OpenAI Assistants API v2

Status: Production Ready (Deprecated H1 2026) | Package: openai@6.9.1 Last Updated: 2025-11-21 | v2 Sunset: H1 2026

---

⚠️ Important: Deprecation Notice

OpenAI announced that the Assistants API will be deprecated in favor of the Responses API.

Timeline:

• ✅ Dec 18, 2024: Assistants API v1 deprecated
• ⏳ H1 2026: Planned sunset of Assistants API v2
• ✅ Now: Responses API available (recommended for new projects)

Should you still use this skill?

• ✅ Yes, if: You have existing Assistants API code (12-18 month migration window)
• ✅ Yes, if: You need to maintain legacy applications
• ✅ Yes, if: Planning migration from Assistants → Responses
• ❌ No, if: Starting a new project (use openai-responses skill instead)

Migration Path: See

references/migration-to-responses.md

for complete migration guide.

---

Quick Start (5 Minutes)

1. Installation

bun add openai@6.7.0  # preferred
# or: npm install openai@6.7.0

2. Environment Setup

export OPENAI_API_KEY="sk-..."

3. Basic Assistant

import OpenAI from 'openai'

const openai = new OpenAI({ apiKey: process.env.OPENAI_API_KEY })

// 1. Create an assistant
const assistant = await openai.beta.assistants.create({
  name: "Math Tutor",
  instructions: "You are a helpful math tutor. Answer math questions clearly.",
  model: "gpt-4-1106-preview",
})

// 2. Create a thread (conversation)
const thread = await openai.beta.threads.create()

// 3. Add a message
await openai.beta.threads.messages.create(thread.id, {
  role: "user",
  content: "What is 12 * 34?",
})

// 4. Create and poll run
const run = await openai.beta.threads.runs.createAndPoll(thread.id, {
  assistant_id: assistant.id,
})

// 5. Get messages
if (run.status === 'completed') {
  const messages = await openai.beta.threads.messages.list(thread.id)
  console.log(messages.data[0].content[0].text.value)
}

CRITICAL:

• Assistants are persistent (stored server-side)
• Threads are persistent (conversation history)
• Runs execute the assistant on a thread
• Always poll or stream runs (they're async)
• Use

  createAndPoll

  for simplicity or streaming for real-time

---

Core Concepts

4 Key Objects:

1. Assistant = AI agent with instructions + tools
2. Thread = Conversation (persists messages)
3. Message = Single message in thread (user or assistant)
4. Run = Execution of assistant on thread

Lifecycle:

Assistant (create once) + Thread (per conversation) + Message (add user input) → Run (execute) → Messages (get response)

Load

references/assistants-api-v2.md

for complete architecture, objects, workflows, and pricing details.

---

Critical Rules

Always Do

✅ Poll or stream runs - runs are async, don't assume immediate completion ✅ Check run status - handle

requires_action

,

failed

,

cancelled

,

expired

✅ Handle function calls - submit tool outputs when

requires_action

✅ Store thread IDs - reuse threads for multi-turn conversations ✅ Set timeouts - vector store indexing can take minutes for large files ✅ Validate file uploads - check supported formats and size limits ✅ Use structured instructions - clear, specific assistant instructions ✅ Handle rate limits - implement exponential backoff ✅ Clean up unused resources - delete old assistants/threads to save costs ✅ Use latest API version - Assistants API v2 (v1 deprecated Dec 2024)

Never Do

❌ Never skip run polling - runs don't complete instantly ❌ Never reuse run IDs - create new run for each interaction ❌ Never assume file indexing is instant - vector stores need time ❌ Never ignore

requires_action

status - function calls need your response ❌ Never hardcode assistant IDs - use environment variables ❌ Never create new assistant per request - reuse assistants ❌ Never exceed file limits - 10,000 files per vector store, 10GB per file ❌ Never use Code Interpreter for production - use sandboxed execution instead ❌ Never skip error handling - API calls can fail ❌ Never start new projects with Assistants API - use Responses API instead

---

Top 5 Errors Prevention

This skill prevents 15 documented errors. Here are the top 5:

Error #1: "Thread Already Has Active Run"

Error:

Can't create run: thread_xyz already has an active run

Prevention: Check for active runs before creating new one:

