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Monthly contractor invoice builder

Builds your monthly invoice and timesheet PDF from weekly timesheet screenshots. It checks the hours before filling your template.

OperationsWorks with Claude Code · Claude Desktop with MCP+1Community example
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What it does

  • Reads each weekly timesheet screenshot
  • Checks the totals you typed against the screenshots
  • Splits weeks that cross the month boundary
  • Merges the timesheets into one PDF
  • Previews the filled invoice template

Your approval boundaries

Approval required

These actions always wait for your yes:

  • Creating the final invoice
  • Sending the invoice to the client

You decide what happens next.

More about this workflow

This setup is for operators and managers who keep the busywork moving. It takes a repeat chore off your plate and hands back something you can check quickly.

First, it reads each weekly timesheet screenshot. Next, it checks the totals you typed against the screenshots. Then it splits weeks that cross the month boundary. After that, it merges the timesheets into one PDF. Finally, it previews the filled invoice template. It works with your spreadsheets, docs and photo storage, each on its own login with limited access.

You get the prep work done and waiting for you. The agent stops and asks for your yes before creating the final invoice and sending the invoice to the client, and says plainly if a step cannot be undone.

“A small agent that does my monthly contractor invoicing.”
biancanoel biancanoel on GitHub · Oct 6, 2026
Before you startSpreadsheets · Docs accessScoped permissionsClaude Code or Claude Desktop with MCP
Explore required tools and model recommendations

Tools and access

  • Google Sheets

    Handles the spreadsheets part of this job. Grant access to the single sheet it needs.

    API required: Yes. Needs a Google Cloud OAuth app or a service account with the Sheets API turned on.

    Sign up: Google Workspace

  • Google Docs

    Handles the docs part of this job. Grant one folder, create and edit only.

    API required: Yes. Needs a Google Cloud OAuth app with the Docs API turned on.

    Sign up: Google Workspace

  • Photo storage

    Handles the photo storage part of this job. Grant read-only access to one photo folder.

    API required: No. A shared folder or drive for item photos. No API needed if the agent can read it.

    No sign-up needed

Official links only. Not sponsored, no affiliate links.

Model recommendations

Best pick

GPT-6.1 Sol

Cheap cached input suits jobs that rerun the same instructions each week.

$2 per million input tokens, $10 per million output tokens, for prompts up to 272K tokens. Longer prompts cost $4 in and $15 out.

OpenAI docs as of October 11, 2026

Cheaper backup

Gemini 3.5 Flash-Lite

Low cost for simple data pulls and matching.

$0.30 per million input tokens, $2.50 per million output tokens.

Google docs as of October 11, 2026

Our own picks. Not sponsored, no affiliate links.

Build your prompt

Add your details, then copy the prompt into your tool.

1Your details

Fill these in and the prompt updates as you type.

e.g. April 2026

2Your prompt

4 of 4 still empty
Fill these in before you run it: [YOUR INVOICE TEMPLATE] [TIMESHEET SCREENSHOTS FOLDER] [WEEKLY HOURS YOU LOGGED] [BILLING MONTH: e.g. April 2026] You are the Monthly contractor invoice builder agent. Builds your monthly invoice and timesheet PDF from weekly timesheet screenshots. It checks the hours before filling your template. Use only the details filled in above. If any [BRACKETED] item is still blank or unclear, stop and ask for it first. Do not guess. What you do on your own: - Reads each weekly timesheet screenshot - Checks the totals you typed against the screenshots - Splits weeks that cross the month boundary - Merges the timesheets into one PDF - Previews the filled invoice template What you must never do without a yes from a person: - Creating the final invoice - Sending the invoice to the client Rules: - Before any step on the list above, stop and ask. Say in plain words what you want to do, who it affects, and whether it can be undone. - If something cannot be undone, say so first, in one short line. - Write drafts, not final actions. A person sends, pays, posts, or deletes. - Keep a short log of every action you took and every source you read. - If you are unsure, ask instead of guessing.
View run instructionsPaste into: Claude Code, Claude Desktop with MCP, Make

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Run your workflow

Connect your tools with only the access this setup needs, then follow these steps.

Steps

Do these in order. Test on old data before it touches live work.

  1. 1Connect Google Sheets with its own login, not yours. Grant access to the single sheet it needs.
  2. 2Connect Google Docs with its own login, not yours. Grant one folder, create and edit only.
  3. 3Set up Photo storage. Keep it to read-only access to one photo folder.
  4. 4Paste the prompt where your harness takes instructions. See the note under the Copy button.
  5. 5Do a dry run on old or test data first. Check every draft and every stop point by hand before you let it near live work.
  6. 6Read its log after the first real run. Only widen access once a week of runs looks clean.

Safeguards and trust score

The score describes this example setup’s access, approval boundaries, ability to undo changes, and scope.

Access18 / 30

Can draft things that send or spend, so it sits close to risky actions.

Human approval30 / 30

Waits for a yes on: creating the final invoice, sending the invoice to the client.

Undo and logs14 / 20

Proposes changes to live records, so the setup needs a change log and a way back.

Scope16 / 20

Runs on its own login across 3 tools. Fewer connections means a smaller blast radius.

How to raise it

  • Access: Take away its ability to send, post or spend. Let it only write drafts, and have a person press send or pay from their own account +6
  • Undo and logs: Stop it from editing live records. Have it write the change as a proposal you apply, and keep a log of every change with a way to roll it back +3
  • Scope: Cut it down from 3 connected tools to the 2 it needs most, each with its own limited login instead of your full account +2

Do all of these to reach 89, up from 78.

Want help getting there? Get an AI Trust Audit from Pixeldesigns

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