## Description
> Should include a concise description of the changes (bug or feature),
it's
> impact, along with a summary of the solution
## PR Checklist
> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:
- [x] Make sure you reviewed
[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [ ] Make sure to open an issue as a
[bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
- [ ] Ensure the tests and linter pass
- [ ] Code coverage does not decrease (if any source code was changed)
- [ ] Appropriate docs were updated (if necessary)
- [ ] Make sure to add `!` if this involve a breaking change
🛠️ Fixes #<issue_number_goes_here>
## Description
This PR introduces support for merging multiple prebuilt configurations.
To ensure compatibility, the following restrictions apply:
- No Naming Collisions: Configurations cannot share duplicate names for
any resources (Tools, Sources, Toolsets, Auth Services, etc.).
- Shared Environment Variables: If multiple sources rely on the same
environment variable, they must share the same value; unique values for
the same variable are not supported
## Usage Examples
### Successful Initialization
You can load multiple prebuilt configurations by either repeating the
--prebuilt flag or by providing a comma-separated list.
**Option 1:** Multiple Flags
```
./toolbox --prebuilt alloydb-postgres --prebuilt alloydb-postgres-admin
```
**Option 2:** Comma-Separated Values
```
./toolbox --prebuilt alloydb-postgres,alloydb-postgres-admin
```
### Initialization Failure (Resource Conflict)
If two or more configurations define a resource with the same name (such
as a Tool or Source, etc.), the server will fail to start and display a
conflict error.
```
./toolbox --prebuilt alloydb-postgres --prebuilt cloud-sql-mysql
2026-01-13T11:14:50.758121799Z INFO "Using prebuilt tool configurations for: alloydb-postgres, cloud-sql-mysql"
2026-01-13T11:14:50.764578167Z ERROR "resource conflicts detected:\n - tool 'execute_sql' (file #2)\n - tool 'list_active_queries' (file #2)\n - tool 'get_query_plan' (file #2)\n - tool 'list_tables' (file #2)\n\nPlease ensure each source, authService, tool, toolset and prompt has a unique name across all files"
```
## PR Checklist
> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:
- [x] Make sure you reviewed
[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [x] Make sure to open an issue as a
[bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
- [x] Ensure the tests and linter pass
- [x] Code coverage does not decrease (if any source code was changed)
- [x] Appropriate docs were updated (if necessary)
- [x] Make sure to add `!` if this involve a breaking change
🛠️Fixes#1855
---------
Co-authored-by: Averi Kitsch <akitsch@google.com>
## Description
Add a new `--user-agent-metadata` flag that allows user to append
additional user agent metadata. The flag takes in []string and will
concatenate it with `.`.
```
go run . --user-agent-metadata=foo
```
produces `0.25.0+dev.darwin.arm64+foo` user agent string
```
go run . --user-agent-metadata=foo,bar
```
produces `0.25.0+dev.darwin.arm64+foo+bar` user agent string
## PR Checklist
> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:
- [x] Make sure you reviewed
[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [x] Make sure to open an issue as a
[bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
- [x] Ensure the tests and linter pass
- [x] Code coverage does not decrease (if any source code was changed)
- [x] Appropriate docs were updated (if necessary)
- [x] Make sure to add `!` if this involve a breaking change
🛠️ Fixes #<issue_number_goes_here>
## Description
Previously added `allowed-origins` (for CORs) is not sufficient for
preventing DNS rebinding attacks. We'll have to check host headers.
To test, run Toolbox with the following:
```
go run . --allowed-hosts=127.0.0.1:5000
```
Test with the following:
```
// curl successfully
curl -H "Host: 127.0.0.1:5000" http://127.0.0.1:5000
// will show Invalid Host Header error
curl -H "Host: attacker:5000" http://127.0.0.1:5000
```
## PR Checklist
> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:
- [ ] Make sure you reviewed
[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [ ] Make sure to open an issue as a
[bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
- [ ] Ensure the tests and linter pass
- [ ] Code coverage does not decrease (if any source code was changed)
- [ ] Appropriate docs were updated (if necessary)
- [ ] Make sure to add `!` if this involve a breaking change
🛠️ Fixes #<issue_number_goes_here>
## Description
This PR updates the CLI to allow the --prebuilt flag to be used
simultaneously with custom tool flags (--tools-file, --tools-files, or
--tools-folder). This enables users to extend a standard prebuilt
environment with their own custom tools and configurations.
### Key changes
- Sequential Loading: Load prebuilt configurations first, then
accumulate any specified custom configurations before merging.
- Smart Defaults: Updated logic to only default to tools.yaml if no
configuration flags are provided.
- Legacy Auth Compatibility: Implemented an additive merge strategy for
authentication. Legacy authSources from custom files are merged into the
modern authServices map used by prebuilt tools.
- Strict Validation: To prevent ambiguity, the server will throw an
explicit error if a legacy authSource name conflicts with an existing
authService name (e.g., from a prebuilt config).
## PR Checklist
> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:
- [x] Make sure you reviewed
[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [x] Make sure to open an issue as a
[bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
- [x] Ensure the tests and linter pass
- [x] Code coverage does not decrease (if any source code was changed)
- [x] Appropriate docs were updated (if necessary)
- [x] Make sure to add `!` if this involve a breaking change
🛠️ Fixes https://github.com/googleapis/genai-toolbox/issues/1220
---------
Co-authored-by: Yuan Teoh <45984206+Yuan325@users.noreply.github.com>
Support `allowed-origins` flag to allow secure deployment of Toolbox.
Current Toolbox is **insecure by default**, which allows all origin
(`*`). This PR also updated docs to notify user of the new
`allowed-origins` flag in the Cloud Run, kubernetes, and docker
deployment docs.
This PR was tested manually by mocking a browser access:
1. Created a HTML file with Javascript fetch named
`malicious-client.html`:
```
<!DOCTYPE html>
<html>
<head>
<title>Malicious CORS Test</title>
</head>
<body>
<h1>Attempting to access API at http://127.0.0.1:5000/mcp</h1>
<p>Check the **Chrome Developer Console** (F12 -> Console tab) for the result.</p>
<script>
fetch('http://127.0.0.1:5000/mcp', {
method: 'POST',
headers: {
'Content-Type': 'application/json',
// The browser automatically adds the 'Origin' header based on where this HTML is served from (http://localhost:8000)
},
body: JSON.stringify({
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
})
})
.then(response => {
console.log('Success (but check console for CORS enforcement details):', response);
return response.json();
})
.then(data => console.log('Data received (only if CORS passes):', data))
.catch(error => console.error('Fetch Error:', error));
</script>
</body>
</html>
```
2. Run `python3 -m http.server 8000`
3. Open `http://localhost:8000/malicious-client.html` in browser.
4. Tried without `--allowed-origins` flag -- success.
Tried with `--allowed-origins=http://localhost:8000` -- success.
Tried with `--allowed-origins=http://foo.com` -- unsuccessful.
---------
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: Averi Kitsch <akitsch@google.com>
## Description
---
Add reference documentation
## PR Checklist
---
> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:
- [ ] Make sure you reviewed
[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [ ] Make sure to open an issue as a
[bug/issue](https://github.com/googleapis/langchain-google-alloydb-pg-python/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
- [ ] Ensure the tests and linter pass
- [ ] Code coverage does not decrease (if any source code was changed)
- [ ] Appropriate docs were updated (if necessary)
- [ ] Make sure to add `!` if this involve a breaking change
🛠️ Fixes #<issue_number_goes_here>
---------
Co-authored-by: Yuan Teoh <45984206+Yuan325@users.noreply.github.com>
