PostGrid provides APIs for automating direct mail and address verification services, enabling businesses to send letters, postcards, and checks, as well as verify and standardize addresses in real-time.
PostGrid provides APIs for automating direct mail and address verification services, enabling businesses to send letters, postcards, and checks, as well as verify and standardize addresses in real-time. On Nagent, Postgrid is exposed as a fully-configurable developer tools integration that any agent can call — 60 actions, and API key authentication. No code is required to wire Postgrid into your workflow — connect it once via the External Integrations panel and reuse it across every agent you build.
Agent builders use Postgrid to automate the kinds of tasks developer tools teams previously handled manually. Concrete examples — each one is a single agent step in Nagent — include:
Every action and trigger is paired with a structured input/output schema (visible in the sections below), so when you wire Postgrid into Helix — our agentic agent builder — the editor knows exactly what each step expects and produces. Configure once, deploy anywhere across your Nagent agents.
Every operation an agent can call against Postgrid, with input parameters and output schema. Drop these into any step of an agent built in Helix.
POSTGRID_CANCEL_BOXTool to cancel a box order by its ID. Use when you need to cancel a pending box shipment.
Input parameters
Unique identifier of the box to cancel (format: box_XXXX)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CANCEL_CHEQUETool to cancel a cheque order by its ID. Only works when the cheque has 'ready' status. Use when you need to cancel a pending cheque before it is mailed.
Input parameters
Unique identifier of the cheque to cancel (starts with cheque_). The cheque must have 'ready' status to be cancelled.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CANCEL_CHEQUE_WITH_NOTETool to cancel a cheque order with a cancellation note. Use when you need to cancel a cheque and provide a reason for the cancellation.
Input parameters
The ID of the cheque to cancel (format: cheque_*)
Cancellation note explaining the reason for cancellation. Must not be empty.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CANCEL_POSTCARDTool to cancel a postcard order. Use when you need to cancel a postcard that has status 'ready'.
Input parameters
The unique identifier of the postcard to cancel. Only postcards with status 'ready' can be cancelled.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CANCEL_POSTCARD_WITH_NOTETool to cancel a postcard order with an optional cancellation note. Use when you need to cancel a postcard that is in 'ready' status. Once cancelled, the status changes to 'cancelled' and the response includes cancellation details.
Input parameters
The postcard ID to cancel. The postcard must be in 'ready' status to be cancelled.
Cancellation note explaining why the postcard is being cancelled. This field is required and must not be empty.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CANCEL_RETURN_ENVELOPE_ORDERTool to cancel a return envelope order. Use when you need to cancel a pending return envelope order using the return envelope ID and order ID.
Input parameters
Unique identifier of the return envelope
Unique identifier of the return envelope order to cancel
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CREATE_BANK_ACCOUNTTool to create a new bank account for print & mail service.
Input parameters
Name of the bank
Type of bank account
Contact email for the account
Contact phone number
Bank account number
9-digit bank routing number
Signature text
URL or file path for signature image
Country code (ISO 3166-1 alpha-2)
Name of the bank account holder
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CREATE_BOXTool to create a box mailing order for letters with plastic cards or cheques. Use when you need to send multiple cheques in a secure box.
Input parameters
Contact ID (e.g., 'contact_xxx') or inline contact object for the recipient
Contact ID (e.g., 'contact_xxx') or inline contact object for the sender
Array of cheque objects to be included in the box (minimum 1, maximum 500). Each cheque must include to, from, bankAccount, amount, and number fields.
Mailing class for delivery (e.g., 'first_class'). Defaults to first_class.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CREATE_CHEQUETool to create a cheque order for physical cheque mailing. Use when you need to send a payment via printed cheque. Requires a valid bank account ID and recipient contact details.
Input parameters
Recipient contact details (payee)
Memo line on the cheque
Cheque amount in cents. For example, 5000 = $50.00
Custom cheque number. If not provided, will auto-increment.
HTML message to include above the cheque (max 7 inches from top of page)
Custom key-value pairs for metadata
Scheduled send date in ISO 8601 format
Bank account ID for the cheque. Must be created via bank_accounts endpoint first.
