Novel writing software with AI built in

Write long.AI reads back before it writes.

Outline, characters, foreshadowing and manuscript live in one place. Before the AI continues or revises, it checks what you have already written.

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macOS available · Windows coming soon

The Letter in the Trunk

Vol. 1 · Mist Town / In progress · 141 / 3,000 words

closed her hand around the . She did not offer it to . It had been her father’s; the teeth were polished bright, and her thumb rested on the bow as if holding down a name she would not say.

“You open it.” stepped back. “The trunk has waited ten years for me. It can wait another moment.”

The lock clicked. went down first. Lamplight reached the writing on the lid: his handwriting from ten years ago, not a stroke faded. She asked no question. She only moved the lamp closer.

Inside lay a new letter. The address was still blank, but the sealing wax was soft. As reached for it, caught the edge of the trunk.

“Let us look first,” she said. This time, she had said us.

Draft chapter four after chapter three. Have Lin Wan open the cellar with her father’s brass key and build her trust with Shen Yu. Do not reveal who sent the letter yet.

I’ll continue from the cellar trunk and keep the sender a mystery.

From the manuscript: chapter three establishes that the key belonged to Lin Wan’s father. The trunk bears Shen Yu’s handwriting from ten years ago.

Character constraint: Lin Wan is quiet and stubborn. She would not suddenly hand over her father’s keepsake.

Chapter plan: she opens the door → Shen Yu steps back → they examine the new letter together.

Trust develops through action rather than an explicit confession.

The new letter has no address, but its sealing wax is still soft: a question for the next chapter.

Chapter four is drafted. The key’s history carries through, and the sender remains unknown.

Click an underlined name in the manuscript to see its notes.

Writing a long novel in an AI chat? You have probably run into these.

How NovelThread handles it

Chapter one

Let AI draft the next chapter from your latest outline

Before it writes, the AI reads the previous chapters, this chapter’s plan and where each plotline stands. If the plan saves a reveal for later, it keeps the secret.

The Letter in the Trunk

Vol. 1 · Mist Town / In progress · 141 / 3,000 words

Lin Wan closed her hand around the brass key. She did not offer it to Shen Yu. It had been her father’s; the teeth were polished bright, and her thumb rested on the bow as if holding down a name she would not say.

“You open it.” Shen Yu stepped back. “The trunk has waited ten years for me. It can wait another moment.”

The lock clicked. Lin Wan went down first. Lamplight reached the writing on the lid: his handwriting from ten years ago, not a stroke faded. She asked no question. She only moved the lamp closer.

Chapter two

Click a character’s name to see their notes

Characters, places and objects are marked in the manuscript. Click one to read its notes without leaving the page or searching old chats.

Prologue to Mist Town

Vol. 1 · Mist Town / In progress · 64 / 3,000 words

The fog had not lifted when the boat docked. Shen Yu swung his canvas bag over his shoulder and jumped onto the wet stone steps.

The old post office was lit. Behind the counter sat Lin Wan, holding an addressless letter up to the lamp, reading it over and over.

"Ten years," she said without looking up. "You finally came back for your letter."

Chapter three

Rewrite only the passage you select

The original stays in place, struck through, while the new version is written beneath it. Ask for up to three versions, keep the one you like or discard them all.

The Letter in the Trunk

Vol. 1 · Mist Town / In progress · 141 / 3,000 words

“You open it.” Shen Yu stepped back. “The trunk has waited ten years for me. It can wait another moment.”

The lock clicked. Lin Wan went down first. Lamplight reached the writing on the lid: his handwriting from ten years ago, not a stroke faded. She asked no question. She only moved the lamp closer.

The lock gave with a hard click. Lin Wan went down first. The lamp swung and caught the writing on the lid: his hand, ten years old, not one stroke faded. Her throat tightened. She did not ask. She only edged the lamp closer.

Inside lay a new letter. The address was still blank, but the sealing wax was soft. As Shen Yu reached for it, Lin Wan caught the edge of the trunk.

Chapter four

See what every chapter is for, on one page

Each chapter’s goal, point-of-view character and word count sit side by side. One look tells you what to write today.

One line per chapter: goal, POV, threads tied off. Edit the outline and chapter goals follow.

Volumes

Vol. 1 · Mist Town

4 chapters · 291 words in total

01
Chapter POV
64 words
02
Chapter POV
44 words
03
Chapter POV
42 words
04
Chapter POV
141 words

Try it yourself

This demo is clickable. It does not call an AI or save anything.

