OpenAPITools · abhishekmsingh · Oct 5, 2025
diff --git a/bin/configs/python-langchain-tools-petstore-new.yaml b/bin/configs/python-langchain-tools-petstore-new.yaml
@@ -0,0 +1,6 @@
+generatorName: python-langchain-tools
+outputDir: samples/client/petstore/python/langchain/tools
+inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore.yaml
+templateDir: modules/openapi-generator/src/main/resources/python-langchain-tools
+additionalProperties:
+  hideGenerationTimestamp: "true"
diff --git a/docs/generators/python-langchain-tools.md b/docs/generators/python-langchain-tools.md
@@ -0,0 +1,247 @@
+---
+title: Documentation for the python-langchain-tools Generator
+---
+
+## METADATA
+
+| Property | Value | Notes |
+| -------- | ----- | ----- |
+| generator name | python-langchain-tools | pass this to the generate command after -g |
+| generator stability | STABLE | |
+| generator type | CLIENT | |
+| generator language | Python | |
+| generator language version | 3.9+ | |
+| generator default templating engine | mustache | |
+| helpTxt | Generates a Python client for LangChain agent tools, grouped by tags. | |
+
+## CONFIG OPTIONS
+These options may be applied as additional-properties (cli) or configOptions (plugins). Refer to [configuration docs](https://openapi-generator.tech/docs/configuration) for more details.
+
+| Option | Description | Values | Default |
+| ------ | ----------- | ------ | ------- |
+|dateFormat|date format for query parameters| |%Y-%m-%d|
+|datetimeFormat|datetime format for query parameters| |%Y-%m-%dT%H:%M:%S%z|
+|disallowAdditionalPropertiesIfNotPresent|If false, the 'additionalProperties' implementation (set to true by default) is compliant with the OAS and JSON schema specifications. If true (default), keep the old (incorrect) behaviour that 'additionalProperties' is set to false by default.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>Keep the old (incorrect) behaviour that 'additionalProperties' is set to false by default.</dd></dl>|true|
+|generateSourceCodeOnly|Specifies that only a library source code is to be generated.| |false|
+|hideGenerationTimestamp|Hides the generation timestamp when files are generated.| |true|
+|lazyImports|Enable lazy imports.| |false|
+|library|library template (sub-template) to use: asyncio, tornado (deprecated), urllib3, httpx| |urllib3|
+|mapNumberTo|Map number to Union[StrictFloat, StrictInt], StrictStr or float.| |Union[StrictFloat, StrictInt]|
+|packageName|python package name (convention: snake_case).| |openapi_client|
+|packageUrl|python package URL.| |null|
+|packageVersion|python package version.| |1.0.0|
+|poetry1|Fallback to formatting pyproject.toml to Poetry 1.x format.| |null|
+|projectName|python project name in setup.py (e.g. petstore-api).| |null|
+|recursionLimit|Set the recursion limit. If not set, use the system default value.| |null|
+|setEnsureAsciiToFalse|When set to true, add `ensure_ascii=False` in json.dumps when creating the HTTP request body.| |false|
