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/agents-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 | $0.00610 | $0.00610 |
| Opus 5 | $0.00305 | $0.00305 |
| Sonnet 5 | $0.00122 | $0.00122 |
| Haiku 4.5 | $0.00061 | $0.00061 |
Grade A, and why
contextception AGENTS.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 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.
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 — 62 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AI Agent Guidelines
When working on this codebase:
Getting Oriented
- Read
CLAUDE.mdfor project overview and tech stack - Read
docs/ARCHITECTURE.mdfor the full architecture with diagrams - Run
contextception statusto check index health
Development Commands
make build # Build binary
make test # Run all tests (includes race detector in CI)
make lint # Run golangci-lint
make check # Run vet + lint + test in one command
make coverage # Generate HTML coverage report
Code Conventions
- Standard Go conventions:
gofmt,go vet,golangci-lint - Error handling: wrap errors with
fmt.Errorf("context: %w", err) - No
panic()— always return errors - Parameterized SQL queries only (never string concatenation)
- Test files go alongside source:
foo_test.gonext tofoo.go - Integration test fixtures go in
testdata/
Architecture Quick Reference
internal/extractor/ Language-specific import extraction (Python, TS, Go, Java, Rust)
internal/resolver/ Module specifier → file path resolution (per-language)
internal/indexer/ Scan → extract → resolve → store pipeline
internal/analyzer/ Dependency graph traversal, scoring, categorization
internal/change/ PR/branch diff impact analysis
internal/db/ SQLite storage (migrations in internal/db/migrations/)
internal/mcpserver/ MCP server with 9 tools
internal/history/ Usage tracking, feedback storage, analytics queries
internal/session/ Claude Code session parser (discover, adoption)
Adding a New Language
- Create extractor in
internal/extractor/<lang>/implementingextractor.ExtractorExtensions()must return the file extensions (e.g.,[]string{".cs"})- This is enforced by the interface. The
contextception extensionscommand automatically picks up new extensions.
- Create resolver in
internal/resolver/<lang>/implementingresolver.Resolver - Register both in
internal/indexer/indexer.go(instantiate extractor + resolver inNewIndexer)- Also add the extractor to
internal/cli/extensions.gosocontextception extensionsincludes it
- Also add the extractor to
- Add test fixtures in
testdata/ - Verify:
contextception extensionsshould list your new file extensions - See existing implementations (e.g.,
internal/extractor/python/) for reference
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.
- yesterday First seen · 62 lines · 610 tokens per session scan A 717ac195b84e
contextception AGENTS.md is an instructions file published in the GitHub repository kehoej/contextception (6 stars, last pushed 1mo ago), licensed MIT. It adds 610 tokens to every session, about $0.0030 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.
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.
serpentine CLAUDE.md
Claude Code instructions for serpentine-parser/serpentine, covering project, dev environment, features, reading files and key conventions & patterns.
ollama CLAUDE.md
Instructions for ollama/ollama: See AGENTS.md for the shared agent instructions for this repository.
azure-sdk-for-go go-code.instructions.md
Instructions for Azure/azure-sdk-for-go: All code should follow the guidelines from the Azure Go SDK Guidelines. This document is a summary of the most important guidelines to follow when contributing to the Azure Go SDK.
gorest AGENTS.md
Instructions for pilinux/gorest, covering agents.md, project overview, build and run commands, build and tidy dependencies.