Playground の「 生成 」ボタンを使うと、タスクの説明だけでプロンプト、関数、スキーマを生成できます。このガイドでは、その仕組みを詳しく説明します。
概要
プロンプトやスキーマを一から作成するには時間がかかることがあるため、生成機能を使うとすぐに取りかかれます。「生成」ボタンでは、主に次の 2 つの方法を使います。
- プロンプト: ベストプラクティスを取り入れた メタプロンプト を使って、プロンプトを生成または改善します。
- スキーマ: 正しい構文の JSON や関数を生成する メタスキーマ を使います。
現在はメタプロンプトとメタスキーマを使用していますが、今後は DSPy や「勾配降下法」など、より高度な手法を取り入れる可能性があります。
プロンプト
メタプロンプト は、タスクの説明に基づいて適切なプロンプトを作成するか、既存のプロンプトを改善するようモデルに指示します。Playground のメタプロンプトには、OpenAI のプロンプトエンジニアリングのベストプラクティスと、ユーザーとの実践で得た経験が反映されています。
音声などの出力タイプごとに専用のメタプロンプトを使い、生成されるプロンプトが想定の形式に合うようにしています。
メタプロンプト
import OpenAI from "openai";
const client = new OpenAI();
const metaPrompt = `Given a task description or existing prompt, produce a detailed system prompt to guide a language model in completing the task effectively.
# Guidelines
- Understand the Task: Grasp the main objective, goals, requirements, constraints, and expected output.
- Minimal Changes: If an existing prompt is provided, improve it only if it's simple. For complex prompts, enhance clarity and add missing elements without altering the original structure.
- Reasoning Before Conclusions**: Encourage reasoning steps before any conclusions are reached. ATTENTION! If the user provides examples where the reasoning happens afterward, REVERSE the order! NEVER START EXAMPLES WITH CONCLUSIONS!
- Reasoning Order: Call out reasoning portions of the prompt and conclusion parts (specific fields by name). For each, determine the ORDER in which this is done, and whether it needs to be reversed.
- Conclusion, classifications, or results should ALWAYS appear last.
- Examples: Include high-quality examples if helpful, using placeholders [in brackets] for complex elements.
- What kinds of examples may need to be included, how many, and whether they are complex enough to benefit from placeholders.
- Clarity and Conciseness: Use clear, specific language. Avoid unnecessary instructions or bland statements.
- Formatting: Use markdown features for readability. DO NOT USE \`\`\` CODE BLOCKS UNLESS SPECIFICALLY REQUESTED.
- Preserve User Content: If the input task or prompt includes extensive guidelines or examples, preserve them entirely, or as closely as possible. If they are vague, consider breaking down into sub-steps. Keep any details, guidelines, examples, variables, or placeholders provided by the user.
- Constants: DO include constants in the prompt, as they are not susceptible to prompt injection. Such as guides, rubrics, and examples.
- Output Format: Explicitly the most appropriate output format, in detail. This should include length and syntax (e.g. short sentence, paragraph, JSON, etc.)
- For tasks outputting well-defined or structured data (classification, JSON, etc.) bias toward outputting a JSON.
- JSON should never be wrapped in code blocks (\`\`\`) unless explicitly requested.
The final prompt you output should adhere to the following structure below. Do not include any additional commentary, only output the completed system prompt. SPECIFICALLY, do not include any additional messages at the start or end of the prompt. (e.g. no "---")
[Concise instruction describing the task - this should be the first line in the prompt, no section header]
[Additional details as needed.]
[Optional sections with headings or bullet points for detailed steps.]
# Steps [optional]
[optional: a detailed breakdown of the steps necessary to accomplish the task]
# Output Format
[Specifically call out how the output should be formatted, be it response length, structure e.g. JSON, markdown, etc]
# Examples [optional]
[Optional: 1-3 well-defined examples with placeholders if necessary. Clearly mark where examples start and end, and what the input and output are. User placeholders as necessary.]
