Generate ボタンを使うと、Playground でタスクの内容を説明するだけで、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解説します。
概要
プロンプトやスキーマを一から作るには時間がかかることがあります。自動生成を使えば、すぐに作業を始められます。Generate ボタンでは、生成するものに応じて主に次の 2 つの手法を使います。
- 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: メタスキーマを使って、構文が正しい JSON や関数定義を生成します。
現在はメタプロンプトとメタスキーマを使っていますが、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したり、既存のプロンプトを改善したりするようモデルに指示するものです。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、ユーザーとの実際のやり取りから得た知見を反映しています。
生成されるプロンプトが想定した形式に合うよう、音声などの出力の種類に応じて専用のメタプロンプトを使います。
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
プロンプトを編集するときは、メタプロンプトを少し変更して使います。具体的な編集指示はそのまま反映できますが、修正の仕方を任されている場合は、どこを変えるべきか判断しにくいことがあります。そこで、応答の冒頭に推論セクションを設けています。このセクションでモデルは、既存のプロンプトの明確さ、思考の連鎖におけるステップの順序、全体の構成、指示の具体性などを評価し、必要な変更を判断します。モデルが推論セクションで改善案を示した後、応答を解析する際にこのセクションを取り除きます。
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も関数のスキーマも、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できます。 構造化出力を使うには、目的の出力を記述するスキーマを定義する必要があります。今回は出力そのものがスキーマなので、スキーマ自体を記述するスキーマ、つまりメタスキーマを使います。
関数スキーマの parameters フィールドもそれ自体がスキーマなので、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
構造化出力には、strict=true と strict=false の 2 つのモードがあります。どちらも、指定されたスキーマに従うように学習した同じモデルを使います。ただし、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「厳格モード」だけです。
目標は、厳格モードを使って厳格モード用のスキーマを生成することです。しかし、JSON Schema 仕様の公式メタスキーマでは、厳格モードで現在サポートされていない機能を使っています。そのため、入力スキーマと出力スキーマの両方に次の制約があります。
- 入力スキーマ: 入力スキーマで出力スキーマを記述する際に、サポート対象外の機能は使えません。
- 出力スキーマ: 生成するスキーマには、サポート対象外の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には、入力のメタスキーマで additionalProperties を使う必要があります。このため、現時点ではスキーマの生成に厳格モードを使えません。それでも、生成したスキーマは厳格モードの制約を満たす必要があります。
この制限に対処するために、疑似メタスキーマを定義します。これは、厳格モードではサポートされていない機能を使って、厳格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。こうすれば、メタスキーマの定義には厳格モードの制約を適用せずに、生成するスキーマがその制約を満たすようにできます。
制約付きメタスキーマを作るのは難しいため、設計には OpenAI のモデルを活用しました。
まず、o1-preview と gpt-4o を JSON モードで使い、構造化出力のドキュメントをもとに目標を説明しました。
何度か試行を重ね、実際に使える最初のメタスキーマができました。
次に、gpt-4o で構造化出力を使い、その最初のスキーマをタスクの説明やドキュメントとともに渡して、よりよい候補を生成しました。毎回、改善したスキーマを使って次の候補を生成し、最後に人の手で入念に確認しました。
その後、出力を整えたうえで、スキーマと関数向けの一連の評価テストを使って、生成したスキーマを検証しました。
出力の整形
厳格モードでは、出力がスキーマに完全に準拠することが保証されます。ただし、スキーマの生成時には厳格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。
スキーマを生成した後は、次の手順で出力を整えます。
- 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オブジェクトでスキーマを包みます。 - 関数の場合は、
functionオブジェクトで関数定義を包みます。
Realtime API の関数オブジェクトは Chat Completions API のものと少し異なりますが、使用するスキーマは同じです。
メタスキーマ
各メタスキーマに対応するプロンプトには、フューショットの例が含まれています。構造化出力の信頼性を活かし、これらのプロンプトと組み合わせることで、厳格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 schemaDefinition = {
type: "object",
properties: {
description: { type: "string" },
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" },
enum: { type: "array", minItems: 1, uniqueItems: true },
$ref: { type: "string" },
$defs: {
type: "object",
additionalProperties: { $ref: "#/$defs/schema_definition" },
},
anyOf: {
type: "array",
minItems: 1,
items: { $ref: "#/$defs/schema_definition" },
},
},
additionalProperties: false,
if: { required: ["type"], properties: { type: { const: "object" } } },
then: { required: ["properties"] },
};
const metaSchema = {
name: "metaschema",
schema: {
...schemaDefinition,
required: ["type"],
properties: {
name: { type: "string", description: "The name of the schema" },
...schemaDefinition.properties,
},
$defs: {
schema_definition: {
...schemaDefinition,
anyOf: [
{ required: ["type"] },
{ required: ["$ref"] },
{ required: ["anyOf"] },
],
},
},
},
};
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: {
description: {
type: "string",
},
enum: {
type: "array",
minItems: 1,
uniqueItems: true,
},
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
)
);