{ "@context": "https://schema.org", "@id": "https://aggr.aymericbeaumet.com/items/philschmid-de/2026-03-24-combine-built-in-tools-and-function-calling-in-the-gemini/#webpage", "@type": [ "WebPage", "ArchiveComponent" ], "articleBody": "Most useful agents need several tools at once. A DevOps agent that spots a CVE also needs to file a ticket for it. Until recently, you had orchestrate those handoffs yourself or only use custom tools without built-in tools.\n\n[Tool combination in the Gemini API](https://ai.google.dev/gemini-api/docs/interactions?ua=chat#combining_built-in_tools_and_function_calling) now lets you combine [built-in tools](https://ai.google.dev/gemini-api/docs/tools) with custom function declarations in a single request. Gemini decides which tools to call, in what order, and circulates context between them automatically.\n\nBelow are two examples of tool combination.\n\n## Example 1: Tool Combination with Function Calling\n\nCombine Google Search, URL Context, and a custom function in one request. The model searches the web, reads a page, and calls your function without you specifying the order.\n\nGet a [Gemini API key](https://aistudio.google.com/apikey) and install the SDK:\n\n```plaintext\npip install google-genai\n```\n\nDefine a custom function and pass it alongside built-in tools:\n\nPython\n\n```python\nfrom google import genai\n \nclient = genai.Client()\n \nfile_incident = {\n \"type\": \"function\",\n \"name\": \"file_incident\",\n \"description\": \"Files a security incident in the internal tracking system.\",\n \"parameters\": {\n \"type\": \"object\",\n \"properties\": {\n \"cve_id\": {\"type\": \"string\", \"description\": \"CVE identifier\"},\n \"severity\": {\"type\": \"string\", \"description\": \"Critical, High, Medium, or Low\"},\n \"summary\": {\"type\": \"string\", \"description\": \"Brief description of the vulnerability\"},\n },\n \"required\": [\"cve_id\", \"severity\", \"summary\"],\n },\n}\n \ninteraction = client.interactions.create(\n model=\"gemini-3-flash-preview\",\n input=\"Search for the latest critical CVE affecting react, read the full advisory page, and file an incident for it.\",\n tools=[\n {\"type\": \"google_search\"},\n {\"type\": \"url_context\"},\n {\"type\": \"function\", \"name\": \"file_incident\", \"parameters\": ...},\n ],\n)\n \nfor output in interaction.outputs:\n print(f\"{output.type}...\")\n if output.type == \"function_call\":\n print(f\"Function: {output.name}\")\n print(f\"Arguments: {output.arguments}\")\n \n# google_search_call...\n# google_search_result...\n# google_search_call...\n# google_search_result...\n# thought...\n# function_call...\n# Function: file_incident\n# Arguments: {'summary': 'Unauthenticated remote code execution (RCE) vulnerability in React Server Components (RSC) affecting React 19.0, 19.1.x, and 19.2.0. The vulnerability (React2Shell) stems from insecure deserialization in the RSC \"Flight\" protocol, allowing an attacker to execute arbitrary code via a crafted HTTP request. Patches are available in React versions 19.0.1, 19.1.2, and 19.2.1.', 'severity': 'Critical', 'cve_id': 'CVE-2025-55182'}\n```\n\n## Example 2: Cross-Turn Context Circulation\n\nContext circulation preserves built-in tool results across turns. Pass `previous_interaction_id` and follow-up questions can reason over earlier results without re-executing tools. The model can still make new tool calls if it needs fresh data or thinks it needs to.\n\nPython\n\n```python\nfrom google import genai\n \nclient = genai.Client()\n \n# Turn 1: URL Context reads Philipp's about page\nturn1 = client.interactions.create(\n model=\"gemini-3-flash-preview\",\n input=\"Who is Philipp Schmid? https://www.philschmid.de/philipp-schmid\",\n tools=[{\"type\": \"url_context\"}],\n)\nprint(turn1.outputs[-1].text)\n \n# Turn 2: Follow-up uses context from turn 1\nturn2 = client.interactions.create(\n model=\"gemini-3-flash-preview\",\n input=\"What is his twitter handle?\",\n tools=[{\"type\": \"url_context\"}],\n previous_interaction_id=turn1.id,\n)\nprint(turn2.outputs[-1].text)\n```\n\n* * *\n\nThanks for reading! If you have any questions or feedback, please let me know on [Twitter](https://twitter.com/_philschmid) or [LinkedIn](https://www.linkedin.com/in/philipp-schmid-a6a2bb196/).\n", "authors": [], "captured_at": "2026-09-27T19:29:15.293681927+00:00", "category": "programming", "content_html": "

Most useful agents need several tools at once. A DevOps agent that spots a CVE also needs to file a ticket for it. Until recently, you had orchestrate those handoffs yourself or only use custom tools without built-in tools.

\n

Tool combination in the Gemini API now lets you combine built-in tools with custom function declarations in a single request. Gemini decides which tools to call, in what order, and circulates context between them automatically.

