What is backend-service-spec-skill?

A workflow for building a factual map of backend systems, including legacy applications, microservices, APIs, message queues, scheduled jobs, and service chains. A microservice is a small service that performs part of a larger application’s work.

Use it to map services, trace API and message flows, document platform systems, create service knowledge pages, or extract current requirements from existing code.

It helps teams understand unfamiliar or poorly documented backend code without turning guesses into facts. It organizes code evidence into reusable documentation.

backend-service-spec-skill — Cursor rule by SYZ-Coder

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.

agentmods

npx agentmods add rules/syz-coder/codebase-knowledge-wiki/backend-service-spec-skill

Clone the repo

git clone --depth 1 https://github.com/SYZ-Coder/codebase-knowledge-wiki

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.

When invoked 1,282 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

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.

Model	Per session	Once invoked
Fable 5	$0.00000	$0.01282
Opus 5	$0.00000	$0.00641
Sonnet 5	$0.00000	$0.00256
Haiku 4.5	$0.00000	$0.00128

Measured 2d ago against content hash f3fc940a39c6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

backend-service-spec-skill 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 2d 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.

.cursor/rules/backend-service-spec-skill.mdc · 158 lines

How it starts

The opening of the file, as written. The whole thing — 158 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Backend Service Spec Skill

Use this rule when the user asks to understand, map, document, or maintain reusable knowledge for backend systems, legacy systems, microservices, platform services, service chains, APIs, MQ flows, scheduled jobs, or central knowledge base pages.

Do not use this rule for ordinary feature implementation, bug fixes, test writing, or refactors unless the user explicitly asks for code knowledge mapping as part of the work.

Required Skill Source

Before producing artifacts, read the skill source from one of these locations:

If this skill library exists in the target project: backend-service-spec-skill/SKILL.md
If copied under a shared skill folder: skills/backend-service-spec-skill/SKILL.md
If cloned as a project-local rule source: ai-skill-lib/backend-service-spec-skill/SKILL.md
If only this rule is available, follow the summarized workflow below and state that the full skill source was not found.

Also read only the directly relevant reference files when they exist:

backend-service-spec-skill/references/workspace-classification.md
backend-service-spec-skill/references/codemap-modes.md
backend-service-spec-skill/references/router-map.md
backend-service-spec-skill/references/domain-layering.md
backend-service-spec-skill/references/service-deep-dive.md
backend-service-spec-skill/references/central-repo-conventions.md
backend-service-spec-skill/references/quality-checklist.md
backend-service-spec-skill/references/output-templates.md
backend-service-spec-skill/references/diagram-output-guidelines.md
backend-service-spec-skill/references/mermaid-safety-checklist.zh-CN.md

Command Intents

Treat these text commands as workflow intents, not as built-in executable commands:

create_codemap
service_deep_dive
crate_router_map
create_router_map
build_domain_map

If the target project provides scripts or CLI commands for these intents, prefer running them from the integrated terminal. Common locations to check:

Read the full file on GitHub · 158 lines

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.

2d ago First seen · 158 lines · 0 tokens per session scan A f3fc940a39c6

Subscribe to this mod's changes

backend-service-spec-skill is a cursor rule published in the GitHub repository SYZ-Coder/codebase-knowledge-wiki (9 stars, last pushed 2mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,282 tokens. 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 2026-08-31.

Backend and APIs Documents Planning

backend-service-spec-skill

Getting it into your agent

What it costs to keep this loaded

Grade A, and why

Nothing flagged

How it starts

Backend Service Spec Skill

Required Skill Source

Command Intents

What this file has done since we first saw it

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