[If the examples are shorter than what a realistic example is expected to be, make a reference with () explaining how real examples should be longer / shorter / different. AND USE PLACEHOLDERS! ]
# Notes [optional]
[optional: edge cases, details, and an area to call or repeat out specific important considerations]`;
async function generatePrompt(taskOrPrompt) {
const completion = await client.chat.completions.create({
model: "gpt-6-astra",
messages: [
{ role: "system", content: metaPrompt },
{
role: "user",
content: "Task, Goal, or Current Prompt:\n" + taskOrPrompt,
},
],
});
return completion.choices[0].message.content;
}
console.log(
await generatePrompt("Write a concise product launch announcement.")
);import OpenAI from "openai";
const client = new OpenAI();
const metaPrompt = `Given a task description or existing prompt, produce a detailed system prompt to guide a realtime audio output language model in completing the task effectively.
# Guidelines
- Understand the Task: Grasp the main objective, goals, requirements, constraints, and expected output.
- Tone: Make sure to specifically call out the tone. By default it should be emotive and friendly, and speak quickly to avoid keeping the user just waiting.
- Audio Output Constraints: Because the model is outputting audio, the responses should be short and conversational.
- Minimal Changes: If an existing prompt is provided, improve it only if it's simple. For complex prompts, enhance clarity and add missing elements without altering the original structure.
- Examples: Include high-quality examples if helpful, using placeholders [in brackets] for complex elements.
- What kinds of examples may need to be included, how many, and whether they are complex enough to benefit from placeholders.
- It is very important that any examples included reflect the short, conversational output responses of the model.
Keep the sentences very short by default. Instead of 3 sentences in a row by the assistant, it should be split up with a back and forth with the user instead.
- By default each sentence should be a few words only (5-20ish words). However, if the user specifically asks for "short" responses, then the examples should truly have 1-10 word responses max.
- Make sure the examples are multi-turn (at least 4 back-forth-back-forth per example), not just one questions an response. They should reflect an organic conversation.
- Clarity and Conciseness: Use clear, specific language. Avoid unnecessary instructions or bland statements.
- Preserve User Content: If the input task or prompt includes extensive guidelines or examples, preserve them entirely, or as closely as possible. If they are vague, consider breaking down into sub-steps. Keep any details, guidelines, examples, variables, or placeholders provided by the user.
- Constants: DO include constants in the prompt, as they are not susceptible to prompt injection. Such as guides, rubrics, and examples.
The final prompt you output should adhere to the following structure below. Do not include any additional commentary, only output the completed system prompt. SPECIFICALLY, do not include any additional messages at the start or end of the prompt. (e.g. no "---")
[Concise instruction describing the task - this should be the first line in the prompt, no section header]
[Additional details as needed.]
[Optional sections with headings or bullet points for detailed steps.]
# Examples [optional]
[Optional: 1-3 well-defined examples with placeholders if necessary. Clearly mark where examples start and end, and what the input and output are. User placeholders as necessary.]
[If the examples are shorter than what a realistic example is expected to be, make a reference with () explaining how real examples should be longer / shorter / different. AND USE PLACEHOLDERS! ]
# Notes [optional]
[optional: edge cases, details, and an area to call or repeat out specific important considerations]`;
async function generatePrompt(taskOrPrompt) {
const completion = await client.chat.completions.create({
model: "gpt-6-astra",
messages: [
{ role: "system", content: metaPrompt },
{
role: "user",
content: "Task, Goal, or Current Prompt:\n" + taskOrPrompt,
},
],
});
return completion.choices[0].message.content;
}
console.log(
await generatePrompt("Create a friendly voice assistant for a bike shop.")
);プロンプトの編集
プロンプトの編集には、少し変更を加えたメタプロンプトを使います。具体的な編集指示は簡単に反映できますが、自由度の高い修正では、どのような変更が必要かを見極めるのが難しい場合があります。そのため、応答の冒頭に 推論セクション を設けています。このセクションでは、既存のプロンプトの明確さ、思考の連鎖の順序、全体の構成、具体性などを評価し、必要な変更をモデルが判断できるようにします。推論セクションで改善案を提示した後、その部分を解析処理で最終的な応答から取り除きます。
import OpenAI from "openai";
const client = new OpenAI();
const metaPrompt = `Given a current prompt and a change description, produce a detailed system prompt to guide a language model in completing the task effectively.
Your final output will be the full corrected prompt verbatim. However, before that, at the very beginning of your response, use <reasoning> tags to analyze the prompt and determine the following, explicitly:
<reasoning>
- Simple Change: (yes/no) Is the change description explicit and simple? (If so, skip the rest of these questions.)
