build-agent
Turns a task the owner keeps doing by hand into a named, reusable skill they can trigger by name or put on a schedule. Watches them do it once or listens to them describe it, works out what varies and what stays fixed, writes the skill with approval checkpoints in the right places, registers it with…
Install / Use
npx skills add anthropics/knowledge-work-plugins --skill build-agentInstalls into whichever agent you are using.
SKILL.md
Installable skill definition
Quality Score
Category
AutomationSupported Platforms
Tags
Our assessment of build-agent
build-agent scores 90/100 on our quality scale, 528th of 1,267 Automation skills we index (top 42%).
Its SKILL.md is 6.4 KB long, well organised into 11 sections and no code examples: a thorough specification that gives an agent plenty to work with.
With 25,526 GitHub stars, it is one of the more widely adopted skills in the catalogue.
Maintenance, license and trust
- The repository was last updated yesterday, so build-agent is actively maintained.
- It is released under the Apache-2.0 license, a permissive license that allows use, modification and commercial use with attribution.
- Its trust signals score 100/100, with no cautions. These come from repository metadata, not a code audit — read the skill file before letting an agent act on it.
Safety scan
No issues foundOur scan of the whole file found no instruction hijacking, hidden characters, credential access, data exfiltration or destructive commands.
Automated pattern scan on 2026-09-26. It catches known dangerous patterns, not every risk — read a skill before letting an agent act on it.
build-agent compared with similar skills
All 4 of these similar skills score higher than build-agent; compare them before choosing.
| Skill | Score | Stars | Updated | Format |
|---|---|---|---|---|
| build-agent (this skill)by anthropics | 90 | 25.5k | 1d ago | SKILL.md |
| Agent-Reachby Panniantong | 100 | 85.4k | 10d ago | CLAUDE.md |
| rufloby ruvnet | 100 | 73.3k | 1d ago | CLAUDE.md |
| Scraplingby D4Vinci | 100 | 83.7k | today | MCP Server |
| algorithmic-artby anthropics | 100 | 177.9k | 3d ago | SKILL.md |
Frequently asked questions
- How do I install build-agent?
- Run
npx skills add anthropics/knowledge-work-plugins --skill build-agent. The install tabs above show the steps for each supported agent. - Which AI agents does build-agent work with?
- It is written for Universal, as a SKILL.md file. Other agents that read the same format can often use it too.
- Is build-agent safe to use?
- Our scan of the whole file found no instruction hijacking, hidden characters, credential access, data exfiltration or destructive commands. It is Apache-2.0-licensed and scores 100/100 on trust signals. Skills are instructions an agent will follow, so read the file before installing it and do not approve commands you do not understand.
- Is build-agent still maintained?
- The repository was last updated yesterday, so build-agent is actively maintained.
Skill content
View source on GitHubname: build-agent description: > Turns a task the owner keeps doing by hand into a named, reusable skill they can trigger by name or put on a schedule. Watches them do it once or listens to them describe it, works out what varies and what stays fixed, writes the skill with approval checkpoints in the right places, registers it with the router, and shares it with the team. This is how a business gets a workflow nobody shipped for them. Use this whenever the owner describes something repetitive they wish were automatic — including phrasings like "I do this every week," "can you remember how to do this," "make this a thing I can just ask for," "build me an agent," "automate this for me," "turn this into a workflow," or "I want this to happen every Monday." Reach for it when they describe a routine, even without asking for automation. allowed-tools: Read, WebFetch
Build Agent
Turn something the owner does every week into something they ask for by name.
This is what keeps the plugin from having to ship every industry's workflow. No catalog can cover a septic contractor's permit routine or an insurance agency's carrier commission reconciliation. Those owners can build them.
Step 1 — Watch it happen, or hear it described
Two starting points, and the first is much better.
Best: they just did it in this conversation. If the owner has walked through the task with you — pulled the files, made the decisions, corrected you twice — that transcript is the specification. Extract it rather than re-interviewing them. The corrections they made are the most valuable part, because they encode judgment the owner would never have thought to state.
Otherwise: they describe it. Ask them to walk through the last time they did it, concretely. Real specifics beat an abstract description every time — "last Tuesday I pulled the carrier file, matched it against what we'd booked, and chased six discrepancies" tells you more than "I reconcile commissions."
Read reference/capture.md for how to get a complete picture without an interrogation.
Step 2 — Separate what varies from what stays fixed
This is the whole craft of the step. A skill that hardcodes last Tuesday's specifics only works on last Tuesday.
