diff --git a/.github/workflows/check_code_formatting.yml b/.github/workflows/check_code_formatting.yml
index 60f46606b..e5303906d 100644
--- a/.github/workflows/check_code_formatting.yml
+++ b/.github/workflows/check_code_formatting.yml
@@ -21,5 +21,8 @@ jobs:
       - name: Install dependencies
         run: npm install
 
+      - name: Test request parameter mappings
+        run: npm run test:parameters
+
       - name: Check formatting
         run: npm run format:check
diff --git a/package.json b/package.json
index 30ba6551b..1492a9e40 100644
--- a/package.json
+++ b/package.json
@@ -35,6 +35,7 @@
     "format": "prettier --write \"./**/*.{js,jsx,ts,tsx,json}\"",
     "format:check": "prettier --check \"./**/*.{js,jsx,ts,tsx,json}\"",
     "test:gateway": "jest src/",
+    "test:parameters": "tsx --test tests/unit/src/services/transformToProviderRequest.node.ts",
     "test:plugins": "jest plugins/",
     "pre-push": "npm run build && node start-test.js",
     "prepare": "node -e \"if (process.env.NODE_ENV !== 'production'){process.exit(1)} \" || husky",
diff --git a/src/providers/azure-openai/chatComplete.ts b/src/providers/azure-openai/chatComplete.ts
index 4a89911d1..a07a208c2 100644
--- a/src/providers/azure-openai/chatComplete.ts
+++ b/src/providers/azure-openai/chatComplete.ts
@@ -79,6 +79,9 @@ export const AzureOpenAIChatCompleteConfig: ProviderConfig = {
   tool_choice: {
     param: 'tool_choice',
   },
+  parallel_tool_calls: {
+    param: 'parallel_tool_calls',
+  },
   response_format: {
     param: 'response_format',
   },
diff --git a/src/providers/bedrock/chatComplete.ts b/src/providers/bedrock/chatComplete.ts
index 2a132a1fd..d570d901d 100644
--- a/src/providers/bedrock/chatComplete.ts
+++ b/src/providers/bedrock/chatComplete.ts
@@ -71,6 +71,9 @@ export interface BedrockConverseAnthropicChatCompletionsParams
     type: string;
     budget_tokens: number;
   };
+  output_config?: {
+    effort?: string;
+  };
   anthropic_beta?: string | string[];
 }
 
