backend-feature-flags

backend-feature-flags is a skill for Claude Code, Codex from j4flmao/agent-skills. It costs 86 tokens per session (5,351 once invoked), scanned A, original, MIT.

A guide for feature flags, which let software turn features on or off or release them to selected users without changing the main code path.

In plain words
What is it for?
It helps design targeting rules, percentage rollouts, cached flag checks, safe defaults, canary releases, A/B tests, and kill switches.
Why use it?
It helps control gradual releases, experiments, and emergency shutoffs while keeping track of who owns each flag and when it should be removed.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions Codex.

Good fit It helps design targeting rules, percentage rollouts, cached flag checks, safe defaults, canary releases, A/B tests, and kill switches.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/j4flmao/agent-skills/feature-flags
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add j4flmao/agent-skills --skill feature-flags
Clone the repo
git clone --depth 1 https://github.com/j4flmao/agent-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for backend-feature-flags

README.md
[![agentmods](https://agentmods.dev/badge/skills/j4flmao/agent-skills/feature-flags/github.svg)](https://agentmods.dev/skills/j4flmao/agent-skills/feature-flags)
Your own site
<a href="https://agentmods.dev/skills/j4flmao/agent-skills/feature-flags"><img src="https://agentmods.dev/badge/skills/j4flmao/agent-skills/feature-flags/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for backend-feature-flags

Your own site · 80×15
<a href="https://agentmods.dev/skills/j4flmao/agent-skills/feature-flags"><img src="https://agentmods.dev/badge/skills/j4flmao/agent-skills/feature-flags.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 86 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,351 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high System Prompt Leakage · line 426
    Skill contains instructions that could directly expose system prompts, internal rules, or hidden instructions to users or external parties.
    Fix: Remove any instructions that reveal, print, or output system prompts or internal rules. System instructions should never be exposed to end users.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00086 $0.05351
Opus 5 $0.00043 $0.02676
Sonnet 5 $0.00017 $0.01070
Haiku 4.5 $0.00009 $0.00535

Measured 8d ago against content hash 4fa9c6415628, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

backend-feature-flags scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/backend/universal/feature-flags/SKILL.md · 561 lines

How it starts

The opening of the file, as written. The whole thing — 561 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Backend Feature Flags

Purpose

Design feature flag systems with lifecycle management, targeting, and risk controls.

Agent Protocol

Trigger

Exact user phrases: "feature flag", "feature toggle", "canary release", "gradual rollout", "A/B test", "kill switch", "flag management", "LaunchDarkly", "Unleash", "flag evaluation", "targeting rule", "percentage rollout", "feature gate".

Input Context

Before activating, verify:

  • Number of flags expected (10s, 100s, 1000s)
  • Targeting requirements (user ID, group, percentage, custom attributes)
  • Flag lifespan (short-lived release toggles vs long-lived ops toggles)
  • Evaluation performance needs (latency budget, cache TTL tolerance)
  • Flag management platform (LaunchDarkly, Unleash, Flagsmith, custom)

Output Artifact

Feature flag strategy as formatted text.

Response Format

# Flag definitions with targeting rules
# Evaluation configuration
// Flag evaluation code
// SDK setup

No preamble. No postamble. No explanations. No filler/hedging/transitions. Compress output — why use many token when few do trick.

Completion Criteria

  • Flag types classified (release/experiment/ops/permission)
  • Evaluation strategy with caching and bulk evaluation
  • Targeting rules defined (user, group, percentage, prerequisites)
  • Flag lifecycle with creation, evaluation, stabilization, cleanup
  • Risk controls (kill switch, auto-rollback, audit log)
  • Stale flag detection and removal deadline configured

Max Response Length

200 lines of configuration and code.

Decision Tree

What Type of Flag?

How long does this flag live?
  ├── Days to weeks (feature under development)
  │   └── Release toggle — remove immediately after full rollout
  ├── Weeks to months (A/B test, experiment)
  │   └── Experiment toggle — remove after analysis complete
  ├── Months to years (kill switch, operational control)
  │   └── Ops toggle — highest risk, requires kill switch
  └── Permanent (access control, early access)
      └── Permission toggle — effectively access control, use RBAC instead

Read the full file on GitHub · 561 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 561 lines · 86 tokens per session scan A 4fa9c6415628

Subscribe to this mod's changes

backend-feature-flags is a skill published in the GitHub repository j4flmao/agent-skills (23 stars, last pushed 5d ago), licensed MIT. It adds 86 tokens to every session and 5,351 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

Related

Other skills, from other repositories

opentelemetry

OpenTelemetry observability patterns: traces, metrics, logs, context propagation, OTLP export, Collector pipelines, and troubleshooting.

bobmatnyc/claude-mpm-skills · 29 tokens

mem0-oss-to-platform

Plan and then execute a migration of a project from the mem0 open-source / self-hosted SDK (the local Memory class) to the mem0 Platform / hosted / managed SDK (the MemoryClient class). Use this whenever a developer wants to move, switch, or migrate their mem0 usage off OSS/self-hosted to the hosted API — e.g.…

mem0ai/mem0 · 273 tokens

agui-dotnet-protobuf

Use the protobuf wire transport (instead of the default Server-Sent Events) for an AG-UI connection with the AG-UI .NET SDK — a compact binary event stream negotiated via the Accept header. USE FOR: making an AGUIChatClient prefer protobuf by wiring an AGUIEventStreamHandler with ProtobufEventStreamFormatter (then…

ag-ui-protocol/ag-ui · 162 tokens

azure-mgmt-botservice-dotnet

Azure Resource Manager SDK for Bot Service in .NET. Management plane operations for creating and managing Azure Bot resources, channels (Teams, DirectLine, Slack), and connection settings. Triggers: "Bot Service", "BotResource", "Azure Bot", "DirectLine channel", "Teams channel", "bot management .NET", "create bot".

microsoft/skills · 78 tokens

fastapi-router-py

Create FastAPI routers with CRUD operations, authentication dependencies, and proper response models. Use when building REST API endpoints, creating new routes, implementing CRUD operations, or adding authenticated endpoints in FastAPI applications.

microsoft/skills · 46 tokens

aws-sdk-java-v2-core

Provides AWS SDK for Java 2.x client configuration, credential resolution, HTTP client tuning, timeout, retry, and testing patterns. Use when creating or hardening AWS service clients, wiring Spring Boot beans, debugging auth or region issues, or choosing sync vs async SDK usage.

giuseppe-trisciuoglio/developer-kit · 62 tokens