Sender contact details (payer)
Extra service option: 'certified' or 'certified_return_receipt'
Mailing class for delivery (e.g., 'first_class', 'standard')
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CREATE_CONTACTTool to create a new contact in PostGrid. Use after collecting contact's name, address, and optional metadata.
Input parameters
City name
Email address
Last name of the contact
Custom metadata as key-value pairs
First name of the contact
Country ISO code
Phone number in E.164 format
Postal or ZIP code
Street address line 1
Street address line 2
Organization name
Province or state
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CREATE_LETTERTool to create and send a letter via PostGrid. Use when recipient, sender, and content details are ready.
Input parameters
Recipient's address details
URL to a PDF file for the letter content. Required if html is not provided
HTML content of the letter. Required if pdf is not provided
Request express shipping
Custom metadata associated with the letter
Description of the letter
Sender's address details
Key-value pairs for merging data into the letter content
Page number to be perforated
Return envelope ID to include with the letter (e.g., 'return_envelope_...'). Pass 'true' to use the default return envelope.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CREATE_POSTCARDTool to create and send a postcard via PostGrid. Use when recipient, sender, and content (HTML, template, or PDF) are ready.
Input parameters
Recipient's address details
URL or file for a 2-page PDF (front and back). Required if HTML/template options are not provided
Sender's address details
Supported postcard sizes.
HTML content for the back of the postcard. Required if backTemplate and pdf are not provided
Custom metadata associated with the postcard
Scheduled send date in ISO8601 format
HTML content for the front of the postcard. Required if frontTemplate and pdf are not provided
Template ID for the back of the postcard. Required if backHTML and pdf are not provided
Mailing class for the postcard delivery
Template ID for the front of the postcard. Required if frontHTML and pdf are not provided
Key-value pairs for merging data into template content
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CREATE_RETURN_ENVELOPETool to create a return envelope for mail recipients to respond. Use when you need to include a prepaid return envelope for recipients to send back responses.
Input parameters
Recipient contact information (return address where the envelope will be sent back to)
Optional description to identify the return envelope
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CREATE_RETURN_ENVELOPE_ORDERTool to create a batch order of return envelopes to be printed and delivered. Use when you need to order return envelopes in bulk (minimum 5000 units).
Input parameters
The ID of the return envelope to create an order for
The quantity of return envelopes to order. Must be at least 5000.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CREATE_TEMPLATETool to create a new mail template in PostGrid. Use when you need to define reusable HTML content with dynamic placeholders. Use after confirming required template details.
Input parameters
HTML content of the template (supports Handlebars/Mustache syntax)
Name of the template
Description of the template
Data model used for testing the template rendering
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CREATE_TEMPLATE_EDITOR_SESSIONTool to create a template editor session for interactive template editing. Use when you need to generate an embeddable URL for editing a template. The session URL allows users to modify template HTML content in a visual editor.
Input parameters
The ID of an existing template to open in the editor session. Must be a valid template ID with format template_*
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CREATE_TRACKERTool to create a tracker for monitoring mail delivery status via URL tracking. Use when you need to track recipient engagement with personalized URLs.
Input parameters
Custom metadata as key-value pairs
Optional description for the tracker
Number of days until generated URLs expire. Must be 30, 60, or 90 days.
The base URL template for personalized redirects. Supports merge variables like {{to.firstName}}, {{to.lastName}}, {{from.city}}, {{to.metadata.id}}, etc. Any merge variable available in the order can be accessed.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_CREATE_WEBHOOKTool to create a new webhook to receive order event notifications. Use after configuring your endpoint to handle webhook payloads.
Input parameters
The URL where webhook payloads will be sent.
List of events that trigger the webhook. Possible values include: 'letter.created', 'letter.updated', 'postcard.created', 'postcard.updated', 'cheque.created', 'cheque.updated', 'self_mailer.created', 'self_mailer.updated', 'return_envelope_order.created', 'return_envelope_order.updated'.
Format of the webhook payload: 'jwt' (signed) or 'json' (plain JSON). Defaults to 'jwt'.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_DELETE_BANK_ACCOUNTTool to delete a bank account by its ID. Use when you need to remove a bank account after confirming its identifier.
Input parameters
Unique identifier of the bank account to delete
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_DELETE_CONTACTTool to delete a contact by its ID. Use when you need to remove obsolete contacts after confirming their identifier.
