New: 98,000+ skills indexed from GitHub repos with 100+ stars · every skill safety-checkedBrowse top skillsTop skills
Esc to closeBrowse all skills
Submit a skillBrowse skills
Submit a skillBrowse skills

Agent skill

Fastbill

by HybridAIOne in HybridAIOne/hybridclaw

Work with FastBill invoices, customers, payments, reminders, and e-invoice exports through the FastBill XML API.

MITAuto-check passedDocuments & Office

Install Fastbill

skills CLI
$ npx skills add HybridAIOne/hybridclaw --skill fastbill -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install HybridAIOne/hybridclaw fastbill --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/HybridAIOne/hybridclaw.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/fastbill .claude/skills/fastbill && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
fastbill
GitHub stars
159
Token cost
~1.6k tokens
SKILL.md length
404 words
Files
5 (incl. references)
Skills in repo
72
Repo updated
First seen
Licence
MIT

At a glance

Work with FastBill invoices, customers, payments, reminders, and e-invoice exports through the FastBill XML API.

  • Works in 5 steps: Use one targeted invoice.get; prefer… → Select one source invoice. If ambiguous,… → Copy relevant source fields:… → …
  • Tasks that involve Forms and invoices
  • SKILL.md covers Core Rules, Commands, Clone / Copy Invoice and Invoice Title Fields, plus 4 more sections
  • Runs JavaScript scripts from its folder; calls node and python3; reaches apidocs.fastbill.com; needs WEB_API_TOKEN and GATEWAY_API_TOKEN

What it does

Fastbill is an agent skill from HybridAIOne/hybridclaw. Work with FastBill invoices, customers, payments, reminders, and e-invoice exports through the FastBill XML API.

Its SKILL.md is about 1.6k tokens, which your agent loads only when the skill is triggered. The skill folder holds 6 other files, including reference files (for example `evals/scenarios.json` and `references/operator-setup.md`).

It sits in Documents & Office, covering Forms and invoices. The repository describes itself as: Enterprise-ready self-hosted AI assistant runtime with sandboxed execution, secure credentials, approvals, and memory. The licence is MIT.

When your agent uses it

  • Tasks that involve Forms and invoices

Example prompts

  • “/fastbill”

Requirements

  • Python 3
  • A credential in WEB_API_TOKEN
  • A credential in GATEWAY_API_TOKEN

Workflow steps

5 steps, taken from the first numbered list in SKILL.md.

  1. Use one targeted invoice.get; prefer date, customer/project text, title,
  2. Select one source invoice. If ambiguous, ask for the invoice ID.
  3. Copy relevant source fields: CUSTOMER_ID, CUSTOMER_COSTCENTER_ID,
  4. Omit lifecycle/source fields: INVOICE_ID, INVOICE_NUMBER, STATE,
  5. Apply requested changes, then create the draft with

What it can do on your machine

Read from SKILL.md and the folder at commit 8162701. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    Ships script files (JavaScript), which the agent can run.

    Shell commands in SKILL.md call:

    • node
    • python3

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    Hosts in commands or code, which the agent is likely to contact:

    • apidocs.fastbill.com

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names these keys or tokens, usually read from environment variables:

    • WEB_API_TOKEN
    • GATEWAY_API_TOKEN

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Fastbill loads about 1.6k tokens when it runs, and up to ~3.1k if it reads all its reference files. Until then it costs about 30 tokens; SKILL.md has 404 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~30
When it runs · the whole SKILL.md, loaded when a task matches
~1.6k
With references · SKILL.md plus every file in references/, read only if the agent opens them
~3.1k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from HybridAIOne/hybridclaw at commit 8162701, republished under its MIT licence (© HybridAIOne). 404 words, ~1,633 tokens.

Download SKILL.mdSave it as .claude/skills/fastbill/SKILL.md (or your agent's skills folder). This skill also uses 4 other files; get the full folder from GitHub.
name
fastbill
description
Work with FastBill invoices, customers, payments, reminders, and e-invoice exports through the FastBill XML API.
user-invocable
true
requires.bins
node

FastBill

Use this skill for FastBill invoices, customers, payments, reminders, and document metadata. The helper wraps concrete FastBill API services: it serializes JSON-shaped inputs to XML and parses XML responses.