+|useOneOfDiscriminatorLookup|Use the discriminator's mapping in oneOf to speed up the model lookup. IMPORTANT: Validation (e.g. one and only one match in oneOf's schemas) will be skipped.| |false|
+
+## IMPORT MAPPING
+
+| Type/Alias | Imports |
+| ---------- | ------- |
+
+
+## INSTANTIATION TYPES
+
+| Type/Alias | Instantiated By |
+| ---------- | --------------- |
+
+
+## LANGUAGE PRIMITIVES
+
+<ul class="column-ul">
+<li>Dict</li>
+<li>List</li>
+<li>bool</li>
+<li>bytearray</li>
+<li>bytes</li>
+<li>date</li>
+<li>datetime</li>
+<li>decimal.Decimal</li>
+<li>dict</li>
+<li>float</li>
+<li>int</li>
+<li>list</li>
+<li>none_type</li>
+<li>object</li>
+<li>str</li>
+</ul>
+
+## RESERVED WORDS
+
+<ul class="column-ul">
+<li>all_params</li>
+<li>and</li>
+<li>as</li>
+<li>assert</li>
+<li>async</li>
+<li>auth_settings</li>
+<li>await</li>
+<li>base64</li>
+<li>body_params</li>
+<li>break</li>
+<li>class</li>
+<li>continue</li>
+<li>date</li>
+<li>def</li>
+<li>del</li>
+<li>elif</li>
+<li>else</li>
+<li>except</li>
+<li>exec</li>
+<li>false</li>
+<li>field</li>
+<li>finally</li>
+<li>float</li>
+<li>for</li>
+<li>form_params</li>
+<li>from</li>
+<li>global</li>
+<li>header_params</li>
+<li>if</li>
+<li>import</li>
+<li>in</li>
+<li>is</li>
+<li>json</li>
+<li>lambda</li>
+<li>local_var_files</li>
+<li>none</li>
+<li>nonlocal</li>
+<li>not</li>
+<li>or</li>
+<li>pass</li>
+<li>path_params</li>
+<li>print</li>
+<li>property</li>
+<li>query_params</li>
+<li>raise</li>
+<li>resource_path</li>
+<li>return</li>
+<li>schema</li>
+<li>self</li>
+<li>true</li>
+<li>try</li>
+<li>while</li>
+<li>with</li>
+<li>yield</li>
+</ul>
+
+## FEATURE SET
+
+
+### Client Modification Feature
+| Name | Supported | Defined By |
+| ---- | --------- | ---------- |
+|BasePath|✗|ToolingExtension
+|Authorizations|✗|ToolingExtension
+|UserAgent|✗|ToolingExtension
+|MockServer|✗|ToolingExtension
+
+### Data Type Feature
+| Name | Supported | Defined By |
+| ---- | --------- | ---------- |
+|Custom|✗|OAS2,OAS3
+|Int32|✓|OAS2,OAS3
+|Int64|✓|OAS2,OAS3
+|Float|✓|OAS2,OAS3
+|Double|✓|OAS2,OAS3
+|Decimal|✓|ToolingExtension
+|String|✓|OAS2,OAS3
+|Byte|✓|OAS2,OAS3
+|Binary|✓|OAS2,OAS3
+|Boolean|✓|OAS2,OAS3
+|Date|✓|OAS2,OAS3
+|DateTime|✓|OAS2,OAS3
+|Password|✓|OAS2,OAS3
+|File|✓|OAS2
+|Uuid|✗|
+|Array|✓|OAS2,OAS3
+|Null|✗|OAS3
+|AnyType|✗|OAS2,OAS3
+|Object|✓|OAS2,OAS3
+|Maps|✓|ToolingExtension
+|CollectionFormat|✓|OAS2
+|CollectionFormatMulti|✓|OAS2
+|Enum|✓|OAS2,OAS3
+|ArrayOfEnum|✓|ToolingExtension
+|ArrayOfModel|✓|ToolingExtension
+|ArrayOfCollectionOfPrimitives|✓|ToolingExtension
+|ArrayOfCollectionOfModel|✓|ToolingExtension
+|ArrayOfCollectionOfEnum|✓|ToolingExtension
+|MapOfEnum|✓|ToolingExtension
+|MapOfModel|✓|ToolingExtension
+|MapOfCollectionOfPrimitives|✓|ToolingExtension
+|MapOfCollectionOfModel|✓|ToolingExtension
+|MapOfCollectionOfEnum|✓|ToolingExtension
+
+### Documentation Feature
+| Name | Supported | Defined By |
+| ---- | --------- | ---------- |
+|Readme|✓|ToolingExtension
+|Model|✓|ToolingExtension
+|Api|✓|ToolingExtension
+
+### Global Feature
+| Name | Supported | Defined By |
+| ---- | --------- | ---------- |
+|Host|✓|OAS2,OAS3
