Agent skill

Bff Design

Decide whether a system needs a backend-for-frontend, how many, and what each one may own: adoption signals and honest costs, one-experience-one-BFF granularity with frontend-team ownership, the…

Custom licenceAuto-check passedBackend & APIs

Install Bff Design

skills CLI

$ npx skills add citypaul/.dotfiles --skill bff-design -a claude-code

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

GitHub CLI

$ gh skill install citypaul/.dotfiles bff-design --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/citypaul/.dotfiles.git skills-src && mkdir -p .claude/skills && cp -r skills-src/claude/.claude/skills/bff-design .claude/skills/bff-design && 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/

Paste into Claude Code

Install the "bff-design" agent skill from https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/bff-design into .claude/skills/bff-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bff-design", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/bff-design

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add citypaul/.dotfiles --skill bff-design -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install citypaul/.dotfiles bff-design --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/citypaul/.dotfiles.git skills-src && mkdir -p .agents/skills && cp -r skills-src/claude/.claude/skills/bff-design .agents/skills/bff-design && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "bff-design" agent skill from https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/bff-design into .agents/skills/bff-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bff-design", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add citypaul/.dotfiles --skill bff-design -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install citypaul/.dotfiles bff-design --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/citypaul/.dotfiles.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/claude/.claude/skills/bff-design .cursor/skills/bff-design && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "bff-design" agent skill from https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/bff-design into .cursor/skills/bff-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bff-design", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/citypaul/.dotfiles.git --path claude/.claude/skills/bff-design

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add citypaul/.dotfiles --skill bff-design -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install citypaul/.dotfiles bff-design --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/citypaul/.dotfiles.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/claude/.claude/skills/bff-design .gemini/skills/bff-design && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "bff-design" agent skill from https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/bff-design into .gemini/skills/bff-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bff-design", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install citypaul/.dotfiles bff-design

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add citypaul/.dotfiles --skill bff-design -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/citypaul/.dotfiles.git skills-src && mkdir -p .github/skills && cp -r skills-src/claude/.claude/skills/bff-design .github/skills/bff-design && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "bff-design" agent skill from https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/bff-design into .github/skills/bff-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bff-design", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add citypaul/.dotfiles --skill bff-design -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install citypaul/.dotfiles bff-design --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/citypaul/.dotfiles.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/claude/.claude/skills/bff-design .opencode/skills/bff-design && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "bff-design" agent skill from https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/bff-design into .opencode/skills/bff-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bff-design", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: bff-design
GitHub stars: 740
Token cost: ~3.4k tokens
SKILL.md length: 1,737 words
Files: 6 (incl. references)
Skills in repo: 44
Repo updated: Oct 9, 2026
First seen: Oct 7, 2026
Licence: Custom licence

At a glance

Decide whether a system needs a backend-for-frontend, how many, and what each one may own: adoption signals and honest costs, one-experience-one-BFF granularity with frontend-team ownership, the…

Works in 3 steps: Separate surfaces, honestly policed.… → A new consumer gets its own surface.… → Watch for it: record the accepted…
Aggregating upstream services
SKILL.md covers Do You Need One?, One Experience, One BFF, Shape, Don't Decide and Aggregation, Resilience,…, plus 3 more sections
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Bff Design is an agent skill from citypaul/.dotfiles. Decide whether a system needs a backend-for-frontend, how many, and what each one may own: adoption signals and honest costs, one-experience-one-BFF granularity with frontend-team ownership, the shape-don't-decide rule, upstream aggregation with partial-failure and resilience budgets, identity-keyed BFF caching, mediating user identity toward upstream services (token exchange, confused-deputy prevention), and the alternatives (shared gateway, GraphQL federation, token-mediating backend, direct SPA→API…

Its SKILL.md is about 3.4k tokens, which your agent loads only when the skill is triggered. The skill folder holds 7 other files, including reference files (for example `agents/openai.yaml`, `references/adoption-and-granularity.md` and `references/aggregation-and-resilience.md`).

It sits in Backend & APIs, covering OAuth and OpenID Connect, API design and GraphQL. It works with GraphQL.