- Reasoning: (yes/no) Does the current prompt use reasoning, analysis, or chain of thought?
- Identify: (max 10 words) if so, which section(s) utilize reasoning?
- Conclusion: (yes/no) is the chain of thought used to determine a conclusion?
- Ordering: (before/after) is the chain of though located before or after
- Structure: (yes/no) does the input prompt have a well defined structure
- Examples: (yes/no) does the input prompt have few-shot examples
- Representative: (1-5) if present, how representative are the examples?
- Complexity: (1-5) how complex is the input prompt?
- Task: (1-5) how complex is the implied task?
- Necessity: ()
- Specificity: (1-5) how detailed and specific is the prompt? (not to be confused with length)
- Prioritization: (list) what 1-3 categories are the MOST important to address.
- Conclusion: (max 30 words) given the previous assessment, give a very concise, imperative description of what should be changed and how. this does not have to adhere strictly to only the categories listed
</reasoning>
# Guidelines
- Understand the Task: Grasp the main objective, goals, requirements, constraints, and expected output.
- Minimal Changes: If an existing prompt is provided, improve it only if it's simple. For complex prompts, enhance clarity and add missing elements without altering the original structure.
- Reasoning Before Conclusions**: Encourage reasoning steps before any conclusions are reached. ATTENTION! If the user provides examples where the reasoning happens afterward, REVERSE the order! NEVER START EXAMPLES WITH CONCLUSIONS!
- Reasoning Order: Call out reasoning portions of the prompt and conclusion parts (specific fields by name). For each, determine the ORDER in which this is done, and whether it needs to be reversed.
- Conclusion, classifications, or results should ALWAYS appear last.
- Examples: Include high-quality examples if helpful, using placeholders [in brackets] for complex elements.
- What kinds of examples may need to be included, how many, and whether they are complex enough to benefit from placeholders.
- Clarity and Conciseness: Use clear, specific language. Avoid unnecessary instructions or bland statements.
- Formatting: Use markdown features for readability. DO NOT USE \`\`\` CODE BLOCKS UNLESS SPECIFICALLY REQUESTED.
- Preserve User Content: If the input task or prompt includes extensive guidelines or examples, preserve them entirely, or as closely as possible. If they are vague, consider breaking down into sub-steps. Keep any details, guidelines, examples, variables, or placeholders provided by the user.
- Constants: DO include constants in the prompt, as they are not susceptible to prompt injection. Such as guides, rubrics, and examples.
- Output Format: Explicitly the most appropriate output format, in detail. This should include length and syntax (e.g. short sentence, paragraph, JSON, etc.)
- For tasks outputting well-defined or structured data (classification, JSON, etc.) bias toward outputting a JSON.
- JSON should never be wrapped in code blocks (\`\`\`) unless explicitly requested.
The final prompt you output should adhere to the following structure below. Do not include any additional commentary, only output the completed system prompt. SPECIFICALLY, do not include any additional messages at the start or end of the prompt. (e.g. no "---")
[Concise instruction describing the task - this should be the first line in the prompt, no section header]
[Additional details as needed.]
[Optional sections with headings or bullet points for detailed steps.]
# Steps [optional]
[optional: a detailed breakdown of the steps necessary to accomplish the task]
# Output Format
[Specifically call out how the output should be formatted, be it response length, structure e.g. JSON, markdown, etc]
# Examples [optional]
[Optional: 1-3 well-defined examples with placeholders if necessary. Clearly mark where examples start and end, and what the input and output are. User placeholders as necessary.]
[If the examples are shorter than what a realistic example is expected to be, make a reference with () explaining how real examples should be longer / shorter / different. AND USE PLACEHOLDERS! ]
# Notes [optional]
[optional: edge cases, details, and an area to call or repeat out specific important considerations]
[NOTE: you must start with a <reasoning> section. the immediate next token you produce should be <reasoning>]`;
async function generatePrompt(taskOrPrompt) {
const completion = await client.chat.completions.create({
model: "gpt-6-astra",
messages: [
{ role: "system", content: metaPrompt },
{
role: "user",
content: "Task, Goal, or Current Prompt:\n" + taskOrPrompt,
},
],
});
return completion.choices[0].message.content;
}
console.log(
await generatePrompt("Make this support prompt more concise and empathetic.")
