> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.merge.dev/merge-unified/writing-data/writes/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.merge.dev/_mcp/server.

# Writes

> Build once. Connect to every API, tool, and LLM. Ship products and agents to production without owning the integration stack.

## Docs

- [Writes](https://docs.merge.dev/merge-unified/writing-data/writes/introduction.md): How to create and update records in third-party platforms via POST and PATCH requests to Merge's Unified API.
- [Related and Nested Writes](https://docs.merge.dev/merge-unified/writing-data/writes/nested.md): How to create records that reference existing objects (related writes) or create parent and child objects in a single request (nested writes).
- [Async operations](https://docs.merge.dev/merge-unified/writing-data/writes/async-operations.md): How to use Merge's async write endpoints to create records without blocking. Covers polling for completion and handling async response statuses.
- [Idempotency](https://docs.merge.dev/merge-unified/writing-data/writes/idempotency.md): How to use the Idempotency-Key header to safely retry POST requests without creating duplicate records.