---
title: "Create a custom notation"
method: POST
path: "/custom-notations"
tags: ["customNotations"]
---

# Create a custom notation

`POST /custom-notations`

## Request

- Base URL: `https://{tenant_name}.benchling.com/api/v2-beta`
- URL: `https://{tenant_name}.benchling.com/api/v2-beta/custom-notations`
- Auth: HTTP bearer

Create a custom notation

## Request body

- CustomNotationCreate
  - `isCaseSensitive` boolean: Whether the custom notation is case sensitive.
  - `name` string: Name of custom notation
  - `nullifyEndPhosphate` boolean: When enabled, the parser will emit a null phosphate for any token mapped to a natural phosphate when it occurs as the final 3' nucleotide in a sequence.
  - `prefilterTerminals` CustomNotationPrefilterTerminals: Configuration for an optional feature where unrecognized tokens at the 5'/3' terminal ends of an input sequence can be stripped and output to schema fields.
    - `fivePrimeLeftDelimiter` string, nullable
    - `fivePrimeRightDelimiter` string
    - `maxDepth` integer, nullable
    - `threePrimeLeftDelimiter` string
    - `threePrimeRightDelimiter` string, nullable
  - `useSharedDelimiter` CustomNotationCreateUseSharedDelimiter: By default the system assumes that all delimiters "belong" to a single token (such as in a notation like "[A][B][C]"). This setting allows specifying a single "shared" delimiter instead, e.g. the commas in "A,B,C".
    - `delimiter` string

## Response `201`

Created

- CustomNotation
  - `aliases` CustomNotationAlias[]
    - `baseMonomerId` string
    - `customNotationId` string
    - `id` string
    - `phosphateMonomerId` string, nullable
    - `rank` number, double
    - `sugarMonomerId` string
    - `token` string
    - `tokenVariantEnd` string, nullable
    - `tokenVariantStart` string, nullable
  - `id` string
  - `name` string

## Other responses

- `400`: Bad Request

---

[API](https://skmtc.dev/benchling/apis/benchling-api-beta.md) - [All operations](https://skmtc.dev/benchling/apis/benchling-api-beta/llms.txt) - [OpenAPI document](https://skmtc.dev/benchling/apis/benchling-api-beta/revisions/eba0b3d5b98e?raw)