Input parameters
Unique identifier of the contact to delete
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_DELETE_TEMPLATETool to delete a template by its ID. Use when you need to remove an existing template after confirming its identifier.
Input parameters
Unique identifier of the template to delete
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_DELETE_TEMPLATE_EDITOR_SESSIONTool to delete a template editor session by its ID. Use when you need to remove an existing template editor session.
Input parameters
Unique identifier of the template editor session to delete
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_DELETE_TRACKERTool to delete a tracker by its ID. Use when you need to remove an existing tracker after confirming its identifier.
Input parameters
Unique identifier of the tracker to delete
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_DELETE_WEBHOOKTool to delete a webhook subscription. Use when you need to remove an existing webhook by its ID.
Input parameters
Unique identifier of the webhook to delete
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_FILL_TEST_RETURN_ENVELOPE_ORDERTool to fill a test return envelope order for testing purposes. This simulates filling a return envelope order in test mode, changing the status from 'placed' to 'filled'. Only works in test mode.
Input parameters
The return envelope ID (prefixed with return_envelope_)
The return envelope order ID (prefixed with return_envelope_order_)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_GET_BANK_ACCOUNTTool to retrieve a bank account. Use after obtaining the bank account ID to fetch its details.
Input parameters
Unique identifier of the bank account to retrieve
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_GET_BOXTool to retrieve a specific box order by ID. Use after obtaining the box ID to fetch its details.
Input parameters
Unique identifier of the box to retrieve. Format: box_\[alphanumeric\]
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_GET_CHEQUETool to retrieve a specific cheque by ID. Use when you need to fetch details of a specific cheque order.
Input parameters
Unique identifier of the cheque to retrieve (starts with 'cheque_')
Array of nested resources to expand (e.g., \['bankAccount', 'template'\]). When expanded, the response will include full objects instead of just IDs.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_GET_CONTACTTool to retrieve a contact. Use after obtaining the contact ID to fetch its details.
Input parameters
Unique identifier of the contact to retrieve
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_GET_LETTERTool to retrieve a letter. Use after you have the letter ID to fetch its details.
Input parameters
Unique identifier of the letter to retrieve
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_GET_POSTCARDTool to retrieve a specific postcard by ID. Use when you have a postcard ID and need to fetch its details.
Input parameters
Unique identifier of the postcard to retrieve
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_GET_RETURN_ENVELOPETool to retrieve a return envelope. Use after obtaining the return envelope ID to fetch its details.
Input parameters
Unique identifier of the return envelope to retrieve, prefixed with 'return_envelope_'
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_GET_RETURN_ENVELOPE_ORDERTool to retrieve a specific return envelope order. Use when you need to get details about an order by its return envelope ID and order ID.
Input parameters
Unique identifier of the return envelope
Unique identifier of the return envelope order
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_GET_TEMPLATETool to retrieve a template. Use when you have the template ID and need its details.
Input parameters
Unique identifier of the template to retrieve
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_GET_TRACKERTool to retrieve a tracker. Use when you have the tracker ID and need its details.
Input parameters
Unique identifier of the tracker to retrieve
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_GET_WEBHOOKTool to retrieve details of a specific webhook by its ID. Use after creating a webhook to fetch its configuration and status.
Input parameters
Unique identifier of the webhook to retrieve
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_BANK_ACCOUNTSTool to list bank accounts. Use when retrieving bank accounts with optional status filter and pagination.
Input parameters
Number of records to skip for pagination (default 0)
Maximum number of bank accounts to return (default 10, max 100)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_BOXESTool to list box orders. Use when you need to retrieve a paginated list of box orders from PostGrid.
Input parameters
Number of box orders to skip for pagination
Maximum number of box orders to return per page (1-100, default 10)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_CHEQUESTool to list cheques with optional filters and pagination. Use when you need to retrieve batches of cheque records for processing or reporting.
Input parameters
Cursor for pagination. Fetch items after this cursor.
Number of items to return per page. Maximum is 100.
Filter by cheque status.
ISO-8601 timestamp. Only return cheques created before this time.
