---
title: "Batch create AaMonomer"
method: POST
path: "/api/v3/aa-monomer:batch-create"
tags: ["AA Monomer"]
---

# Batch create AaMonomer

`POST /api/v3/aa-monomer:batch-create`

## Request

- Base URL: `https://{tenant_name}.benchling.com`
- URL: `https://{tenant_name}.benchling.com/api/v3/aa-monomer:batch-create`
- Auth: HTTP bearer

Batch create AaMonomer synchronously in one transaction. Maximum 25 items per request.

## Headers

- `EARLY-ACCESS` string

## Request body

- object
  - `items` CreateAaMonomerInput[], required
    - `chemicalStructure` AaMonomerChemicalStructureInput, required
      - `structureFormat` 'smiles', required
      - `value` string, required
    - `customMolecularWeight` number, double: Optional molecular weight value that the user can provide to override the calculated value.
    - `name` string, required
    - `naturalAnalog` 'A' | 'B' | 'C' | 'D' | 'E' | 'F' | 'G' | 'H' | 'I' | 'J' | 'K' | 'L' | 'M' | 'N' | 'O' | 'P' | 'Q' | 'R' | 'S' | 'T' | 'U' | 'V' | 'W' | 'X' | 'Y' | 'Z', required: The standard amino acid single-letter code that this monomer is an analog of.
    - `symbol` string, required: User-defined identifier of the monomer, unique per tenant.

## Response `201`

Created

- AaMonomerBatchcreateResponse201
  - `items` AaMonomer[], required
    - `__typename` string
    - `archiveReason` string, nullable
    - `archived` boolean
    - `attachmentPoints` AaMonomerAttachmentPointsItems[]: The capping groups present at each attachment point where the monomer bonds to other monomers.
    - `calculatedMolecularWeight` number, double: The molecular weight of the monomer with capping groups removed, computed using the average atomic weights of each element weighted by natural isotopic frequency.
    - `canonicalSmiles` string: The SMILES representation of the chemical structure after being standardized.
    - `createdAt` string, datetime
    - `creator` PrincipalRef
      - `__typename` string
      - `id` string, api_id
    - `customMolecularWeight` number, double, nullable: Optional molecular weight value that the user can provide to override the calculated value.
    - `exactMolecularWeight` number, double: The exact (monoisotopic) molecular weight of the monomer with capping groups removed, computed using the atomic weight of the most frequent isotope of each element.
    - `id` string
    - `isNatural` boolean: Whether this monomer represents a natural (unmodified) amino acid, as opposed to a modified or synthetic variant.
    - `modifiedAt` string, datetime
    - `molfile` string: The molfile representation of the chemical structure.
    - `name` string
    - `naturalAnalog` 'A' | 'B' | 'C' | 'D' | 'E' | 'F' | 'G' | 'H' | 'I' | 'J' | 'K' | 'L' | 'M' | 'N' | 'O' | 'P' | 'Q' | 'R' | 'S' | 'T' | 'U' | 'V' | 'W' | 'X' | 'Y' | 'Z': The standard amino acid single-letter code that this monomer is an analog of.
    - `originalSmiles` string, nullable: The SMILES string that was originally provided upon creation. Null if the user did not originally provide SMILES.
    - `symbol` string: User-defined identifier of the monomer, unique per tenant.

## 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)