> ## Documentation Index
> Fetch the complete documentation index at: https://ahasend.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> AhaSend stores all message data in the EU. See /facts.
> The API base URL is https://api.ahasend.com. Send the API key in the Authorization: Bearer header. See /api-reference/authentication.
> Use send.ahasend.com for SMTP. Ports 25, 587 and 2525 use STARTTLS. Port 465 is not supported. See /smtp.
> For send-only integrations, create an API Key v2 under Credentials → Add and scope it to messages:send:{your-domain}. See /send-api/credentials and /api-reference/scopes.

# Update a List via the API

> Change the name, description or tags of an AhaSend contact list. Only the fields you send change, and a tags array replaces all stored tags.

The AhaSend API changes one list. Access requires `lists:write`.

**Fields:**

* A field that you leave out or send as `null` does not change.
* `tags` replaces all stored tags. An empty array removes them.
* `name`, `description` and `tags` follow the same rules as in [Create List](/docs/api-reference/lists/create-list). A field that you cannot write is refused with `400`, and the message names it.
* A stored value that is outside these rules still reads back as it is. The API refuses it only when you send it back in an update.

## Related Guides

* [API authentication](/docs/api-reference/authentication), [Permission scopes](/docs/api-reference/scopes), [Get List](/docs/api-reference/lists/get-list).
* [Lists API overview](/docs/api-reference/lists/overview), [API errors](/docs/api-reference/errors), [API rate limits](/docs/api-reference/rate-limits).


