> Call POST /v1/check before a tool that writes. DENY means do not invoke the tool. For clean Markdown of any page, append .md to the page URL. For the complete index, fetch https://docs.withwrit.com/llms.txt.

# Validate an ALLOW auth token

POST https://api.withwrit.com/v1/tokens/verify
Content-Type: application/json

API key required. Checks an `authToken` from an ALLOW response:
signature, expiry (90 seconds from mint), and — when `verb`,
`target`, or `purpose` are supplied — that the token is bound to
exactly that write. Anything else is purpose drift and returns
`valid: false`. **Important:** an invalid token is HTTP 200 with
`{"valid": false, "reason": "..."}` — only a bad API key is a 401.
Call this at the point of action, after the agent performs the write, to
prove the write matches what Writ allowed.

Reference: https://docs.withwrit.com/api-reference/checks/validate-an-allow-auth-token

## Authentication

- `Authorization` header (bearer token, required) — Bearer authentication of the form `Bearer <token>`, where token is your auth token.

## Servers

- `https://api.withwrit.com` (Writ gate, default)
- `https://j72ckh66ukck2kcbq3oiwxaalm0olxwb.lambda-url.us-east-1.on.aws` (Direct Lambda Function URL (fallback))

## Request

### Body (application/json)

This endpoint expects an object.

- `token` (string, required) — The writ_at_... auth token from an ALLOW response.
- `verb` (string, optional) — If given, the token must be bound to exactly this verb.
- `target` (string, optional) — If given, the token must be bound to exactly this target.
- `purpose` (string, optional) — If given, the token must be bound to exactly this purpose.

## Response

### 200

`{valid: true, claims}` or `{valid: false, reason}`. Possible reasons: not a Writ auth token, malformed token, bad signature, malformed payload, token expired, or token not bound to this verb/target/purpose.

## Errors

### 400 Bad Request Error

The body is not a JSON object.

- `any`

### 401 Unauthorized Error

API key required — missing, malformed, or unknown key.

- `any`

## Examples

### valid

**Response**

```json
{
  "claims": {
    "agentId": "support-agent-07",
    "exp": 1759000090,
    "grantId": "grnt_1a2b...",
    "iat": 1759000000,
    "purpose": "Refund order #88412, close ticket #2210",
    "receiptId": "rcpt_9d2f...",
    "sponsorId": "s_42",
    "target": "order #88412",
    "verb": "refund"
  },
  "valid": true
}
```

**SDK Code**

```python valid
import requests

url = "https://api.withwrit.com/v1/tokens/verify"

headers = {"Authorization": "Bearer <token>"}

response = requests.post(url, headers=headers)

print(response.json())
```

```javascript valid
const url = 'https://api.withwrit.com/v1/tokens/verify';
const options = {method: 'POST', headers: {Authorization: 'Bearer <token>'}};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go valid
package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://api.withwrit.com/v1/tokens/verify"

	req, _ := http.NewRequest("POST", url, nil)

	req.Header.Add("Authorization", "Bearer <token>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby valid
require 'uri'
require 'net/http'

url = URI("https://api.withwrit.com/v1/tokens/verify")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'

response = http.request(request)
puts response.read_body
```

```java valid
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.withwrit.com/v1/tokens/verify")
  .header("Authorization", "Bearer <token>")
  .asString();
```

```php valid
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.withwrit.com/v1/tokens/verify', [
  'headers' => [
    'Authorization' => 'Bearer <token>',
  ],
]);

echo $response->getBody();
```

```csharp valid
using RestSharp;

var client = new RestClient("https://api.withwrit.com/v1/tokens/verify");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "Bearer <token>");
IRestResponse response = client.Execute(request);
```

```swift valid
import Foundation

let headers = ["Authorization": "Bearer <token>"]

let request = NSMutableURLRequest(url: NSURL(string: "https://api.withwrit.com/v1/tokens/verify")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```

### drift

**Response**

```json
{
  "claims": {
    "target": "order #88412",
    "verb": "refund"
  },
  "reason": "token not bound to this target",
  "valid": false
}
```

**SDK Code**

```python drift
import requests

url = "https://api.withwrit.com/v1/tokens/verify"

headers = {"Authorization": "Bearer <token>"}

response = requests.post(url, headers=headers)

print(response.json())
```

```javascript drift
const url = 'https://api.withwrit.com/v1/tokens/verify';
const options = {method: 'POST', headers: {Authorization: 'Bearer <token>'}};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go drift
package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://api.withwrit.com/v1/tokens/verify"

	req, _ := http.NewRequest("POST", url, nil)

	req.Header.Add("Authorization", "Bearer <token>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby drift
require 'uri'
require 'net/http'

url = URI("https://api.withwrit.com/v1/tokens/verify")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'

response = http.request(request)
puts response.read_body
```

```java drift
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.withwrit.com/v1/tokens/verify")
  .header("Authorization", "Bearer <token>")
  .asString();
```

```php drift
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.withwrit.com/v1/tokens/verify', [
  'headers' => [
    'Authorization' => 'Bearer <token>',
  ],
]);

echo $response->getBody();
```

```csharp drift
using RestSharp;

var client = new RestClient("https://api.withwrit.com/v1/tokens/verify");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "Bearer <token>");
IRestResponse response = client.Execute(request);
```