+|BasePath|✓|OAS2,OAS3
+|Info|✓|OAS2,OAS3
+|Schemes|✗|OAS2,OAS3
+|PartialSchemes|✓|OAS2,OAS3
+|Consumes|✓|OAS2
+|Produces|✓|OAS2
+|ExternalDocumentation|✓|OAS2,OAS3
+|Examples|✓|OAS2,OAS3
+|XMLStructureDefinitions|✗|OAS2,OAS3
+|MultiServer|✗|OAS3
+|ParameterizedServer|✗|OAS3
+|ParameterStyling|✗|OAS3
+|Callbacks|✗|OAS3
+|LinkObjects|✗|OAS3
+
+### Parameter Feature
+| Name | Supported | Defined By |
+| ---- | --------- | ---------- |
+|Path|✓|OAS2,OAS3
+|Query|✓|OAS2,OAS3
+|Header|✓|OAS2,OAS3
+|Body|✓|OAS2
+|FormUnencoded|✓|OAS2
+|FormMultipart|✓|OAS2
+|Cookie|✗|OAS3
+
+### Schema Support Feature
+| Name | Supported | Defined By |
+| ---- | --------- | ---------- |
+|Simple|✓|OAS2,OAS3
+|Composite|✓|OAS2,OAS3
+|Polymorphism|✓|OAS2,OAS3
+|Union|✗|OAS3
+|allOf|✓|OAS2,OAS3
+|anyOf|✓|OAS3
+|oneOf|✓|OAS3
+|not|✗|OAS3
+
+### Security Feature
+| Name | Supported | Defined By |
+| ---- | --------- | ---------- |
+|BasicAuth|✓|OAS2,OAS3
+|ApiKey|✓|OAS2,OAS3
+|OpenIDConnect|✗|OAS3
+|BearerToken|✓|OAS3
+|OAuth2_Implicit|✓|OAS2,OAS3
+|OAuth2_Password|✗|OAS2,OAS3
+|OAuth2_ClientCredentials|✗|OAS2,OAS3
+|OAuth2_AuthorizationCode|✗|OAS2,OAS3
+|SignatureAuth|✓|OAS3
+|AWSV4Signature|✗|ToolingExtension
+
+### Wire Format Feature
+| Name | Supported | Defined By |
+| ---- | --------- | ---------- |
+|JSON|✓|OAS2,OAS3
+|XML|✓|OAS2,OAS3
+|PROTOBUF|✗|ToolingExtension
+|Custom|✓|OAS2,OAS3
diff --git a/...r/src/main/java/org/openapitools/codegen/languages/PythonLangchainToolsClientCodegen.java b/...r/src/main/java/org/openapitools/codegen/languages/PythonLangchainToolsClientCodegen.java
@@ -0,0 +1,94 @@
+package org.openapitools.codegen.languages;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.StandardOpenOption;
+
+import org.openapitools.codegen.SupportingFile;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class PythonLangchainToolsClientCodegen extends PythonClientCodegen {
+    public static final String PROJECT_NAME = "projectName";
+
+    private final Logger LOGGER = LoggerFactory.getLogger(PythonLangchainToolsClientCodegen.class);
+
+    public PythonLangchainToolsClientCodegen() {
+        super();
+        apiTemplateFiles.put("api_tools.mustache", "_tools.py");
+        supportingFiles.add(new SupportingFile("all_tools.mustache", "", "all_tools.py"));
+    }
+
+    @Override
+    public String getName() {
+        return "python-langchain-tools";
+    }
+
+    @Override
+    public String getHelp() {
+        return "Generates a Python client for LangChain agent tools, grouped by tags.";
+    }
+
+    @Override
+    public String apiFileFolder() {
+        return outputFolder + File.separator + apiPackage().replace('.', File.separatorChar);
+    }
+
+    @Override
+    public String modelFileFolder() {
+        return outputFolder + File.separator + modelPackage().replace('.', File.separatorChar);
+    }
+
+    @Override
+    public void processOpts() {
+        super.processOpts();
+
+        // Now that packageName is processed and available, we can add the supporting file
+        // for the tools package __init__.py in the correct directory.