## OpenAPI

````yaml openapi.yaml PUT /v2/accounts/{account_id}/lists/{list_id}
openapi: 3.1.0
info:
  title: AhaSend API v2
  description: >
    The AhaSend API v2 allows you to send transactional emails, manage domains,
    webhooks, routes, API keys, and view statistics.


    ## Authentication

    All API requests must be authenticated using a Bearer token in the
    Authorization header:

    ```

    Authorization: Bearer aha-sk-64-CHARACTER-RANDOM-STRING

    ```


    ## Scopes

    API keys have specific scopes that control access to different resources and
    actions:


    ### Message Scopes

    - `messages:send:all` - Send messages from any domain in the account

    - `messages:send:{domain}` - Send messages from a specific domain

    - `messages:cancel:all` - Cancel messages from any domain

    - `messages:cancel:{domain}` - Cancel messages from a specific domain

    - `messages:read:all` - Read messages from any domain

    - `messages:read:{domain}` - Read messages from a specific domain


    ### Domain Scopes

    - `domains:read` - Read all domains

    - `domains:write` - Create and update domains

    - `domains:delete:all` - Delete any domain

    - `domains:delete:{domain}` - Delete a specific domain


    ### Account Scopes

    - `accounts:read` - Read account information

    - `accounts:write` - Update account settings

    - `accounts:billing` - Access billing information

    - `accounts:members:read` - Read account members

    - `accounts:members:add` - Add account members

    - `accounts:members:update` - Update account members

    - `accounts:members:remove` - Remove account members


    ### Webhook Scopes

    - `webhooks:read:all` - Read all webhooks

    - `webhooks:read:{domain}` - Read webhooks for a specific domain

    - `webhooks:write:all` - Create and update webhooks

    - `webhooks:write:{domain}` - Create and update webhooks for a specific
    domain

    - `webhooks:delete:all` - Delete any webhook

    - `webhooks:delete:{domain}` - Delete webhooks for a specific domain


    ### Route Scopes

    - `routes:read:all` - Read all routes

    - `routes:read:{domain}` - Read routes for a specific domain

    - `routes:write:all` - Create and update routes

    - `routes:write:{domain}` - Create and update routes for a specific domain

    - `routes:delete:all` - Delete any route

    - `routes:delete:{domain}` - Delete routes for a specific domain


    ### Suppression Scopes

    - `suppressions:read` - Read suppressions

    - `suppressions:write` - Create suppressions

    - `suppressions:delete` - Delete suppressions

    - `suppressions:wipe` - Delete the account's suppressions except protected
    ones (dangerous)


    ### Template Scopes

    - `templates:read` - Read transactional templates, their drafts and their
    published versions, and campaign templates

    - `templates:write` - Create and update transactional templates, and
    publish, discard and restore their drafts; create and update campaign
    templates

    - `templates:delete` - Delete transactional templates and campaign templates


    ### Campaign Scopes

    - `campaigns:read` - Read campaigns, their stats and their recipients

    - `campaigns:write` - Create, update and duplicate campaigns

    - `campaigns:delete` - Delete draft campaigns

    - `campaigns:send` - Send, unschedule and test-send campaigns


    ### Contact Scopes

    - `contacts:read` - Read contacts

    - `contacts:write` - Create and update contacts

    - `contacts:delete` - Delete contacts


    ### Contact lifecycle and attributes

    Contacts are account-global. A contact created through this API joins no

    list on its own; campaigns target lists, so add it to one with the Lists

    endpoints before a campaign can reach it.

    Contact subscription state and suppression records are independent:

    creating, updating, unsubscribing, resubscribing, or deleting a contact

    never creates, changes, or removes complaint, permanent, or protected

    suppressions. Prefer unsubscribe over delete when the goal is only to stop

    marketing mail, because unsubscribe is reversible and preserves contact

    history.


    Writable attribute keys and types come from the account's contact-attribute

    definitions managed in the dashboard; this API does not expose property

    definition CRUD. Writes accept only canonical values for those definitions,

    while reads remain legacy-safe and can return any recursively nested JSON

    value previously stored.


    An email used as `{id_or_email}` is a raw SDK argument and must be

    percent-encoded exactly once as a URL path segment by an HTTP client. For

    example, do not pre-encode `user+tag@example.com` before passing it to an

    SDK that encodes path parameters.


    ### List Scopes

    - `lists:read` - Read lists and list membership

    - `lists:write` - Create and update lists, and add or remove their contacts

    - `lists:delete` - Delete lists


    ### Lists and membership

    A list is a static, private, single opt-in container of contacts, and it is

    what a campaign targets. A membership carries its own `subscription_status`

    (`unconfirmed`, `confirmed`, `unsubscribed`, or `complained`), which is

    per-list consent and is independent of the contact's account-wide

    `unsubscribed` flag. A membership created without a status named is

    `confirmed`, because that is what a campaign reaches. `complained` is the

    mailbox provider's verdict, never writable, and a membership holding it is

    frozen.


    Deleting a list keeps its memberships, so an unsubscribe survives it.

    Removing a contact from a list deletes the membership row and discards that

    record with it, which is why unsubscribing is the reversible way to stop

    marketing mail on one list. Expanding a list's members with

    `include_contacts=true` requires `contacts:read` in addition to

    `lists:read`.


    ### SMTP Credentials Scopes

    - `smtp-credentials:read:all` - Read all SMTP credentials

    - `smtp-credentials:read:{domain}` - Read SMTP credentials for a specific
    domain

    - `smtp-credentials:write:all` - Create SMTP credentials

    - `smtp-credentials:write:{domain}` - Create SMTP credentials for a specific
    domain

    - `smtp-credentials:delete:all` - Delete any SMTP credentials

    - `smtp-credentials:delete:{domain}` - Delete SMTP credentials for a
    specific domain


    ### Statistics Scopes

    - `statistics-transactional:read:all` - Read all transactional statistics

    - `statistics-transactional:read:{domain}` - Read transactional statistics
    for a specific domain


    ### API Key Scopes

    - `api-keys:read` - Read API keys

