Response Headers
Set custom HTTP response headers for the endpoint.
Syntax
<Header-Name>: <value>Response headers use standard HTTP header format with a colon separator. Header names are case-insensitive.
Examples
Set Content-Type
sql
create function get_html_page()
returns text
language sql
as $$select '<html><body><h1>Hello</h1></body></html>'$$;
comment on function get_html_page() is
'HTTP GET
Content-Type: text/html';Response includes: Content-Type: text/html
Multiple Headers
sql
create function get_api_data()
returns json
language sql
as $$select '{"status": "ok"}'::json$$;
comment on function get_api_data() is
'HTTP GET
Content-Type: application/json
Cache-Control: no-store
X-Custom-Header: custom-value';Response includes all three headers.
Multi-Value Headers
Headers with the same name are combined:
sql
create function set_cookies()
returns text
language sql
as $$select 'OK'$$;
comment on function set_cookies() is
'HTTP GET
Set-Cookie: session=abc123
Set-Cookie: theme=dark
Set-Cookie: lang=en';Response includes: Set-Cookie: session=abc123, theme=dark, lang=en
Cache Control
sql
create function get_static_config()
returns json
language sql
as $$select config from app_config where id = 1$$;
comment on function get_static_config() is
'HTTP GET
Cache-Control: public, max-age=3600';Clients can cache the response for 1 hour.
Combined with Other Annotations
sql
create function export_report()
returns text
language sql
as $$...$$;
comment on function export_report() is
'HTTP GET
@authorize manager
Content-Type: text/csv
Content-Disposition: attachment; filename="report.csv"
Cache-Control: no-cache';Dynamic Headers from Parameters
Header values can include parameter values using the {param_name} template syntax:
sql
create function export_report(_type text, _file text)
returns text
language sql
as $$...$$;
comment on function export_report(text, text) is
'HTTP GET
@authorize manager
Content-Type: {_type}
Content-Disposition: attachment; filename={_file}
Cache-Control: no-cache';Request: GET /api/export-report?_type=text/csv&_file=report.csv
Response headers:
Content-Type: text/csv
Content-Disposition: attachment; filename=report.csvCORS Headers
sql
create function cors_endpoint()
returns json
language sql
as $$select '{}'::json$$;
comment on function cors_endpoint() is
'HTTP GET
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET, POST
Access-Control-Allow-Headers: Content-Type';Note: For comprehensive CORS support, use the CORS configuration instead.
Common Headers
| Header | Purpose |
|---|---|
Content-Type | Response media type |
Cache-Control | Caching directives |
Content-Disposition | Download filename |
X-* | Custom application headers |
Set-Cookie | Set cookies |
Related
- CORS configuration - Configure CORS headers globally
- Comment Annotations Guide - How annotations work
- Configuration Guide - How configuration works