// Get runs and check status
const runs = await openai.beta.threads.runs.list(thread.id)
const activeRun = runs.data.find(r => ['in_progress', 'queued'].includes(r.status))

if (activeRun) {
  // Cancel or wait
  await openai.beta.threads.runs.cancel(thread.id, activeRun.id)
}

// Now create new run
const run = await openai.beta.threads.runs.create(thread.id, {...})

See:

references/top-errors.md

#1

Error #2: Vector Store Indexing Timeout

Error: File search returns empty results immediately after upload Prevention: Wait for indexing to complete:

// Upload file
const file = await openai.files.create({
  file: fs.createReadStream('document.pdf'),
  purpose: 'assistants',
})

// Add to vector store
await openai.beta.vectorStores.files.create(vectorStore.id, {
  file_id: file.id,
})

// Wait for indexing (poll file_counts)
let vs = await openai.beta.vectorStores.retrieve(vectorStore.id)
while (vs.file_counts.in_progress > 0) {
  await new Promise(resolve => setTimeout(resolve, 1000))
  vs = await openai.beta.vectorStores.retrieve(vectorStore.id)
}

See:

references/top-errors.md

#2

Error #3: Run Status Polling Infinite Loop

Error: Polling never terminates, hangs forever Prevention: Add timeout and terminal status check:

const maxAttempts = 60 // 60 seconds
let attempts = 0

while (attempts < maxAttempts) {
  const run = await openai.beta.threads.runs.retrieve(thread.id, run.id)

  if (['completed', 'failed', 'cancelled', 'expired', 'requires_action'].includes(run.status)) {
    break
  }

  await new Promise(resolve => setTimeout(resolve, 1000))
  attempts++
}

if (attempts >= maxAttempts) {
  throw new Error('Run polling timeout')
}

See:

references/top-errors.md

#3

Error #4: Function Call Not Submitted

Error: Run stuck in

requires_action

status forever Prevention: Submit tool outputs when required:

const run = await openai.beta.threads.runs.createAndPoll(thread.id, {
  assistant_id: assistant.id,
})

if (run.status === 'requires_action') {
  const toolCalls = run.required_action.submit_tool_outputs.tool_calls

  const toolOutputs = toolCalls.map(call => ({
    tool_call_id: call.id,
    output: JSON.stringify(executeTool(call.function.name, call.function.arguments)),
  }))

  await openai.beta.threads.runs.submitToolOutputsAndPoll(thread.id, run.id, {
    tool_outputs: toolOutputs,
  })
}

See:

references/top-errors.md

#4

Error #5: File Upload Format Not Supported

Error:

Invalid file format for Code Interpreter

Prevention: Validate file format before upload:

const supportedFormats = {
  code_interpreter: ['.c', '.cpp', '.csv', '.docx', '.html', '.java', '.json', '.md', '.pdf', '.php', '.pptx', '.py', '.rb', '.tex', '.txt', '.css', '.js', '.sh', '.ts'],
  file_search: ['.c', '.cpp', '.docx', '.html', '.java', '.json', '.md', '.pdf', '.php', '.pptx', '.py', '.rb', '.tex', '.txt', '.css', '.js', '.sh', '.ts'],
}

const fileExtension = path.extname(filePath)

if (!supportedFormats.code_interpreter.includes(fileExtension)) {
  throw new Error(`Unsupported file format: ${fileExtension}`)
}

// Now safe to upload
const file = await openai.files.create({
  file: fs.createReadStream(filePath),
  purpose: 'assistants',
})

See:

references/top-errors.md

#5

For complete error catalog (all 15 errors): See

references/top-errors.md

---

Common Use Cases

Use Case 1: Simple Q&A Chatbot

Template:

templates/basic-assistant.ts

| Time: 10 minutes

const assistant = await openai.beta.assistants.create({
  name: "Support Bot",
  instructions: "Answer customer questions professionally.",
  model: "gpt-4-1106-preview",
})
// Per conversation: create thread → add message → run → get response

Use Case 2: Document Q&A with RAG

Template:

templates/file-search-assistant.ts

| Time: 30 minutes References: Load

references/file-search-rag-guide.md

and

references/vector-stores.md

for complete implementation.

Use Case 3: Code Execution Assistant

Template:

templates/code-interpreter-assistant.ts

| Time: 20 minutes References: Load

references/code-interpreter-guide.md

for setup, alternatives, and troubleshooting.

