New: 97,000+ 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

Frontend API Contracts

by OpenHands in OpenHands/OpenHands

This skill should be used when the user asks to "add an API call", "change a backend", "update settings persistence", "change conversation events", "fix backend auth", "add Agent Server support", or…

MITAuto-check passedBackend & APIs

Install Frontend API Contracts

skills CLI
$ npx skills add OpenHands/OpenHands --skill frontend-api-contracts -a claude-code

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

GitHub CLI
$ gh skill install OpenHands/OpenHands frontend-api-contracts --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/OpenHands/OpenHands.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/frontend-api-contracts .claude/skills/frontend-api-contracts && 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
frontend-api-contracts
GitHub stars
90k
Token cost
~390 tokens
SKILL.md length
142 words
Files
2 (incl. references)
Skills in repo
8
Repo updated
First seen
Licence
MIT

At a glance

This skill should be used when the user asks to "add an API call", "change a backend", "update settings persistence", "change conversation events", "fix backend auth", "add Agent Server support", or…

  • Works in 6 steps: Read references/guide.md before… → Determine whether the contract belongs… → Use typed clients and centralized option… → …
  • Asks to add an API call
  • SKILL.md covers Workflow and Reference
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Frontend API Contracts is an agent skill from OpenHands/OpenHands. This skill should be used when the user asks to "add an API call", "change a backend", "update settings persistence", "change conversation events", "fix backend auth", "add Agent Server support", or changes src/api, backend registry, Cloud/runtime transport, settings, secrets, compatibility, or conversation resume behavior.

Its SKILL.md is about 390 tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files, including reference files (for example `references/guide.md`).

It sits in Backend & APIs, covering API design. It works with OpenAI. The repository describes itself as: 🙌 OpenHands: AI-Driven Development. The licence is MIT.

When your agent uses it

  • Asks to add an API call
  • Change a backend
  • Update settings persistence
  • Change conversation events

Example prompts

  • “add an API call”
  • “change a backend”
  • “update settings persistence”
  • “/frontend-api-contracts”

Workflow steps

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

  1. Read references/guide.md before modifying frontend API access, backend selection, settings, secrets, Agent Server compatibility, or Cloud…
  2. Determine whether the contract belongs in software-agent-sdk and its TypeScript client before adding Canvas code.
  3. Use typed clients and centralized option builders for Agent Server/runtime calls; use callCloudProxy only for Cloud App-API calls.
  4. Raise compatibility.minimumAgentServer when Canvas begins requiring new server behavior.
  5. Verify Local and Cloud paths, authentication, persistence transitions, and affected conversation modes.
  6. Run the direct-call guard and focused API/state tests.

What it can do on your machine

Read from SKILL.md and the folder at commit 7ea83ba. 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

Frontend API Contracts loads about 390 tokens when it runs, and up to ~7.9k if it reads all its reference files. Until then it costs about 87 tokens; SKILL.md has 142 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~87
When it runs · the whole SKILL.md, loaded when a task matches
~390
With references · SKILL.md plus every file in references/, read only if the agent opens them
~7.9k

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 OpenHands/OpenHands at commit 7ea83ba, republished under its MIT licence (© OpenHands). 142 words, ~390 tokens.

Download SKILL.mdSave it as .claude/skills/frontend-api-contracts/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.
name
frontend-api-contracts
description
This skill should be used when the user asks to "add an API call", "change a backend", "update settings persistence", "change conversation events", "fix backend auth", "add Agent Server support", or changes src/api, backend registry, Cloud/runtime transport, settings, secrets, compatibility, or conversation resume behavior.

Frontend API and Backend Contracts

Keep Canvas as a typed consumer of Agent Server and Cloud contracts. Preserve repository ownership, compatibility floors, transport boundaries, authentication modes, and durable state invariants.

Workflow

  1. Read references/guide.md before modifying frontend API access, backend selection, settings, secrets, Agent Server compatibility, or Cloud runtime behavior.
  2. Determine whether the contract belongs in software-agent-sdk and its TypeScript client before adding Canvas code.
  3. Use typed clients and centralized option builders for Agent Server/runtime calls; use callCloudProxy only for Cloud App-API calls.
  4. Raise compatibility.minimumAgentServer when Canvas begins requiring new server behavior.
  5. Verify Local and Cloud paths, authentication, persistence transitions, and affected conversation modes.
  6. Run the direct-call guard and focused API/state tests.

Reference

  • references/guide.md — API transport rules, allowed exceptions, published-client constraints, compatibility conventions, backend registry and auth behavior, settings/secrets persistence, backend UI invariants, and Cloud resume gating.

© OpenHands, 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 1 other file (references) in .agents/skills/frontend-api-contracts of OpenHands/OpenHands.

  • SKILL.md
  • references/guide.md

Open the folder on GitHubat commit 7ea83ba

Compare with similar skills

Frontend API Contracts 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.

Frontend API Contracts compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Frontend API Contracts this skillOpenHands/OpenHands90k—~390Automated safety check: PassMIT
Goinference-gateway/inference-gateway214—~2.4kAutomated safety check: PassApache-2.0
API Reviewermitchdenny/hex1b177—~4kAutomated safety check: PassMIT
System Designopenxlings/xlings6151 repos~328Automated safety check: PassApache-2.0
Frontend Request Skilljiushiwon/wg-skills110—~3.6kAutomated safety check: PassApache-2.0
Ariasickn33/agentic-awesome-skills47k1 repos~1.5kAutomated safety check: PassMIT

Similar skills

  • Go

    inference-gateway/inference-gateway

    Idiomatic Go - package and interface design, error wrapping, table-driven tests, generics, the modern standard library (slices/maps/cmp/errors.Join), current syntax, and logging discipline.

