---
title: "Create a related_record"
method: POST
path: "/v1/related_records"
tags: ["Related records"]
---

# Create a related_record

`POST /v1/related_records`

## Request

- Base URL: `https://api.slant.app`
- URL: `https://api.slant.app/v1/related_records`
- Auth: HTTP bearer

Create a related record link. The source must belong to book_id and both endpoints must be accessible. Use Household for clients/prospects, and the contact person ID with Person for contact sources.

## Headers

- `Idempotency-Key` string

## Request body

- object
  - `book_id` string, required
  - `source_type` 'Household' | 'Person' | 'Business' | 'Trust' | 'User' | 'Contact', required: Contact is resolved to its Person record in the saved link
  - `source_id` string, required
  - `target_type` 'Household' | 'Person' | 'Business' | 'Trust' | 'User' | 'Contact', required
  - `target_id` string, required
  - `relationship_to_source` string, nullable: How the source relates to the target
  - `relationship_to_target` string, nullable: How the target relates to the source

## Response `201`

related_record created

- object
  - `id` string, required
  - `book_id` string, required
  - `source_type` string, required
  - `source_id` string, required
  - `target_type` string, required
  - `target_id` string, required
  - `source_label` string
  - `target_label` string
  - `relationship_to_source` string, nullable
  - `relationship_to_target` string, nullable
  - `created_at` string, date-time
  - `updated_at` string, date-time

## Other responses

- `400`: Bad Request - malformed JSON, invalid filters, or missing required book context
- `401`: unauthorized - missing or invalid token
- `403`: Access denied. Policy and membership failures may have an empty body. A read-only personal token cannot perform writes.
- `422`: unprocessable entity - invalid payload
- `429`: An hourly API rate limit was exceeded. Wait Retry-After seconds before retrying.

## Changes

- **2026-11-03** `173c41bf6be9`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/slant/apis/slant-public-api-v1/changes/v1/related_records/post.md)

---

[API](https://skmtc.dev/slant/apis/slant-public-api-v1.md) - [All operations](https://skmtc.dev/slant/apis/slant-public-api-v1/llms.txt) - [OpenAPI document](https://skmtc.dev/slant/apis/slant-public-api-v1/revisions/173c41bf6be9?raw)