1. How-To Guides
  2. Getting Started

Step-by-step guide for getting up and running with the Vessel API. If you get stuck or have trouble - email us at support@vessel.land. This API is for getting set up with the CRM API, but will work for the Engagement API as well.

Get Access

The first step to getting up and running with the Vessel API is to get access to the API via an API-token. You can request an API-token on our website or by emailing support@vessel.land.

Test API Call

After receiving your API token, you can quickly gut-check that everything is working by making a request to the /link/token endpoint. Here’s an example of how to make such a request via curl:

curl -X POST https://api.vessel.land/link/token
  --header "vessel-api-token: [YOUR_API_TOKEN]"

If you get linkToken back, everything’s working and you’re good to move on to the next step.

{ "linkToken": "[SOME_TOKEN]" }

Setup a Test Account

The easiest way to test the Vessel CRM endpoints is to set up test accounts with at least one CRM provider. While you can technically test by installing Vessel into the CRM your company uses (assuming your company uses a supported CRM), it is highly advised that you create a dedicated testing environment. This ensures that the data in your company’s CRM is preserved and also provides cleaner testing data.

Here are links for setting up a test account with some of the CRMs we support:

It is vital that you create an account through the links above, otherwise you risk creating an account that will not have API access. Once you’ve set up an account with at least one of the above CRMs and loaded in some dummy data, you can move on to the next step.

Next, use Vessel’s drop-in UI component to quickly set up authentication for your users. This componet is used to open the Vessel modal which provides a UI for connecting to the CRMs we support.


Start by installing the official vessel-link npm package in your FE service. In the next step, you’ll see how to get a linkToken so you can summon the auth modal provided by the package.

Once you’ve installed the vessel-link package and read the README, you can move on to the next step.

Creating a Connection to the user’s CRM

Next, we’ll see how to connect to your user’s CRM using the Vessel API.

A connection consists of:

  1. An accessToken: The private secret used to query the Vessel API.
  2. A connectionId: The public identifier of the connection.

During the authentication step, after your user has authenticated their CRM, Vessel will return a publicToken (not the user’s credentials) which can be exchanged for an accessToken to query the API with. This process plays an important part in ensuring the security of the Vessel API and you can read more about the linkToken / accessToken exchange here. The accessToken is used to query our APIs, it should be kept secret and stored securely.

It is also recommended that you save the connectionId. The connectionId is used when referencing the state of the connection via the /connection/ endpoints (e.g., to tell if the connection is still syncing or if it’s fully synced).

Here’s some example code for how to exchange a publicToken for an accessToken and a connectionId:

BE Server

import express from "express";
import fetch from "node-fetch";
import db from "../utils/database";

const app = express();
const port = 3000;

app.post("/link-token", async (req, res) => {
  // @reference https://docs.vessel.land/api-reference/link/create-link-token
  const response = await fetch("https://api.vessel.land/link/token", {
    method: "POST",
    headers: {
      "vessel-api-token": process.env.VESSEL_API_TOKEN,

  const body = await response.json();
  res.send({ linkToken: body.linkToken });

app.post("/store-token", async (req, res) => {
  const { publicToken } = req.body;
  // @reference https://docs.vessel.land/api-reference/link/exchange-tokens
  const response = await fetch("https://api.vessel.land/link/exchange", {
    method: "POST",
    headers: {
      "vessel-api-token": process.env.VESSEL_API_TOKEN,
    body: JSON.stringify({
  const { connectionId, accessToken } = await response.json();
  await db.storeSecrets(accessToken, connectionId);

  res.send({ success: true });


FE Client

import { useState } from "React";
import { VesselConnectButton } from "@vesselapi/react-vessel-link";

function App() {
  return (
      onSuccess={async (publicToken) => {
        // Pass the publicToken back to the BE so it can be exchanged for an accessToken
        await fetch("https://my-company.api.com/store-token", {
          method: "POST",
          body: JSON.stringify({
      getLinkToken={async () => {
        // Retrieve the linkToken
        const response = await fetch("https://my-company.api.com/link-token", {
          method: "POST",

        const { linkToken } = await response.json();
        return linkToken;

Try authenticating through the test account you set up in the Setup a Test Account step. If you’re able to go through the authentication flow with no issues, and you’re successfully storing the accessToken and connectionId, you can move on to the next step.

Connection status

When a user first connects, the CRM APIs (/crm/) are blocked until the initial data pull completes. All other APIs, such as /webhook/ and /connection/, will be available. You can setup a webhook to be notified when the data pull completes, so you’ll know when you can start making /crm/ APIs calls. Below is a summary of the various connection statuses.

NEW_CONNECTIONWhen a connection is newly created. All CRM APIs are blocked.
INITIAL_SYNCEDFirst 30 days of data synced. CRM APIs are unblocked.
READYAll data has been synced

Putting it all together

Finally, we can tie the above pieces together and make an end-to-end request to the Vessel API!

app.get("contacts", async (req, res) => {
  const { user } = req.body;

  const accessToken = await getAccessToken(user);

  // @reference https://docs.vessel.land/api-reference/crm/get-all-contacts
  const response = await fetch(
      method: "POST",
      headers: {
        "vessel-api-token": process.env.VESSEL_API_TOKEN,

  const { contacts } = await response.json();
  res.send({ contacts });

You can read the API reference for all supported operations.

Cleaning up Connections

It’s very important that you provide a way for your users to disconnect their CRM accounts from your app. This not only helps maintain good CRM hygiene (which your users will thank you for), but also allows Vessel to de-allocate resources for connections that are no longer in use. Additionally, development environments are allotted five connections, meaning that if you try to connect a sixth connection without first removing previous connection, the authentication call will fail with an error message indicating the connection limit has been reached.

To disconnect a connection, call the DELETE /connection/connection endpoint.


Did this process take you longer than 1.5 hours? If so, want to hear about it. Please send an email to support@vessel.land so we can inquire more about what went wrong, where we need to improve, and how we can help.