    214 GitHub stars~2.4k tokensUpdated yesterday
    DevelopmentAuto-check passed

  • API Reviewer

    mitchdenny/hex1b

    Guidelines for reviewing API design in the Hex1b codebase. An agent skill from mitchdenny/hex1b.

    177 GitHub stars~4k tokensUpdated 5 days ago
    Backend & APIsAuto-check passed

  • System Design

    openxlings/xlings

    Design systems, services, and architectures. An agent skill from openxlings/xlings.

    615 GitHub starsUsed in 1 repo~328 tokens
    Backend & APIsAuto-check passed

  • Frontend Request Skill

    jiushiwon/wg-skills

    A skill your agent uses when designing or reviewing the request layer of a frontend project (web / uni-app / mini-program), including request.ts wrappers, interceptors, deduplication, mocks, error…

    110 GitHub stars~3.6k tokensUpdated 3 days ago
    Backend & APIsAuto-check passed

  • Aria

    sickn33/agentic-awesome-skills

    Designs the data model, API contracts, and structural foundation of the system.

    47k GitHub starsUsed in 1 repo~1.5k tokens
    Backend & APIsAuto-check passed

  • API Designer

    Jeffallan/claude-skills

    Designs REST and GraphQL APIs from resource modeling to an OpenAPI 3.1 contract, with versioning, pagination and RFC 7807 error handling.

    12k GitHub starsUsed in 2 repos~2k tokens
    Backend & APIsAuto-check passed

More from OpenHands/OpenHands

All 8 skills in this repo

  • PR Design Doc

    OpenHands/OpenHands

    For a non-trivial pull request, write a self-contained HTML design doc under the temporary .pr/ directory and link a visibility-appropriate preview in the PR description, so maintainers grasp the…

    90k GitHub stars~2.4k tokensUpdated today
    Auto-check passed

  • Verify Openhands

    OpenHands/OpenHands

    This skill should be used to "verify OpenHands features", "test the Canvas UI like a user", "drive Agent Canvas", "check a UI change in the real app", "create or update the feature map", "run the…

    90k GitHub stars~2.9k tokensUpdated today
    Auto-check passed

  • Desktop Electron

    OpenHands/OpenHands

    This skill should be used when the user asks to "change the desktop app", "package Electron", "build a universal macOS app", "bundle Node or uv", "fix Electron startup", or changes electron/…

    90k GitHub stars~302 tokensUpdated today
    Auto-check passed

  • E2E Testing

    OpenHands/OpenHands

    This skill should be used when the user asks to "add an E2E test", "run live E2E", "run mock-LLM tests", "debug Playwright CI", "test the Docker image", or changes tests/e2e, Playwright configs, E2E…

    90k GitHub stars~308 tokensUpdated today
    Auto-check passed

  • Frontend Development

    OpenHands/OpenHands

    This skill should be used when the user asks to "add UI copy", "add a translation", "optimize the frontend bundle", "change onboarding", "change conversation UI", "add a query key", "change MSW…

    90k GitHub stars~324 tokensUpdated today
    Auto-check passed

  • Local Stack Runtime

    OpenHands/OpenHands

    This skill should be used when the user asks to "change the dev stack", "add a runtime service", "change the launcher", "update Docker", "bump Agent Server", "change ingress routing", or changes…

    90k GitHub stars~375 tokensUpdated today
    Auto-check passed

Works with

Categories

Questions about Frontend API Contracts

What does Frontend API Contracts do?

This skill should be used when the user asks to "add an API call", "change a backend", "update settings persistence", "change conversation events", "fix backend auth", "add Agent Server support", or…. Frontend API Contracts is an agent skill from OpenHands/OpenHands. This skill should be used when the user asks to "add an API call", "change a backend", "update settings persistence", "change conversation events", "fix backend auth", "add Agent Server support", or changes src/api, backend registry, Cloud/runtime transport, settings, secrets, compatibility, or conversation resume behavior.

When should I use Frontend API Contracts?

Frontend API Contracts fits situations like: asks to add an API call; change a backend; update settings persistence; change conversation events.

How do I install Frontend API Contracts in Claude Code?

Run `npx skills add OpenHands/OpenHands --skill frontend-api-contracts -a claude-code`. Or copy the skill folder (.agents/skills/frontend-api-contracts in OpenHands/OpenHands) into .claude/skills/frontend-api-contracts in your project. Claude Code loads it when a task matches its description.

How do I install Frontend API Contracts in Codex?

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

Can I use Frontend API Contracts 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 OpenHands/OpenHands --skill frontend-api-contracts -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/frontend-api-contracts, .gemini/skills/frontend-api-contracts, .github/skills/frontend-api-contracts and .opencode/skills/frontend-api-contracts in your project.

What does Frontend API Contracts need to run?

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

Does Frontend API Contracts 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 Frontend API Contracts 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 Frontend API Contracts use?

Frontend API Contracts 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 Frontend API Contracts use?

About 390 tokens (SKILL.md is roughly 1.6k 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 7.5k tokens, read only when the agent opens those files.

What are the alternatives to Frontend API Contracts?

Skills that share tags, products or a category with Frontend API Contracts: Go (inference-gateway/inference-gateway, 214 stars), API Reviewer (mitchdenny/hex1b, 177 stars), System Design (openxlings/xlings, 615 stars) and Frontend Request Skill (jiushiwon/wg-skills, 110 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Frontend API Contracts?

OpenHands (a GitHub organization) maintains it in OpenHands/OpenHands, which has 90,141 GitHub stars. The repository holds 8 skills in this directory. The repository was last updated on October 7, 2026.

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