Global chat

Mist-Town Letters

Pick up your story. Draft the next chapter.

Three chapters, character notes, and a chapter goal are ready. Watch the agent consult them and draft chapter four.

Click send to start

Draft chapter four after chapter three. Have Lin Wan open the cellar with her father’s brass key and build her trust with Shen Yu. Do not reveal who sent the letter yet.

Preset task · simulated run, no AI request

Write with the model you like

Works with

The free plan includes several models. Plus and above can also connect your own model provider.

Models and providers

Immersive mode

Hide everything but the page

Immersive mode folds away the sidebar and toolbars, leaving you and the chapter. Choose a light, sepia or dark page.

About immersive writing

The Letter in the Trunk

Vol. 1 · Mist Town / In progress · 141 / 3,000 words

“You open it.” Shen Yu stepped back. “The trunk has waited ten years for me. It can wait another moment.”

The lock clicked. Lin Wan went down first. Lamplight reached the writing on the lid: his handwriting from ten years ago, not a stroke faded. She asked no question. She only moved the lamp closer.

Inside lay a new letter. The address was still blank, but the sealing wax was soft. As Shen Yu reached for it, Lin Wan caught the edge of the trunk.

“Let us look first,” she said. This time, she had said us.

All features

Writing

Story notes and checks

AI and your data

Your manuscript stays on your computer

AI and privacy

Manuscripts are saved on your computer and you can write offline.
NovelThread does not train models on your writing.
Cloud sync is off until you turn it on.
You can make the AI ask before it changes your manuscript.

Pricing

Plans and pricing

Writing locally is free. Upgrade when you need more AI or cloud sync.

Compare all plans

FreeFree foreverLocal writing, unlimited words

AI credits: 10,000 (one-time)
Cloud sync storage: Local only, unlimited words
Bring your own API key (BYOK): Requires Plus or higher

Plus$5 / month$51 / yearSave 15% yearlyFor regular serial writing

AI credits: 500,000 / month
Cloud sync storage: 512 MiB (~50M Chinese characters)
Bring your own API key (BYOK): Included

Pro$20 / month$204 / yearSave 15% yearlyFor prolific and professional authors

AI credits: 2,000,000 / month
Cloud sync storage: 2 GiB (~200M Chinese characters)
Bring your own API key (BYOK): Included

Max$50 / month$510 / yearSave 15% yearlyHigher limits for heavy production and long serials

AI credits: 5,000,000 / month
Cloud sync storage: 5 GiB (~500M Chinese characters)
Bring your own API key (BYOK): Included

Plus and above can connect your own model provider, billed by that provider, and turn on cloud sync. Built-in models use your plan’s credits.

Frequently Asked Questions

Is the free tier enough? What does paying add?

The free tier includes local writing and exports, forever. Plus and higher subscriptions add support for your own API key, larger official AI quotas and cross-device sync. Using your own API key does not consume NovelThread credits, but your model provider bills you separately.

How do I cancel? Can I get a refund?

Cancel any time in Settings → Account; access continues to the end of the current billing period. Once charged, fees are not voluntarily refundable or prorated, except where required by law or for cases such as duplicate or unauthorised charges. See the Terms of Service.

Will NovelThread train models on my writing?

NovelThread does not use your creative writing to train models or sell user data. The desktop app has no advertising or behavioral analytics. External model and tool providers, including your chosen BYOK provider, process submitted material under their own policies. Review those policies before sending content.

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Write long.AI reads back before it writes.

The Letter in the Trunk

Writing a long novel in an AI chat? You have probably run into these.

Let AI draft the next chapter from your latest outline

The Letter in the Trunk

Related assets

Click a character’s name to see their notes

Prologue to Mist Town

Rewrite only the passage you select

The Letter in the Trunk

See what every chapter is for, on one page

Vol. 1 · Mist Town

Try it yourself

Pick up your story. Draft the next chapter.

Write with the model you like

Hide everything but the page

The Letter in the Trunk

All features

Writing

Story notes and checks

AI and your data

Your manuscript stays on your computer

Plans and pricing

Frequently Asked Questions

Is the free tier enough? What does paying add?

How do I cancel? Can I get a refund?

Will NovelThread train models on my writing?

Free tools and writing guides.

Writing guides.

Subtext, Spatial Logic, and Combat Momentum: Paragraph-by-Paragraph Benchmarking of Haiku 5.5 and Gemini 4

AI Novel Writing Software Comparison: Web Chatbots, Sudowrite, Novelcrafter, and Local Workspaces

Finish the bookyou started.