---
title: "Add counsel's side letter"
method: POST
path: "/side-letters"
tags: ["side_letter"]
---

# Add counsel's side letter

`POST /side-letters`

## Request

- Base URL: `https://localhost:4410/api/v1`
- URL: `https://localhost:4410/api/v1/side-letters`
- Auth: HTTP bearer

Records a side letter your counsel prepared (information rights, MFN, board observer, pro rata or other), uploaded as a document first, with its main terms in a sentence. With safe_id it goes out with that SAFE, in its own envelope with the same signers; its text is never changed.

## Request body

- object
  - `investor_id` string, required
  - `document_id` string, required
  - `kind` 'information_rights' | 'mfn' | 'board_observer' | 'pro_rata' | 'other', required
  - `terms` string, required
  - `safe_id` string

## Response `200`

The result.

- object
  - `side_letter` object, required
    - `id` string, required
    - `investor_id` string, required
    - `safe_id` string, nullable, required
    - `kind` 'information_rights' | 'mfn' | 'board_observer' | 'pro_rata' | 'other', required
    - `title` string, required
    - `terms` string, required
    - `document_id` string, required
    - `status` 'draft' | 'sent' | 'executed', required
    - `envelope_id` string, nullable, required

## Other responses

- `default`: An RFC 9457 problem.

---

[API](https://skmtc.dev/binderwork/apis/binderwork-api.md) · [All operations](https://skmtc.dev/binderwork/apis/binderwork-api/llms.txt) · [OpenAPI document](https://skmtc.dev/binderwork/apis/binderwork-api/revisions/f8fab0ebee53?raw)