Public API v1

Base URL

https://api.verba.ink

How the API works (short answer)

Create an API key in Dashboard -> Settings -> Security -> API Keys (Pro and Ultra plans).
Call POST /v1/response with character + messages.
Save the returned session_id and reuse it for follow-up requests.
Use stream: true for SSE streaming on Ultra plans.
Use POST /v1/image when you need image generation.

Minimal text request:

{
  "character": "mycharacter_abc",
  "messages": [
    { "role": "user", "content": "How does the API work?" }
  ]
}

Fast answers

Base URL: https://api.verba.ink
Text endpoint: POST /v1/response
Image endpoint: POST /v1/image
Auth: Authorization: Bearer vka_... or x-api-key: vka_...
Session memory: reuse session_id on later calls to continue context
API access: Pro and Ultra plans
Streaming: stream: true on /v1/response (Ultra)
Image generation allowance: Free 20/mo, Plus 50/mo, Pro 100/mo, Ultra unlimited
Message count limit: up to 60 items in messages
Message size limits: each message text up to 4000 chars, total up to 20000 chars
Session ID format: optional, max 128 chars, allowed chars A-Z a-z 0-9 : _ -
Image URL limit: up to 4 combined URLs
Tool limits: up to 8 tool definitions, up to 2 executed tool calls per request

Request limits (fast reference)

Field	Limit
`messages` length	`60` max
Per-message text	`4000` chars max
Total text across `messages`	`20000` chars max
`session_id`	optional, `128` chars max
`image_urls` (combined)	`4` max
`tools` definitions	`8` max
Executed tool calls	`2` max per request
`/v1/image` prompt	`1500` chars max
`/v1/image` size	only `1024x1024`

Quick start

Create an API key

Go to Verba Settings -> Security -> API Keys and create a key. API keys are available on Pro and Ultra plans.

Pick a character

Use your character vanity slug or vanity URL (for example mycharacter_abc or https://verba.ink/v/mycharacter_abc).

Call an endpoint

Use POST /v1/response for text replies, or POST /v1/image for image generation.

Authentication

Send your API key in either header:

Authorization: Bearer vka_...
x-api-key: vka_...

If no key is provided, or the key is invalid/revoked, the API returns 401.

API key quick facts

API key prefix is vka_.
Maximum active keys per account: 3.
Key revocation is immediate.

Character identifier

Both endpoints use character (not verb_id). Accepted formats:

Vanity slug: mycharacter_abc
Vanity path: /v/mycharacter_abc
Full vanity URL: https://verba.ink/v/mycharacter_abc

Endpoints

POST /v1/response for text chat completions
POST /v1/image for image generation

POST `/v1/response`

Text completion endpoint. You can optionally attach image URLs for vision-enabled prompting.

Supports both standard JSON and streaming. Set stream: true to receive Server-Sent Events (SSE) chunks.

Streaming on /v1/response is available on Ultra plans.

Required:

character string (vanity URL or vanity slug)
messages array (role + content)

Optional:

session_id string
temperature number (0..2)
top_p number (0..1)
max_tokens number
stream boolean (true for SSE stream, default false)
image_urls array of image URLs (http/https, max 4)
tools array (OpenAI-style function tools, max 8)
tool_choice ("auto" or "none")
debug object ({ "tools": true } to include tool traces)

Session memory on `/v1/response`

How it works:

Send your first request with or without session_id.
If omitted, the API generates one and returns it in the response.
Reuse that same session_id in later requests to keep context for that caller + character.

If you use a new session_id, you start a new conversation state. messages[].content supports:

String text content
Array parts with:
- { "type": "text", "text": "..." }
- { "type": "image_url", "image_url": { "url": "https://..." } }

You can pass image URLs either in messages[].content or top-level image_urls (both are merged, max 4 total). You cannot pass custom system messages on /v1/response; character personality + system instructions are applied automatically. Tool configuration is request-scoped only (not stored on your character/dashboard).

