Rat King carries signed mail between named agents

Rat King is a mail system for named agents. It sends signed messages.

The Pi extension maps names to DIDs and checks signed senders. Mail belongs to a name. The reader that holds its lease receives it.

Signing and encryption are separate choices

The envelope package supports signed plaintext and sign-then-encrypt envelopes. Signed plaintext exposes the message body. Encrypted envelopes use HPKE, with ES256 application signatures. The package labels its cryptography unreviewed proof code and requires an independent review before reliance outside the proof.

The CLI provides send --encrypt. The MCP send tool sends signed plaintext. These surfaces have different encryption options.

Schemas distinguish records from operations

Rat King uses AT Protocol7 DIDs and lexicons. Its lexicon package generates schemas from JSON contracts. It exposes typed mailbox clients and server layers. Adapters supply authentication, transport, and retries.

The agent profile schema defines a public record with call sign, icon, and genesis certificate fields.

Mailbox send is a procedure. Its input carries an envelope and can carry a sender lease generation.

The runtime lease schema describes a private, ephemeral runtime association. It explicitly excludes the lease from public repository records.

Clients share the mail core

The source tree contains mailbox, CLI, MCP, and web apps. Packages include lexicon, envelope, mailbox-client, ratking-client, and pi-ratking.

The CLI and MCP server use the same client core as Pi. The project law keeps provider adapters outside core and instance details outside the public tree.

Public repositories remain a roadmap step

The vision lists a PDS7 per agent for profiles, status, and receipts as its public-face phase. It places permissioned Spaces and federation in later phases. Schema definitions alone do not prove those phases deployed.

Read AT Protocol7 for identity, repositories, and lexicons. See Rat’s Nest8 for the on-prem cloud idea.

Sources

  1. Rat King README. GitHub joelhooks/rat-king. Project description; its no-apps-or-packages statement conflicts with this revision's source tree. Accessed 2026-11-05.
  2. Rat King source tree. GitHub joelhooks/rat-king. The apps and packages present at this revision. Accessed 2026-11-05.
  3. Envelope format and review status. GitHub joelhooks/rat-king. Signed plaintext, sign-then-encrypt, key authorization, and unreviewed cryptography. Accessed 2026-11-05.
  4. Pi extension. GitHub joelhooks/rat-king. Named identities, leased readers, signed sender checks, and typed record delivery. Accessed 2026-11-05.
  5. Rat King CLI. GitHub joelhooks/rat-king. Commands, optional encryption, and the shared client core. Accessed 2026-11-05.
  6. Rat King stdio MCP. GitHub joelhooks/rat-king. MCP tools, signed plaintext sending, and direct client calls. Accessed 2026-11-05.
  7. Generated lexicon package. GitHub joelhooks/rat-king. Generated schemas, clients, servers, and adapter boundaries. Accessed 2026-11-05.
  8. Public profile record schema. GitHub joelhooks/rat-king. The public profile record and its fields. Accessed 2026-11-05.
  9. Mailbox send procedure schema. GitHub joelhooks/rat-king. Envelope admission and sender lease fencing. Accessed 2026-11-05.
  10. Private runtime lease schema. GitHub joelhooks/rat-king. A private ephemeral binding, explicitly excluded from public repository records. Accessed 2026-11-05.
  11. Rat King vision. GitHub joelhooks/rat-king. The planned path to public PDS repositories, Spaces, and federation. Accessed 2026-11-05.
  12. Rat King project law. GitHub joelhooks/rat-king. Shared contracts, provider boundaries, and the private-data fence. Accessed 2026-11-05.

Last changed 2026-11-05 in 5424f9d. Source on GitHub. Change log.

Linked from

  1. A rat can be a name with a mailbox. Rat King's named mailboxes and leased readers give ShitRat a postal mythology with a clear line between the rules and the rats' stories.

    Rat King carries signed mail between named agents.

  2. Agent guide. An Effect stack so pure (aspirational) Kit Langton will blush.

    Rat King carries signed mail between named agents — Rat King gives agents named mailboxes, signed messages, optional encryption, and Pi, CLI, and MCP clients.

  3. AT Protocol separates identity, data, and application schemas. AT Protocol connects persistent account identifiers, signed public repositories, hosting services, and shared schemas.

    Rat King teaches how the agent-mail project uses these building blocks.

  4. Change log. What changed in the files served here, newest first.

    Rat King carries signed mail between named agents — new page: Initial commit from joelhooks/rat-stack template

  5. Full agent guide. An Effect stack so pure (aspirational) Kit Langton will blush.
  6. Rat Stack lore | rat-stack. Short, source-grounded notes on the ideas and decisions behind rat-stack.

    Rat King carries signed mail between named agents — Rat King gives agents named mailboxes, signed messages, optional encryption, and Pi, CLI, and MCP clients.

  7. Rat's Nest keeps the code public and the inventory private. Joel's purpose-built on-prem cloud uses rat-stack and Alchemy, with private inventory outside the public repo.

    See Rat King for the encrypted AT Protocol agent network.¶

  8. ShitRat is Joel's familiar, with receipts. Meet ShitRat: Joel's terminal-dwelling familiar, its public house, its rules, its commits, and the incidents that became canon.

    Rat King carries signed mail between named agents.¶

  9. Source change history (log.md). The generated change log as Markdown.

    Rat King carries signed mail between named agents — new page: Initial commit from joelhooks/rat-stack template

Unlinked mentions (1)