::: info Also known as define_param (with or without @ prefix) :::

Define HTTP parameters that are not bound to the PostgreSQL command. These virtual parameters exist in the HTTP request (query string or JSON body) but do not correspond to any $N positional parameter in the SQL query.

This is useful for SQL file endpoints where you need HTTP parameters for:

• Custom parameter placeholders — parameters that feed into annotation placeholders like {format} without being part of the SQL
• Claim mapping — auto-filling parameters from authenticated user claims without referencing them in the query
• HTTP request matching — parameters that affect endpoint behavior without participating in the database query

@define_param name
@define_param name type

• name — the HTTP parameter name
• type — optional PostgreSQL type (default: text)

Pass HTTP parameters that control endpoint behavior without referencing them in SQL:

-- sql/users_report.sql
-- @define_param format text
-- @table_format = {format}
-- @param $1 department_id
select id, name, email from users where department_id = $1;

GET /api/users-report?department_id=5&format=html_table

The format parameter feeds into the @table_format annotation via the {format} placeholder, selecting the output format (JSON, HTML table, Excel, etc.) without being part of the SQL query. Without @define_param, there would be no format parameter in the endpoint — the {format} placeholder would have nothing to resolve.

Auto-fill a parameter from the authenticated user's claims without including it in the SQL query:

-- sql/user_dashboard.sql
-- @authorize
-- @user_parameters
-- @define_param _user_id
select * from user_dashboard_data;

Here _user_id is created as a virtual parameter that maps to the name_identifier claim (via standard User Parameters claim mapping). The authenticated user's ID is injected automatically — but unlike @param, this parameter doesn't correspond to any $N in the SQL. The query itself doesn't filter by user — the virtual parameter exists solely for the claim mapping mechanism.

This is different from using @param with @user_parameters:

-- This uses @param — $1 IS in the SQL query
-- @authorize
-- @user_parameters
-- @param $1 _user_id
select * from orders where user_id = $1;

Use @define_param when the parameter shouldn't appear in the SQL at all. Use @param when you need the value both as a claim-mapped parameter and as a query parameter.

If no type is specified, the parameter defaults to text:

-- These are equivalent:
-- @define_param _user_id
-- @define_param _user_id text

Specify a type when needed:

-- @define_param _user_id integer

• SQL File Endpoints Guide — parameters, includes, and multi-command files
• PARAM — rename, retype, and configure parameters that are bound to SQL ($N)
• USER_PARAMETERS — enable claim-to-parameter mapping
• Custom Parameters — custom key-value annotation settings with {param} placeholders
• SQL File Source configuration — enable and configure SQL file endpoints