--- title: Custom Auth Parameters description: Inject custom credentials in headers or parameters keywords: [inject headers, custom credentials, BYOT, bring your own token, OAuth token, access token] llmGuardrails: "direct-execution" --- If you're building an agent, we recommend using [sessions](/docs/configuring-sessions) instead. Sessions handle authentication automatically via [in-chat authentication](/docs/authenticating-users/in-chat-authentication) or [manual authentication](/docs/authenticating-users/manually-authenticating). If you already manage OAuth tokens or API keys yourself and want Composio to execute tools using your credentials, you can pass them directly at execution time — no connected account or redirect flow required. ## Passing credentials directly Pass `customAuthParams` in the `tools.execute()` call to inject your own token as a header or query parameter. ```python from composio import Composio composio = Composio() result = composio.tools.execute( slug="GOOGLECALENDAR_LIST_EVENTS", user_id="user_123", arguments={}, custom_auth_params={ "parameters": [ { "name": "Authorization", "value": "Bearer YOUR_ACCESS_TOKEN", "in": "header", } ], }, ) print(result) ``` ```typescript import { Composio } from "@composio/core"; const composio = new Composio({ apiKey: process.env.COMPOSIO_API_KEY, }); const result = await composio.tools.execute( "GOOGLECALENDAR_LIST_EVENTS", { userId: "user_123", arguments: {}, customAuthParams: { parameters: [ { in: "header", name: "Authorization", value: `Bearer ${process.env.GOOGLE_ACCESS_TOKEN}`, }, ], }, } ); console.log(JSON.stringify(result, null, 2)); ``` This bypasses Composio's automatic token refresh. You are responsible for refreshing expired tokens yourself. ### Parameter options Each entry in the `parameters` array accepts: | Field | Description | |-------|-------------| | `name` | The parameter name (e.g., `Authorization`, `X-API-Key`) | | `value` | The credential value | | `in` | Where to inject — `"header"` or `"query"` | You can also set `base_url` (Python) / `baseURL` (TypeScript) to override the default API base URL for the toolkit. ## Using a beforeExecute modifier For more control — such as conditionally injecting credentials based on toolkit or tool — use a `beforeExecute` modifier. Before Execute Modifiers are a way to modify the parameters of a tool before it is executed. In this case, they are useful for adding custom authentication headers or parameters to a tool. ```python from composio import Composio, before_execute from composio.types import ToolExecuteParams composio = Composio() @before_execute(toolkits=["NOTION"]) def add_custom_auth( tool: str, toolkit: str, params: ToolExecuteParams, ) -> ToolExecuteParams: if params["custom_auth_params"] is None: params["custom_auth_params"] = {"parameters": []} params["custom_auth_params"]["parameters"].append( { "name": "x-api-key", "value": os.getenv("NOTION_API_KEY"), "in": "header", } ) return params result = composio.tools.execute( slug="NOTION_GET_DATABASE_ITEMS", user_id="user_123", arguments={}, modifiers=[ add_custom_auth, ], ) print(result) ``` ```typescript import { Composio } from '@composio/core'; const composio = new Composio({ apiKey: 'your_api_key' }); // ---cut--- const authModifier = ({ toolSlug, toolkitSlug, params }: { toolSlug: string; toolkitSlug: string; params: any }) => { if (toolkitSlug === "NOTION") { if (!params.customAuthParams) { params.customAuthParams = { parameters: [] }; } params.customAuthParams.parameters.push({ in: "header", name: "X-API-Key", value: process.env.CUSTOM_API_KEY, }); } return params; }; const result = await composio.tools.execute( "NOTION_GET_DATABASE_ITEMS", { userId: "user_123", arguments: { database_id: "1234567890", }, }, { beforeExecute: authModifier, } ); console.log(JSON.stringify(result, null, 2)); ``` ## What to read next } title="Before execution modifiers" href="/docs/tools-direct/modify-tool-behavior/before-execution-modifiers" description="Modify tool arguments before execution" /> } title="Authenticating tools" href="/docs/tools-direct/authenticating-tools" description="Create auth configs and connect user accounts" /> } title="Executing tools" href="/docs/tools-direct/executing-tools" description="Run tools with providers, agentic frameworks, or direct execution" />