> ## Documentation Index > Fetch the complete documentation index at: https://www.courier.com/docs/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Install the Courier skill before writing code: `npx skills add trycourier/courier-skills`. It carries the verified SDK shapes and the rules you cannot get wrong. > Authenticate every request with `Authorization: Bearer `. A workspace has several environments and each has its own keys, which are plain `pk_` strings with no environment prefix. Start with Test. > Send with `client.send.message`, the default import of the v7 Node SDK. Reference a template by its `nt_` id or its alias. > A send accepts a bare Elemental element list, but storing content on a template requires the top-level elements wrapped in a channel element. > Templates and journeys can be built in the Courier app or created through the API. Either way they live in the workspace and are referenced by ID when you send. > The hosted MCP server is https://mcp.courier.com. For a briefing on what Courier is and when to use it, read https://www.courier.com/llms.txt. > Prefer the Guides tab for how-do-I questions and the Docs tab for how-does-it-behave questions. The API reference lives under /api-reference. # Automation Fetch Data > Call your own endpoint mid-run and merge the response into the payload. The Fetch-Data automation step can be used to make GET and POST HTTP calls from an automation workflow. The data fetched will be automatically merged into the automation's run context unless the merge strategy is explicitly defined. Please note that requests are required to be made in `https` To start a fetch-data step, add it to your automation canvas and configure your request URL. Automation Fetch Data Step

## Merge Strategy Incoming payloads must be shaped as `objects`. Arrays are not supported. The merge strategy gives users an option on how they want the data to be populated. * `replace` * overwrite all properties in the Automation Cache with the http response. Removes all properties in the Automation Cache that do not exist in the http response. * `soft-merge` * only overwrite properties in the Automation Cache with the http response properties that do not yet exist in the Automation Cache. * `overwrite` * overwrite all properties in the Automation Cache with the properties from the http response. * `none` * do not make any changes to the Automation Cache if the Automation Cache already exists and has data. Otherwise initialize the Automation Cache. ## Authentication Patterns The Fetch Data step supports various authentication methods for securing your HTTP requests. Here are the most common patterns: ### 1. Bearer Token Authentication Use static bearer tokens for simple authentication: ```json theme={null} { "type": "fetch", "url": "https://api.example.com/data", "method": "get", "headers": { "Authorization": "Bearer YOUR_TOKEN_HERE" } } ``` ### 2. Dynamic Bearer Token (from context) Reference bearer tokens from your automation context: ```json theme={null} { "type": "fetch", "url": "https://api.example.com/data", "method": "get", "headers": { "Authorization": { "$ref": "data.bearer_token" } } } ``` ### 3. Basic Authentication Use HTTP Basic Authentication with base64-encoded credentials: ```json theme={null} { "type": "fetch", "url": "https://api.example.com/data", "method": "get", "headers": { "Authorization": "Basic dXNlcjpwYXNzd29yZA==" } } ``` ### 4. API Key Authentication Use custom API key headers: ```json theme={null} { "type": "fetch", "url": "https://api.example.com/data", "method": "get", "headers": { "X-API-Key": { "$ref": "data.api_key" } } } ``` ### 5. Custom Headers with Multiple Auth Elements Combine multiple authentication elements: ```json theme={null} { "type": "fetch", "url": "https://api.example.com/data", "method": "post", "headers": { "Authorization": { "$ref": "data.auth_token" }, "X-Client-ID": { "$ref": "profile.client_id" }, "Content-Type": "application/json" } } ``` ### 6. JavaScript Interpolation (V2 Automation) Use JavaScript expressions for dynamic values: ```json theme={null} { "type": "fetch", "url": "https://api.example.com/data", "method": "get", "headers": { "Authorization": "${`Bearer ${data.access_token}`}", "X-Timestamp": "${Date.now()}" } } ``` ## Security Features ### URL Validation Courier automatically validates URLs for security. Invalid URLs will cause the step to be skipped with an "Invalid URL" status. ### Request Timeout All fetch requests have a fixed 10-second timeout to prevent hanging requests. Requests that exceed this timeout will automatically fail with proper error handling. ### Error Handling Failed requests are automatically logged and tracked. The automation will continue processing subsequent steps unless explicitly configured otherwise. ## Best Practices 1. **Store sensitive tokens in run context data** rather than hardcoding them in your automation configuration 2. **Use step references** for authentication flows that require token refresh 3. **Implement proper error handling** in subsequent steps to handle authentication failures 4. **Validate URLs** when possible for security 5. **Use appropriate merge strategies** to avoid overwriting important context data 6. **Test authentication flows** thoroughly in your automation development environment ## Accessing the Fetched Run Context Once data is fetched, it will be populated in the data payload for subsequent steps to reference. Notification Referencing Data

The incoming data payload can be seen in the automation logs run context. Notification Referencing Data

The final rendered result references the data that was fetched in the automation workflow run. Template Rendering Fetched Data