AGENTS.md — Rules for AI agents working in this repo

This repository builds a security tool. The same discipline applies to agents that develop it.

Secret handling (hard rules)

Never read key.txt or secrets.enc directly (test fixtures excepted, and even then only via the store package API).
Never print, log, or commit a secret value — including in test output.
When debugging the store, use the store's own List() (masked) or assert on masked forms, not raw Get().
e2e_test.py intentionally asserts plaintext does NOT appear in MCP output. Keep it that way.
If you must inspect an on-disk blob, read it as bytes and check only for the armor markers / absence of plaintext — never dump the decrypted data.

secrets.enc must never contain plaintext key material (age-encrypted).
key.txt must be 0600, store dir 0700.
Every MCP tool result and resource must be masked — no plaintext in tool results, ever.
put must accept a value_file path, read it, and delete it after.
Masking rules live in internal/mask — keep the entropy/prefix/URL segmentation tests green.

Run go test ./... before committing — all packages must pass.
Run go vet ./... — no warnings.
Run python3 e2e_test.py after any change to internal/mcp or internal/store — the protocol round-trip must stay green.
Keep the Go SDK (github.com/modelcontextprotocol/go-sdk) on a version with no open OSV advisories; bump deliberately.