);import OpenAI from "openai";
const client = new OpenAI();
const metaPrompt = `Given a current prompt and a change description, produce a detailed system prompt to guide a realtime audio output language model in completing the task effectively.
Your final output will be the full corrected prompt verbatim. However, before that, at the very beginning of your response, use <reasoning> tags to analyze the prompt and determine the following, explicitly:
<reasoning>
- Simple Change: (yes/no) Is the change description explicit and simple? (If so, skip the rest of these questions.)
- Reasoning: (yes/no) Does the current prompt use reasoning, analysis, or chain of thought?
- Identify: (max 10 words) if so, which section(s) utilize reasoning?
- Conclusion: (yes/no) is the chain of thought used to determine a conclusion?
- Ordering: (before/after) is the chain of though located before or after
- Structure: (yes/no) does the input prompt have a well defined structure
- Examples: (yes/no) does the input prompt have few-shot examples
- Representative: (1-5) if present, how representative are the examples?
- Complexity: (1-5) how complex is the input prompt?
- Task: (1-5) how complex is the implied task?
- Necessity: ()
- Specificity: (1-5) how detailed and specific is the prompt? (not to be confused with length)
- Prioritization: (list) what 1-3 categories are the MOST important to address.
- Conclusion: (max 30 words) given the previous assessment, give a very concise, imperative description of what should be changed and how. this does not have to adhere strictly to only the categories listed
</reasoning>
# Guidelines
- Understand the Task: Grasp the main objective, goals, requirements, constraints, and expected output.
- Tone: Make sure to specifically call out the tone. By default it should be emotive and friendly, and speak quickly to avoid keeping the user just waiting.
- Audio Output Constraints: Because the model is outputting audio, the responses should be short and conversational.
- Minimal Changes: If an existing prompt is provided, improve it only if it's simple. For complex prompts, enhance clarity and add missing elements without altering the original structure.
- Examples: Include high-quality examples if helpful, using placeholders [in brackets] for complex elements.
- What kinds of examples may need to be included, how many, and whether they are complex enough to benefit from placeholders.
- It is very important that any examples included reflect the short, conversational output responses of the model.
Keep the sentences very short by default. Instead of 3 sentences in a row by the assistant, it should be split up with a back and forth with the user instead.
- By default each sentence should be a few words only (5-20ish words). However, if the user specifically asks for "short" responses, then the examples should truly have 1-10 word responses max.
- Make sure the examples are multi-turn (at least 4 back-forth-back-forth per example), not just one questions an response. They should reflect an organic conversation.
- Clarity and Conciseness: Use clear, specific language. Avoid unnecessary instructions or bland statements.
- Preserve User Content: If the input task or prompt includes extensive guidelines or examples, preserve them entirely, or as closely as possible. If they are vague, consider breaking down into sub-steps. Keep any details, guidelines, examples, variables, or placeholders provided by the user.
- Constants: DO include constants in the prompt, as they are not susceptible to prompt injection. Such as guides, rubrics, and examples.
The final prompt you output should adhere to the following structure below. Do not include any additional commentary, only output the completed system prompt. SPECIFICALLY, do not include any additional messages at the start or end of the prompt. (e.g. no "---")
[Concise instruction describing the task - this should be the first line in the prompt, no section header]
[Additional details as needed.]
[Optional sections with headings or bullet points for detailed steps.]
# Examples [optional]
[Optional: 1-3 well-defined examples with placeholders if necessary. Clearly mark where examples start and end, and what the input and output are. User placeholders as necessary.]
[If the examples are shorter than what a realistic example is expected to be, make a reference with () explaining how real examples should be longer / shorter / different. AND USE PLACEHOLDERS! ]
# Notes [optional]
[optional: edge cases, details, and an area to call or repeat out specific important considerations]
[NOTE: you must start with a <reasoning> section. the immediate next token you produce should be <reasoning>]`;
async function generatePrompt(taskOrPrompt) {
const completion = await client.chat.completions.create({
model: "gpt-6-astra",
messages: [
{ role: "system", content: metaPrompt },
{
role: "user",
content: "Task, Goal, or Current Prompt:\n" + taskOrPrompt,
},
],
});
return completion.choices[0].message.content;
}
console.log(
await generatePrompt(
"Make this voice assistant prompt warmer and more direct."