Core Rules

  • Use the helper plus built-in http_request for live API calls. Do not use curl, ad hoc node -e, grep, or shell parsing for FastBill.
  • FastBill API URL: https://my.fastbill.com/api/1.0/api.php. The /api/1.0/ prefix is only for secret-route matching.
  • Basic auth is injected by the gateway from FASTBILL_BASIC_AUTH. Never print, build, or ask for the FastBill API key.
  • Writes require explicit operator intent and --operator-grant. Prefer --dry-run when converting free text, CSV, or time tracking into invoice data.
  • Prefer invoice IDs for writes. If multiple invoices/customers match, ask for the exact ID before writing.
  • If unsure about a service or field, check https://apidocs.fastbill.com.

Commands

Show commands:

bash
node skills/fastbill/fastbill.cjs --help

Build an http_request payload for the built-in http_request tool:

bash
node skills/fastbill/fastbill.cjs http-request invoice.get --filter-json '{"INVOICE_ID":"123"}'
node skills/fastbill/fastbill.cjs http-request customer.create --data-json '{"CUSTOMER_TYPE":"business","ORGANIZATION":"Acme GmbH","COUNTRY_CODE":"DE"}' --operator-grant

Parse a saved http_request response wrapper/body:

bash
node skills/fastbill/fastbill.cjs parse-response --body-file /tmp/fastbill-response.json

Direct helper network calls are only for operator-controlled shell tests with a valid gateway token already exported:

bash
node skills/fastbill/fastbill.cjs request invoice.get --filter-json '{"INVOICE_ID":"123"}'

Common invoice payloads:

bash
node skills/fastbill/fastbill.cjs http-request invoice.get --filter-json '{"END_DUE_DATE":"2026-04-08"}' --limit 100
node skills/fastbill/fastbill.cjs http-request invoice.create --data-json '{"CUSTOMER_ID":"123","INVOICE_TITLE":"Consulting Januar - Juni 2026","ITEMS":{"ITEM":[{"DESCRIPTION":"Consulting","QUANTITY":"8","UNIT_PRICE":"120.00","VAT_PERCENT":"19"}]}}' --operator-grant
node skills/fastbill/fastbill.cjs http-request invoice.update --data-json '{"INVOICE_ID":"456","INVOICE_TITLE":"YouGov SVOD Januar - Juni 2026"}' --operator-grant
node skills/fastbill/fastbill.cjs http-request invoice.setpaid --data-json '{"INVOICE_ID":"456","PAID_DATE":"2026-05-07","PAYMENT_METHOD":"bank transfer"}' --operator-grant
node skills/fastbill/fastbill.cjs http-request invoice.sendbyemail --data-json '{"INVOICE_ID":"456","RECIPIENT":{"TO":"billing@example.com"},"SUBJECT":"Payment reminder","MESSAGE":"Please review the outstanding invoice and payment status."}' --operator-grant

Clone / Copy Invoice

FastBill's API does not expose a dedicated invoice clone/copy service, even though the UI has one. Implement clone as invoice.get then invoice.create.

  1. Use one targeted invoice.get; prefer date, customer/project text, title, and service-period terms over broad account-wide searches.
  2. Select one source invoice. If ambiguous, ask for the invoice ID.
  3. Copy relevant source fields: CUSTOMER_ID, CUSTOMER_COSTCENTER_ID, CONTACT_ID, CURRENCY_CODE, TEMPLATE_ID/TEMPLATE_HASH, INTROTEXT, INVOICE_TITLE, references, discounts, VAT settings, and ITEMS.
  4. Omit lifecycle/source fields: INVOICE_ID, INVOICE_NUMBER, STATE, PAID_DATE, PAYMENTS, DOCUMENT_URL, DETAILS_URL, totals, and cancellation flags.
  5. Apply requested changes, then create the draft with invoice.create --operator-grant. Extra reads need a concrete missing field.
Show full SKILL.md (129 more words)Show less

Invoice Title Fields

  • Invoice title field: INVOICE_TITLE in invoice.create and invoice.update. Do not use TITLE, NAME, or SUBJECT.
  • Existing draft title edit: invoice.update with INVOICE_ID and INVOICE_TITLE.
  • INTROTEXT is intro/body text before line items.
  • ITEMS.ITEM[].DESCRIPTION is line-item text.
  • SUBJECT is only for email actions such as invoice.sendbyemail.
  • Do not set INVOICE_NUMBER when creating or editing a draft title.

