code-map

A code map that records symbols, such as functions and classes, and the calls between them using a language server, a tool that understands source-code structure.

In plain words
What is it for?
Use it to find definitions, trace callers and callees, explore code relationships, and estimate the impact of proposed changes.
Why use it?
It helps navigate an unfamiliar codebase and assess what a change might affect without relying only on text search.

Skill for Claude CodeCodex

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 skills/juxt/claude-plugins/code-map
Any agent
npx skills add juxt/claude-plugins --skill code-map
Clone the repo
git clone --depth 1 https://github.com/juxt/claude-plugins

Made for: Claude Code, Codex.

Per session 92 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,849 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 1 finding. 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.

ModelPer sessionOnce invoked
Fable 5 $0.00092 $0.02849
Opus 5 $0.00046 $0.01425
Sonnet 5 $0.00018 $0.00570
Haiku 4.5 $0.00009 $0.00285

Measured yesterday against content hash 70c9e3269c20, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade C, and why

code-map scanned grade C with 1 finding 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 yesterday.

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.

Tells the agent never to refusehighAnti-refusal

Suppressing the ability to decline removes a core safety control; a later harmful request then succeeds.

The map is an optimisation, not a prerequisite. If you cannot produce one — no adapter matches, the required LSP plugin is missing, the LSP is installed but not indexing — do not refuse the invocation:
plugins/code-map/skills/code-map/SKILL.md · 195 lines

How it starts

The opening of the file, as written. The whole thing — 195 lines — stays where its author put it; the contents beside it link to each section on GitHub.

code-map

You build and query a code-only symbol and call-graph map of the current project, driven entirely by LSP. The map is a cache that lets other reasoning steps navigate code by definition and call relationship rather than by blind grep.

You are narrow and mechanical. You do not write application code, you do not write tests, you do not judge the code. Your only side effect is writing JSON under .codemap/ at the project root.

Startup

  1. Read adapters/README.md for the adapter contract.
  2. Detect target language(s) from the project's fingerprint files (see §Adapters). Load the matching adapter(s). If no adapter matches, exit degraded (see §Degraded exit).
  3. Verify the LSP tool is available for each chosen language by running the adapter's sentinel — typically a documentSymbol call against any source file. The Claude Code harness tends to run LSP servers in single-file mode (confirmed for pyright at time of writing), so do not rely on workspaceSymbol. If the sentinel errors with Executable not found in $PATH or equivalent, exit degraded with reason: lsp-unavailable. If it returns empty on a file known to contain symbols, exit degraded with reason: lsp-not-indexing.

Degraded exit

The map is an optimisation, not a prerequisite. If you cannot produce one — no adapter matches, the required LSP plugin is missing, the LSP is installed but not indexing — do not refuse the invocation:

  1. Do not write or modify any .codemap/<lang>.json.
  2. Print a short, actionable message quoting the exact cause. Callers will relay this message verbatim to the user; do not paraphrase.
  3. Return a summary with degraded: true, a reason tag, and a details string containing the raw signal that produced the diagnosis.

Reason tags (use exactly one):

  • no-adapter — no language adapter matched the project's fingerprints. details lists which fingerprints were checked.
  • lsp-unavailable — the LSP binary isn't on PATH, the plugin isn't installed, or the sentinel call errored. details quotes the LSP tool's error message verbatim (e.g. Executable not found in $PATH: "pyright-langserver").
  • lsp-not-indexing — LSP responds but returns empty for a file that is known to contain symbols. Typically means single-file mode with a mis-rooted workspace. details says which sentinel was used and what it returned.
  • lsp-single-file-mode — LSP responds per-file but cross-file queries (workspaceSymbol, cross-file findReferences, project-internal goToDefinition) consistently return empty. This is the expected behaviour for the Claude Code pyright wrapper today. details notes that symbol discovery is driven by documentSymbol + Glob rather than workspace-wide calls.

Read the full file on GitHub · 195 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. yesterday First seen · 195 lines · 92 tokens per session scan C 70c9e3269c20

Subscribe to this mod's changes

code-map is a skill published in the GitHub repository juxt/claude-plugins (10 stars, last pushed 4d ago), licensed MIT. It adds 92 tokens to every session and 2,849 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it C with 1 finding (tells the agent never to refuse). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

babysit-pr

Babysit a GitHub pull request after creation by continuously polling review comments, CI checks/workflow runs, and mergeability state until the PR is merged/closed or user help is required. Diagnose failures, retry likely flaky failures up to 3 times, auto-fix/push branch-related issues when appropriate, and keep…

openai/codex · 114 tokens

imagegen

Generate or edit raster images when the task benefits from AI-created bitmap visuals such as photos, illustrations, textures, sprites, mockups, or transparent-background cutouts. Use when Codex should create a brand-new image, transform an existing image, or derive visual variants from references, and the output…

openai/codex · 113 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens

next-cache-components-optimizer

Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…

vercel/next.js · 170 tokens