)
);スキーマ
構造化出力のスキーマと関数スキーマは、それ自体が JSON オブジェクトなので、構造化出力を使って生成します。 そのためには、生成したい出力のスキーマを定義する必要がありますが、この場合は出力自体もスキーマです。そこで、スキーマそのものを記述するスキーマである メタスキーマを使います。
関数スキーマの parameters フィールド自体もスキーマなので、関数の生成にも同じメタスキーマを使います。
制約付きメタスキーマの定義
構造化出力は、strict=true と strict=false の 2 つのモードに対応しています。どちらも指定されたスキーマに従うよう学習した同じモデルを使いますが、制約付きサンプリングによってスキーマへの完全な準拠を保証するのは「厳密モード」だけです。
目標は、厳密モード自体を使って、厳密モード用のスキーマを生成することです。しかし、JSON Schema 仕様で提供されている公式のメタスキーマは、厳密モードでは現在サポートされていない機能に依存しています。これは、入力と出力の両方のスキーマに関わる課題です。
- 入力スキーマ: 出力スキーマを記述するために、入力スキーマでサポートされていない機能を使うことはできません。
- 出力スキーマ: 生成されるスキーマに、サポートされていない機能を含めてはいけません。
出力スキーマに新しいキーを生成する必要があるため、入力のメタスキーマでは additionalProperties を使う必要があります。このため、現時点では厳密モードでスキーマを生成できません。それでも、生成されるスキーマは厳密モードの制約に準拠させる必要があります。
この制限に対処するため、 擬似メタスキーマ を定義します。これは、厳密モードでサポートされていない機能を使って、厳密モードでサポートされている機能だけを記述するメタスキーマです。つまり、メタスキーマの定義には厳密モードの範囲外の機能を使いつつ、生成されるスキーマが厳密モードの制約に準拠するようにする方法です。
制約付きメタスキーマの構築は難しいため、OpenAI のモデルを活用しました。
まず、JSON モードの o1-preview と gpt-4o に、構造化出力のドキュメントを使って目標を説明しました。
何度か試行を重ね、最初の実用的なメタスキーマを作成しました。
次に、構造化出力を有効にした gpt-4o に、 その初期スキーマ とタスクの説明、ドキュメントを渡し、より良い候補を生成しました。改善されたスキーマを使って次のスキーマを生成する作業を繰り返し、最後に人の手で入念にレビューしました。
最後に、出力を整えたうえで、スキーマと関数向けの一連の評価を使ってスキーマを検証しました。
出力の整形
厳密モードはスキーマへの完全な準拠を保証します。しかし、生成時には厳密モードを使えないため、生成後に出力を検証し、変換する必要があります。
スキーマの生成後、次の手順を実行します。
- すべてのオブジェクトで、
additionalPropertiesをfalseに設定します 。 - すべてのプロパティを必須に設定します。
- 構造化出力のスキーマの場合は、
json_schemaオブジェクトで囲みます。 - 関数の場合は、
functionオブジェクトで囲みます。
Realtime API の function オブジェクトは、 Chat Completions API のものとは少し異なりますが、同じスキーマを使います。
メタスキーマ
各メタスキーマには、フューショットの例を含む対応するプロンプトがあります。これを構造化出力の信頼性と組み合わせることで、厳密モードを使わなくてもスキーマを生成できました。
import OpenAI from "openai";
const client = new OpenAI();
const metaSchema = {
name: "metaschema",
schema: {
type: "object",
properties: {
name: {
type: "string",
description: "The name of the schema",
},
type: {
type: "string",
enum: ["object", "array", "string", "number", "boolean", "null"],
},
properties: {
type: "object",
additionalProperties: {
$ref: "#/$defs/schema_definition",
},
},
items: {
anyOf: [
{
$ref: "#/$defs/schema_definition",
},
{
type: "array",
items: {
$ref: "#/$defs/schema_definition",
},
},
],
},
required: {
type: "array",
items: {
type: "string",
},
},
additionalProperties: {
type: "boolean",
},
},
required: ["type"],
additionalProperties: false,
if: {
properties: {
type: {
const: "object",
},
},
},
then: {
required: ["properties"],
},
$defs: {
schema_definition: {
type: "object",
properties: {
type: {
type: "string",
enum: ["object", "array", "string", "number", "boolean", "null"],
},
properties: {
type: "object",
additionalProperties: {
$ref: "#/$defs/schema_definition",
},
},
items: {
anyOf: [
{
$ref: "#/$defs/schema_definition",
},
{
type: "array",
items: {
$ref: "#/$defs/schema_definition",
},
},
],
},
required: {
type: "array",
items: {
type: "string",
},
},
additionalProperties: {
type: "boolean",
},
},
required: ["type"],
additionalProperties: false,
if: {
properties: {
type: {
const: "object",
},
},
},
then: {
required: ["properties"],
},
},
},
},
};
const metaPrompt = `# Instructions
Return a valid schema for the described JSON.
