Sendgrid Twilio SendGrid Legacy Marketing Campaigns Contacts API
Browse all Sendgrid APIs★ Only Publicly Available OpenAPI DocumentMarketingEmail Marketingbearer36 EndpointsREST
For Agents
Programmatically create a custom field, retrieve all custom fields. Covers 36 operations with bearer authentication.
Use for: I need to a custom field, I want to all custom fields, Search for a custom field, Find all a custom field
Not supported: Does not handle payments, communications, or crm — use for marketing only.
The Twilio SendGrid Legacy Marketing Campaigns Contacts API allows you to manage your marketing contacts programmatically. This API is operational, but we recommend using the current version of Marketing Campaigns' [Contacts API](https://docs.sendgrid.com/api-reference/contacts/), [Lists API](https://docs.sendgrid.com/api-reference/lists/), and [Segments API](https://docs.sendgrid.com/api-referenc. The API exposes 36 endpoints secured with bearer authentication.
Install Jentic One Beta
Connect the Twilio SendGrid Legacy Marketing Campaigns Contacts API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Twilio SendGrid Legacy Marketing Campaigns Contacts API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
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Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with Twilio SendGrid Legacy Marketing Campaigns Contacts API.
Create a Custom Field
Retrieve all custom fields
Delete a Custom Field
Query and filter Twilio SendGrid Legacy Marketing Campaigns Contacts API records by parameters
Monitor Twilio SendGrid Legacy Marketing Campaigns Contacts API operational status and events
Use Cases
Patterns agents use Twilio SendGrid Legacy Marketing Campaigns Contacts API for, with concrete tasks.
★ Marketing Operations
Use the Twilio SendGrid Legacy Marketing Campaigns Contacts API to perform marketing operations programmatically. The API provides 36 endpoints covering core functionality including create a custom field, retrieve all custom fields, retrieve a custom field.
Call POST /v3/contactdb/custom_fields to create a custom field
Automated Custom Fields Management
Automate custom fields operations by combining multiple Twilio SendGrid Legacy Marketing Campaigns Contacts API endpoints. Agents can retrieve all custom fields and then retrieve a custom field in a single workflow.
Call GET /v3/contactdb/custom_fields to retrieve all custom fields, then verify the result
AI Agent Integration via Jentic
AI agents discover and call Twilio SendGrid Legacy Marketing Campaigns Contacts API endpoints through Jentic without managing credentials directly. An agent searches for the required operation by intent, receives the matching endpoint schema, and executes the call with Jentic-managed authentication. This eliminates the need to read API documentation or handle bearer tokens manually.
Search Jentic for 'create a custom field', load the operation schema, and execute with Jentic-managed credentials
Key Endpoints
36 endpoints — the twilio sendgrid legacy marketing campaigns contacts api allows you to manage your marketing contacts programmatically.
METHOD
PATH
DESCRIPTION
POST
/v3/contactdb/custom_fields
Create a Custom Field
GET
/v3/contactdb/custom_fields
Retrieve all custom fields
GET
/v3/contactdb/custom_fields/{custom_field_id}
Retrieve a Custom Field
DELETE
/v3/contactdb/custom_fields/{custom_field_id}
Delete a Custom Field
POST
/v3/contactdb/lists
Create a List
GET
/v3/contactdb/lists
Retrieve all lists
DELETE
/v3/contactdb/lists
Delete Multiple lists
GET
/v3/contactdb/lists/{list_id}
Retrieve a single list
POST
/v3/contactdb/custom_fields
Create a Custom Field
GET
/v3/contactdb/custom_fields
Retrieve all custom fields
GET
/v3/contactdb/custom_fields/{custom_field_id}
Retrieve a Custom Field
DELETE
/v3/contactdb/custom_fields/{custom_field_id}
Delete a Custom Field
POST
/v3/contactdb/lists
Create a List
GET
/v3/contactdb/lists
Retrieve all lists
DELETE
/v3/contactdb/lists
Delete Multiple lists
GET
/v3/contactdb/lists/{list_id}
Retrieve a single list
Why Jentic?
Three things that make agents converge on Jentic-routed access.
Credential isolation
Twilio SendGrid Legacy Marketing Campaigns Contacts API bearer credentials are stored encrypted in the Jentic vault (MAXsystem). Agents receive scoped access tokens — raw secrets never enter the agent context.
Intent-based discovery
Agents search by intent (e.g., 'create a custom field') and Jentic returns the matching Twilio SendGrid Legacy Marketing Campaigns Contacts API operation with its input schema, so the agent can call the right endpoint without browsing docs.
Time to first call
Direct Twilio SendGrid Legacy Marketing Campaigns Contacts API integration: 1-3 days for auth handling, response parsing, and error cases. Through Jentic: under 1 hour — search, load schema, execute.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Twilio SendGrid Legacy Marketing Campaigns Contacts API through Jentic.
What authentication does the Twilio SendGrid Legacy Marketing Campaigns Contacts API use?
The Twilio SendGrid Legacy Marketing Campaigns Contacts API uses a Bearer token in the Authorization header. Through Jentic, these credentials are stored encrypted in the MAXsystem vault and injected at execution time, so raw secrets never enter the agent context.
Can I create a custom field with the Twilio SendGrid Legacy Marketing Campaigns Contacts API?
Yes. Use the POST /v3/contactdb/custom_fields endpoint. The API returns structured JSON responses that agents can parse and act on directly.
What are the rate limits for the Twilio SendGrid Legacy Marketing Campaigns Contacts API?
Rate limits are not specified in the OpenAPI spec. Check the vendor documentation for current limits. Through Jentic, rate limiting is handled automatically with retry logic built into the execution layer.
How do I create a custom field through Jentic?
Install the Jentic SDK with pip install jentic, authenticate at https://app.jentic.com/sign-up, then search for 'create a custom field'. Jentic returns the matching Twilio SendGrid Legacy Marketing Campaigns Contacts API operation with its input schema. Load the schema and execute the call — credentials are injected automatically.
How many endpoints does the Twilio SendGrid Legacy Marketing Campaigns Contacts API have?
The Twilio SendGrid Legacy Marketing Campaigns Contacts API exposes 36 endpoints covering custom fields, lists, recipients operations.
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