---
title: "Create Salt"
method: POST
path: "/api/v3/salt"
tags: ["Salt"]
---

# Create Salt

`POST /api/v3/salt`

## Request

- Base URL: `https://{tenant_name}.benchling.com`
- URL: `https://{tenant_name}.benchling.com/api/v3/salt`
- Auth: HTTP bearer

Create a salt in the tenant's Salt & Solvate library.

The Salt & Solvate library requires the salt and solvate forms feature to be enabled on your tenant; contact your Benchling representative to turn it on. Creating an entry requires tenant admin permissions. Structures are neutralized (uncharged) on creation and are immutable afterwards. The library is limited to 2000 non-archived entries, and each structure is limited to 50 atoms. Names, structures, and the optional `code` must each be unique (case-insensitive for names and codes) across all salts and solvates in the tenant. Archived entries still reserve their name and structure, so an archived match must be unarchived rather than recreated.

## Headers

- `EARLY-ACCESS` string

## Request body

- CreateSaltInput
  - `code` string, nullable: Optional configurable identifier for this salt (e.g., "HCl"). Must be unique (case-insensitive) across the Salt & Solvate library.
  - `name` string, required: The name of the salt. Must be unique (case-insensitive) across the Salt & Solvate library.
  - `smiles` string, required: The SMILES of the salt. It is neutralized (uncharged) before storage, and the canonical SMILES and molecular formula are derived from it. Immutable after creation.

## Response `201`

Created

- Salt: A Salt is an ionic compound used to represent the salt form of a chemical compound in a tenant's salt library. Salts are referenced when creating molecules to describe the final form of a compound (e.g., hydrochloride, sulfate). Each salt has a required SMILES representing the neutral form, from which the molecular formula is derived.
  - `__typename` string
  - `archiveReason` string, nullable
  - `archived` boolean
  - `calculatedMolecularWeight` number, double, nullable: The molecular weight of the salt.
  - `canonicalSmiles` string: The SMILES representation of the salt after standardization.
  - `code` string, nullable: Optional configurable identifier for this salt (e.g., "HCl", "MS"). Unique across both salts and solvents within a tenant.
  - `createdAt` string, datetime
  - `id` string
  - `modifiedAt` string, datetime
  - `molecularFormula` string: The molecular formula (e.g., "HCl").
  - `molfile` string: The molfile representation of the salt.
  - `name` string

## Other responses

- `400`: Bad Request
- `403`: Forbidden
- `404`: Not Found
- `409`: Conflict
- `429`: Too Many Requests
- `500`: Internal Server Error

---

[API](https://skmtc.dev/benchling/apis/benchling-api.md) - [All operations](https://skmtc.dev/benchling/apis/benchling-api/llms.txt) - [OpenAPI document](https://skmtc.dev/benchling/apis/benchling-api/revisions/c9f087b98b8b?raw)