Continue Task

curl -X POST 'https://agent.blackbox.ai/api/v1/tasks/a1b2c3d4-e5f6-7890-abcd-ef1234567890/continue' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "prompt": "Now add unit tests for the new payment module"
  }'

curl -X POST 'https://agent.blackbox.ai/api/v1/tasks/a1b2c3d4-e5f6-7890-abcd-ef1234567890/continue' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "prompt": "Refactor the authentication logic to use middleware",
    "model": "blackboxai/anthropic/claude-opus-4.7"
  }'

const API_KEY = "YOUR_API_KEY";
const PREVIOUS_RUN_ID = "a1b2c3d4-e5f6-7890-abcd-ef1234567890";

const response = await fetch(
  `https://agent.blackbox.ai/api/v1/tasks/${PREVIOUS_RUN_ID}/continue`,
  {
    method: "POST",
    headers: {
      Authorization: `Bearer ${API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      prompt: "Now add unit tests for the new payment module",
    }),
  }
);

const data = await response.json();
console.log(`New runId: ${data.runId}`);
console.log(`ChatId: ${data.chatId}`);

// Poll the new run for completion
const DONE = ["completed", "failed", "cancelled", "interrupted"];
while (true) {
  const statusRes = await fetch(
    `https://agent.blackbox.ai/api/v1/tasks/${data.runId}/status`,
    { headers: { Authorization: `Bearer ${API_KEY}` } }
  );
  const s = await statusRes.json();
  console.log(`${s.status} — ${s.progress}%`);
  if (DONE.includes(s.status)) break;
  await new Promise(r => setTimeout(r, 3000));
}

import requests
import time

API_KEY = "YOUR_API_KEY"
PREVIOUS_RUN_ID = "a1b2c3d4-e5f6-7890-abcd-ef1234567890"

headers = {
    "Authorization": f"Bearer {API_KEY}",
    "Content-Type": "application/json",
}

# Continue the task
response = requests.post(
    f"https://agent.blackbox.ai/api/v1/tasks/{PREVIOUS_RUN_ID}/continue",
    headers=headers,
    json={"prompt": "Now add unit tests for the new payment module"},
)
data = response.json()
new_run_id = data["runId"]
print(f"New runId: {new_run_id}")

# Poll until done
DONE = {"completed", "failed", "cancelled", "interrupted"}
while True:
    s = requests.get(
        f"https://agent.blackbox.ai/api/v1/tasks/{new_run_id}/status",
        headers={"Authorization": f"Bearer {API_KEY}"},
    ).json()
    print(f"{s['status']} — {s['progress']}%")
    if s["status"] in DONE:
        break
    time.sleep(3)

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "io"
    "net/http"
)

func main() {
    apiKey := "YOUR_API_KEY"
    previousRunId := "a1b2c3d4-e5f6-7890-abcd-ef1234567890"
    url := fmt.Sprintf("https://agent.blackbox.ai/api/v1/tasks/%s/continue", previousRunId)

    body, _ := json.Marshal(map[string]string{
        "prompt": "Now add unit tests for the new payment module",
    })

    req, _ := http.NewRequest("POST", url, bytes.NewBuffer(body))
    req.Header.Set("Authorization", "Bearer "+apiKey)
    req.Header.Set("Content-Type", "application/json")

    client := &http.Client{}
    resp, _ := client.Do(req)
    defer resp.Body.Close()

    respBody, _ := io.ReadAll(resp.Body)
    fmt.Println(string(respBody))
}

{
  "runId": "c3d4e5f6-a7b8-9012-cdef-123456789012",
  "assistantMessageId": "msg_new_run_abc123",
  "chatId": "chat_def789ghi012",
  "previousRunId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890"
}

{
  "error": "Task not found"
}

{
  "error": "prompt: prompt is required"
}

{
  "error": "Claude Agent requires a Pro subscription. Please upgrade at https://www.blackbox.ai/pricing"
}

POST

api

tasks

{runId}

continue

curl -X POST 'https://agent.blackbox.ai/api/v1/tasks/a1b2c3d4-e5f6-7890-abcd-ef1234567890/continue' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "prompt": "Now add unit tests for the new payment module"
  }'

curl -X POST 'https://agent.blackbox.ai/api/v1/tasks/a1b2c3d4-e5f6-7890-abcd-ef1234567890/continue' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "prompt": "Refactor the authentication logic to use middleware",
    "model": "blackboxai/anthropic/claude-opus-4.7"
  }'

const API_KEY = "YOUR_API_KEY";
const PREVIOUS_RUN_ID = "a1b2c3d4-e5f6-7890-abcd-ef1234567890";

const response = await fetch(
  `https://agent.blackbox.ai/api/v1/tasks/${PREVIOUS_RUN_ID}/continue`,
  {
    method: "POST",
    headers: {
      Authorization: `Bearer ${API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      prompt: "Now add unit tests for the new payment module",
    }),
  }
);

const data = await response.json();
console.log(`New runId: ${data.runId}`);
console.log(`ChatId: ${data.chatId}`);

