Before you start
Follow-Up writes three versions of a follow-up message for one lead. It runs in your browser and calls Anthropic's API directly with your own API key. You need two things:
- An Anthropic API key, created in the Anthropic Console (console.anthropic.com).
- API credit on that account. API usage is billed separately from a claude.ai subscription. What a set costs depends on the model you pick and how much text you paste in. Check current pricing in the Console, since the charges are yours.
Quick start
- Add your key. Open Settings at the top of the left panel and paste your key. The model list loads from Anthropic.
- Pick a model. The dropdown lists the models your key can use, newest first. Sonnet is the default and a good balance of quality and cost.
- Fill in your profile (optional). Name and company are used to sign off your emails.
- Describe the lead. Write who they are, how you met, and what you proposed. Add the last point of contact.
- Choose a goal and medium. Then click Write Three Options.
- Pick one, edit it, and send it. Use Email to open your mail app, or Copy to paste it anywhere.
Settings and model
The Settings panel holds your API key and the model.
- Anthropic API Key
- Saved in this browser only. Use Show to check what you pasted, and Forget key to remove it from this computer.
- Model
- Populated from Anthropic's live model list every time the page loads. When Anthropic adds or retires models, the dropdown changes with them. Use Refresh model list to reload it on demand.
- If the list cannot load
- The page shows the last list it saved. If it has never loaded one, it shows a short built-in list. The status line under the dropdown tells you which.
The model you pick is remembered. You can switch models for any single set or regeneration.
Your profile
The Your Profile panel is collapsed by default. It holds:
- Name and Company. Used for sign-offs. Messages close with your first name, or with your full signature if you turn on the signature option.
- City/State. Gives the model general context about where you are based.
- Phone and Email. Stored for your reference. They reach the model only when you tick Add phone and email under my name on email messages, in which case they appear in the signature block.
Nothing in the profile is included in exports.
Describing the lead
The more specific the lead description, the more specific the messages. Fill in the fields in this order of importance:
- Lead Name and Context
- Who they are, how you connected, what was discussed, and what you quoted or proposed. Messy notes are fine. The model reads them, but its messages do not quote them back.
- Last Point of Contact
- What happened last, and how long ago. For example, Sent a quote three weeks ago. They replied once, then went quiet. This shapes the tone more than anything else.
- Thread or Quote Material (optional)
- Paste the email thread, proposal wording, or quote lines. The messages then use real names, dates and numbers from it. Keep it to the relevant part.
- What You Want to Happen
- Get a decision on the quote asks for a yes or no, with an easy out. Book a call or meeting suggests a window and gets the conversation into the room. Re-open a cold conversation restarts a dormant thread without apologising for the silence. Stay visible, no ask keeps you on their radar with no action required.
- Medium
- Email gives a subject line and a fuller body. DM or text is shorter, casual, and has no subject or sign-off.
Voice and style
The Voice / Style Guide field shapes how every message sounds. Paste a style guide, a sample of your writing, or a few sentences about your tone. It saves automatically and applies to every set and regeneration.
Build a style card from samples
If you do not have a written guide, open Build from Samples under the style field. Paste two or three emails you have actually sent, separated by a line of three dashes (---), and click Distill Style Card. The model writes a short card covering rhythm, formality, openings and closings, and phrases to avoid, then fills the style field with it. Read it over and edit anything that does not sound like you.
The three options
Each set contains three messages built on different strategies, not just different tones. Pick the one that fits your read of the person.
Gets to the point in the first sentence. Assumes they are busy, not disinterested. Best when the ask is clear and the relationship is warm.
Opens with something useful for this lead before asking for anything. Best when they need a reason to read on.
Makes no ask. Keeps you visible with warmth or relevance. Best for cold leads and long-running relationships.
Each message is an editable box. Click into it and change anything. The subject line is editable too. Your edits are saved automatically, so the set you return to later is the one you finished.
Each box shows whether it is an email or a DM. On emails, the subject line appears above the body.
Quick checks
Under each message, a line of small text checks the draft. Items in amber are guidelines. Items in red are problems to fix.
| Shows | What it means |
|---|---|
| Word count | Amber when over 150 words for email or 100 for a DM. |
| Filler phrase | Red for stock lines such as "just checking in", "touch base", "circle back" or "at your earliest convenience". |
| Unfilled [placeholder] | Red when a bracketed placeholder is still in the text. Replace it before sending. |
| Email or phone not on your profile | Red when the model has written a contact detail that is not yours. Remove it, or check your profile. |
The checks update as you edit, so you can see the effect of each change.