Request examples

curl https://api.verba.ink/v1/response \
  -X POST \
  -H "Authorization: Bearer $VERBA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "character": "mycharacter_abc",
    "messages": [
      { "role": "user", "content": "Tell me a short story about space pirates." }
    ],
    "stream": false
  }'

const response = await fetch("https://api.verba.ink/v1/response", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.VERBA_API_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    character: "mycharacter_abc",
    messages: [
      { role: "user", content: "Tell me a short story about space pirates." }
    ],
    stream: false
  })
});

const data = await response.json();
console.log(data);

import os
import requests

response = requests.post(
    "https://api.verba.ink/v1/response",
    headers={
        "Authorization": f"Bearer {os.environ['VERBA_API_KEY']}",
        "Content-Type": "application/json",
    },
    json={
        "character": "mycharacter_abc",
        "messages": [
            {"role": "user", "content": "Tell me a short story about space pirates."}
        ],
        "stream": False,
    },
    timeout=60,
)

print(response.status_code)
print(response.json())

$headers = @{
  Authorization = "Bearer $env:VERBA_API_KEY"
  "Content-Type" = "application/json"
}

$body = @{
  character = "mycharacter_abc"
  messages = @(
    @{
      role = "user"
      content = "Tell me a short story about space pirates."
    }
  )
  stream = $false
} | ConvertTo-Json -Depth 10

Invoke-RestMethod `
  -Method Post `
  -Uri "https://api.verba.ink/v1/response" `
  -Headers $headers `
  -Body $body

Session memory example

First call:

{
  "character": "mycharacter_abc",
  "messages": [
    { "role": "user", "content": "My name is Sam. Remember that." }
  ]
}

Response includes session_id:

{
  "session_id": "sess_abc123",
  "choices": [
    {
      "message": {
        "role": "assistant",
        "content": "Got it, Sam."
      }
    }
  ]
}

Follow-up call (same session):

{
  "character": "mycharacter_abc",
  "session_id": "sess_abc123",
  "messages": [
    { "role": "user", "content": "What's my name?" }
  ]
}

Vision input example

{
  "character": "mycharacter_abc",
  "messages": [
    {
      "role": "user",
      "content": [
        { "type": "text", "text": "Describe what is happening here." },
        { "type": "image_url", "image_url": { "url": "https://example.com/city.jpg" } }
      ]
    }
  ],
  "stream": false
}

Request-scoped tool calling

/v1/response supports server-executed HTTP function tools passed in the request.

Tools are not persisted.
Allowed methods: GET, POST.
Tool URLs support only http/https on ports 80 or 443.
Local/private network targets are blocked.
Tool responses must be application/json (or +json) or text/plain.
Max executed tool calls per request: 2.
Tool requests execute through Verba-managed outbound egress.
Built-in character webSearch remains separate and unchanged.

Tool object shape:

{
  "type": "function",
  "function": {
    "name": "search_web",
    "description": "Search latest web results",
    "parameters": {
      "type": "object",
      "properties": {
        "query": { "type": "string" }
      },
      "required": ["query"]
    },
    "x_verba_http": {
      "url": "https://example.com/search",
      "method": "GET",
      "query_param": "q",
      "headers": {
        "Authorization": "Bearer sk_live_..."
      },
      "timeout_ms": 8000
    }
  }
}

tool_choice supports:

"auto" (default model decides)
"none" (disable tool calls for this request)

How auto works:

Verba first lets the model decide natively (provider tool_calls if supported).
If the provider does not emit native tool_calls, Verba runs an internal model planner step to decide whether one tool should be used.
This preserves model-driven behavior while improving compatibility across providers.

When debug.tools=true:

Non-stream response includes debug.tool_runs[].
Stream response emits extra SSE frames with object: "chat.completion.tool_trace".

Tool example (`GET` web search)

{
  "character": "mycharacter_abc",
  "messages": [
    { "role": "user", "content": "What happened in AI this week?" }
  ],
  "tools": [
    {
      "type": "function",
      "function": {
        "name": "search_web",
        "description": "Search web headlines",
        "parameters": {
          "type": "object",
          "properties": {
            "query": { "type": "string" }
          },
          "required": ["query"]
        },
        "x_verba_http": {
          "url": "https://example-search-api.com/search",
          "method": "GET",
          "query_param": "q",
          "headers": {
            "Authorization": "Bearer sk_live_..."
          }
        }
      }
    }
  ],
  "tool_choice": "auto",
  "debug": { "tools": true }
}

Tool example (`POST` JSON)