// Poll the new run for completion
const DONE = ["completed", "failed", "cancelled", "interrupted"];
while (true) {
  const statusRes = await fetch(
    `https://agent.blackbox.ai/api/v1/tasks/${data.runId}/status`,
    { headers: { Authorization: `Bearer ${API_KEY}` } }
  );
  const s = await statusRes.json();
  console.log(`${s.status} — ${s.progress}%`);
  if (DONE.includes(s.status)) break;
  await new Promise(r => setTimeout(r, 3000));
}

import requests
import time

API_KEY = "YOUR_API_KEY"
PREVIOUS_RUN_ID = "a1b2c3d4-e5f6-7890-abcd-ef1234567890"

headers = {
    "Authorization": f"Bearer {API_KEY}",
    "Content-Type": "application/json",
}

# Continue the task
response = requests.post(
    f"https://agent.blackbox.ai/api/v1/tasks/{PREVIOUS_RUN_ID}/continue",
    headers=headers,
    json={"prompt": "Now add unit tests for the new payment module"},
)
data = response.json()
new_run_id = data["runId"]
print(f"New runId: {new_run_id}")

# Poll until done
DONE = {"completed", "failed", "cancelled", "interrupted"}
while True:
    s = requests.get(
        f"https://agent.blackbox.ai/api/v1/tasks/{new_run_id}/status",
        headers={"Authorization": f"Bearer {API_KEY}"},
    ).json()
    print(f"{s['status']} — {s['progress']}%")
    if s["status"] in DONE:
        break
    time.sleep(3)

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "io"
    "net/http"
)

func main() {
    apiKey := "YOUR_API_KEY"
    previousRunId := "a1b2c3d4-e5f6-7890-abcd-ef1234567890"
    url := fmt.Sprintf("https://agent.blackbox.ai/api/v1/tasks/%s/continue", previousRunId)

    body, _ := json.Marshal(map[string]string{
        "prompt": "Now add unit tests for the new payment module",
    })

    req, _ := http.NewRequest("POST", url, bytes.NewBuffer(body))
    req.Header.Set("Authorization", "Bearer "+apiKey)
    req.Header.Set("Content-Type", "application/json")

    client := &http.Client{}
    resp, _ := client.Do(req)
    defer resp.Body.Close()

    respBody, _ := io.ReadAll(resp.Body)
    fmt.Println(string(respBody))
}

{
  "runId": "c3d4e5f6-a7b8-9012-cdef-123456789012",
  "assistantMessageId": "msg_new_run_abc123",
  "chatId": "chat_def789ghi012",
  "previousRunId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890"
}

{
  "error": "Task not found"
}

{
  "error": "prompt: prompt is required"
}

{
  "error": "Claude Agent requires a Pro subscription. Please upgrade at https://www.blackbox.ai/pricing"
}

This endpoint continues an existing task by spawning a new agent run on the same chat thread (chatId). The agent receives the full conversation history as context and picks up where the previous run left off. If the original task worked on a GitHub repository, the agent will continue from the branch it created.

Authentication

To use this API, you need a BLACKBOX API Key. Follow these steps to get your API key:

Go to app.blackbox.ai/agent-api and click Get an API Key (requires a Pro subscription)
Once provisioning completes, you will be redirected to your Dashboard
From the Dashboard, create an API key to use with all Agent API requests

Your API key will be in the format: sk-xxxxxxxxxxxxxxxxxxxxxx

GitHub Connection Required

For GitHub-related tasks: If the original task worked on a repository, the agent will automatically continue from the branch it created. Make sure your GitHub token is still stored via POST /api/v1/git/config — see Store GitHub Token for details.

Headers

string

required

API Key of the form Bearer <api_key>.Example: Bearer sk_b41b647ffbfed27f616560

string

required

Must be set to application/json.

Path Parameters

string

required

The runId of the previous task run to continue from.Example: a1b2c3d4-e5f6-7890-abcd-ef1234567890

Request Body

string

required

The follow-up instruction for the agent. The agent will receive the full prior conversation as context.Examples:

"Now add unit tests for the new module"
"The webhook handler is missing error handling, please fix it"
"Summarize what was done so far"

string

Override the model for this follow-up run. If you set model, you must also set agent (see the inheritance rule below). Omit both to keep the original run’s model.Example: "blackboxai/anthropic/claude-opus-4.7" — see Models for all available IDs.

string

Explicit agent runtime for this turn — "claude" or "codex". Required whenever you change model (or otherwise override the runtime). Omit — together with model — to inherit the original run’s runtime.

Runtime inheritance rule. Continuation is designed so a plain follow-up “just continues” on the same setup:

Neither model nor agent specified → the follow-up inherits the original run’s model and agent runtime (even an explicit codex+opus override is preserved).
model and/or agent specified → you are overriding, so agent is required. This prevents a model swap from silently flipping the runtime. Omitting agent while setting model returns 400.

Example — continue on Codex with an Opus model: { "prompt": "...", "model": "blackboxai/anthropic/claude-opus-4.7", "agent": "codex" }.

Response Fields

string

Unique identifier for the new agent run. Use this to poll status or stream logs.

string

ID of the assistant message being generated for this follow-up.

string

UUID of the shared chat thread (same as the original task’s chatId).

string

The runId of the task that was continued (the path parameter).

