One prompt. A finished book.

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FAQ

Common questions about the Nellie API.


General

What is the Nellie API?

The Nellie API allows you to generate novels, comics, manga, and other written books using AI. You send a prompt, and Nellie generates a complete, formatted book.

What can I create with the API?

Any type of book can be created with Nellie. For example:

  • Novels: Full-length fiction
  • Short stories: Brief narratives
  • Comics: Illustrated comic books
  • Manga: Japanese-style comics
  • Children’s books: Illustrated stories for kids
  • Non-fiction: Factual content and historical events
  • Textbooks: Educational material
  • Self-help: Personal development content and guides

What formats can I export to?

  • txt: Plain text
  • pdf: PDF document
  • epub: E-book format
  • md: Markdown
  • html: Web page
  • json: Structured data for custom delivery and apps

How long does generation take?

Typical generation times:

Type/ModelTime
Nellie 2.0 no images15 minutes
Nellie 2.0 with images45 minutes
Nellie 3.0 no images30 minutes
Nellie 3.0 with images60 minutes

Authentication

How do I get an API key?

  1. Open the Nellie mobile app
  2. Go to Settings (User icon) → API Management
  3. Or visit https://app.nelliewriter.com/api
  4. Go to the ‘API Keys’ tab
  5. Click “Create Key”
  6. Copy and save your key immediately

Why can’t I see my API key again?

For security, keys are only shown once at creation. If you lose your key, you’ll need to create a new one and revoke the old one.

Can I have multiple API keys?

Yes, you can create multiple keys for different environments (development, staging, production) or different applications. Each key has its own rate limits but shares your credit pool.

My key stopped working. What happened?

Possible causes:

  • Key was entered incorrectly (check for typos)
  • Ran out of credits
  • Key was revoked in the dashboard
  • Rate limits exceeded
  • Account issues

Check the dashboard to verify your key is active.


Rate Limits & Credits

What are the rate limits?

  • Burst limit: 1 request per 6 seconds
  • Daily limit: 15 requests per day per API key

How do I check my remaining credits?

from nellie_api import Nellie

client = Nellie()
usage = client.get_usage()
print(f"Credits used: {usage.total_credits_used}")

Or check in the Nellie app on the Wallet page, or on the website at https://app.nelliewriter.com/wallet.

How much does generation cost?

ModelCredits per Book
Nellie 2.0250 credits
Nellie 3.0500 credits

Can I create or finish template books with the API?

Currently you cannot create or finish book templates with the API, this is only a feature within the Nellie app. Please contact us if you believe this feature should be added to the API.

What happens if I run out of credits?

Jobs will fail with “Insufficient credits” error. Purchase more credits in the Nellie app or on the site to continue.

Do failed jobs cost credits?

No, credits are only charged for successfully completed generations. If you are charged for an unsuccessful generation, please do not try again as it may be due to an account issue, and contact us at support@buzzleco.com.

How do I get more credits?

Purchase credits through the Nellie mobile app or web dashboard.

Can I get higher rate limits?

Contact support@buzzleco.com for enterprise plans with higher limits.


Generation

Do I need to provide a prompt?

No! All parameters are optional. If you don’t provide a prompt, Nellie will generate a unique creative prompt automatically.

What makes a good prompt?

Good prompts include:

  • Clear premise or concept
  • Setting description
  • Tone/mood guidance

Example:

A mystery novel set in 1920s Paris. The protagonist is a jazz musician 
who witnesses a murder at a speakeasy. Tone should be atmospheric with 
witty dialogue. Include a romantic subplot.

What’s the difference between 2.0 and 3.0?

AspectNellie 2.0Nellie 3.0
Cost250 credits500 credits
SpeedFasterSlower
Plot complexityExcellentExcellent
Character depthGoodExcellent
ConsistencyGoodExcellent
Image QualityGoodExcellent
Characters in ImagesNoYes

Use 2.0 for quicker stories or high volume. Use 3.0 for complex narratives requiring deep focus.

Can I generate images?

Yes! Set images: true in your request. Nellie will generate plot relevant AI illustrations throughout the book. This increases generation time but not credit cost.

What styles are available?

Unlimited genres including: action, adventure, comedy, crime, cyberpunk, drama, fantasy, gothic, horror, mystery, noir, romance, sci-fi, thriller, western, and more. Set to ‘automatic’ to dynamically determine a genre based on the prompt.

Use GET /v1/configuration to see all available options.

Can I control the length?