When your agent uses it

Aggregating upstream services
Handling upstream failures
Forwarding user identity downstream
Weighing GraphQL against per-client BFFs

Example prompts

“/bff-design”

Workflow steps

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

Separate surfaces, honestly policed. Browser and native apps are public clients — nothing they carry cryptographically authenticates the…
A new consumer gets its own surface. Another experience (including a partner integration you build and own — SoundCloud runs dedicated…
Watch for it: record the accepted credential mode, issuer, and client registration per request (see observability for the wide-event…

What it can do on your machine

Read from SKILL.md and the folder at commit cd4028d. 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
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Bff Design loads about 3.4k tokens when it runs, and up to ~15k if it reads all its reference files. Until then it costs about 256 tokens; SKILL.md has 1,737 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~256
When it runs · the whole SKILL.md, loaded when a task matches: ~3.4k
With references · SKILL.md plus every file in references/, read only if the agent opens them: ~15k

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

Its licence (Custom licence) doesn't allow us to republish the file, so here is its outline and opening line. It has 1,737 words (~3,357 tokens).

“A backend-for-frontend is an ownership pattern before it is a technology: the API a client application uses is part of that application, owned by the team that owns the frontend, and consumed by no other application (Calçado, the pattern's originator)…”

— opening of SKILL.md by citypaul, Custom licence

name: bff-design

Read the full SKILL.md on GitHub

Files

SKILL.md and 5 other files (references) in claude/.claude/skills/bff-design of citypaul/.dotfiles.

SKILL.md
agents/openai.yaml
references/adoption-and-granularity.md
references/aggregation-and-resilience.md
references/alternatives.md
references/upstream-identity.md

Open the folder on GitHubat commit cd4028d

Compare with similar skills

Bff Design 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.

Bff Design compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Bff Design this skillcitypaul/.dotfiles	740	—	~3.4k	Automated safety check: Pass	Custom licence	2 days ago
Discover APIrand/cc-polymath	181	—	~1.5k	Automated safety check: Pass	MIT	7 mo ago
Nodejs Backend Patternsever-works/ever-works	162	18 repos	~4k	Automated safety check: Pass	AGPL-3.0	yesterday
API DesignerJeffallan/claude-skills	12k	1 repos	~2k	Automated safety check: Pass	MIT	7 days ago
API Design Principlesjh941213/my-cc-harness	125	18 repos	~3.4k	Automated safety check: Pass	None	2 mo ago
API And Interface Designdzhalaevd/Donatello	135	8 repos	~2.6k	Automated safety check: Pass	Apache-2.0	7 days ago

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All 44 skills in this repo

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Structure Codebase
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Test Design Reviewer
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Review test quality using Dave Farley's eight properties of good tests.
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Characterisation Tests
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CI Debugging
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Systematic CI/CD failure diagnosis using hypothesis-first investigation, local reproduction, and environment delta analysis.
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Works with

GraphQL

Questions about Bff Design

What does Bff Design do?

Decide whether a system needs a backend-for-frontend, how many, and what each one may own: adoption signals and honest costs, one-experience-one-BFF granularity with frontend-team ownership, the…. dotfiles.

When should I use Bff Design?

Bff Design fits situations like: aggregating upstream services; handling upstream failures; forwarding user identity downstream; weighing GraphQL against per-client BFFs.

How do I install Bff Design in Claude Code?

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

How do I install Bff Design in Codex?

Run `npx skills add citypaul/.dotfiles --skill bff-design -a codex`. Or copy the skill folder (claude/.claude/skills/bff-design in citypaul/.dotfiles) into .agents/skills/bff-design in your project. Codex loads it when a task matches its description.

Can I use Bff Design 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 citypaul/.dotfiles --skill bff-design -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/bff-design, .gemini/skills/bff-design, .github/skills/bff-design and .opencode/skills/bff-design in your project.

What does Bff Design need to run?

SKILL.md names no scripts, command-line tools or credentials: Bff Design is instructions for the agent only.

Does Bff Design access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Bff Design 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 Bff Design use?

Bff Design has a licence file (the repository's licence) that doesn't match a standard licence. Read it on GitHub before reusing the skill.

How many tokens does Bff Design use?

About 3.4k tokens (SKILL.md is roughly 13k 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 11k tokens, read only when the agent opens those files.

What are the alternatives to Bff Design?

Skills that share tags, products or a category with Bff Design: Discover API (rand/cc-polymath, 181 stars), Nodejs Backend Patterns (ever-works/ever-works, 162 stars), API Designer (Jeffallan/claude-skills, 12k stars) and API Design Principles (jh941213/my-cc-harness, 125 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Bff Design?

citypaul (a GitHub user) maintains it in citypaul/.dotfiles, which has 740 GitHub stars. The repository holds 44 skills in this directory. The repository was last updated on October 9, 2026.

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

Install Bff Design

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Files

Compare with similar skills

Similar skills

More from citypaul/.dotfiles

Related

Questions about Bff Design