> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Demo Using Tokens with the Consul API
> This article demonstrates how to use an ACL token to authenticate HTTP requests with the Consul Key/Value store.
Welcome to the final lab of this guide. Here you’ll leverage an existing bootstrap ACL token to authenticate HTTP requests against the Consul Key/Value (K/V) store. This demonstration covers:
1. Loading the token from a file
2. Creating or recreating an ACL policy
3. Retrieving K/V entries via `curl` and `jq`
4. Two authentication methods for the Consul API
Before proceeding, ensure Consul is running and you have access to the `consul` binary. For more details, see the [Consul documentation](https://www.consul.io/docs).
## 1. Export the ACL Token
Set the `CONSUL_HTTP_TOKEN_FILE` environment variable to read your token from `token.txt`:
```bash theme={null}
export CONSUL_HTTP_TOKEN_FILE=token.txt
```
Keep your token file secure. Avoid committing it to version control or sharing it publicly.
## 2. Create (or Recreate) an ACL Policy
Use `consul acl policy create` to define a policy with the required rules. If the policy name already exists, choose a new one:
```bash theme={null}
consul acl policy create -name "test123" -rules @rules.hcl
# On error (name exists), try:
consul acl policy create -name "test456" -rules @rules.hcl
```
Sample output after creating `test456`:
```text theme={null}
ID: 51eff8b-4581-7009-2d44-78edf6f105da
Name: test456
Namespace: default
Rules:
node "web-server-01" {
policy = "write"
}
key_prefix "apps/eCommerce" {
policy = "write"
}
session_prefix "" {
policy = "write"
}
service "eCommerce-Front-End" {
policy = "write"
}
```
## 3. Verify Your Token and List K/V Entries
Clear your terminal and display the token:
```bash theme={null}
clear
cat token.txt
# Example output:
# c7142d5a-aba1-78ba-f521-189971e29c24
```
Then list all keys in the K/V store:
```bash theme={null}
consul kv get -recurse
```
Expected output:
```text theme={null}
apps/eCommerce/database:billing
apps/eCommerce/database_host:customer_db
apps/eCommerce/environment:production
apps/eCommerce/version:4.5
apps/search/url:search.service.consul
apps/search/version:4
```
## 4. Authenticate API Requests
Now that you know the key (`apps/eCommerce/database_host`) and have your ACL token, you can fetch its value using the Consul HTTP API. Below are two supported methods:
| Header Type | Description | Header Example |
| -------------- | ---------------------------- | --------------------------------------------- |
| X-Consul-Token | Consul-specific token header | `X-Consul-Token: c7142d5a-aba1-78ba-f521-...` |
| Authorization | Standard HTTP Bearer token | `Authorization: Bearer c7142d5a-aba1-78ba...` |
### Method 1: X-Consul-Token Header
```bash theme={null}
curl \
--header "X-Consul-Token: c7142d5a-aba1-78ba-f521-189971e29c24" \
http://127.0.0.1:8500/v1/kv/apps/eCommerce/database_host | jq
```
Response:
```json theme={null}
[
{
"LockIndex": 0,
"Key": "apps/eCommerce/database_host",
"Flags": 0,
"Value": "Y3VzdG9tZXJzZGI=",
"Namespace": "default",
"CreateIndex": 2336,
"ModifyIndex": 2336
}
]
```
### Method 2: Authorization Bearer Header
```bash theme={null}
curl \
--header "Authorization: Bearer c7142d5a-aba1-78ba-f521-189971e29c24" \
http://127.0.0.1:8500/v1/kv/apps/eCommerce/database_host | jq
```
The JSON payload returned is identical to **Method 1**.
***
You’ve now learned how to authenticate Consul API requests using an ACL token—either via `X-Consul-Token` or the standard `Authorization: Bearer` header. For more information, refer to the [Consul API KV documentation](https://www.consul.io/api-docs/kv).