Prompt Template Variable Filler
Replaces matching `{{key}}` and `{key}` placeholders with raw string values from JSON. Replacement values are not sanitized or escaped.
About this prompt template variable filler
Replaces matching `{{key}}` and `{key}` placeholders with raw string values from JSON. Replacement values are not sanitized or escaped Validates and converts interface schemas client-side without transmitting private endpoint specifications.
API contract & interface schema logic
Calculates sub-word token counts across major AI tokenizer architectures (OpenAI Tiktoken cl100k_base / o200k_base for GPT-4o, Anthropic Claude byte-pair encodings, and SentencePiece tokenizers for Gemini and Llama). Validates Structured Outputs JSON Schemas and tool definitions for Function Calling APIs, enforcing strict schema constraints (e.g. additionalProperties: false, all properties in required array).
Worked schema conversion scenario
Scenario: Substitute supplied variables into a local prompt template.
Sample input:
Processing: Replace `{{key}}` and `{key}` placeholders with the string form of supplied values and report missing keys. Values are not sanitized for later HTML or prompt use.
Illustrative output:
Schema version & syntax constraints
Only balanced {key} or {{key}} tokens with supported names are replaced in one pass; mismatched or triple braces remain literal. Values are raw text, not escaped for JSON, HTML or prompts. Inserted text is not scanned again.
API specifications and schema models in Prompt Template Variable Filler reflect OpenAPI and JSON Schema standards. Verify generated schemas against your runtime validator.
Client-side schema processing boundary
Schema analysis and protocol mapping in Prompt Template Variable Filler execute locally in the browser tab without uploading endpoint definitions.
OpenAPI Specification & JSON Schema standards
OpenAPI Specification standards and JSON Schema draft definitions:
- Implementation-specific browser utility or reference guide (no single governing external standard)
Prompt Template Variable Filler verification · Audit standards
How to use it
- Paste JSON with template and variables or vars.
- Replace matching {{key}} and {key} tokens with raw string values.
- Read output and unresolved token names.
Frequently asked questions
How does Prompt Template Filler replace variables?+
It parses JSON, takes template and variables or vars, then replaces every exact {{name}} and {name} occurrence for each supplied key. It returns the resulting output plus distinct unresolved placeholder names.
Can you show an input and its result?+
Hi {{name}}, {role}; {{missing}} with Ada and admin produced Hi Ada, admin; {{missing}}, and the missing array contained only missing.
Which placeholder and value rules apply?+
Names must match the page regular expression when reported as unresolved. Replacement is literal text conversion; it does not evaluate expressions, support defaults, nested paths, conditionals, escaping policy, loops or safe HTML rendering.
Does filling a template execute a prompt?+
No. The page transforms submitted JSON only. It does not send text to an AI model, enforce instructions, validate output, retain a prompt history or protect data in another application.