Write Services

These require --operator-grant: customer.create/update/delete, contact.create/update/delete, invoice.create/update/delete/complete/cancel/lock/sendbyemail/sendbypost/setpaid, estimate.create/delete/sendbyemail/createinvoice, article.create/update/delete, recurring.create/update/delete, revenue.create/setpaid/delete, expense.create, project.create/update/delete, time.create/update/delete, and document.create, webhook.create/delete.

Errors

  • Gateway 401 mentioning WEB_API_TOKEN or GATEWAY_API_TOKEN: the request did not reach FastBill; use built-in http_request in normal runtime.
  • Missing/forbidden secret route: fix FASTBILL_BASIC_AUTH or its route.
  • FastBill 401 with Wrong API KEY / credentials: the route worked, but FastBill rejected the stored Basic credential.

References

Validation

Run:

bash
python3 skills/skill-creator/scripts/quick_validate.py skills/fastbill
node skills/fastbill/fastbill.cjs --help
node skills/fastbill/fastbill.cjs http-request invoice.get --filter-json '{"INVOICE_ID":"123"}'
node skills/fastbill/fastbill.cjs request invoice.get --filter-json '{"INVOICE_ID":"123"}' --dry-run

© HybridAIOne, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 4 other files (references) in skills/fastbill of HybridAIOne/hybridclaw.

  • SKILL.md
  • evals/scenarios.json
  • fastbill.cjs
  • index.cjs
  • references/operator-setup.md

Open the folder on GitHubat commit 8162701

Compare with similar skills

Fastbill next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Fastbill compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Fastbill this skillHybridAIOne/hybridclaw159—~1.6kAutomated safety check: PassMIT
PDFzai-org/ZCode7.7k—~18kAutomated safety check: NotesProprietary
Form Fillingplatonai/Browser41.2k—~1.1kAutomated safety check: PassApache-2.0
Code2mediatsingliuwin/autoclaw283—~985Automated safety check: PassMIT
Token ReceiptHchen1218/token-receipt126—~2.1kAutomated safety check: PassNone
Invoice Makertsingliuwin/autoclaw283—~619Automated safety check: PassMIT

Similar skills

  • PDF

    zai-org/ZCode

    Professional PDF toolkit covering four production workflows: reports, creative visuals, academic LaTeX, and existing PDF processing.

    7.7k GitHub stars~18k tokensUpdated today
    Documents & OfficeAuto-check: notes

  • Form Filling

    platonai/Browser4

    Automatically fills web forms using provided field data and can optionally submit the form.

    1.2k GitHub stars~1.1k tokensUpdated yesterday
    Documents & OfficeAuto-check passed

  • Code2media

    tsingliuwin/autoclaw

    Universal media renderer with no fixed template — any custom layout, size or style becomes pixel-perfect images (PNG/JPEG/WebP), vector SVG, paged PDFs or animations (WebP/GIF).

    283 GitHub stars~985 tokensUpdated today
    Documents & OfficeAuto-check passed

  • Token Receipt

    Hchen1218/token-receipt

    A skill your agent uses when the user wants to view AI conversation token usage as a receipt, invoice, checkout slip, token bill, usage receipt, cost snapshot, or creative monospace thermal-paper…

    126 GitHub stars~2.1k tokensUpdated 4 mo ago
    Documents & OfficeAuto-check passed

  • Invoice Maker

    tsingliuwin/autoclaw

    开发票/生成发票/报价单/收据/采购单/对账单/账单/付款通知 — formal business documents as paged PDFs with proper tables, right-aligned amounts, tax lines, repeating headers and page-number footers.

    283 GitHub stars~619 tokensUpdated today
    Documents & OfficeAuto-check passed

  • Invoice Generator

    luzhenqian/ai-coding-lab

    从 Excel 时间表或手动输入生成专业发票。当用户提到生成发票、创建账单、invoice、billing、开发票、时间表转发票、账单生成时使用此技能。

    153 GitHub stars~955 tokensUpdated 4 mo ago
    Documents & OfficeAuto-check passed

More from HybridAIOne/hybridclaw

All 72 skills in this repo

  • Hermes3000 Writing

    HybridAIOne/hybridclaw

    Use Hermes3000 to plan, draft, revise, save, check consistency, and export long-form manuscripts through the Hermes3000 AI writing portal API.