+        final String toolsPackagePath = packageName.replace(".", File.separator) + File.separator + "tools";
+        supportingFiles.add(new SupportingFile("init.mustache", toolsPackagePath, "__init__.py"));
+    }
+
+    @Override
+    public boolean isEnablePostProcessFile() {
+        return true;
+    }
+
+    /**
+     * This is a way to add a dependency without duplicating the parent template.
+     */
+    @Override
+    public void postProcessFile(File file, String fileType) {
+        super.postProcessFile(file, fileType);
+        if (file == null) {
+            return;
+        }
+        final String filename = file.getName();
+        if ("requirements.txt".equals(filename)) {
+            try {
+                String langchainDep = "\nlangchain >=0.3, <0.4\n";
+                Files.write(file.toPath(), langchainDep.getBytes(StandardCharsets.UTF_8), StandardOpenOption.APPEND);
+            } catch (IOException e) {
+                throw new RuntimeException("Unable to write to requirements.txt", e);
+            }
+        }
+    }
+
+    /**
+     * Overriding this method to change the output location of our tool files.
+     */
+    @Override
+    public String apiFilename(String templateName, String tag) {
+        final String originalFilename = super.apiFilename(templateName, tag);
+
+        if ("api_tools.mustache".equals(templateName)) {
+            return originalFilename.replace(apiPackage().replace(".", File.separator),
+                packageName.replace(".", File.separator) + File.separator + "tools");
+        }
+
+        return originalFilename;
+    }
+
+}
diff --git a/...api-generator/src/main/resources/META-INF/services/org.openapitools.codegen.CodegenConfig b/...api-generator/src/main/resources/META-INF/services/org.openapitools.codegen.CodegenConfig
@@ -118,6 +118,7 @@ org.openapitools.codegen.languages.PythonFastAPIServerCodegen
 org.openapitools.codegen.languages.PythonFlaskConnexionServerCodegen
 org.openapitools.codegen.languages.PythonAiohttpConnexionServerCodegen
 org.openapitools.codegen.languages.PythonBluePlanetServerCodegen
+org.openapitools.codegen.languages.PythonLangchainToolsClientCodegen
 org.openapitools.codegen.languages.RClientCodegen
 org.openapitools.codegen.languages.RubyClientCodegen
 org.openapitools.codegen.languages.RubyOnRailsServerCodegen

diff --git a/modules/openapi-generator/src/main/resources/python-langchain-tools/README.mustache b/modules/openapi-generator/src/main/resources/python-langchain-tools/README.mustache
diff --git a/modules/openapi-generator/src/main/resources/python-langchain-tools/all_tools.mustache b/modules/openapi-generator/src/main/resources/python-langchain-tools/all_tools.mustache
@@ -0,0 +1,40 @@
+# -*- coding: utf-8 -*-
+"""
+An aggregator for all generated LangChain tools.
+
+This file provides a single list, `all_tools`, that you can import and
+provide to your LangChain agent.
+"""
+from typing import List
+from langchain.tools import StructuredTool
+
+from {{packageName}}.api_client import ApiClient
+from {{packageName}}.configuration import Configuration
+
+# Import the factory functions from each tool module
+{{#apiInfo}}
+{{#apis}}
+from {{packageName}}.tools.{{classFilename}}_tools import get_{{classVarName}}_tools
+{{/apis}}
+{{/apiInfo}}
+
+def get_all_tools() -> List[StructuredTool]:
+    """
+    Initializes the API client and aggregates tools from all API modules.
+    """
+    # TODO: You may need to customize this based on your API's authentication needs.
+    configuration = Configuration(host="{{{serverUrl}}}")
+
+    all_tools_list = []
+
+    with ApiClient(configuration) as api_client:
+        {{#apiInfo}}
+        {{#apis}}
+            all_tools_list.extend(get_{{classVarName}}_tools(api_client))
+        {{/apis}}
+        {{/apiInfo}}
+
+    return all_tools_list
+
+# A pre-initialized list of all tools for convenience.
+all_tools = get_all_tools()