io.usefulapi/enginemailer

None of its 17 tools are described as changing anything. For 17 the reading was uncertain, so no mark is shown.

• enginemailer_get_subscriber

  “One subscriber by email: id, status and all custom field values.”

  Publisher declares: read-only yes · destructive no · open-world yes

  1 input, 1 required

  • emailstringrequired“An email address (max 128 characters).”
• enginemailer_list_subscriber_categories

  “The subscriber category tree: each category with its subcategories (ids, names).”

  Publisher declares: read-only yes · destructive no · open-world yes

  1 input

  • include_active_subscriber_countboolean“Also return active subscriber counts (only for accounts the vendor has enabled this for).”
• enginemailer_list_custom_fields

  “The subscriber custom field definitions (key, name, type).”

  Publisher declares: read-only yes · destructive no · open-world yes

  Takes no inputs.

• enginemailer_add_subscriber

  “WRITE: add a subscriber to the account (optionally into subcategories, with custom field values).”

  Publisher declares: read-only no · destructive no · idempotent no · open-world yes

  4 inputs, 1 required

  • emailstringrequired“An email address (max 128 characters).”
  • subcategory_idsarray“Subcategory (list/segment) ids from enginemailer_list_subscriber_categories.”
  • custom_fieldsarray“Custom field values to set.”
  • source_typestring“Where the subscriber came from, e.g.”
• enginemailer_update_subscriber

  “WRITE: change an existing subscriber's subcategories and/or custom fields.”

  Publisher declares: read-only no · destructive yes · idempotent yes · open-world yes

  5 inputs, 1 required

  • emailstringrequired“An email address (max 128 characters).”
  • subcategory_idsarray“Subcategory (list/segment) ids from enginemailer_list_subscriber_categories.”
  • subcategories_modestring“How subcategory_ids apply (default append).”
  • custom_fieldsarray“Custom field values to set.”
  • custom_fields_modestring“update_given changes only the listed fields; replace_all (the vendor default) clears the others.”
• enginemailer_unsubscribe_subscriber

  “WRITE: unsubscribe a subscriber so they no longer receive campaigns.”

  Publisher declares: read-only no · destructive yes · idempotent yes · open-world yes

  1 input, 1 required

  • emailstringrequired“An email address (max 128 characters).”
• enginemailer_save_subscriber_category

  “WRITE: create a subscriber category (category_id 0) or update one (its id), with subcategories (subcategory_id 0 creates one).”

  Publisher declares: read-only no · destructive yes · idempotent no · open-world yes

  5 inputs, 2 required

  • category_idintegerrequired“0 to create a new category, else the existing category id.”
  • namestringrequired
  • descriptionstring
  • is_visibleboolean“Visible to subscribers (default true).”
  • subcategoriesarray
• enginemailer_list_campaigns

  “List campaigns that have NOT been delivered yet (drafts and scheduled ones): id, name, subject, sender and schedule.”

  Publisher declares: read-only yes · destructive no · open-world yes

  Takes no inputs.

• enginemailer_get_campaign_stats

  “Delivery results of a DELIVERED campaign: emails sent, delivered, bounces, opens, unique opens, clicks, unique clicks, unsubscribes, spam complaints.”

  Publisher declares: read-only yes · destructive no · open-world yes

  1 input, 1 required

  • campaign_idintegerrequired“Campaign id.”
• enginemailer_list_campaign_categories

  “The categories that campaign recipients can be filtered by (id, name, description).”

  Publisher declares: read-only yes · destructive no · open-world yes

  Takes no inputs.

• enginemailer_list_campaign_subcategories

  “The subcategories of one campaign category (id, name, description); use these ids in enginemailer_assign_campaign_recipients.”

  Publisher declares: read-only yes · destructive no · open-world yes

  1 input, 1 required

  • category_idintegerrequired“Category id from enginemailer_list_campaign_categories.”
• enginemailer_create_campaign

  “WRITE: create a campaign DRAFT.”

  Publisher declares: read-only no · destructive no · idempotent no · open-world yes

  6 inputs, 5 required

  • namestringrequired“Internal campaign name.”
  • sender_namestringrequired
  • sender_emailstringrequired“Sender address on a verified domain.”
  • reply_tostring“An email address (max 128 characters).”
  • subjectstringrequired
  • content_htmlstringrequired“The email body, HTML (max 256 KB).”

Each quoted sentence is the first sentence of the publisher’s own description. The kind of tool and the “changes data” mark are our AI model’s reading of that description, not something we tested: two differently worded runs had to agree, otherwise no label is shown, and nobody has checked them by hand. A tool without the “changes data” mark is described as only reading, searching or calculating, or the two runs did not agree. No tool was called. Read the publisher’s full description before relying on it. “Publisher declares” lists the hints the server itself sends with the tool (MCP annotations: read-only, destructive, idempotent, open-world); they are the publisher's claims, not checked by us. Inputs are the parameters in the tool's own input schema: name, declared type, whether it is required, and the first sentence of its description. Read 2026-10-24.

The registry verifies a package once, when it is published, and does not re-check it. A difference below is about the listing, not a judgement of the publisher.