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.
npx agentmods add instructions/kehoej/contextception/claude-mdgit clone --depth 1 https://github.com/kehoej/contextceptionWhat 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 | $0.01007 | $0.01007 |
| Opus 5 | $0.00504 | $0.00504 |
| Sonnet 5 | $0.00201 | $0.00201 |
| Haiku 4.5 | $0.00101 | $0.00101 |
Grade A, and why
contextception CLAUDE.md 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.
How it starts
The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
Project Overview
Contextception is a code context intelligence engine written in Go. It answers: "What code must be understood before making a safe change?" It is not a code generator, AI assistant, or IDE — it determines what matters, not what to do.
Supports 6 languages: Python, TypeScript/JavaScript, Go, Java, Rust, and C#. Available as a CLI (16 commands) and MCP server (9 tools).
Tech Stack
- Language: Go (single binary, concurrency for indexing)
- Storage: SQLite via
modernc.org/sqlite(pure-Go, embedded) - CLI:
spf13/cobra - TS/JS Extraction:
smacker/go-tree-sitter(CGO) with regex fallback - MCP Server:
modelcontextprotocol/go-sdk(stdio transport) - Config:
gopkg.in/yaml.v3 - Semver:
golang.org/x/mod/semver - Release Signing:
jedisct1/go-minisign(signature verification for self-update)
Architecture
See docs/ARCHITECTURE.md for the full architecture guide with diagrams.
Repository → Language Extractors → SQLite Index → Analysis Engine → Context Bundle (JSON)
Key components: Indexer (internal/indexer/), Language Extractors (internal/extractor/), Resolvers (internal/resolver/), Analysis Engine (internal/analyzer/), Change Analysis (internal/change/), MCP Server (internal/mcpserver/), Update (internal/update/).
Key Design Principles
- Deterministic first — outputs are explainable and reproducible; no model-dependent core logic
- Static truth before AI — signals from dependency graphs, repo structure, change patterns
- Read-only by design — never modifies source, never executes arbitrary commands
- Incremental — only changed files reprocessed; schema migrations are versioned
- Pluggable extractors — language-specific extractors emit facts; core is language-agnostic
Development
make build # Build binary to ./bin/contextception
make test # Run all tests
make lint # Run golangci-lint
make check # Run vet + lint + test
make coverage # Generate HTML coverage report
make install # go install to $GOPATH/bin
make generate # Regenerate protocol JSON schemas
make release # Show release info (latest tag, next version, pending commits)
make help # List all targets
/release # Full release: generate changelog, commit, tag, push (Claude Code)
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 · 93 lines · 1,007 tokens per session scan A f86606fa2271
contextception CLAUDE.md is an instructions file published in the GitHub repository kehoej/contextception (6 stars, last pushed 1mo ago), licensed MIT. It adds 1,007 tokens to every session, about $0.0050 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.
Other instructions, from other repositories
semgrep AGENTS.md
AGENTS.md instructions for semgrep/semgrep, covering semgrep oss codebase overview, architecture, key concepts, python-to-ocaml migration strategy and developer setup.
warden AGENTS.md
Instructions for stephnangue/warden, covering warden — agent guide, where to start, the agent loop, provider skills and adding a skill for a new provider.
semgrep CLAUDE.md
Claude Code instructions for semgrep/semgrep, a project described as: Lightweight static analysis for many languages. Find bug variants with patterns that look like source code.
gridctl AGENTS.md
Instructions for gridctl/gridctl, covering agents.md, what gridctl is, build and run, code architecture and constitution.
agent-lsp CLAUDE.md
Instructions for blackwell-systems/agent-lsp, a project described as: MCP server that orchestrates language servers into agent-native workflows. 65 tools, 30 CI-verified languages.
uzomuzo-oss agent-orchestration.instructions.md
Instructions for future-architect/uzomuzo-oss, covering agent orchestration, agent invocation, available subagent types, available skills and immediate agent usage.