You must also make sure:
- all fields in an object are set as required
- I REPEAT, ALL FIELDS MUST BE MARKED AS REQUIRED
- all objects must have additionalProperties set to false
- because of this, some cases like "attributes" or "metadata" properties that would normally allow additional properties should instead have a fixed set of properties
- all objects must have properties defined
- field order matters. any form of "thinking" or "explanation" should come before the conclusion
- $defs must be defined under the schema param
Notable keywords NOT supported include:
- For objects: unevaluatedProperties, propertyNames, minProperties, maxProperties
- For arrays: unevaluatedItems, contains, minContains, maxContains, uniqueItems
Other notes:
- definitions and recursion are supported
- only if necessary to include references e.g. "$defs", it must be inside the "schema" object
# Examples
Input: Generate a math reasoning schema with steps and a final answer.
Output: {
"name": "math_reasoning",
"type": "object",
"properties": {
"steps": {
"type": "array",
"description": "A sequence of steps involved in solving the math problem.",
"items": {
"type": "object",
"properties": {
"explanation": {
"type": "string",
"description": "Description of the reasoning or method used in this step."
},
"output": {
"type": "string",
"description": "Result or outcome of this specific step."
}
},
"required": [
"explanation",
"output"
],
"additionalProperties": false
}
},
"final_answer": {
"type": "string",
"description": "The final solution or answer to the math problem."
}
},
"required": [
"steps",
"final_answer"
],
"additionalProperties": false
}
Input: Give me a linked list
Output: {
"name": "linked_list",
"type": "object",
"properties": {
"linked_list": {
"$ref": "#/$defs/linked_list_node",
"description": "The head node of the linked list."
}
},
"$defs": {
"linked_list_node": {
"type": "object",
"description": "Defines a node in a singly linked list.",
"properties": {
"value": {
"type": "number",
"description": "The value stored in this node."
},
"next": {
"anyOf": [
{
"$ref": "#/$defs/linked_list_node"
},
{
"type": "null"
}
],
"description": "Reference to the next node; null if it is the last node."
}
},
"required": [
"value",
"next"
],
"additionalProperties": false
}
},
"required": [
"linked_list"
],
"additionalProperties": false
}
Input: Dynamically generated UI
Output: {
"name": "ui",
"type": "object",
"properties": {
"type": {
"type": "string",
"description": "The type of the UI component",
"enum": [
"div",
"button",
"header",
"section",
"field",
"form"
]
},
"label": {
"type": "string",
"description": "The label of the UI component, used for buttons or form fields"
},
"children": {
"type": "array",
"description": "Nested UI components",
"items": {
"$ref": "#"
}
},
"attributes": {
"type": "array",
"description": "Arbitrary attributes for the UI component, suitable for any element",
"items": {
"type": "object",
"properties": {
"name": {
"type": "string",
"description": "The name of the attribute, for example onClick or className"
},
"value": {
"type": "string",
"description": "The value of the attribute"
}
},
"required": [
"name",
"value"
],
"additionalProperties": false
}
}
},
"required": [
"type",
"label",
"children",
"attributes"
],
"additionalProperties": false
}`;
async function generateSchema(description) {
const completion = await client.chat.completions.create({
model: "gpt-5.6-terra",
response_format: { type: "json_schema", json_schema: metaSchema },
messages: [
{ role: "system", content: metaPrompt },
{ role: "user", content: "Description:\n" + description },
],
});
const content = completion.choices[0].message.content;
if (!content) throw new Error("The model did not return a schema.");
return JSON.parse(content);
}
console.log(
JSON.stringify(await generateSchema("Describe a calendar event."), null, 2)
);import OpenAI from "openai";
const client = new OpenAI();
const metaSchema = {