@@ -717,6 +720,26 @@ export const BedrockChatCompleteStreamChunkTransform: (
 
 export const BedrockConverseAnthropicChatCompleteConfig: ProviderConfig = {
   ...BedrockConverseChatCompleteConfig,
+  response_format: {
+    param: 'outputConfig',
+    transform: (params: BedrockConverseAnthropicChatCompletionsParams) => {
+      if (params.response_format?.type !== 'json_schema') return;
+      const { name, description, schema } =
+        params.response_format.json_schema || {};
+      return {
+        textFormat: {
+          type: 'json_schema',
+          structure: {
+            jsonSchema: {
+              name,
+              description,
+              schema: JSON.stringify(schema),
+            },
+          },
+        },
+      };
+    },
+  },
   additionalModelRequestFields: {
     param: 'additionalModelRequestFields',
     transform: (
@@ -765,6 +788,14 @@ export const BedrockConverseAnthropicChatCompleteConfig: ProviderConfig = {
     ) =>
       transformAnthropicAdditionalModelRequestFields(params, providerOptions),
   },
+  output_config: {
+    param: 'additionalModelRequestFields',
+    transform: (
+      params: BedrockConverseAnthropicChatCompletionsParams,
+      providerOptions?: Options
+    ) =>
+      transformAnthropicAdditionalModelRequestFields(params, providerOptions),
+  },
   anthropic_beta: {
     param: 'additionalModelRequestFields',
     transform: (
diff --git a/src/providers/bedrock/utils.ts b/src/providers/bedrock/utils.ts
index 40b72983d..e5fb19e5c 100644
--- a/src/providers/bedrock/utils.ts
+++ b/src/providers/bedrock/utils.ts
@@ -133,6 +133,12 @@ export const transformAnthropicAdditionalModelRequestFields = (
   if (params['thinking']) {
     additionalModelRequestFields['thinking'] = params['thinking'];
   }
+  if (params.output_config?.effort !== undefined) {
+    additionalModelRequestFields['output_config'] = {
+      ...additionalModelRequestFields['output_config'],
+      effort: params.output_config.effort,
+    };
+  }
   const anthropicBeta =
     providerOptions?.anthropicBeta || params['anthropic_beta'];
   if (anthropicBeta) {
diff --git a/src/providers/openai/chatComplete.ts b/src/providers/openai/chatComplete.ts
index 1186061af..b7dcd6a00 100644
--- a/src/providers/openai/chatComplete.ts
+++ b/src/providers/openai/chatComplete.ts
@@ -42,6 +42,9 @@ export const OpenAIChatCompleteConfig: ProviderConfig = {
     min: 0,
     max: 1,
   },
+  top_k: {
+    param: 'top_k',
+  },
   n: {
     param: 'n',
     default: 1,
diff --git a/tests/unit/src/services/transformToProviderRequest.node.ts b/tests/unit/src/services/transformToProviderRequest.node.ts
new file mode 100644
index 000000000..b768fdd31
--- /dev/null
+++ b/tests/unit/src/services/transformToProviderRequest.node.ts
@@ -0,0 +1,155 @@
+import assert from 'node:assert/strict';
+import { describe, it } from 'node:test';
+import { AZURE_OPEN_AI, BEDROCK, OPEN_AI } from '../../../../src/globals';
+import { BedrockConverseAnthropicChatCompletionsParams } from '../../../../src/providers/bedrock/chatComplete';
+import { Params } from '../../../../src/types/requestBody';
+import { transformToProviderRequest } from '../../../../src/services/transformToProviderRequest';
+
+const chatRequest = (provider: string, params: Params) =>
+  JSON.parse(
+    JSON.stringify(
+      transformToProviderRequest(
+        provider,
+        params,
+        params,
+        'chatComplete',
+        {},
+        {
+          provider,
+        }
+      )
+    )
+  );
+
+describe('explicit chat parameters', () => {
+  for (const top_k of [0, 40]) {
+    it(`forwards OpenAI-compatible top_k=${top_k} unchanged`, () => {
+      assert.equal(
+        chatRequest(OPEN_AI, { model: 'example', top_k }).top_k,
+        top_k
+      );
+    });
+  }
+
+  for (const value of [true, false]) {
+    it(`forwards Azure parallel_tool_calls=${value}`, () => {
+      const params = { model: 'example', parallel_tool_calls: value };
+      assert.equal(
+        chatRequest(AZURE_OPEN_AI, params).parallel_tool_calls,
+        value
+      );
+    });
+  }
+
+  for (const provider of [OPEN_AI, AZURE_OPEN_AI]) {
+    it(`does not inject optional ${provider} parameters`, () => {
+      const request = chatRequest(provider, { model: 'example' });
+      assert.equal('top_k' in request, false);
+      assert.equal('parallel_tool_calls' in request, false);
+    });
+  }
+
+  it('still filters unrelated parameters', () => {
+    const params = { model: 'example', unknown_parameter: true };
+    assert.equal('unknown_parameter' in chatRequest(OPEN_AI, params), false);
+  });
+});
+
+describe('Claude Converse parameters', () => {
+  const model = 'us.anthropic.claude-sonnet-4-6';
+  const json_schema = {
+    name: 'answer',
+    description: 'A short answer',
+    strict: true,
+    schema: {
+      type: 'object',
+      properties: { answer: { type: 'string' } },
+      required: ['answer'],
+      additionalProperties: false,
+    },
+  };
+
+  it('maps JSON schema to the Converse output format, not native response_format', () => {
+    const params: Params = {
+      model,
+      response_format: { type: 'json_schema', json_schema },
+    };
+    const request = chatRequest(BEDROCK, params);
+    assert.deepEqual(request.outputConfig, {
+      textFormat: {
+        type: 'json_schema',
+        structure: {
+          jsonSchema: {
+            name: json_schema.name,
+            description: json_schema.description,
+            schema: JSON.stringify(json_schema.schema),
+          },
+        },
+      },
+    });
+    assert.equal('response_format' in request, false);
+    assert.equal('additionalModelRequestFields' in request, false);
+  });
+
+  for (const type of ['json_object', 'text'] as const) {
+    it(`does not invent a schema for ${type}`, () => {
+      const request = chatRequest(BEDROCK, {
+        model,
+        response_format: { type },
+      });
+      assert.equal('outputConfig' in request, false);
+      assert.equal('response_format' in request, false);
+    });
+  }
+
+  it('preserves effort, thinking and existing native fields alongside structured output', () => {
+    const params = {
+      model,
+      thinking: { type: 'enabled', budget_tokens: 1024 },
+      output_config: { effort: 'low' },
+      additionalModelRequestFields: { metadata: { user_id: 'example' } },
+      response_format: { type: 'json_schema', json_schema },
+    } satisfies BedrockConverseAnthropicChatCompletionsParams;
+    const request = chatRequest(BEDROCK, params);
+    assert.deepEqual(request.additionalModelRequestFields, {
+      metadata: { user_id: 'example' },
+      thinking: params.thinking,
+      output_config: { effort: 'low' },
+    });
+    assert.equal(
+      request.outputConfig.textFormat.structure.jsonSchema.schema,
+      JSON.stringify(json_schema.schema)
+    );
+  });
+
+  it('forwards effort when it is the only native option', () => {
+    const params = {
+      model,
+      output_config: { effort: 'high' },
+    } satisfies BedrockConverseAnthropicChatCompletionsParams;
+    assert.deepEqual(
+      chatRequest(BEDROCK, params).additionalModelRequestFields,
+      {
+        output_config: { effort: 'high' },
+      }
+    );
+  });
+
+  it('does not inject effort or a schema when omitted', () => {
+    const request = chatRequest(BEDROCK, { model, max_tokens: 64 });
+    assert.equal('outputConfig' in request, false);
+    assert.equal('additionalModelRequestFields' in request, false);
+    assert.deepEqual(request.inferenceConfig, { maxTokens: 64 });
+  });
+
+  it('does not apply Anthropic output settings to other Bedrock models', () => {
+    const params = {
+      model: 'amazon.nova-2-lite-v1:0',
+      output_config: { effort: 'low' },
+      response_format: { type: 'json_schema', json_schema },
+    } satisfies BedrockConverseAnthropicChatCompletionsParams;
+    const request = chatRequest(BEDROCK, params);
+    assert.equal('outputConfig' in request, false);
+    assert.equal('additionalModelRequestFields' in request, false);
+  });
+});