# Class BSV::Overlay::AdminTokenTemplate <a id="class-BSV-Overlay-AdminTokenTemplate"></a>

**Inherits:** `Object`

Script template for creating, unlocking, and decoding SHIP and SLAP
advertisements.

SHIP (Service Host Interconnect) and SLAP (Service Lookup Availability) tokens
are PushDrop scripts containing four data fields:

    Field 0: protocol string — 'SHIP' or 'SLAP'
    Field 1: identity key — 33-byte compressed public key (binary)
    Field 2: domain — UTF-8 string
    Field 3: topic or service name — UTF-8 string

The locking script includes a fifth field containing a wallet signature over
the concatenation of fields 0–3, which authenticates the token at creation
time. The lock is secured with a P2PK condition derived from the wallet using
BRC-42/43 key derivation at security level 2.

Script layout (lock-after PushDrop format):

    <protocol> <identity_key> <domain> <topic> <wallet_sig>
    OP_2DROP OP_2DROP OP_DROP
    <derived_pubkey> OP_CHECKSIG

**@example Lock a SHIP advertisement**
```ruby
wallet = BSV::Wallet::Client.new(private_key, storage: BSV::Wallet::Store::Memory.new)
template = BSV::Overlay::AdminTokenTemplate.new(wallet)
locking_script = template.lock('SHIP', 'myhost.example.com', 'tm_payments')
decoded = BSV::Overlay::AdminTokenTemplate.decode(locking_script)
decoded.identity_key  # => hex public key of the wallet
```

## Constants
### `VALID_PROTOCOLS` <a id="constant-VALID_PROTOCOLS"></a> <a id="VALID_PROTOCOLS-constant"></a>
Not documented.

## Public Class Methods
### `decode(script)` <a id="method-c-decode"></a> <a id="decode-class_method"></a>
Decode a SHIP or SLAP advertisement from a PushDrop locking script.
- **@param** `script` [BSV::Script::Script, nil] the locking script to decode
- **@raise** [BSV::Overlay::OverlayError] if the script is PushDrop but has
fewer than 4 fields, or if the protocol field is not 'SHIP' or 'SLAP'
- **@return** [Advertisement, nil] the decoded advertisement, or +nil+ if the
script is nil, empty, or not a PushDrop script

## Public Instance Methods
### `initialize(wallet, originator: = nil)` <a id="method-i-initialize"></a> <a id="initialize-instance_method"></a>
Construct a new AdminTokenTemplate instance.
- **@param** `wallet` [#get_public_key, #create_signature] any object implementing
the BRC-100 wallet interface (e.g. {BSV::Wallet::Client})
- **@param** `originator` [String, nil] optional FQDN of the originating application
- **@return** [AdminTokenTemplate] a new instance of AdminTokenTemplate

### `lock(protocol, domain, topic_or_service)` <a id="method-i-lock"></a> <a id="lock-instance_method"></a>
Create a SHIP or SLAP advertisement locking script.

Derives the wallet's identity key, builds the four advertisement fields, signs
them with the protocol-derived key, and constructs a PushDrop locking script
with a P2PK spending condition.
- **@param** `protocol` [String] 'SHIP' or 'SLAP'
- **@param** `domain` [String] domain where the service or topic is available
- **@param** `topic_or_service` [String] topic or service name to advertise
- **@raise** [BSV::Overlay::OverlayError] if protocol is not 'SHIP' or 'SLAP'
- **@return** [BSV::Script::Script] the locking script

### `unlock(protocol)` <a id="method-i-unlock"></a> <a id="unlock-instance_method"></a>
Return an unlocker for spending an advertisement token.

The returned object follows the {BSV::Transaction::UnlockingScriptTemplate}
interface and can be assigned to an input's `unlocking_script_template`.
- **@param** `protocol` [String] 'SHIP' or 'SLAP' — must match the locked token
- **@raise** [BSV::Overlay::OverlayError] if protocol is not 'SHIP' or 'SLAP'
- **@return** [Unlocker] an object with +#sign+ and +#estimated_length+