name: "function-metaschema",
schema: {
type: "object",
properties: {
name: {
type: "string",
description: "The name of the function",
},
description: {
type: "string",
description: "A description of what the function does",
},
parameters: {
$ref: "#/$defs/schema_definition",
description: "A JSON schema that defines the function's parameters",
},
},
required: ["name", "description", "parameters"],
additionalProperties: false,
$defs: {
schema_definition: {
type: "object",
properties: {
type: {
type: "string",
enum: ["object", "array", "string", "number", "boolean", "null"],
},
properties: {
type: "object",
additionalProperties: {
$ref: "#/$defs/schema_definition",
},
},
items: {
anyOf: [
{
$ref: "#/$defs/schema_definition",
},
{
type: "array",
items: {
$ref: "#/$defs/schema_definition",
},
},
],
},
required: {
type: "array",
items: {
type: "string",
},
},
additionalProperties: {
type: "boolean",
},
},
required: ["type"],
additionalProperties: false,
if: {
properties: {
type: {
const: "object",
},
},
},
then: {
required: ["properties"],
},
},
},
},
};
const metaPrompt = `# Instructions
Return a valid schema for the described function.
Pay special attention to making sure that "required" and "type" are always at the correct level of nesting. For example, "required" should be at the same level as "properties", not inside it.
Make sure that every property, no matter how short, has a type and description correctly nested inside it.
# Examples
Input: Assign values to NN hyperparameters
Output: {
"name": "set_hyperparameters",
"description": "Assign values to NN hyperparameters",
"parameters": {
"type": "object",
"required": [
"learning_rate",
"epochs"
],
"properties": {
"epochs": {
"type": "number",
"description": "Number of complete passes through dataset"
},
"learning_rate": {
"type": "number",
"description": "Speed of model learning"
}
}
}
}
Input: Plans a motion path for the robot
Output: {
"name": "plan_motion",
"description": "Plans a motion path for the robot",
"parameters": {
"type": "object",
"required": [
"start_position",
"end_position"
],
"properties": {
"end_position": {
"type": "object",
"properties": {
"x": {
"type": "number",
"description": "End X coordinate"
},
"y": {
"type": "number",
"description": "End Y coordinate"
}
}
},
"obstacles": {
"type": "array",
"description": "Array of obstacle coordinates",
"items": {
"type": "object",
"properties": {
"x": {
"type": "number",
"description": "Obstacle X coordinate"
},
"y": {
"type": "number",
"description": "Obstacle Y coordinate"
}
}
}
},
"start_position": {
"type": "object",
"properties": {
"x": {
"type": "number",
"description": "Start X coordinate"
},
"y": {
"type": "number",
"description": "Start Y coordinate"
}
}
}
}
}
}
Input: Calculates various technical indicators
Output: {
"name": "technical_indicator",
"description": "Calculates various technical indicators",
"parameters": {
"type": "object",
"required": [
"ticker",
"indicators"
],
"properties": {
"indicators": {
"type": "array",
"description": "List of technical indicators to calculate",
"items": {
"type": "string",
"description": "Technical indicator",
"enum": [
"RSI",
"MACD",
"Bollinger_Bands",
"Stochastic_Oscillator"
]
}
},
"period": {
"type": "number",
"description": "Time period for the analysis"
},
"ticker": {
"type": "string",
"description": "Stock ticker symbol"
}
}
}
}`;
async function generateFunctionSchema(description) {
const completion = await client.chat.completions.create({
model: "gpt-5.6-terra",
response_format: { type: "json_schema", json_schema: metaSchema },
messages: [
{ role: "system", content: metaPrompt },
{ role: "user", content: "Description:\n" + description },
],
});
const content = completion.choices[0].message.content;
if (!content) throw new Error("The model did not return a schema.");
return JSON.parse(content);
}
console.log(
JSON.stringify(
await generateFunctionSchema(
"Create a function that checks the weather in a city."
),
null,
2
)
);