\n

Below are two examples of tool combination.

\n

Example 1: Tool Combination with Function Calling

\n

Combine Google Search, URL Context, and a custom function in one request. The model searches the web, reads a page, and calls your function without you specifying the order.

\n

Get a Gemini API key and install the SDK:

\n
pip install google-genai\n
\n

Define a custom function and pass it alongside built-in tools:

\n

Python

\n
from google import genai\n \nclient = genai.Client()\n \nfile_incident = {\n    "type": "function",\n    "name": "file_incident",\n    "description": "Files a security incident in the internal tracking system.",\n    "parameters": {\n        "type": "object",\n        "properties": {\n            "cve_id": {"type": "string", "description": "CVE identifier"},\n            "severity": {"type": "string", "description": "Critical, High, Medium, or Low"},\n            "summary": {"type": "string", "description": "Brief description of the vulnerability"},\n        },\n        "required": ["cve_id", "severity", "summary"],\n    },\n}\n \ninteraction = client.interactions.create(\n    model="gemini-3-flash-preview",\n    input="Search for the latest critical CVE affecting react, read the full advisory page, and file an incident for it.",\n    tools=[\n        {"type": "google_search"},\n        {"type": "url_context"},\n        {"type": "function", "name": "file_incident", "parameters": ...},\n    ],\n)\n \nfor output in interaction.outputs:\n    print(f"{output.type}...")\n    if output.type == "function_call":\n        print(f"Function: {output.name}")\n        print(f"Arguments: {output.arguments}")\n \n# google_search_call...\n# google_search_result...\n# google_search_call...\n# google_search_result...\n# thought...\n# function_call...\n# Function: file_incident\n# Arguments: {'summary': 'Unauthenticated remote code execution (RCE) vulnerability in React Server Components (RSC) affecting React 19.0, 19.1.x, and 19.2.0. The vulnerability (React2Shell) stems from insecure deserialization in the RSC "Flight" protocol, allowing an attacker to execute arbitrary code via a crafted HTTP request. Patches are available in React versions 19.0.1, 19.1.2, and 19.2.1.', 'severity': 'Critical', 'cve_id': 'CVE-2025-55182'}\n
\n

Example 2: Cross-Turn Context Circulation

\n

Context circulation preserves built-in tool results across turns. Pass previous_interaction_id and follow-up questions can reason over earlier results without re-executing tools. The model can still make new tool calls if it needs fresh data or thinks it needs to.

\n

Python

\n
from google import genai\n \nclient = genai.Client()\n \n# Turn 1: URL Context reads Philipp's about page\nturn1 = client.interactions.create(\n    model="gemini-3-flash-preview",\n    input="Who is Philipp Schmid? https://www.philschmid.de/philipp-schmid",\n    tools=[{"type": "url_context"}],\n)\nprint(turn1.outputs[-1].text)\n \n# Turn 2: Follow-up uses context from turn 1\nturn2 = client.interactions.create(\n    model="gemini-3-flash-preview",\n    input="What is his twitter handle?",\n    tools=[{"type": "url_context"}],\n    previous_interaction_id=turn1.id,\n)\nprint(turn2.outputs[-1].text)\n
\n
\n

Thanks for reading! If you have any questions or feedback, please let me know on Twitter or LinkedIn.