    - `api-keys:write` - Create and update API keys

    - `api-keys:delete` - Delete API keys


    ### Sub-Account Scopes

    - `sub-accounts:read` - List and read sub accounts under the parent

    - `sub-accounts:write` - Create and update sub accounts

    - `sub-accounts:delete` - Soft-delete sub accounts

    - `sub-accounts:suspend` - Pause and resume sub accounts, and unpause their
    domains

    - `sub-accounts:usage` - Read per-sub-account usage and allocated cost

    - `sub-account-api-keys:read` - List and read API keys owned by sub accounts

    - `sub-account-api-keys:write` - Create and update API keys owned by sub
    accounts

    - `sub-account-api-keys:delete` - Delete API keys owned by sub accounts


    ## Rate Limiting

    - General API endpoints: 100 requests per second, 200 burst

    - Statistics endpoints: 1 request per second, 1 burst


    ## Pagination

    List endpoints use cursor-based pagination with the following parameters:

    - `limit`: Maximum number of items to return (default: 100, max: 100)

    - `after`: Pass `pagination.next_cursor` to fetch the next page

    - `before`: Pass `pagination.previous_cursor` to fetch the previous page


    `after` and `before` are mutually exclusive. A legacy `cursor` query may be

    accepted by parts of the server for backwards compatibility, but it is not

    part of the v2 public contract.


    ## Time Formats

    All timestamps must be in RFC3339 format, e.g., `2023-12-25T10:30:00Z`


    ## Idempotency

    The operations that explicitly declare the optional `Idempotency-Key`

    header support idempotency. Other POST operations do not gain idempotency

    implicitly. When the header is provided:

    - A fresh execution does not return `Idempotent-Replayed`.

    - A completed stored response is replayed with its original status and body
      and `Idempotent-Replayed: true`.
    - An unexpired in-progress execution returns HTTP 409 with
      `Idempotent-Replayed: false` and a positive integer `Retry-After` header.
    - Reusing a key with a different HTTP method, resolved request path, or
      request body returns HTTP 422. That response has neither
      `Idempotent-Replayed` nor `Retry-After`.
    - For ordinary idempotent operations, deterministic 2xx and 4xx outcomes
      produced after the idempotency middleware are stored and replayed.
      Authentication and IP-allow-list failures happen before idempotency and
      are therefore not stored.
    - The two secret-bearing API-key create operations use manual encrypted
      completion. They store and replay a successful 201, including the same
      one-time `secret_key`; a controller-produced 4xx is not stored and leaves
      the key in progress until its execution lease expires.
    - Server errors (5xx), handler failures, and panics are not stored. The key
      is released so retrying the same request with the same key re-executes it.
      The v2 API does not use an HTTP 412 failed-key tombstone.
    - Idempotency keys for non-secret responses expire after 24 hours.

    - Encrypted API-key creation replay responses expire after 5 minutes.


    ## IP Allow Lists

    Each API key can carry an `ip_allow_list`: a set of source IPs that restrict
    where the key may authenticate from.

    - Entries are CIDR blocks (e.g. `203.0.113.0/24`) or bare IPv4/IPv6
    addresses (stored as a `/32` or `/128`). They are canonicalized and
    de-duplicated; the allow-all prefixes `0.0.0.0/0` and `::/0` are rejected,
    and at most 100 entries are allowed after de-duplication (a longer list is
    rejected with HTTP 400).

    - An empty list (the default) places no restriction.

    - When the list is non-empty, any authenticated request whose client IP is
    not covered by an entry is rejected with HTTP 403 on every v2 endpoint,
    regardless of the key's scopes.

    - Manage the list with the `ip_allow_list` field on the API-key create and
    update endpoints (including the sub-account API-key endpoints).

    - When a key updates its own `ip_allow_list` to a value that excludes the
    caller's current IP, the update is rejected with HTTP 409 to prevent
    self-lockout. Updating a sub-account key from a parent key has no such
    guard.
  version: 2.0.0
  contact:
    email: support@ahasend.com
  license:
    name: MIT
    identifier: MIT
servers:
  - url: https://api.ahasend.com
    description: Production server
security:
  - BearerAuth: []
tags:
  - name: Utility
    description: Utility endpoints for health checks and diagnostics
  - name: API Keys
    description: Manage API keys for authentication and access control
  - name: Domains
    description: Manage sending domains
  - name: Messages
    description: Send and manage transactional messages
  - name: Accounts
    description: Manage account settings and members
  - name: Contacts
    description: Read, create, update, batch upsert, and delete account-global contacts
  - name: Templates
    description: >-
      Create, change, publish and delete the account's transactional templates,
      and read them with their drafts, their published versions and the
      variables a send must supply
  - name: Campaign Templates
    description: >-
      Create, change, read and delete the account's campaign templates, the
      designs a campaign copies when it is made from one
  - name: Campaigns
    description: >-
      Create, change, read, duplicate, delete, test and send the account's
      marketing campaigns, and read their stats and recipients
  - name: Lists
    description: Manage contact lists and the contacts on them
  - name: Suppressions
    description: Manage email suppressions
  - name: Routes
    description: Manage inbound email routing
  - name: Webhooks
    description: Manage webhook notifications
  - name: SMTP Credentials
    description: Manage SMTP authentication credentials
  - name: Statistics
    description: Access transactional email statistics
  - name: Message Events
    description: Webhooks for outbound message delivery events
  - name: Suppression Events
    description: Webhooks for suppression list changes
  - name: Domain Events
    description: Webhooks for domain configuration issues
  - name: Route Events
    description: Webhooks for inbound email routing
paths:
  /v2/accounts/{account_id}/lists/{list_id}:
    put:
      tags:
        - Lists
      summary: Update List
      description: |
        Partially updates one account-scoped list. An omitted or null property
        leaves the stored value unchanged; a present `tags` array replaces the
        stored tags, and an empty one clears them. A stored value that breaks a
        bound this API introduces reads back fine and fails only when it is