For each part of the task, decide:
- Fixed — the sequence, the sources, the output format, the rules
- Varies — dates, names, amounts, which file, which customer
- Judgment — the parts where the owner decides, which become approval gates
The corrections the owner made while walking through it usually mark the judgment points. When someone says "no, not that one — we skip anything under USD 50," that is a rule. When they say "hmm, depends," that is an approval gate.
Step 3 — Find the approval gates
Every step that sends, spends, publishes, or deletes needs a gate. So does every step where the owner hesitated.
Do not gate everything — a skill that asks permission nine times is worse than doing it by hand. Gate the consequential and the ambiguous, and let the rest run.
Read reference/skill_authoring.md for where gates belong and how to phrase them.
Step 4 — Write it
Produce a real skill in the same shape as everything else in this plugin: a SKILL.md with frontmatter and numbered steps, plus a reference/ folder if the detail warrants it.
Requirements it must meet, same as every shipped skill:
- Name and folder match, lowercase with hyphens
- Description says what it does and when to trigger, in third person
- A real fallback for when a connector is missing
- Approval gates on anything consequential
- Never invents a number; missing data is reported as missing
Write it in the owner's terms, not in generic business language. If they call it "the carrier file," the skill says carrier file. A skill full of unfamiliar vocabulary is one they will not trust to run unattended.
Step 5 — Test it on a real case, before they rely on it
Run the new skill against a case the owner already knows the answer to — ideally the exact one they walked through. Show the output next to what they got by hand.
This is the step that determines whether the skill gets used. An owner who has seen it reproduce a known-good result will schedule it. One who hasn't will run it manually and check it every time, which saves nothing.
If it doesn't match, fix the skill and run it again. Do not ask the owner to accept a near-miss.
Step 6 — Register and set the cadence
Add it to smb-router so plain-English requests reach it, and record the trigger phrases the owner actually uses.
If it is a recurring task, offer to schedule it. Scheduling is what converts "a skill I could run" into "something that happens without me," which is the outcome they wanted.
Step 7 — Share it, with approval
Offer to share with the team. Say what sharing means: who gets it, what data it can reach, and what it can do unattended.
Be specific about the risk when a skill sends, spends, or writes. A skill that emails customers, running for someone who did not build it and does not know its assumptions, is a real hazard. Recommend draft-only for shared skills that send anything.
What not to do
- Do not re-interview about a task they just walked through. The transcript is the spec.
- Do not hardcode the example. Names, dates, and amounts vary; the sequence does not.
- Do not gate every step. Nine approvals is worse than doing it by hand.
- Do not skip the test run. An untested skill gets checked manually forever, which saves nothing.
- Do not write it in generic business language. Their words, or they won't trust it.
- Do not build something that sends or spends without approval gates. Ever, regardless of what the owner asks for.
After the build
The owner now has a named skill they can trigger or schedule. If the new skill hit a tool that isn't connected, "connect to my ERP" (build-connector) is the natural next step — it turns the missing system into a working source. Also nearby: "brief me" to fold the new output into the daily picture, and "Monday brief" if the skill should feed the weekly one. Offer at most three, and skip any offer the owner already declined this session.
Reference files
reference/capture.md— getting a complete picture of the task without an interrogationreference/skill_authoring.md— the structure, frontmatter, and where approval gates belongreference/gotchas.md— the failure modes that produce a skill nobody uses
Related Skills
Agent-Reach
85.4kGive your AI agent eyes to see the entire internet. Read & search Twitter, Reddit, YouTube, GitHub, Bilibili, XiaoHongShu — one CLI, zero API fees.
ruflo
73.3k🌊 The original agent harness. Deploy intelligent multi-player swarms, coordinate autonomous workflows, and build conversational AI systems. Features adaptive memory, self-learning intelligence, federation, vector RAG integration, and native Claude Code / Codex / Hermes and many more Integrated
Scrapling
83.7k🕷️ An adaptive Web Scraping framework that handles everything from a single request to a full-scale crawl! Don't be shy, join here: https://discord.gg/EMgGbDceNQ and follow here for daily tips and tricks: https://x.com/Scrapling_dev
algorithmic-art
177.9kCreating algorithmic art using p5.js with seeded randomness and interactive parameter exploration. Use this when users request creating art using code, generative art, algorithmic art, flow fields, or particle systems.
Languages
Trust signals
From repository metadata: license, adoption, age and documentation. Not a code audit — see the Safety scan above for what the skill file itself contains.
