sign-cli AGENTS.md

Instructions for using sign-cli, a command-line tool for signing and verifying data, from an automated agent or other non-interactive program.

In plain words
What is it for?
Use them when integrating sign-cli into agents, scripts, or services that need to discover commands, handle failures, and request signatures safely.
Why use it?
They define machine-readable success and error output, exit codes, discovery commands, and the boundary around the human signing action.

Instructions file for CodexOpenCode

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 instructions/drbaher/sign-cli/agents-md
Clone the repo
git clone --depth 1 https://github.com/DrBaher/sign-cli

Made for: Codex, OpenCode.

Per session 1,179 This file is loaded in full into every session.
When invoked 1,179 The same file — it is already loaded in full.
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 $0.01179 $0.01179
Opus 5 $0.00589 $0.00589
Sonnet 5 $0.00236 $0.00236
Haiku 4.5 $0.00118 $0.00118

Measured yesterday against content hash b452a009fe16, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

sign-cli 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.

AGENTS.md · 90 lines

How it starts

The opening of the file, as written. The whole thing — 90 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agents

Drive sign-cli from an LLM or non-interactive client. This is the quickstart; the full canonical reference is docs/agent-guide.md.

Output contract

  • Success: JSON to stdout, exit 0.
  • Failure: { ok: false, error: { code, message, hint?, details? } } to stderr, non-zero exit.
  • Toggle to plain text: SIGN_ERROR_FORMAT=text.

Exit codes

Code Meaning
0 Success
2 Invalid input (missing/malformed flag, schema fail)
3 Policy / chain / verification failed
4 Not found / out of range

Full code table and the failure-mode → recovery map: docs/reference/exit-codes.md.

Discovery

Never hardcode tool names, flag lists, or counts — call these at startup:

sign --catalog json    # full CLI command + flag inventory
sign mcp tools         # live MCP tool catalog (with inputSchema/outputSchema)
sign --version

The signing asymmetry

The whole architecture is built around one rule: the agent does every step except the signing gesture. sign (CLI / MCP tool / POST /v1/sign) requires a per-signer token that's scoped to one email, TTL-bounded, single-use. The requester (which can be the agent) holds and DMs the token to the human signer; the signer pastes it into sign sign --token .... The agent never sees signer tokens.

Pre-sign safety checks (--require-hash, --require-title, --require-signer-email) throw structured errors before any state mutation, so an agent computing a hash earlier can refuse to sign if the document was swapped in flight.

Read-only mode

For sandboxed agents that should inspect and track but not mutate:

sign mcp serve --read-only true \
  --tool request_show --tool audit_verify --tool pdf_detect_signature_field
sign serve --read-only true --rate-limit 5

Mutating tools/routes return FORBIDDEN_READ_ONLY (exit 3 / HTTP 403). The set is in READ_ONLY_BLOCKED_TOOLS and READ_ONLY_BLOCKED_ROUTES in the source.

Read the full file on GitHub · 90 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. yesterday First seen · 90 lines · 1,179 tokens per session scan A b452a009fe16

Subscribe to this mod's changes

sign-cli AGENTS.md is an instructions file published in the GitHub repository DrBaher/sign-cli (0 stars, last pushed 1mo ago), licensed MIT. It adds 1,179 tokens to every session, about $0.0059 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.