Regenerating and refining
You can change any option without rewriting the rest.
- Regenerate on one option writes a new version of that strategy. It is told to avoid the wording of the previous draft, so you get a genuinely new take.
- Refine Notes is a short field for instructions such as shorter, drop the discount line, mention the June shoot. Notes apply to the next write or regeneration. Leave them blank for a fresh take.
- Write Three Options starts a new set for the lead. The earlier set stays in Recent.
Sending
- Email opens your default mail app with the subject and body filled in. The address stays blank, so add the recipient yourself. Opening it also records that option as the one you sent, which you can change in Track This Lead.
- Copy copies the subject and body as plain text, for any app.
Very long messages can be cut off when opened through the Email button. If the page warns about length, use Copy instead.
The page never sends a message for you. Nothing leaves this computer except the requests to Anthropic when you write or regenerate.
Tracking and results
The Track This Lead panel sits above the messages once you have a set. Use it to log what happened:
- Sent option and date
- Which of the three you sent, and when.
- Status
- Open, Replied, Won, Lost or Dormant.
- Next touch
- A date for the next follow-up. Once it arrives, the lead shows a red DUE tag in Recent and the count appears in the Recent heading.
- They replied
- A tick box that feeds the results below.
Results by Strategy, in the left panel, shows for each option how many you sent and what share got a reply. It fills in as you log sends. Early numbers are small, so treat them as a hint rather than a verdict.
Recent leads
The Recent panel lists your last five follow-up sets, newest first. Click one to reopen it with its inputs, messages, and tracking.
The most recent set reopens automatically when you load the page, so a refresh does not lose your work.
Backup, export and import
Everything in this tool lives in your browser on this computer. Clearing your browser data, using a different browser, or using a different computer means starting from empty. Export is your backup.
- Export JSON
- Saves the current set as a file. It contains the lead description, thread material, notes, the three messages, the tracking fields, and the model used. It does not include your profile or your API key.
- Import JSON
- Loads a file as a new set. Use it to restore a set, move it to another computer, or reopen one you want to refine. Imported sets appear at the top of Recent.
Files from earlier versions of the tool can still be imported. Any fields they do not have are left blank.
Privacy and where data lives
- Stored on this computer only: your API key, model choice, profile, style guide, Recent leads, and tracking. The tool keeps them in this browser's local storage. The tool has no server and no account.
- Sent to Anthropic when you write or regenerate: the lead description, last point of contact, thread material, refine notes, style guide, and the profile fields used for sign-offs. Phone and email reach Anthropic only if you tick the signature option.
- Sent to Anthropic when you build a style card: the samples you paste, once.
- Sent to Anthropic when the model list loads: your API key, in the request header, and nothing else.
Anthropic's own terms and data policies govern what happens to data sent through the API. Check them before you paste anything you would not want shared with a third party, such as a client's confidential figures.
Troubleshooting
| What you see | What to do |
|---|---|
| "Add your Anthropic API key in Settings first." | Open Settings and paste your key. The key must be in the field, and the field must lose focus so the page saves it. |
| "Couldn't refresh the list (401 …)" | The key was rejected. Check it for typos, or create a new one in the Console. |
| "Couldn't refresh the list" with a network message | The page could not reach Anthropic. Check your connection, then use Refresh model list. |
| Error mentioning credit or billing | Your account has no API credit or has hit a limit. Check billing in the Console. |
| "Add the lead context first." | The lead description is required. Everything else is optional. |
| "Import failed: not a Follow-Up export file." | The file was not made by this tool, or it was edited and broken. Import only files saved from Export JSON. |
| A message keeps repeating the same phrasing | Click Regenerate on that option, or add a refine note asking for a different opening. |
| The style card is generic | Use longer, more representative samples. Two or three real emails work better than one short one. |
If the page stops responding, reload it. Your last set reopens and anything you have saved stays put.
Tips for better messages
- Lead with the last real interaction. "You asked about the June dates on Tuesday" beats "I wanted to follow up".
- Paste the numbers. The thread or quote lines give the model real figures and dates to use instead of vague references.
- Say what you want to avoid. Refine notes such as no discount language or do not mention the competitor steer the next write.
- Read the Light Touch version first for cold leads. It is often the one that gets a reply after a long silence.
- Edit before you send. A specific edit of your own, even one sentence, makes a message sound more like you.
- Track every send. Within a month, Results by Strategy will show which approach works with your leads.
- Export sets you care about. Keep a copy outside the browser.