I’m experiencing a frustrating issue with MCP (Model Context Protocol) server integration when using Deep Research models. The MCP tool calls consistently return None with these models, while working perfectly with other OpenAI models.
The Problem
When using o3-deep-research or o4-mini-deep-research models with MCP servers (both via Responses API and Agents SDK), the tool calls return None even though:
- The server receives and processes the requests correctly
- The same MCP server works perfectly with other models
- I can verify server-side that the tool calls are being invoked and processed
Working vs. Non-Working Models
Working Models (return actual data):
gpt-4o-minio3-mini- Also works with Anthropic’s Claude models
Not Working Models (return None):
o3-deep-researcho4-mini-deep-research
Code Examples
Responses API Setup:
from openai import AsyncOpenAI
client = AsyncOpenAI(timeout=60*60)
async def run_deep_research(model: str, input: str):
stream = await client.responses.create(
model=model,
tools=[
{
"type": "mcp",
"server_label": "web_search_server",
"server_url": f"{url}/mcp/",
"require_approval": "never",
"headers": {
"Authorization": f"Bearer {access_token}"
}
},
],
input=input,
stream=True
)
return await stream_response(stream)
Working Example (gpt-4o-mini):
response = await run_deep_research(model="gpt-4o-mini", input="Find latest stock market news")
Output (truncated):
MCP List Tools
==========================================================================================
MCP Tool Call
Name: search
Arguments: {"query":"latest news stock market"}
Output:
[{"id": "https://finance.yahoo.com/news/stock-market-today-stocks-jump-161248598.html", "title": "Stock Market Today: Stocks soar on bullish jobs report", "text": "## In This Article:\n\n_[Stock Market Today: Stocks soar on bullish jobs report](https://www.thestreet.com/investing/stock-market-today-more-jobs-than-expected) originally appeared on [TheStreet](https://www.thestreet.com)._\n\n**Updated: 1:45 p.m. EDT**\n\nStocks surged Thursday after the Labor Department reported a surprising gain in payroll employment in its monthly jobs report.\n\nPayrolls jumped by 147,000 in June, the report said, much higher than consensus economic estimate of 106,000. The unempl...", "url": "https://finance.yahoo.com/news/stock-market-today-stocks-jump-161248598.html"}, {"id": "https://www.usatoday.com/story/money/markets/2025/06/30/us-stocks-monday-tax-bill-tariff/84411064007/", "title": "US stocks end up on trade hope, tax bill voting. S&P 500, Nasdaq hit record high again", "text": "U.S. stocks ended strong, with the broad S&P 500 and tech-laden Nasdaq scoring fresh record highs and closing out their best three months in more than a year.\n\nInvestors were heartened on progress in trade negotiations, especially with Canada backing down from a digital services tax over the weekend. They also are watching Congress' attempt to pass the so-called \" [One Big Beautiful Bill\"](https://www.usatoday.com/story/news/politics/2025/06/29/live-senate-debates-trump-legislative-package/84401...", "url": "https://www.usatoday.com/story/money/markets/2025/06/30/us-stocks-monday-tax-bill-tariff/84411064007/"}, {"id": "https://finance.yahoo.com/news/stock-market-news-jul-3-084600925.html", "title": "Stock Market News for Jul 3, 2025", "text": "## In This Article:\n\nU.S. stock markets closed mixed on Wednesday for second consecutive day. Market participants appreciated the U.S.-Vietnam trade deal and expectations of a U.S.-India trade deal. On the other hand, a tepid private jobs data and uncertainty about President Trump\u2019s \u201cBig Beautiful Bill\u201d unnerved investors. The S&P 500 and the Nasdaq Composite ended at record-high level while the Dow finished in negative territory.\n\nThe Dow Jones Industrial Average (DJI) fell 10.25 points to clos...", "url": "https://finance.yahoo.com/news/stock-market-news-jul-3-084600925.html"}, {"id": "https://finance.yahoo.com/news/live/stock-market-today-dow-sp-500-nasdaq-climb-after-better-than-expected-jobs-report-123750403.html", "title": "S&P 500, Nasdaq clinch records for third time this week as optimism sweeps Wall Street", "text": "Updated Thu, July 3, 2025 at 7:35 AM PDT 2 min read In This Article: US stocks popped on Thursday as investors digested a stronger-than-expected June jobs report that dampened hopes for a Federal Reserve interest-rate cut coming soon. The S&P 500 ( ^GSPC) moved up about 0.7%, while the Nasdaq Composite ( ^IXIC) rose around 0.8%, after both indices closed at fresh record highs on Wednesday. The Dow Jones Industrial Average ( ^DJI) gained over 0.6%. The jobs report showed an increase of 147,00...", "url": "https://finance.yahoo.com/news/live/stock-market-today-dow-sp-500-nasdaq-climb-after-better-than-expected-jobs-report-123750403.html"}]
==========================================================================================
MCP Tool Call
Name: fetch
Arguments: {"id":"https://finance.yahoo.com/news/stock-market-today-stocks-jump-161248598.html"}