ISO-8601 timestamp. Only return cheques created after this time.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_CONTACTSTool to list contacts. Use when you need to retrieve a paginated list of contacts with optional filters like date range, metadata, name, or email.
Input parameters
Number of contacts to skip for pagination
Maximum number of contacts to return per page (1-100)
Search query to filter contacts by name, address, email, or other fields
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_EVENTSTool to retrieve a list of webhook events with optional pagination. Use when you need to view all webhook events that have occurred.
Input parameters
Number of events to skip for pagination
Maximum number of events to return per page (1-100)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_LETTERSTool to list letters. Use when retrieving letters with optional filters and pagination.
Input parameters
Cursor for pagination to fetch records created after a specific ID
Maximum number of records to return (default 10, max 100)
Cursor for pagination to fetch records created before a specific ID
Filter letters created on or before this date (ISO 8601)
Filter letters by status (ready, printing, processed, completed, cancelled)
Filter letters created on or after this date (ISO 8601)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_POSTAL_STATEMENTSTool to list all postal statements for billing and tracking purposes. Use when you need to retrieve statements for accounting or audit purposes.
Input parameters
Number of postal statements to skip for pagination
Maximum number of postal statements to return per page (1-100)
Search query to filter postal statements by various fields
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_POSTCARDSTool to retrieve a list of postcards with optional filtering and pagination. Use when you need to browse or filter postcards list.
Input parameters
Number of records to skip (offset).
Number of records per page (1-100).
Filter by postcard status.
Return postcards created before this ISO8601 timestamp.
Filter by custom metadata key-value pairs.
Return postcards created after this ISO8601 timestamp.
Filter by the contact's unique ID.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_RETURN_ENVELOPE_ORDERSTool to list all return envelope orders for a specific return envelope. Use when retrieving orders associated with a return envelope ID.
Input parameters
The return envelope ID (prefixed with return_envelope_)
Number of records to skip for pagination
Maximum number of records to return (default 10, max 100)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_RETURN_ENVELOPESTool to list return envelopes. Use when you need to retrieve a paginated list of business reply envelopes (BREs) with optional pagination.
Input parameters
Number of return envelopes to skip for pagination
Maximum number of return envelopes to return per page (1-100)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_SELF_MAILERSTool to list self-mailers. Use when you need to fetch self-mailers with filters and pagination.
Input parameters
Number of records to skip (offset)
Number of records per page (1-100)
Filter by status (e.g., 'draft', 'queued', 'processing', 'completed', 'failed')
Filter self-mailers created on or before this ISO 8601 timestamp (inclusive)
Key-value metadata pairs to filter self-mailers
Filter self-mailers created on or after this ISO 8601 timestamp (inclusive)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_SUB_ORGANIZATIONSTool to list sub-organizations. Use when you need to retrieve a paginated list of sub-organizations with optional search filter.
Input parameters
Number of records to skip for pagination (default 0)
Maximum number of sub-organizations to return (default 10, max 100)
Search query to filter sub-organizations by name or other fields
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_TEMPLATE_EDITOR_SESSIONSTool to list template editor sessions. Use when you need to retrieve a paginated list of template editor sessions.
Input parameters
Number of sessions to skip for pagination
Maximum number of sessions to return per page (1-100)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_TEMPLATESTool to list templates. Use when you need to retrieve a paginated list of templates with optional type filtering.
Input parameters
Number of templates to skip for pagination
Maximum number of templates to return per page (1-100)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_TRACKERSTool to list all trackers. Use when you need to retrieve a paginated list of trackers for tracking mail interactions.
Input parameters
Number of trackers to skip for pagination (defaults to 0)
Maximum number of trackers to return per page (defaults to 10, max 100)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_TRACKER_VISITSTool to list all visits for a tracker. Use when you need to retrieve visit information including device, IP address, and referred tracker/order ID for each visit.
Input parameters
Unique identifier of the tracker to retrieve visits for
Number of visits to skip for pagination
Maximum number of visits to return per page (1-100)
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_WEBHOOK_INVOCATIONSTool to list previous invocations of a webhook with response status codes. Use when you need to view the history of webhook delivery attempts and their outcomes.
Input parameters
The unique identifier of the webhook to retrieve invocations for.
Number of invocations to skip for pagination (default: 0).