\n", "content_markdown": "Most useful agents need several tools at once. A DevOps agent that spots a CVE also needs to file a ticket for it. Until recently, you had orchestrate those handoffs yourself or only use custom tools without built-in tools.\n\n[Tool combination in the Gemini API](https://ai.google.dev/gemini-api/docs/interactions?ua=chat#combining_built-in_tools_and_function_calling) now lets you combine [built-in tools](https://ai.google.dev/gemini-api/docs/tools) with custom function declarations in a single request. Gemini decides which tools to call, in what order, and circulates context between them automatically.\n\nBelow are two examples of tool combination.\n\n## Example 1: Tool Combination with Function Calling\n\nCombine Google Search, URL Context, and a custom function in one request. The model searches the web, reads a page, and calls your function without you specifying the order.\n\nGet a [Gemini API key](https://aistudio.google.com/apikey) and install the SDK:\n\n```plaintext\npip install google-genai\n```\n\nDefine a custom function and pass it alongside built-in tools:\n\nPython\n\n```python\nfrom google import genai\n \nclient = genai.Client()\n \nfile_incident = {\n \"type\": \"function\",\n \"name\": \"file_incident\",\n \"description\": \"Files a security incident in the internal tracking system.\",\n \"parameters\": {\n \"type\": \"object\",\n \"properties\": {\n \"cve_id\": {\"type\": \"string\", \"description\": \"CVE identifier\"},\n \"severity\": {\"type\": \"string\", \"description\": \"Critical, High, Medium, or Low\"},\n \"summary\": {\"type\": \"string\", \"description\": \"Brief description of the vulnerability\"},\n },\n \"required\": [\"cve_id\", \"severity\", \"summary\"],\n },\n}\n \ninteraction = client.interactions.create(\n model=\"gemini-3-flash-preview\",\n input=\"Search for the latest critical CVE affecting react, read the full advisory page, and file an incident for it.\",\n tools=[\n {\"type\": \"google_search\"},\n {\"type\": \"url_context\"},\n {\"type\": \"function\", \"name\": \"file_incident\", \"parameters\": ...},\n ],\n)\n \nfor output in interaction.outputs:\n print(f\"{output.type}...\")\n if output.type == \"function_call\":\n print(f\"Function: {output.name}\")\n print(f\"Arguments: {output.arguments}\")\n \n# google_search_call...\n# google_search_result...\n# google_search_call...\n# google_search_result...\n# thought...\n# function_call...\n# Function: file_incident\n# Arguments: {'summary': 'Unauthenticated remote code execution (RCE) vulnerability in React Server Components (RSC) affecting React 19.0, 19.1.x, and 19.2.0. The vulnerability (React2Shell) stems from insecure deserialization in the RSC \"Flight\" protocol, allowing an attacker to execute arbitrary code via a crafted HTTP request. Patches are available in React versions 19.0.1, 19.1.2, and 19.2.1.', 'severity': 'Critical', 'cve_id': 'CVE-2025-55182'}\n```\n\n## Example 2: Cross-Turn Context Circulation\n\nContext circulation preserves built-in tool results across turns. Pass `previous_interaction_id` and follow-up questions can reason over earlier results without re-executing tools. The model can still make new tool calls if it needs fresh data or thinks it needs to.\n\nPython\n\n```python\nfrom google import genai\n \nclient = genai.Client()\n \n# Turn 1: URL Context reads Philipp's about page\nturn1 = client.interactions.create(\n model=\"gemini-3-flash-preview\",\n input=\"Who is Philipp Schmid? https://www.philschmid.de/philipp-schmid\",\n tools=[{\"type\": \"url_context\"}],\n)\nprint(turn1.outputs[-1].text)\n \n# Turn 2: Follow-up uses context from turn 1\nturn2 = client.interactions.create(\n model=\"gemini-3-flash-preview\",\n input=\"What is his twitter handle?\",\n tools=[{\"type\": \"url_context\"}],\n previous_interaction_id=turn1.id,\n)\nprint(turn2.outputs[-1].text)\n```\n\n* * *\n\nThanks for reading! If you have any questions or feedback, please let me know on [Twitter](https://twitter.com/_philschmid) or [LinkedIn](https://www.linkedin.com/in/philipp-schmid-a6a2bb196/).\n", "dateCreated": "2026-09-27T19:29:15.293681927+00:00", "date_created": "2026-03-24T00:00:00+00:00", "date_modified": "2026-03-24T00:00:00+00:00", "date_published": "2026-03-24T00:00:00+00:00", "description": "Learn how to combine built-in tools and function calling in the Gemini Interactions API.", "external_url": "https://www.philschmid.de/tool-combo", "git": { "commit": "ebb0941c5c06a2ab2377342d607535262a3e969e", "path": "items/philschmid-de/2026/03/2026-03-24-combine-built-in-tools-and-function-calling-in-the-gemini.md", "permalink": "https://github.com/aymericbeaumet/aggr-instance/blob/ebb0941c5c06a2ab2377342d607535262a3e969e/items/philschmid-de/2026/03/2026-03-24-combine-built-in-tools-and-function-calling-in-the-gemini.md" }, "id": "urn:aggr:item:94c9d42f9c4758e504800d1b2c36c3a19eafd592", "isBasedOn": { "@id": "https://www.philschmid.de/tool-combo" }, "mainEntity": { "@id": "https://www.philschmid.de/tool-combo", "@type": "CreativeWork", "archivedAt": { "@id": "https://aggr.aymericbeaumet.com/items/philschmid-de/2026-03-24-combine-built-in-tools-and-function-calling-in-the-gemini/#webpage" }, "dateModified": "2026-03-24T00:00:00+00:00", "datePublished": "2026-03-24T00:00:00+00:00", "headline": "Combine Built-in Tools and Function Calling in the Gemini Interactions API", "timeRequired": "PT3M", "url": "https://www.philschmid.de/tool-combo", "wordCount": 458 }, "name": "Archived snapshot: Combine Built-in Tools and Function Calling in the Gemini Interactions API", "preview": null, "reading_minutes": 3, "replicated_at": null, "source": "philschmid-de", "source_name": "philschmid.de - RSS feed", "summary": "Learn how to combine built-in tools and function calling in the Gemini Interactions API.", "tags": [], "temporalCoverage": "2026-09-27T19:29:15.293681927+00:00", "title": "Combine Built-in Tools and Function Calling in the Gemini Interactions API", "url": "https://aggr.aymericbeaumet.com/items/philschmid-de/2026-03-24-combine-built-in-tools-and-function-calling-in-the-gemini/", "word_count": 458 }