Output:
{"id": "https://finance.yahoo.com/news/stock-market-today-stocks-jump-161248598.html", "title": "Stock Market Today: Stocks soar on bullish jobs report", "text": "## In This Article:\n\n_[Stock Market Today: Stocks soar on bullish jobs report](https://www.thestreet.com/investing/stock-market-today-more-jobs-than-expected) originally appeared on [TheStreet](https://www.thestreet.com)._\n\n**Updated: 1:45 p.m. EDT**\n\nStocks surged Thursday after the Labor Department reported a surprising gain in payroll employment in its monthly jobs report.\n\nPayrolls jumped by 147,000 in June, the report said, much higher than consensus economic estimate of 106,000. The unemployment rate fell slightly to 4.1% in June from 4.2% in April and May.\n\nThe Standard & Poor's 500 Index, Nasdaq Composite and Nasdaq-100 indexes promptly reached 52-week highs after the open on what will be a shortened day of trading.\n\nAt the close, the S&P 500 was up 52 points, or 0.8%, to 6,279 after hitting a 52-week high at 6,284.65. All 11 sectors of the S&P 500 were higher, led by tech and financial stocks.\n\nAmong the leaders were chip-design companies Cadence Design\u00a0 ( **[CDNS](https://finance.yahoo.com/quote/CDNS)**) \u00a0and Synopsis\u00a0 ( **[SNPS](https://finance.yahoo.com/quote/SNPS)**) , up about 5% each. The Trump administration lifted export controls so they can sell their software to Chinese chip companies. The move is seen as a further sign of de-escalating U.S.-Sino trade tensions.\n\nThe Nasdaq was up 208 points, or 1%, to 20,596, with its 52-week high at 20,624.51, and the Nasdaq-100 Index added 225 points, or 1%, to 22,866. Its 52-week high is now 52,896.\n\nNot to be outdone, the Dow Jones Industrial Average jumped 344 points, or 0.8%, to 44,829. The blue-chip index is still 245 points under its 52-week high of 45,074, reached on Dec. 4, 2024.\n\nSome 262 stocks hit 52-week highs on Thursday, with just 11 hitting 52-week lows.\n\nMarkets closed at 1 p.m. ET today ahead of the July 4 holiday on Friday. U.S. markets will be closed on Friday.\n\nThe 10-year Treasury yield moved up to 4.349%, up from 4.284% on Wednesday. Mortgage rates were up slightly at 6.7%. (Home building stocks were lower as a result.)\n\nMeanwhile, crude oil moved moved lower. West Texas Intermediate, the benchmark U.S. crude was off 50 cents to $66.94 per 42-gallon barrel. Brent crude, the global benchmark, was off 38 cents to $68.72 per barrel.\n\nAAA said the average price of gasoline on Thursday was $3.162 per gallon. That's down $3.171 on Wednesday and $3.512 a year ago.\n\nOne effect of the big jobs report it looks like the Federal Reserve won't trim its key federal funds rate at its July 29-30 meeting. The CME Group's FedWatch tool sees a 95% chance the central bank holds its rate at 4.25% to 4.5% at the meeting at month's end.\n\nThat won't cheer President Trump, who daily rails against Fed Chairman Jerome Powell's reluctance to support a rate cut and even calls on him to resign. Bill Pulte, the head of the Federal Housing Finance Administration says Powell should be investigated, whatever that means.\n\n* * *", "url": "https://finance.yahoo.com/news/stock-market-today-stocks-jump-161248598.html", "metadata": {"published_date": "2025-07-03T09:12:00.000Z", "author": "Jason Meshnick, CMT Thu, Jul 3, 2025, 9:12 AM 5 min read", "image": "https://media.zenfs.com/en/thestreet_881/5896cf24ff48698a4e1ef4951e0ffad7", "timestamp": "2025-07-04T08:20:56.081935"}}
==========================================================================================
💬 Message Done
==========================================================================================
Here's a comprehensive report on the latest news related to the stock market, compiled from recent articles:
### 1. **Bullish Jobs Report Boosts Markets**
- **Source:** [Yahoo Finance](https://finance.yahoo.com/news/stock-market-today-stocks-jump-161248598.html)
- **Date:** July 3, 2025
- **Summary:** Stocks surged following a surprising gain in U.S. payroll employment, with 147,000 jobs added in June versus an expected 106,000. The unemployment rate fell to 4.1%, and all sectors of the S&P 500 closed higher, led by tech and financial stocks. Notably, chip-design firms like Cadence and Synopsys rose due to lifted export controls allowing them to sell software to Chinese companies.
- **Market Movement:** S&P 500 (+0.8%), Nasdaq (+1%), Dow Jones (+0.8%).
### 2. **Progress in Trade Negotiations Lifts Market Sentiment**
- **Source:** [USA Today](https://www.usatoday.com/story/money/markets/2025/06/30/us-stocks-monday-tax-bill-tariff/84411064007/)
- **Date:** June 30, 2025
- **Summary:** U.S. stocks finished strong as optimism over trade deals, particularly with Canada, buoyed investor sentiment. The S&P 500 and Nasdaq reached new record highs. Key developments included the rollback of Canada’s proposed digital services tax and ongoing discussions around a major tax bill in Congress.