Number of invocations to return (default: 40, max: 100).
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_LIST_WEBHOOKSTool to retrieve a list of configured webhooks with optional filtering and pagination. Use when you need to view your webhooks.
Input parameters
Number of webhooks to skip for pagination.
Maximum number of webhooks to return per page (1-100).
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_PROGRESS_TEST_BOXTool to progress a test box through processing stages for webhook testing. Use when testing webhook integration by advancing box status.
Input parameters
The ID of the test box to progress through stages. Must be a test mode box.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_PROGRESS_TEST_CHEQUETool to progress a test cheque through processing stages for webhook testing. Use when you need to simulate cheque status changes (ready -> printing -> processed_for_delivery -> completed) to test webhook integrations.
Input parameters
Unique identifier of the test cheque to progress. Must be a test cheque (not a live cheque).
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_PROGRESS_TEST_POSTCARDTool to progress a test postcard through processing stages for webhook testing. Use when testing webhook integration by advancing postcard status.
Input parameters
The ID of the test postcard to progress through stages. Must be a test mode postcard.
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_UPDATE_TEMPLATETool to update an existing mail template in PostGrid. Use when you need to modify the HTML content, description, or metadata of a template.
Input parameters
Unique identifier of the template to update. Must start with 'template_'
Updated HTML content for the template (supports Handlebars/Mustache syntax)
Custom key-value pairs for organizing and tracking the template
Updated description for the template
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_UPDATE_TRACKERTool to update an existing tracker's redirect URL template and/or expiration settings. Use when you need to modify tracker configuration after obtaining its identifier.
Input parameters
Unique identifier of the tracker to update
Number of days before generated URLs expire. Must be 30, 60, or 90
The base URL template for personalized redirects, supporting merge variables like {{to.firstName}} and {{to.metadata.id}}
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
POSTGRID_UPDATE_WEBHOOKTool to update an existing webhook configuration. Use when you need to modify webhook URL, events, or other settings.
Input parameters
Unique identifier of the webhook to update (path parameter).
The URL where webhook payloads will be sent.
Whether the webhook is enabled or disabled.
List of events that trigger the webhook. Possible values include: 'letter.created', 'letter.updated', 'postcard.created', 'postcard.updated', 'cheque.created', 'cheque.updated', 'self_mailer.created', 'self_mailer.updated', 'return_envelope_order.created', 'return_envelope_order.updated'.
Format of the webhook payload: 'jwt' (signed) or 'json' (plain JSON).
Output
Data from the action execution
Error if any occurred during the execution of the action
Whether or not the action execution was successful or not
No publicly available marketplace agent is found using this tool yet. There are 30 agents privately built on Nagent that already use Postgrid.
Build on Nagent
Connect Postgrid to any Nagent agent in minutes — no API key management, no boilerplate. Just configure and deploy.
The five questions agent builders ask before adopting a new integration.
Open the External Integrations panel inside Nagent (app.nagent.ai/externalIntegration), find Postgrid, and click "Connect Now." You'll authenticate with an API key — Nagent handles credential storage and refresh automatically. Once connected, Postgrid is available to any agent in your workspace.
No. Nagent provides no-code integration for every tool. Once Postgrid is connected, you configure its 60 actions directly in the agent builder UI — no API calls, no boilerplate, no schema management.
Helix — Nagent's agentic agent builder — lets you drop Postgrid steps into any workflow visually. Pick an action (e.g., one of those listed above), fill in the inputs (Helix knows the required vs. optional schema for each parameter), and connect it to upstream/downstream steps. Triggers run as the entry point of an agent, so when a Postgrid event fires, the agent kicks off automatically.
Every Postgrid action and trigger ships with a fully-typed schema — input parameters with name, type, required flag, and description, plus the output payload shape. The schemas are documented in the sections above. Helix uses these schemas to validate your configuration at build time and to type-check the data flowing between steps.
Yes. While Postgrid ships with 60 pre-built developer tools actions, you can layer custom logic around them inside Helix — pre/post-processing steps, conditional branches, retries, or stitching Postgrid together with other connected tools. For deeper customization, talk to our team about Nagent's Agentic AI Lab — forward-deployed engineers who build Postgrid-based workflows tailored to your business.