{
  "character": "mycharacter_abc",
  "messages": [
    { "role": "user", "content": "Fetch weather for Paris and summarize it." }
  ],
  "tools": [
    {
      "type": "function",
      "function": {
        "name": "weather_lookup",
        "description": "Return weather by city",
        "parameters": {
          "type": "object",
          "properties": {
            "city": { "type": "string" }
          },
          "required": ["city"]
        },
        "x_verba_http": {
          "url": "https://example.com/weather",
          "method": "POST",
          "headers": {
            "Authorization": "Bearer sk_live_..."
          },
          "body_mode": "json"
        }
      }
    }
  ]
}

Example response

{
  "id": "chatcmpl_...",
  "object": "chat.completion",
  "created": 1739730000,
  "model": "m_free_a",
  "character": "mycharacter_abc",
  "session_id": "sess_...",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "..."
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 0,
    "completion_tokens": 0,
    "total_tokens": 0
  }
}

Example response addition when debug.tools=true:

{
  "debug": {
    "tool_runs": [
      {
        "tool_name": "search_web",
        "method": "GET",
        "url": "https://example-search-api.com/search?q=ai",
        "status": "success",
        "http_status": 200,
        "duration_ms": 412,
        "request_preview": { "query": { "q": "ai" } },
        "response_preview": { "results": [{ "title": "..." }] }
      }
    ]
  }
}

Streaming (`stream: true`)

With stream: true, /v1/response returns text/event-stream and emits data: events.

Each event is an OpenAI-style chat.completion.chunk payload.
If debug.tools=true and tools run, extra events use object: "chat.completion.tool_trace".
The final event is data: [DONE].
You should concatenate choices[0].delta.content chunks to build the assistant message.
Free, Plus, and Pro plans return 403 stream_plan_upgrade_required when stream: true is used.

Example chunk:

{
  "id": "chatcmpl_...",
  "object": "chat.completion.chunk",
  "created": 1739730000,
  "model": "m_free_a",
  "character": "mycharacter_abc",
  "session_id": "sess_...",
  "choices": [
    {
      "index": 0,
      "delta": { "content": "Hello" },
      "finish_reason": null
    }
  ]
}

Final chunk:

{
  "id": "chatcmpl_...",
  "object": "chat.completion.chunk",
  "created": 1739730000,
  "model": "m_free_a",
  "character": "mycharacter_abc",
  "session_id": "sess_...",
  "choices": [
    {
      "index": 0,
      "delta": {},
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 0,
    "completion_tokens": 0,
    "total_tokens": 0
  }
}

Then:

data: [DONE]

Streaming request examples

curl -N https://api.verba.ink/v1/response \
  -X POST \
  -H "Authorization: Bearer $VERBA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "character": "mycharacter_abc",
    "messages": [
      { "role": "user", "content": "Give me a short greeting." }
    ],
    "stream": true
  }'

const response = await fetch("https://api.verba.ink/v1/response", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.VERBA_API_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    character: "mycharacter_abc",
    messages: [{ role: "user", content: "Give me a short greeting." }],
    stream: true
  })
});

const reader = response.body.getReader();
const decoder = new TextDecoder();
let buffer = "";

while (true) {
  const { done, value } = await reader.read();
  if (done) break;

  buffer += decoder.decode(value, { stream: true });
  const events = buffer.split("\\n\\n");
  buffer = events.pop() || "";

  for (const event of events) {
    if (!event.startsWith("data:")) continue;
    const data = event.slice(5).trim();
    if (data === "[DONE]") {
      process.stdout.write("\\n");
      continue;
    }
    const chunk = JSON.parse(data);
    const delta = chunk.choices?.[0]?.delta?.content;
    if (delta) process.stdout.write(delta);
  }
}

import json
import os
import requests

response = requests.post(
    "https://api.verba.ink/v1/response",
    headers={
        "Authorization": f"Bearer {os.environ['VERBA_API_KEY']}",
        "Content-Type": "application/json",
    },
    json={
        "character": "mycharacter_abc",
        "messages": [{"role": "user", "content": "Give me a short greeting."}],
        "stream": True,
    },
    stream=True,
    timeout=120,
)

for line in response.iter_lines(decode_unicode=True):
    if not line or not line.startswith("data:"):
        continue
    data = line[5:].strip()
    if data == "[DONE]":
        print()
        break
    chunk = json.loads(data)
    delta = (((chunk.get("choices") or [{}])[0].get("delta") or {}).get("content"))
    if delta:
        print(delta, end="", flush=True)