```swift drift
import Foundation

let headers = ["Authorization": "Bearer <token>"]

let request = NSMutableURLRequest(url: NSURL(string: "https://api.withwrit.com/v1/tokens/verify")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```

### expired

**Response**

```json
{
  "reason": "token expired",
  "valid": false
}
```

**SDK Code**

```python expired
import requests

url = "https://api.withwrit.com/v1/tokens/verify"

headers = {"Authorization": "Bearer <token>"}

response = requests.post(url, headers=headers)

print(response.json())
```

```javascript expired
const url = 'https://api.withwrit.com/v1/tokens/verify';
const options = {method: 'POST', headers: {Authorization: 'Bearer <token>'}};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go expired
package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://api.withwrit.com/v1/tokens/verify"

	req, _ := http.NewRequest("POST", url, nil)

	req.Header.Add("Authorization", "Bearer <token>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby expired
require 'uri'
require 'net/http'

url = URI("https://api.withwrit.com/v1/tokens/verify")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'

response = http.request(request)
puts response.read_body
```

```java expired
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.withwrit.com/v1/tokens/verify")
  .header("Authorization", "Bearer <token>")
  .asString();
```

```php expired
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.withwrit.com/v1/tokens/verify', [
  'headers' => [
    'Authorization' => 'Bearer <token>',
  ],
]);

echo $response->getBody();
```

```csharp expired
using RestSharp;

var client = new RestClient("https://api.withwrit.com/v1/tokens/verify");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "Bearer <token>");
IRestResponse response = client.Execute(request);
```

```swift expired
import Foundation

let headers = ["Authorization": "Bearer <token>"]

let request = NSMutableURLRequest(url: NSURL(string: "https://api.withwrit.com/v1/tokens/verify")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```

### Checks_validateAnAllowAuthToken_example

**Request**

```json
{
  "token": "writ_at_eyJ...",
  "verb": "refund",
  "target": "order #88412",
  "purpose": "Refund order #88412, close ticket #2210"
}
```

**Response**

```json
{
  "claims": {
    "agentId": "support-agent-07",
    "exp": 1759000090,
    "grantId": "grnt_1a2b...",
    "iat": 1759000000,
    "purpose": "Refund order #88412, close ticket #2210",
    "receiptId": "rcpt_9d2f...",
    "sponsorId": "s_42",
    "target": "order #88412",
    "verb": "refund"
  },
  "valid": true
}
```

**SDK Code**

```python Checks_validateAnAllowAuthToken_example
import requests

url = "https://api.withwrit.com/v1/tokens/verify"

payload = {
    "token": "writ_at_eyJ...",
    "verb": "refund",
    "target": "order #88412",
    "purpose": "Refund order #88412, close ticket #2210"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())
```

```javascript Checks_validateAnAllowAuthToken_example
const url = 'https://api.withwrit.com/v1/tokens/verify';
const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: '{"token":"writ_at_eyJ...","verb":"refund","target":"order #88412","purpose":"Refund order #88412, close ticket #2210"}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go Checks_validateAnAllowAuthToken_example
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.withwrit.com/v1/tokens/verify"

	payload := strings.NewReader("{\n  \"token\": \"writ_at_eyJ...\",\n  \"verb\": \"refund\",\n  \"target\": \"order #88412\",\n  \"purpose\": \"Refund order #88412, close ticket #2210\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby Checks_validateAnAllowAuthToken_example
require 'uri'
require 'net/http'

url = URI("https://api.withwrit.com/v1/tokens/verify")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"token\": \"writ_at_eyJ...\",\n  \"verb\": \"refund\",\n  \"target\": \"order #88412\",\n  \"purpose\": \"Refund order #88412, close ticket #2210\"\n}"

response = http.request(request)
puts response.read_body
```

```java Checks_validateAnAllowAuthToken_example
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.withwrit.com/v1/tokens/verify")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"token\": \"writ_at_eyJ...\",\n  \"verb\": \"refund\",\n  \"target\": \"order #88412\",\n  \"purpose\": \"Refund order #88412, close ticket #2210\"\n}")
  .asString();
```

```php Checks_validateAnAllowAuthToken_example
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.withwrit.com/v1/tokens/verify', [
  'body' => '{
  "token": "writ_at_eyJ...",
  "verb": "refund",
  "target": "order #88412",
  "purpose": "Refund order #88412, close ticket #2210"
}',
  'headers' => [
    'Authorization' => 'Bearer <token>',
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```

```csharp Checks_validateAnAllowAuthToken_example
using RestSharp;

var client = new RestClient("https://api.withwrit.com/v1/tokens/verify");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "Bearer <token>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"token\": \"writ_at_eyJ...\",\n  \"verb\": \"refund\",\n  \"target\": \"order #88412\",\n  \"purpose\": \"Refund order #88412, close ticket #2210\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift Checks_validateAnAllowAuthToken_example
import Foundation

let headers = [
  "Authorization": "Bearer <token>",
  "Content-Type": "application/json"
]
let parameters = [
  "token": "writ_at_eyJ...",
  "verb": "refund",
  "target": "order #88412",
  "purpose": "Refund order #88412, close ticket #2210"
] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.withwrit.com/v1/tokens/verify")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```