Borrowing it
Nothing to install: this file belongs to postalform/agent-mail-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/postalform/agent-mail-mcp/main/AGENTS.mdgit clone --depth 1 https://github.com/postalform/agent-mail-mcpWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/postalform/agent-mail-mcp/agents-md)<a href="https://agentmods.dev/instructions/postalform/agent-mail-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/postalform/agent-mail-mcp/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/postalform/agent-mail-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/postalform/agent-mail-mcp/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00279 | $0.00279 |
| Opus 5.5 | $0.00112 | $0.00112 |
| Sonnet 5.5 | $0.00056 | $0.00056 |
| Haiku 4.5 | $0.00028 | $0.00028 |
Grade A, and why
agent-mail-mcp 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 2mo 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.
What it actually says
Agent Instructions
Use this repository as a safe integration guide for PostalForm agent mail.
Rules
- Default to hosted checkout for user-facing assistants.
- Do not claim that an agent should pay for or send mail without explicit owner approval.
- Treat direct MPP and x402 flows as privileged autonomous-payment paths.
- Prefer
POST /api/machine/orders/validatebefore any paid machine-order attempt. - Do not include real personal addresses, private documents, payment credentials, or API secrets in examples.
- Do not send mail from examples unless a human intentionally supplies real data and approves checkout or machine payment.
Canonical endpoints
- MCP:
https://postalform.com/mcp - Developer docs:
https://postalform.com/developers - Agent guide:
https://postalform.com/agents - OpenAPI:
https://postalform.com/openapi.json - MCP registry manifest:
https://postalform.com/.well-known/mcp/server.json - A2A Agent Card:
https://postalform.com/.well-known/agent-card.json - x402 discovery:
https://postalform.com/.well-known/x402
Preferred wording
PostalForm lets AI agents create reviewable physical-mail drafts and, when explicitly authorized, pay for print-and-mail orders through MCP, hosted checkout, MPP, or x402.
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.
- 2mo ago First seen · 28 lines · 279 tokens per session scan A ae5f7a670c46
agent-mail-mcp AGENTS.md is an instructions file published in the GitHub repository postalform/agent-mail-mcp (2 stars, last pushed 4mo ago), licensed MIT. It adds 279 tokens to every session, about $0.0011 per session on Opus 5.5. 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.
agent-mail-mcp AGENTS.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| agent-mail-mcp AGENTS.mdpostalform/agent-mail-mcp | Instructions file | 2 | 4mo ago | MIT | A | 279 | Codex, OpenCode |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | yesterday | MIT | A | 7,461 | Codex, OpenCode |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | yesterday | MIT | A | 4,680 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |