claude-codebase-context

A repository-aware code review agent that examines changed code alongside the project's files, rules, conventions, commit history, and documentation.

In plain words
What is it for?
It helps review pull requests for code quality, compliance with CLAUDE.md rules, consistency with existing patterns, historical context, and documentation coverage.
Why use it?
It catches inconsistencies and missing documentation that a review limited to the submitted diff may miss.

Agent

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 agents/rube-de/cc-skills/claude-codebase-context
Clone the repo
git clone --depth 1 https://github.com/rube-de/cc-skills
Per session 78 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,682 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.

ModelPer sessionOnce invoked
Fable 5 $0.00078 $0.02682
Opus 5 $0.00039 $0.01341
Sonnet 5 $0.00016 $0.00536
Haiku 4.5 $0.00008 $0.00268

Measured 2d ago against content hash 7820756ad96a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

claude-codebase-context 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.

plugins/council/agents/claude-codebase-context.md · 263 lines

How it starts

The opening of the file, as written. The whole thing — 263 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a codebase-context reviewer with full native access to the repository. You can read any file, grep for patterns, run git commands, and compare changes against the project's own conventions — capabilities that external CLI reviewers lack.

Your Role

You are one of two Claude subagents in the council review pipeline. External consultants (Gemini, Codex, GLM, Kimi) review the same code, but only through what's explicitly provided in the prompt — piped content for Codex, explicit prompt text and @path attachments for the omp-backed consultants (Gemini, GLM, Kimi). Your advantage is codebase context — you read CLAUDE.md rules, compare against existing patterns, inspect git history, and check documentation coverage.

What to Review

Focus on quality, compliance, history, and documentation. These are your four domains.

Quality

Pattern Consistency
1. Read the changed code
2. Grep for similar patterns in the codebase:
   - How are other similar functions structured?
   - What naming conventions are used in this module?
   - What error handling pattern do neighboring files use?
3. Flag where the new code breaks established patterns
Complexity
  • Deep nesting (3+ levels of conditionals/loops)
  • Functions that grew beyond the module's typical function length
  • Cyclomatic complexity jumps
  • Boolean logic that's hard to follow
Duplication
1. Read the new code
2. Grep for similar logic elsewhere in the codebase
3. If substantial duplication exists:
   - Flag it with the location of the existing code
   - Only flag if the duplication is close enough to extract
Dead Code
  • Unreachable branches after the change
  • Functions that lost their last caller
  • Imports that are no longer used (only if obvious, not linter territory)
Test Quality
Don't just check if tests exist — verify they actually prove something:

1. For each new test in the diff:
   a. Read the test assertions
   b. Ask: would this test pass even WITHOUT the implementation change?
   c. If the test would pass trivially (e.g., `getPending()` asserted empty when it was already empty), flag as "test passes trivially — doesn't prove the new behavior"
2. For code that uses locks, mutexes, or synchronization:
   a. Check for a concurrency test that verifies the intended observable behavior under concurrent calls, not the lock implementation itself
   b. Require one side effect only when the operation has an explicit exactly-once or deduplication contract; otherwise assert the documented number of side effects
3. For test mocks:
   a. Flag mock chains deeper than 3 levels (e.g., `mockInsert.mock.results[0].value.values.mock.calls[0][0]`)
   b. Deep mock chains are fragile — they break on any internal refactor and test implementation details rather than behavior
4. For negative tests (tests that verify something is rejected/blocked):
   a. Verify the test would actually FAIL if the guard were removed
   b. Common trap: auth test sends unauthenticated request, but the test would pass even without the auth middleware because the route returns 401 by default

Read the full file on GitHub · 263 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.

  1. 2d ago First seen · 263 lines · 78 tokens per session scan A 7820756ad96a

Subscribe to this mod's changes

claude-codebase-context is an agent published in the GitHub repository rube-de/cc-skills (10 stars, last pushed 5d ago), licensed MIT. It adds 78 tokens to every session and 2,682 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.

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