$json = @{
  character = "mycharacter_abc"
  messages = @(
    @{
      role = "user"
      content = "Give me a short greeting."
    }
  )
  stream = $true
} | ConvertTo-Json -Depth 10

$http = [System.Net.Http.HttpClient]::new()
$request = New-Object System.Net.Http.HttpRequestMessage([System.Net.Http.HttpMethod]::Post, "https://api.verba.ink/v1/response")
$request.Headers.Authorization = [System.Net.Http.Headers.AuthenticationHeaderValue]::new("Bearer", $env:VERBA_API_KEY)
$request.Content = New-Object System.Net.Http.StringContent($json, [System.Text.Encoding]::UTF8, "application/json")

$response = $http.SendAsync($request, [System.Net.Http.HttpCompletionOption]::ResponseHeadersRead).Result
$stream = $response.Content.ReadAsStreamAsync().Result
$reader = New-Object System.IO.StreamReader($stream)

while (-not $reader.EndOfStream) {
  $line = $reader.ReadLine()
  if (-not $line -or -not $line.StartsWith("data:")) { continue }
  $data = $line.Substring(5).Trim()
  if ($data -eq "[DONE]") { break }
  $chunk = $data | ConvertFrom-Json
  $delta = $chunk.choices[0].delta.content
  if ($delta) { Write-Host -NoNewline $delta }
}
Write-Host ""

Streaming with tools works the same way: the API executes tool calls server-side first, then streams final assistant text chunks.

{
  "character": "mycharacter_abc",
  "messages": [{ "role": "user", "content": "Find and summarize today's top AI headline." }],
  "stream": true,
  "tools": [
    {
      "type": "function",
      "function": {
        "name": "search_web",
        "parameters": {
          "type": "object",
          "properties": { "query": { "type": "string" } },
          "required": ["query"]
        },
        "x_verba_http": {
          "url": "https://example-search-api.com/search",
          "method": "GET",
          "query_param": "q"
        }
      }
    }
  ],
  "debug": { "tools": true }
}

POST `/v1/image`

Generates one image URL.

Image generation is limited monthly by the character owner’s plan: Free 20, Plus 50, Pro 100, and Ultra unlimited.

Required:

character string (vanity URL or vanity slug)
prompt string

Optional:

session_id string
image_urls string array (reference images)
size (1024x1024 only)
response_format (url only)

Request examples

curl https://api.verba.ink/v1/image \
  -X POST \
  -H "Authorization: Bearer $VERBA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "character": "mycharacter_abc",
    "prompt": "A cinematic portrait of a cyberpunk fox detective",
    "size": "1024x1024",
    "response_format": "url"
  }'

const response = await fetch("https://api.verba.ink/v1/image", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.VERBA_API_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    character: "mycharacter_abc",
    prompt: "A cinematic portrait of a cyberpunk fox detective",
    size: "1024x1024",
    response_format: "url"
  })
});

const data = await response.json();
console.log(data);

import os
import requests

response = requests.post(
    "https://api.verba.ink/v1/image",
    headers={
        "Authorization": f"Bearer {os.environ['VERBA_API_KEY']}",
        "Content-Type": "application/json",
    },
    json={
        "character": "mycharacter_abc",
        "prompt": "A cinematic portrait of a cyberpunk fox detective",
        "size": "1024x1024",
        "response_format": "url",
    },
    timeout=120,
)

print(response.status_code)
print(response.json())

$headers = @{
  Authorization = "Bearer $env:VERBA_API_KEY"
  "Content-Type" = "application/json"
}

$body = @{
  character = "mycharacter_abc"
  prompt = "A cinematic portrait of a cyberpunk fox detective"
  size = "1024x1024"
  response_format = "url"
} | ConvertTo-Json -Depth 10

Invoke-RestMethod `
  -Method Post `
  -Uri "https://api.verba.ink/v1/image" `
  -Headers $headers `
  -Body $body

Example response

{
  "created": 1739730000,
  "character": "mycharacter_abc",
  "session_id": "sess_...",
  "model": "m_free_a",
  "revised_prompt": "A cinematic portrait of a cyberpunk fox detective",
  "data": [
    {
      "url": "https://api.verba.ink/uploads/generated-images/img_...png"
    }
  ]
}

Sessions and memory

session_id is optional.
If omitted, Verba generates one and returns it.
Reusing the same session_id preserves API conversation context for that caller + verb pair.
API memory is stored in conversation history only (not DM or message logs).

