FlexyChat

Stream a chat response

The response is text/event-stream. Each frame contains an event field (event type) and a data field (JSON payload). Consume text_delta events to progressively render the assistant’s reply.

Event types in order:

stream_start — stream opened, includes model and provider info
step_start — reasoning step started
text_start — text block started
text_delta — incremental text chunk; read data.delta for the token
text_complete — text block finished
step_finish — reasoning step finished
stream_end — stream closed, includes finish_reason and token usage

Example stream:

event: stream_start
data: {"id":"evt_01KPTDR1BWRTJRY7W56MBCGF0R","timestamp":1776855811,"model":"grok-4-1-fast-non-reasoning","provider":"xai","metadata":null}

event: step_start
data: {"id":"evt_01KPTDR1BWRTJRY7W56MBCGF0S","timestamp":1776855811}

event: text_start
data: {"id":"evt_01KPTDR1BWRTJRY7W56MBCGF0T","timestamp":1776855811,"message_id":"evt_abc"}

event: text_delta
data: {"id":"evt_01KPTDR1BXRXHBK6DFSZ3W32H6","timestamp":1776855811,"delta":"Hello","message_id":"evt_def"}

event: text_delta
data: {"id":"evt_01KPTDR1CXK80DJ647VEF68ATW","timestamp":1776855811,"delta":"!","message_id":"evt_klm"}

event: text_complete
data: {"id":"evt_01KPTDR1Q0Z330AKTGKFXYRQ7G","timestamp":1776855811,"message_id":"evt_xyz"}

event: step_finish
data: {"id":"evt_01KPTDR1Q1PD7FG8F9DS2GCAVJ","timestamp":1776855811}

event: stream_end
data: {"id":"evt_01KPTDR1Q1PD7FG8F9DS2GCAVK","timestamp":1776855811,"finish_reason":"Stop","usage":{"prompt_tokens":12,"completion_tokens":8,"cache_write_input_tokens":null,"cache_read_input_tokens":null,"thought_tokens":null},"citations":null}

Note: Use curl -N (no-buffer) or an EventSource client to see tokens arrive in real time. Postman buffers SSE until the connection closes.

POST

flexy-chat

stream

Stream a chat response

curl --request POST \
  --url https://dev.flextell.ai/api/v1/flexy-chat/stream \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'X-Tenant: <x-tenant>' \
  --data '
{
  "prompt": "<string>",
  "history": [
    {
      "content": "<string>"
    }
  ]
}
'

import requests

url = "https://dev.flextell.ai/api/v1/flexy-chat/stream"

payload = {
    "prompt": "<string>",
    "history": [{ "content": "<string>" }]
}
headers = {
    "X-Tenant": "<x-tenant>",
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {
    'X-Tenant': '<x-tenant>',
    Authorization: 'Bearer <token>',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({prompt: '<string>', history: [{content: '<string>'}]})
};

fetch('https://dev.flextell.ai/api/v1/flexy-chat/stream', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://dev.flextell.ai/api/v1/flexy-chat/stream",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'prompt' => '<string>',
    'history' => [
        [
                'content' => '<string>'
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json",
    "X-Tenant: <x-tenant>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

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

func main() {

	url := "https://dev.flextell.ai/api/v1/flexy-chat/stream"

	payload := strings.NewReader("{\n  \"prompt\": \"<string>\",\n  \"history\": [\n    {\n      \"content\": \"<string>\"\n    }\n  ]\n}")

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

	req.Header.Add("X-Tenant", "<x-tenant>")
	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(string(body))

}

HttpResponse<String> response = Unirest.post("https://dev.flextell.ai/api/v1/flexy-chat/stream")
  .header("X-Tenant", "<x-tenant>")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"prompt\": \"<string>\",\n  \"history\": [\n    {\n      \"content\": \"<string>\"\n    }\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://dev.flextell.ai/api/v1/flexy-chat/stream")

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

request = Net::HTTP::Post.new(url)
request["X-Tenant"] = '<x-tenant>'
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"prompt\": \"<string>\",\n  \"history\": [\n    {\n      \"content\": \"<string>\"\n    }\n  ]\n}"

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

{
  "event": "text_delta",
  "data": {}
}

Authorizations

Authorization

string

header

required

The access token received from the authorization server in the OAuth 2.0 flow.

FlowAuthorization Code

Authorization URL: https://dev.flextell.ai/oauth/authorize
Token URL: https://dev.flextell.ai/oauth/token

Headers

X-Tenant

number

required

Tenant identifier. Send the Tenant ID in the X-Tenant header to scope API requests to a specific tenant.

Body

application/json

prompt

string

required

The user prompt to send to the assistant.

Required string length: 1 - 2000

history

object[] | null

Prior conversation messages (max 20 turns).

Maximum array length: 20

Show child attributes

Response

200 - text/event-stream

SSE stream. Listen for text_delta events and read data.delta to render the response progressively.

event

enum<string>

required

Available options:

stream_start,

step_start,

text_start,

text_delta,

text_complete,

step_finish,

stream_end

Example:

"text_delta"

data

object

required

Stream a chat response

curl --request POST \
  --url https://dev.flextell.ai/api/v1/flexy-chat/stream \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'X-Tenant: <x-tenant>' \
  --data '
{
  "prompt": "<string>",
  "history": [
    {
      "content": "<string>"
    }
  ]
}
'

import requests

url = "https://dev.flextell.ai/api/v1/flexy-chat/stream"

payload = {
    "prompt": "<string>",
    "history": [{ "content": "<string>" }]
}
headers = {
    "X-Tenant": "<x-tenant>",
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {
    'X-Tenant': '<x-tenant>',
    Authorization: 'Bearer <token>',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({prompt: '<string>', history: [{content: '<string>'}]})
};

fetch('https://dev.flextell.ai/api/v1/flexy-chat/stream', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://dev.flextell.ai/api/v1/flexy-chat/stream",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'prompt' => '<string>',
    'history' => [
        [
                'content' => '<string>'
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json",
    "X-Tenant: <x-tenant>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

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

func main() {

	url := "https://dev.flextell.ai/api/v1/flexy-chat/stream"

	payload := strings.NewReader("{\n  \"prompt\": \"<string>\",\n  \"history\": [\n    {\n      \"content\": \"<string>\"\n    }\n  ]\n}")

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

	req.Header.Add("X-Tenant", "<x-tenant>")
	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(string(body))

}

HttpResponse<String> response = Unirest.post("https://dev.flextell.ai/api/v1/flexy-chat/stream")
  .header("X-Tenant", "<x-tenant>")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"prompt\": \"<string>\",\n  \"history\": [\n    {\n      \"content\": \"<string>\"\n    }\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://dev.flextell.ai/api/v1/flexy-chat/stream")

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

request = Net::HTTP::Post.new(url)
request["X-Tenant"] = '<x-tenant>'
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"prompt\": \"<string>\",\n  \"history\": [\n    {\n      \"content\": \"<string>\"\n    }\n  ]\n}"

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

{
  "event": "text_delta",
  "data": {}
}