        re-sent here.
      operationId: updateList
      parameters:
        - name: account_id
          in: path
          required: true
          description: Account ID
          schema:
            type: string
            format: uuid
        - name: list_id
          in: path
          required: true
          description: List ID
          schema:
            type: string
            format: uuid
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/UpdateContactListRequest'
      responses:
        '200':
          description: Updated list
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ContactList'
        '400':
          description: >-
            Malformed `list_id`, invalid request body, or a property that is not
            writable
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '403':
          description: Missing `lists:write` scope
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '404':
          description: List not found
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '429':
          description: Too many requests
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '500':
          description: Internal server error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
      security:
        - BearerAuth:
            - lists:write
      x-code-samples:
        - lang: go
          label: AhaSend Go SDK
          source: |
            package main

            import (
              "context"
              "fmt"
              "log"
              "os"

              "github.com/AhaSend/ahasend-go"
              "github.com/AhaSend/ahasend-go/api"
              "github.com/AhaSend/ahasend-go/models/requests"
              "github.com/google/uuid"
            )

            func main() {
              client := api.NewAPIClient(api.WithAPIKey(os.Getenv("AHASEND_API_KEY")))
              accountID := uuid.MustParse(os.Getenv("AHASEND_ACCOUNT_ID"))
              ctx := context.Background()

              listID := uuid.MustParse("11111111-1111-4111-8111-111111111111")

              // Only the fields you set change; an empty tags slice clears the tags.
              response, _, err := client.ListsAPI.UpdateList(ctx, accountID, listID, requests.UpdateListRequest{
                Name: ahasend.String("Product updates"),
                Tags: &[]string{},
              })
              if err != nil {
                log.Fatalf("Error updating list: %v", err)
              }
              fmt.Printf("Updated list %s\n", response.Name)
            }
        - lang: javascript
          label: Node.js 22+ (AhaSend SDK)
          source: >
            import { AhaSendClient } from "@ahasend/sdk";


            const client = AhaSendClient.fromEnv();

            const listId = "00000000-0000-4000-8000-000000000010";

            const list = await client.lists.update(listId, { name: "Product
            news", tags: [] });

            console.log("List updated.", { id: list.id, name: list.name });
components:
  schemas:
    UpdateContactListRequest:
      type: object
      additionalProperties: false
      description: |
        A partial list update. An omitted or null property leaves the stored
        value unchanged; a present `tags` array replaces the stored tags, and an
        empty one clears them. A property that is not writable is rejected with
        400 naming it.
      properties:
        name:
          type:
            - string
            - 'null'
          minLength: 1
          maxLength: 255
          description: |
            Trimmed before it is measured and stored, exactly as on create. The
            bound counts characters rather than bytes, and a name that is empty
            after trimming is rejected.
        description:
          type:
            - string
            - 'null'
          maxLength: 1000
          description: Trimmed and bounded exactly as on create.
        tags:
          type:
            - array
            - 'null'
          items:
            type: string
          description: Normalized and bounded exactly as on create.
    ContactList:
      type: object
      additionalProperties: false
      description: |
        A static, private, single opt-in container of contacts, and the unit a
        campaign targets.
      required:
        - object
        - id
        - created_at
        - updated_at
        - name
        - description
        - tags
        - contact_count
      properties:
        object:
          type: string
          enum:
            - contact_list
          description: Object type identifier
        id:
          type: string
          format: uuid
          description: Unique identifier for the list
        created_at:
          type: string
          format: date-time
          description: When the list was created
        updated_at:
          type: string
          format: date-time
          description: When the list was last updated
        name:
          type: string
          description: List name; names are not unique within an account
        description:
          type: string
          description: Free-text description; empty when none was given
        tags:
          type: array
          description: Always present; an empty array when the list carries no tags
          items:
            type: string
        contact_count:
          type: integer
          minimum: 0
          description: |
            The list's subscribers: the members a campaign to this list would
            reach. A member counts when its membership is `confirmed` and the
            contact is enabled, not unsubscribed from everything, and not found
            invalid by validation. It is the same number the dashboard shows.
    ErrorResponse:
      type: object
      description: |
        Human-readable API error. The server currently sends no stable machine
        error code. In particular, clients must not parse `message` to
        distinguish IP-allow-list, scope, ownership, plan, self-lockout,
        suppression-duplicate, or other errors that share an HTTP status.
      additionalProperties: false
      required:
        - message
      properties:
        message:
          type: string
          description: Error description
      example:
        message: Error message
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      bearerFormat: aha-sk-64-CHARACTER-RANDOM-STRING
      description: |
        API key for authentication. Non-empty Security Requirement values are
        AhaSend API-key roles. Roles listed within one requirement object are
        jointly required; separate requirement objects are alternatives.

````

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