    159 GitHub stars~2.7k tokensUpdated today
    Auto-check passed

  • Manim Video

    HybridAIOne/hybridclaw

    Plan, script, render, and stitch Manim Community Edition videos in Python.

    159 GitHub stars~4.7k tokensUpdated today
    Auto-check: notes

  • Skill Creator

    HybridAIOne/hybridclaw

    Create and update SKILL.md-based skills with strong trigger metadata, lean docs, and reliable init, validate, package, and publish workflows.

    159 GitHub stars~2k tokensUpdated today
    Auto-check passed

  • XLSX

    HybridAIOne/hybridclaw

    Create, edit, inspect, and analyze .xlsx spreadsheets and Excel workbooks.

    159 GitHub stars~1.7k tokensUpdated today
    Auto-check passed

  • Excalidraw

    HybridAIOne/hybridclaw

    Create and revise editable .excalidraw diagrams as Excalidraw JSON for architecture diagrams, flowcharts, sequence diagrams, concept maps, and other hand-drawn explainers.

    159 GitHub stars~1.2k tokensUpdated today
    Auto-check passed

  • Google Ads

    HybridAIOne/hybridclaw

    Manage Google Ads accounts with safe GAQL reporting, campaign planning, guarded mutations, and gateway-proxied REST API calls.

    159 GitHub stars~4k tokensUpdated today
    Auto-check passed

Categories

Questions about Fastbill

What does Fastbill do?

Work with FastBill invoices, customers, payments, reminders, and e-invoice exports through the FastBill XML API. Fastbill is an agent skill from HybridAIOne/hybridclaw. Work with FastBill invoices, customers, payments, reminders, and e-invoice exports through the FastBill XML API.

When should I use Fastbill?

Fastbill fits situations like: tasks that involve Forms and invoices.

How do I install Fastbill in Claude Code?

Run `npx skills add HybridAIOne/hybridclaw --skill fastbill -a claude-code`. Or copy the skill folder (skills/fastbill in HybridAIOne/hybridclaw) into .claude/skills/fastbill in your project. Claude Code loads it when a task matches its description.

How do I install Fastbill in Codex?

Run `npx skills add HybridAIOne/hybridclaw --skill fastbill -a codex`. Or copy the skill folder (skills/fastbill in HybridAIOne/hybridclaw) into .agents/skills/fastbill in your project. Codex loads it when a task matches its description.

Can I use Fastbill in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add HybridAIOne/hybridclaw --skill fastbill -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/fastbill, .gemini/skills/fastbill, .github/skills/fastbill and .opencode/skills/fastbill in your project.

What does Fastbill need to run?

Going by SKILL.md and its folder, Fastbill needs JavaScript for the scripts in its folder, the command-line tools its instructions call (node and python3) and credentials named WEB_API_TOKEN and GATEWAY_API_TOKEN. Our summary lists: Python 3; A credential in WEB_API_TOKEN; A credential in GATEWAY_API_TOKEN.

Does Fastbill access the network?

SKILL.md names 1 domain. In commands or code: apidocs.fastbill.com; the agent is likely to contact it when it follows the instructions. This is read from the text; nothing was executed.

Is Fastbill safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Fastbill use?

Fastbill is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Fastbill use?

About 1.6k tokens (SKILL.md is roughly 6.5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 1.4k tokens, read only when the agent opens those files.

What are the alternatives to Fastbill?

Skills that share tags, products or a category with Fastbill: PDF (zai-org/ZCode, 7.7k stars), Form Filling (platonai/Browser4, 1.2k stars), Code2media (tsingliuwin/autoclaw, 283 stars) and Token Receipt (Hchen1218/token-receipt, 126 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Fastbill?

HybridAIOne (a GitHub organization) maintains it in HybridAIOne/hybridclaw, which has 159 GitHub stars. The repository holds 72 skills in this directory. The repository was last updated on October 9, 2026.

Source: HybridAIOne/hybridclaw on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.