {
    "street": "Bahnhofstrasse",
    "house_number": "1A",
    "postal_code": "8001",
    "city": "Zurich",
    "country": "CH"
  },
  "object_type": "Certificate",
  "valid_until": "2028-12-31",
  "output_image_format": "webp",
  "custom_fields": [
    {
      "label": "Certificate ID",
      "value": "CERT-2026-55"
    },
    {
      "label": "Issued To",
      "value": "Jane Doe"
    },
    {
      "label": "Program",
      "value": "Advanced Compliance"
    },
    {
      "label": "Hours",
      "value": "24"
    }
  ],
  "display_options": {
    "tcode_background": "white",
    "tcode_color": "#1e3a5f",
    "scan_text": {
      "enabled": true,
      "position": "above",
      "alignment": "left",
      "use_custom": true,
      "custom_text": "Scan to verify this certificate",
      "color": "#1e3a5f"
    },
    "app_buttons": {
      "enabled": true,
      "color": "#30acfd",
      "style": "outlined"
    }
  }
}

3) Generate request with linked document + label translations

{
  "creator_name": "LogiHash GmbH",
  "address": {
    "street": "Bahnhofstrasse",
    "house_number": "1A",
    "postal_code": "8001",
    "city": "Zurich",
    "country": "CH"
  },
  "object_type": "Contract",
  "valid_until": "2027-10-15",
  "output_image_format": "svg",
  "custom_fields": [
    {
      "label": "Contract No",
      "value": "CTR-10-2026"
    },
    {
      "label": "Counterparty",
      "value": "Northwind AG"
    },
    {
      "label": "Region",
      "value": "DACH"
    },
    {
      "label": "Signed At",
      "value": "2026-10-15"
    }
  ],
  "linked_document": {
    "file_name": "contract.pdf",
    "mime_type": "application/pdf",
    "data_base64": "<base64-encoded-file-content>",
    "label": "Original Contract",
    "enable_label_translations": true,
    "label_translations": {
      "en": "Original Contract",
      "de": "Originalvertrag",
      "fr": "Contrat original"
    }
  },
  "display_options": {
    "tcode_background": "transparent",
    "tcode_color": "#000000",
    "scan_text": {
      "enabled": true,
      "position": "below",
      "alignment": "center",
      "use_custom": false,
      "custom_text": null,
      "color": "#000000"
    },
    "app_buttons": {
      "enabled": false,
      "color": "#000000",
      "style": "filled"
    }
  }
}

Verify: /api/v1/tcode/verify-retrieve

1) Verify using compact verification value (recommended)

{
  "verification_value": "<134-char header value: version+creator_id+db_entry_id+kid+policy_flags+header_signature>"
}

2) Verify a scanned value from printed material

{
  "verification_value": "01TRYLH01A12B34C56D78E90F1KIDEXAMPLE00000000010Fh4Z8m8tN8qQ2fQ1fR9...<truncated>"
}

Authentication headers

  • Authorization: Bearer <API_KEY> — API credential for the caller.
  • X-Client-ID: <CLIENT_ID> — Client identifier for the caller.
  • Content-Type: application/json — Request body is JSON.
  • Accept: application/json — Response should be JSON.