How Continuation Works

Context restored — The agent loads the full message history from the shared chatId
GitHub context restored — If the original task had a repo, the agent continues from the branch it created (githubCreatedBranch)
New run created — A fresh agent run is spawned with the follow-up prompt appended to the conversation
New runId returned — Use the new runId to track this follow-up independently

curl -X POST 'https://agent.blackbox.ai/api/v1/tasks/a1b2c3d4-e5f6-7890-abcd-ef1234567890/continue' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "prompt": "Now add unit tests for the new payment module"
  }'

curl -X POST 'https://agent.blackbox.ai/api/v1/tasks/a1b2c3d4-e5f6-7890-abcd-ef1234567890/continue' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "prompt": "Refactor the authentication logic to use middleware",
    "model": "blackboxai/anthropic/claude-opus-4.7"
  }'

const API_KEY = "YOUR_API_KEY";
const PREVIOUS_RUN_ID = "a1b2c3d4-e5f6-7890-abcd-ef1234567890";

const response = await fetch(
  `https://agent.blackbox.ai/api/v1/tasks/${PREVIOUS_RUN_ID}/continue`,
  {
    method: "POST",
    headers: {
      Authorization: `Bearer ${API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      prompt: "Now add unit tests for the new payment module",
    }),
  }
);

const data = await response.json();
console.log(`New runId: ${data.runId}`);
console.log(`ChatId: ${data.chatId}`);

// Poll the new run for completion
const DONE = ["completed", "failed", "cancelled", "interrupted"];
while (true) {
  const statusRes = await fetch(
    `https://agent.blackbox.ai/api/v1/tasks/${data.runId}/status`,
    { headers: { Authorization: `Bearer ${API_KEY}` } }
  );
  const s = await statusRes.json();
  console.log(`${s.status} — ${s.progress}%`);
  if (DONE.includes(s.status)) break;
  await new Promise(r => setTimeout(r, 3000));
}

import requests
import time

API_KEY = "YOUR_API_KEY"
PREVIOUS_RUN_ID = "a1b2c3d4-e5f6-7890-abcd-ef1234567890"

headers = {
    "Authorization": f"Bearer {API_KEY}",
    "Content-Type": "application/json",
}

# Continue the task
response = requests.post(
    f"https://agent.blackbox.ai/api/v1/tasks/{PREVIOUS_RUN_ID}/continue",
    headers=headers,
    json={"prompt": "Now add unit tests for the new payment module"},
)
data = response.json()
new_run_id = data["runId"]
print(f"New runId: {new_run_id}")

# Poll until done
DONE = {"completed", "failed", "cancelled", "interrupted"}
while True:
    s = requests.get(
        f"https://agent.blackbox.ai/api/v1/tasks/{new_run_id}/status",
        headers={"Authorization": f"Bearer {API_KEY}"},
    ).json()
    print(f"{s['status']} — {s['progress']}%")
    if s["status"] in DONE:
        break
    time.sleep(3)

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "io"
    "net/http"
)

func main() {
    apiKey := "YOUR_API_KEY"
    previousRunId := "a1b2c3d4-e5f6-7890-abcd-ef1234567890"
    url := fmt.Sprintf("https://agent.blackbox.ai/api/v1/tasks/%s/continue", previousRunId)

    body, _ := json.Marshal(map[string]string{
        "prompt": "Now add unit tests for the new payment module",
    })

    req, _ := http.NewRequest("POST", url, bytes.NewBuffer(body))
    req.Header.Set("Authorization", "Bearer "+apiKey)
    req.Header.Set("Content-Type", "application/json")

    client := &http.Client{}
    resp, _ := client.Do(req)
    defer resp.Body.Close()

    respBody, _ := io.ReadAll(resp.Body)
    fmt.Println(string(respBody))
}

{
  "runId": "c3d4e5f6-a7b8-9012-cdef-123456789012",
  "assistantMessageId": "msg_new_run_abc123",
  "chatId": "chat_def789ghi012",
  "previousRunId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890"
}

{
  "error": "Task not found"
}

{
  "error": "prompt: prompt is required"
}

{
  "error": "Claude Agent requires a Pro subscription. Please upgrade at https://www.blackbox.ai/pricing"
}

Error Codes

Status Code	Error	Description
200	Success	Follow-up run started successfully
400	Bad Request	Missing `prompt` or invalid JSON
401	Unauthorized	Invalid or missing API key
403	Forbidden	Pro subscription required, task belongs to another user, or no API key configured
404	Not Found	Previous task not found
500	Internal Server Error	Failed to spawn agent

Getting Started

API Reference

Authentication

GitHub Connection Required

Headers

Path Parameters

Request Body

Response Fields

How Continuation Works

Error Codes

​Authentication

​GitHub Connection Required

​Headers

​Path Parameters

​Request Body

​Response Fields

​How Continuation Works

​Error Codes

Authentication

GitHub Connection Required

Headers

Path Parameters

Request Body

Response Fields

How Continuation Works

Error Codes