- **Market Movement:** Dow (+0.63%), S&P 500 (+0.52%), Nasdaq (+0.48%).
### 3. **Mixed Market Performance Amid Trade Deal Announcements**
- **Source:** [Yahoo Finance](https://finance.yahoo.com/news/stock-market-news-jul-3-084600925.html)
- **Date:** July 3, 2025
- **Summary:** The stock markets closed mixed as the Dow fell while the S&P 500 and Nasdaq finished at record highs. Traders welcomed a trade deal with Vietnam but were cautious due to lackluster private job data and uncertainty surrounding President Trump’s tax bill. Nike's stock rose significantly after the Vietnam trade deal.
- **Market Movement:** Dow (-0.02%), S&P 500 (+0.5%), Nasdaq (+0.9%).
### 4. **Federal Reserve Rate Cut Expectations Wane**
- **Source:** [Yahoo Finance](https://finance.yahoo.com/news/live/stock-market-today-dow-sp-500-nasdaq-climb-after-better-than-expected-jobs-report-123750403.html)
- **Date:** July 3, 2025
- **Summary:** Following the robust jobs report, expectations for an interest rate cut by the Federal Reserve in July diminished. The market now suggests a mere 5% chance of a rate cut, which dampened some bullish sentiment.
- **Market Movement:** S&P 500 (+0.4%), Nasdaq (+0.6%), Dow (+0.3%).
### Key Market Insights
- **Sector Performance:** Tech and financial stocks were notable leaders, showing resilience amid trade uncertainties.
- **Trade Developments:** The ongoing negotiations with Canada and Vietnam are pivotal; positive outcomes are expected to further bolster market confidence.
- **Inflation Concerns:** Lower oil prices and stable gas prices ahead of the July 4 holiday have temporarily eased inflation concerns for consumers.
### Conclusion
The U.S. stock market continues to show volatility driven largely by economic indicators and trade negotiations. Recent positive data from the jobs report has buoyed investor sentiment, though caution remains as uncertainties surrounding federal policies and international trade persist.
### Sources:
1. [Yahoo Finance - Stocks soar on bullish jobs report](https://finance.yahoo.com/news/stock-market-today-stocks-jump-161248598.html)
2. [USA Today - US stocks end strong on trade hopes](https://www.usatoday.com/story/money/markets/2025/06/30/us-stocks-monday-tax-bill-tariff/84411064007/)
3. [Yahoo Finance - Stock Market News for Jul 3, 2025](https://finance.yahoo.com/news/stock-market-news-jul-3-084600925.html)
4. [Yahoo Finance - S&P 500, Nasdaq clinch records](https://finance.yahoo.com/news/live/stock-market-today-dow-sp-500-nasdaq-climb-after-better-than-expected-jobs-report-123750403.html)
This report highlights the latest movements and factors influencing the stock market as of early July 2025.
Not Working Example (o3-deep-research):
response = await run_deep_research(model="o3-deep-research", input="Find latest stock market news")
Output (truncated):
MCP List Tools
==========================================================================================
🧠 Reasoning Tool Done
NO SUMMARY AVAILABLE
==========================================================================================
MCP Tool Call
Name: search
Arguments: {"query":"July 2025 stock market latest news"}
Output: None
==========================================================================================
🧠 Reasoning Tool Done
NO SUMMARY AVAILABLE
==========================================================================================
MCP Tool Call
Name: search
Arguments: {"query":"latest stock market news 2025"}
Output: None
==========================================================================================
🧠 Reasoning Tool Done
NO SUMMARY AVAILABLE
==========================================================================================
MCP Tool Call
Name: search
Arguments: {"query":"\"stock market\" latest news July 2025 stock"}
Output: None
==========================================================================================
🧠 Reasoning Tool Done
NO SUMMARY AVAILABLE
==========================================================================================
MCP Tool Call
Name: search
Arguments: {"query":"latest stock market news 2025"}
Output: None
==========================================================================================
Agents SDK Example:
from agents import Agent, Runner, HostedMCPTool
agent = Agent(
name="Web search assistant",
model="o4-mini-deep-research",
instructions="You are a helpful assistant that can search the web for information.",
tools=[
HostedMCPTool(
tool_config={
"server_label": "web_search_server",
"server_url": f"{url}/mcp/",
"type": 'mcp',
"headers": {
"Authorization": f"Bearer {access_token}"
},
"require_approval": "never",
}
)
],
)
response = Runner.run_streamed(agent, "Find me the latest news about the stock market")
Same issue - returns None for all MCP tool calls.
What I’ve Verified
- Server-side logging: I can confirm that the MCP server receives and processes all requests from Deep Research models
- Server functionality: The same server works perfectly with other OpenAI models and Anthropic’s Claude
- Network connectivity: No issues with the hosted MCP server (running on Databricks)
Questions
- Is this a known issue with Deep Research models and MCP integration?
- Are there any specific configuration requirements for MCP servers when using Deep Research models?
- Is there a workaround or fix for this issue?
The fact that the server processes the requests correctly but the models receive None suggests this might be an issue with how Deep Research models handle MCP response parsing or integration.
Has anyone else experienced this issueforum.