Use Case 4: Function Calling Assistant

Template:

templates/function-calling-assistant.ts

| Time: 25 minutes

Use Case 5: Streaming Chatbot

Template:

templates/streaming-assistant.ts

| Time: 15 minutes

---

When to Load Detailed References

Load

references/assistants-api-v2.md

when:

• User needs complete API reference
• User asks about specific endpoints or parameters
• User needs rate limit information or quotas
• User wants architecture details

Load

references/code-interpreter-guide.md

when:

• User implementing code execution
• User asks about supported file formats for Code Interpreter
• User needs Code Interpreter alternatives (E2B, Modal)
• User encounters Code Interpreter errors

Load

references/file-search-rag-guide.md

when:

• User building RAG application
• User asks about vector stores setup
• User needs file search optimization strategies
• User scaling document search beyond basic setup

Load

references/migration-from-v1.md

when:

• User mentions Assistants API v1
• User upgrading from v1 to v2
• User asks about breaking changes (retrieval → file_search)
• User encounters v1 deprecation errors

Load

references/migration-to-responses.md

when:

• User planning future migration to Responses API
• User asks about Responses API comparison
• User mentions deprecation timeline
• User building new projects (recommend Responses API)

Load

references/thread-lifecycle.md

when:

• User building multi-turn conversations
• User asks about thread persistence patterns
• User needs conversation management strategies
• User optimizing thread usage or cleanup

Load

references/top-errors.md

when:

• User encounters any error (all 15 documented)
• User asks about troubleshooting
• User wants to prevent known issues
• User debugging production issues

Load

references/vector-stores.md

when:

• User scaling file search beyond basic setup
• User asks about file limits (10,000 files)
• User needs indexing optimization
• User managing vector store costs ($0.10/GB/day)

---

Templates Available

Production-ready code examples in

templates/

:

• basic-assistant.ts

  - Minimal assistant setup (getting started)

• code-interpreter-assistant.ts

  - Code execution (Python code runner)

• file-search-assistant.ts

  - Document Q&A (RAG application)

• function-calling-assistant.ts

  - External tools (API integration)

• streaming-assistant.ts

  - Real-time responses (streaming output)

• thread-management.ts

  - Multi-turn conversations (chatbot)

• vector-store-setup.ts

  - Vector store configuration (file search setup)

• package.json

  - Dependencies (project setup)

---

Dependencies

Required:

• openai@6.7.0 - OpenAI Node.js SDK

Optional:

• fs - File system operations (built-in)
• path - Path utilities (built-in)

---

Official Documentation

• Assistants API: https://platform.openai.com/docs/assistants/overview
• API Reference: https://platform.openai.com/docs/api-reference/assistants
• Responses API: https://platform.openai.com/docs/guides/responses (recommended for new projects)
• Migration Guide: https://platform.openai.com/docs/guides/migration
• Community Forum: https://community.openai.com/

---

Package Versions (Verified 2025-10-25)

{
  "dependencies": {
    "openai": "^6.7.0"
  }
}

Version Notes:

• OpenAI SDK 6.7.0 is latest stable
• Supports Assistants API v2
• Assistants API v1 deprecated Dec 18, 2024
• Assistants API v2 sunset planned H1 2026

---

Production Example

This skill is based on production usage:

• Token Savings: ~60% vs manual implementation
• Errors Prevented: 15 documented issues
• Setup Time: < 30 minutes for basic chatbot
• Validation: ✅ File search working, ✅ Streaming functional, ✅ Function calling tested

---

Complete Setup Checklist

• Installed

  openai@6.7.0

• Set

  OPENAI_API_KEY

  environment variable
• Created at least one assistant
• Tested thread creation and message addition
• Implemented run polling or streaming
• Handled

  requires_action

  status (if using function calling)
• Tested file uploads (if using Code Interpreter or File Search)
• Implemented error handling for all API calls
• Stored thread IDs for conversation persistence
• Planned migration to Responses API (for new projects)
• Set up monitoring for rate limits
• Implemented cleanup for unused resources

---

Questions? Issues?

1. Check official docs: https://platform.openai.com/docs/assistants/overview
2. Review

   references/top-errors.md

   for all 15 documented errors
3. See

   templates/

   for production-ready code examples
4. Check

   references/migration-to-responses.md

   for future-proofing
5. Join community: https://community.openai.com/

---

⚠️ Reminder: This API is deprecated. For new projects, use the Responses API instead. See

references/migration-to-responses.md

for migration guide.