What's template syntax?

Mustache-style `{{variable}}` substitution. Plus `{{#list}}...{{/list}}` for list iteration. Simple, widely understood, no escaping required.

Can I include conditionals?

Basic ones: `{{#if variable}}...{{/if}}`. For complex logic, process the data in code before templating rather than building logic into the template.

Yes — warns if the template has variables your data doesn't provide. Prevents 'Hello {{name}}!' sending literally to users when `name` is missing.

Mustache-compatible subset. Works across Python (chevron, pystache), JS (Mustache.js), and most other languages. Portable templates.

Render prompt templates with variable substitution. Part of the DevTools Surf developer suite. Browse more tools in the AI / Modern Dev collection.

Prompt engineering became a recognized job title in 2023, with salaries reaching $300,000 at major AI companies.
The Mustache template syntax ({{ }}) was created by Chris Wanstrath of GitHub in 2009 and inspired countless template engines.
Research from Microsoft in 2023 showed that structured prompt templates can improve LLM accuracy by up to 30% on reasoning tasks.

What's template syntax?: Mustache-style `{{variable}}` substitution. Plus `{{#list}}...{{/list}}` for list iteration. Simple, widely understood, no escaping required.
Can I include conditionals?: Basic ones: `{{#if variable}}...{{/if}}`. For complex logic, process the data in code before templating rather than building logic into the template.
Does it validate variable coverage?: Yes — warns if the template has variables your data doesn't provide. Prevents 'Hello {{name}}!' sending literally to users when `name` is missing.
Is this Jinja2 or Handlebars?: Mustache-compatible subset. Works across Python (chevron, pystache), JS (Mustache.js), and most other languages. Portable templates.

Render prompt templates with variable substitution. Part of the DevTools Surf developer suite. Browse more tools in the AI / Modern Dev collection.

Prompt engineering became a recognized job title in 2023, with salaries reaching $300,000 at major AI companies.
The Mustache template syntax ({{ }}) was created by Chris Wanstrath of GitHub in 2009 and inspired countless template engines.
Research from Microsoft in 2023 showed that structured prompt templates can improve LLM accuracy by up to 30% on reasoning tasks.

What's template syntax?: Mustache-style `{{variable}}` substitution. Plus `{{#list}}...{{/list}}` for list iteration. Simple, widely understood, no escaping required.
Can I include conditionals?: Basic ones: `{{#if variable}}...{{/if}}`. For complex logic, process the data in code before templating rather than building logic into the template.
Does it validate variable coverage?: Yes — warns if the template has variables your data doesn't provide. Prevents 'Hello {{name}}!' sending literally to users when `name` is missing.
Is this Jinja2 or Handlebars?: Mustache-compatible subset. Works across Python (chevron, pystache), JS (Mustache.js), and most other languages. Portable templates.