What is sima-atlas-navigator?

A navigation skill for Sima Atlas, a contract-first development system where features are organized into directories of documents describing their purpose, requirements, dependencies, tasks, and checks. It defines the minimum reading order for coding agents.

Use it in any repository with an atlas directory containing graph.json and blocks/. It guides implementation and debugging by selecting the relevant project, rule, feature, dependency, task, history, and verification files.

It helps an agent find the information needed for a task without loading every file in the repository. It also helps preserve project rules, operator preferences, and decisions that should not be reversed casually.

How neskuchny/sima_atlas configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to neskuchny/sima_atlas. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/neskuchny/sima_atlas/main/.claude/skills/sima-atlas-navigator/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/neskuchny/sima_atlas

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/neskuchny/sima_atlas/sima-atlas-navigator/github.svg)](https://agentmods.dev/skills/neskuchny/sima_atlas/sima-atlas-navigator)

Your own site

<a href="https://agentmods.dev/skills/neskuchny/sima_atlas/sima-atlas-navigator"><img src="https://agentmods.dev/badge/skills/neskuchny/sima_atlas/sima-atlas-navigator/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/neskuchny/sima_atlas/sima-atlas-navigator"><img src="https://agentmods.dev/badge/skills/neskuchny/sima_atlas/sima-atlas-navigator.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 84 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,532 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.

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 5.1	$0.00084	$0.01532
Opus 5	$0.00042	$0.00766
Sonnet 5	$0.00017	$0.00306
Haiku 4.5	$0.00008	$0.00153

Measured 12d ago against content hash 52111509a743, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

sima-atlas-navigator 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 12d 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.

.claude/skills/sima-atlas-navigator/SKILL.md · 133 lines

How it starts

The opening of the file, as written. The whole thing — 133 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Sima Atlas Navigator

You are working in a Sima Atlas codebase — a contract-first AI development tool where each product feature lives as a directory of contracts (mission.md / kpi.md / acceptance.md / depends_on.md / provides.md / etc.) instead of free-form code.

Before reading anything else, follow this navigation strategy:

1. Standard read order — minimum context, maximum signal

For "implement / fix block X":

atlas/project.md (root) or atlas/clients/<client>/project.md (multi-tenant)
atlas/rules.md — global must-not-do
atlas/tech_stack.md — locked stack choices
atlas/blocks/<X>/mission.md — intent
atlas/blocks/<X>/acceptance.md — how «done» is verified
atlas/blocks/<X>/depends_on.md — upstream blocks
For each dep <D>: only atlas/blocks/<D>/provides.md
atlas/blocks/<X>/tasks.md — decomposed work
atlas/blocks/<X>/narrative.md — human-readable run history (R-7.80)
atlas/blocks/<X>/decisions.log — past architectural choices (don't reverse)
Last 30 lines of atlas/blocks/<X>/checks.log — verdict log
atlas/operator_profile/dont_use.json — NEVER-do rules (filter to this block)
atlas/operator_profile/always_use.json — ALWAYS-do rules (filter to this block)

Stop at the first level that fully answers the question. Don't pre-read sibling blocks unless depends_on.md lists them.

Note: when invoked through run_block_implementation.mjs, items 9-13 are already pre-injected into your prompt under "## ⚠ Block memory" — don't re-fetch them.

2. Prefer MCP tools over raw file reads

Sima exposes ~64 MCP tools (prefix mcp__sima-atlas__* when registered via .mcp.json). The 5 you'll actually need:

read_block(block_id) — full contract digest in one call (replaces 5+ Reads)
list_dependencies(block_id) — single-hop graph walk
update_block(block_id, file, content) — validated write back
verify_block_acceptance(block_id) — run all assertions, returns pass/fail/inconclusive per assertion
sync_check(block_id?) — drift report (dangling deps, orphan provides)

Read the full file on GitHub · 133 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.

12d ago First seen · 133 lines · 84 tokens per session scan A 52111509a743

Subscribe to this mod's changes

sima-atlas-navigator is a skill published in the GitHub repository neskuchny/sima_atlas (6 stars, last pushed 2mo ago), licensed MIT. It adds 84 tokens to every session and 1,532 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 2026-08-31.

Building agents Claude Code acceptance testing agent-orchestration ai-agents claude codex

sima_atlas: Skill for Claude Code

Borrowing it

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Nothing flagged

How it starts

Sima Atlas Navigator

1. Standard read order — minimum context, maximum signal

2. Prefer MCP tools over raw file reads

What this file has done since we first saw it

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