The length is automatically determined based on the type and the complexity of your prompt. Currently there’s no direct length control parameter. Please contact us if you believe this feature should be added to the API.

What if my generation fails?

Check the error message in the status response. Common causes:

  • Insufficient credits
  • Content policy violation
  • Server issues

Failed jobs don’t consume credits. You can retry after addressing the issue. If you are charged for an unsuccessful generation, please do not try again as it may be due to an account issue, and contact us at support@buzzleco.com.


Webhooks

Should I use webhooks or polling?

Webhooks are recommended when possible. They:

  • Notify you immediately when done
  • Don’t require repeated API calls
  • Are more efficient

Use polling if you can’t set up a webhook endpoint.

How do I set up webhooks?

  1. Create a public HTTPS endpoint
  2. Include webhook_url in your generation request
  3. Nellie will POST results to your URL when complete

Why isn’t my webhook receiving calls?

Check:

  • URL is publicly accessible
  • URL uses HTTPS (not HTTP)
  • SSL certificate is valid
  • Server responds within 30 seconds
  • Firewall allows incoming connections

How do I verify webhook signatures?

from nellie_api import Webhook, WebhookSignatureError

try:
    event = Webhook.construct_event(
        payload=request.data,
        sig_header=request.headers.get("X-Nellie-Signature"),
        secret="whsec_your_secret"
    )
except WebhookSignatureError:
    return "Invalid signature", 400

Where do I find my webhook secret?

In the Nellie app or website: Settings (User icon) → API Management → Webhooks tab


Technical

What HTTP methods are used?

EndpointMethod
/v1/bookPOST
/v1/status/{id}GET
/v1/configurationGET
/v1/modelsGET
/v1/usageGET

Is the API RESTful?

Yes, the API follows REST conventions with:

  • Resource-based URLs
  • Standard HTTP methods
  • JSON request/response bodies
  • Stateless requests

What’s the base URL?

https://api.nelliewriter.com/v1

Is there SDK support?

Yes! We provide an official Python SDK:

pip install nellie-api

Does the API support CORS?

The API is designed for server-side use. For browser applications, call the API through your own backend.

How long are result URLs valid?

The download endpoint (/v1/download/{requestId}) works indefinitely and generates a fresh signed URL on each request. Each signed URL is valid for 1 hour. If it expires, simply request the download endpoint again to get a new one.


Errors

“Unauthorized”: what’s wrong?

  • Check X-API-Key header is present
  • Verify key starts with nel_
  • Confirm key hasn’t been revoked

“Rate limit exceeded”: how long to wait?

  • Burst limit: Wait at least 6 seconds
  • Daily limit: Wait until 24 hours from first request of the day. Contact us if you need higher daily limits

“Invalid parameter”: how to fix?

Check valid values using:

config = client.get_configuration()
print(config.styles)  # Valid styles
print(config.types)   # Valid types
print(config.formats) # Valid formats

Generation failed with no error message?

Check the messages array in the status response for details:

status = client.books.retrieve(request_id)
print(status.messages)

Billing & Account

How is billing calculated?

Credits are pre-purchased and deducted per successful generation. Costs vary by model.

Can I get a refund for failed generations?

Failed generations don’t consume credits, so no refund is needed. If you are charged for an unsuccessful generation, please do not try again as it may be due to an account issue, and contact us at support@buzzleco.com.

Is there a free tier?

Check the Nellie app for current pricing and any free trial offers. New accounts in the app get one free template generation that they can complete later for no additional cost or impact on final quality.

How do I cancel my subscription?

Manage your subscription through your mobile device-specific store settings or the nellie website for subscriptions started on the web.


Who owns the generated content?

You own the content generated through your account. See our Terms and Conditions for full details.

Can I use generated content commercially?

Yes, content generated through the API can be used commercially. Review our Terms and Conditions for full details.

Is generated content copyrighted?

Generated content created by AI has complex copyright implications that vary by jurisdiction. We recommend consulting with a up-to-date legal documentation.

What content restrictions exist?

The API enforces content policies prohibiting:

  • Explicit adult content
  • Violence promotion
  • Hate speech
  • Copyright infringement
  • Other harmful content

Prompts violating these policies will be rejected, and if they are terminated mid-generation a refund will not be provided.


Getting More Help

Where can I find code examples?

How do I report a bug?

Email support@buzzleco.com with:

  • Request ID (if applicable)
  • Full error message
  • Steps to reproduce
  • Code snippet (without API keys)

Where can I request features?

Email feedback to support@buzzleco.com or use the feedback form at https://nelliewriter.com/contact.