Access, billing, and limits

API access is available on Pro and Ultra plans.
Verb privacy still applies:
- Private characters: owner only
- Public characters: any API caller
Billing and tier/model enforcement are applied to the character owner account.
/v1/* uses account rate limits via the same per-user limiter model.

Message format (`/v1/response`)

messages must be an array.
Include at least one user message.
Allowed roles: user, assistant (assistant maps internally to model role).
system role is blocked on /v1/response to prevent overriding character instructions.
messages[].content supports text and image_url parts.
Top-level image_urls is also supported.
Combined image URL limit is 4.
tools is optional and request-scoped (max 8 per request).
tool_choice is optional (auto or none).

Error model

Errors return JSON with a top-level message and an error object.

{
  "message": "stream must be a boolean",
  "error": {
    "message": "stream must be a boolean",
    "type": "invalid_stream",
    "code": 400
  }
}

error.type: stable machine-readable error type (for program logic)
error.code: HTTP status code

Common error cases:

401 invalid_api_key for missing/invalid/revoked API key
403 verb_access_denied for private character access by non-owner
403 api_plan_upgrade_required when the API key owner is not on Pro or Ultra
403 stream_plan_upgrade_required when a non-Ultra plan requests stream: true
403 insufficient_credits when the character owner has no credits for the selected model
403 image_limit_reached when the character owner has reached their monthly image generation allowance
400 invalid_message_role when system role is provided in messages
400 invalid_stream when stream is not a boolean
400 invalid_tools for malformed tool schema/config
400 invalid_tool_choice for invalid tool_choice
400 blocked_tool_url when tool URL targets local/private hosts
400 tool_call_limit_exceeded when model attempts more than 2 tool calls
400 invalid_image_urls when image URL payload format is invalid
400 blocked_image_url when image URL targets local/private network hosts
400 too_many_image_urls when more than 4 image URLs are provided
502 tool_proxy_unavailable when managed outbound tool egress is unavailable
502 tool_execution_failed when upstream tool execution fails
400 invalid_size when /v1/image size is not 1024x1024

Getting Started

Build and Customize

Chat and Community

Media and Voice

Deploy and Integrate

Safety and Privacy

Billing and Accounts

Help and FAQ

Base URL

How the API works (short answer)

Fast answers

Request limits (fast reference)

Quick start

Authentication

API key quick facts

Character identifier

Endpoints

POST `/v1/response`

Session memory on `/v1/response`

Request examples

Session memory example

Vision input example

Request-scoped tool calling

Tool example (`GET` web search)

Tool example (`POST` JSON)

Example response

Streaming (`stream: true`)

Streaming request examples

POST `/v1/image`

Request examples

Example response

Sessions and memory

Access, billing, and limits

Message format (`/v1/response`)

Error model

​Base URL

​How the API works (short answer)

​Fast answers

​Request limits (fast reference)

​Quick start

​Authentication

​API key quick facts

​Character identifier

​Endpoints

​POST /v1/response

​Session memory on /v1/response

​Request examples

​Session memory example

​Vision input example

​Request-scoped tool calling

​Tool example (GET web search)

​Tool example (POST JSON)

​Example response

​Streaming (stream: true)

​Streaming request examples

​POST /v1/image

​Request examples

​Example response

​Sessions and memory

​Access, billing, and limits

​Message format (/v1/response)

​Error model

Base URL

How the API works (short answer)

Fast answers

Request limits (fast reference)

Quick start

Authentication

API key quick facts

Character identifier

Endpoints

POST `/v1/response`

Session memory on `/v1/response`

Request examples

Session memory example

Vision input example

Request-scoped tool calling

Tool example (`GET` web search)

Tool example (`POST` JSON)

Example response

Streaming (`stream: true`)

Streaming request examples

POST `/v1/image`

Request examples

Example response

Sessions and memory

Access, billing, and limits

Message format (`/v1/response`)

Error model