How to send registered mail from an AI agent

Yes, an AI agent can prepare and submit registered mail through FrankKi when the exact destination has a supported registered product. The safe sequence is to validate the recipient, draft and render the letter, request a destination-specific quote, show a human the complete preview and price, obtain explicit approval, send with an idempotency key, and then read status and available evidence.

Registered mail is not a synonym for tracking, and neither tracking nor a posting receipt proves that a letter was legally sufficient. This guide separates the postal product, the returned evidence, and the legal question.

Registered, tracked, and evidence are different properties

A tracked product returns a carrier number and status timeline. A registered product is a named postal service for the destination. A proof-of-posting record documents a provider-reported or observed posting event. A delivery event or recipient signature, where the selected service provides one, documents a later carrier event. Do not collapse these into one claim.

• Proof of posting: records when the postal service accepted or was observed to accept the item, plus provider and shipment provenance.
• Tracking: reports carrier status over time. A delivered or collected status is the provider's returned signal.
• Proof of delivery: exists only where the selected service supplies a delivery record.
• Signature: exists only for a handover product that actually records one. Mailbox-deposit products do not imply a recipient signature.

Choose a destination-supported product

FrankKi source defines two German LetterXPress products. Einschreiben Einwurf is the r1 product: it is registered and tracked, and the carrier deposits it in the recipient's mailbox without a recipient signature. Einschreiben mit Uebergabe is r2: it is registered and tracked, and is handed to an authorized recipient against signature.

Switzerland has a named Pingen registered and tracked product. Austria has no registered tier in the checked source. Outside DACH, a request becomes intl_registered only when the destination's named catalog has a real registered marker. A price difference can establish a tracked tier, but never registered mail or proof of delivery. If the required product is unavailable, the source returns LEGAL_PROOF_UNAVAILABLE_FOR_COUNTRY instead of silently downgrading it.

Current country and tier counts are not measured. Product availability must come from the current destination response and shipping_quote, not from a static country list.

Safe agent workflow for registered mail

1. Call address_validate with the complete recipient address. Stop on ADDRESS_INVALID or COUNTRY_NOT_SUPPORTED.
2. Create a draft with letter_create_draft and a stable clientLetterId.
3. Call letter_preview and inspect every rendered page.
4. Call shipping_quote for the exact country and requested registered delivery type. Do not substitute standard mail when registered evidence is required.
5. Run order_send with dryRun:true, the quote fields, maxCostEuros, approvalMode:"review", and a stable clientOrderId.
6. Show the human the recipient, every preview page, exact quote, delivery type, maximum cost, and idempotency key. Obtain explicit approval for that artifact.
7. Submit the unchanged live payload with the same business-operation key. If an approvalId is returned, show the frozen artifact again and call approval_decide only after the authorized human approves.
8. Read order_status. Call order_cancel immediately if the human says stop and the response still reports a cancellable state.
9. For a qualifying sent order, retrieve the proof-of-posting record with order_einlieferungsbeleg.

shipping_quote({
  "letterId": "REVIEWED_LETTER_ID",
  "pageCount": 1,
  "color": false,
  "deliveryType": "einschreiben_einwurf",
  "country": "DE"
})

order_send({
  "letterId": "REVIEWED_LETTER_ID",
  "recipientName": "Example Recipient",
  "recipientStreet": "Example Street",
  "recipientHouseNumber": "1",
  "recipientZip": "10115",
  "recipientCity": "Berlin",
  "recipientCountry": "DE",
  "deliveryType": "einschreiben_einwurf",
  "priceVersion": "VERSION_FROM_QUOTE",
  "quotedUnitPriceCents": 123,
  "maxCostEuros": 10,
  "approvalMode": "review",
  "clientOrderId": "case-482-registered-v1",
  "dryRun": true
})

The recipient, IDs, and 123-cent value are placeholders. This example is non-destructive and makes no price claim. Use the exact value returned for the exact letter and destination.

What order_einlieferungsbeleg returns

The checked source describes order_einlieferungsbeleg as returning an archived, hash-verified proof-of-posting record with a download URL, postmark or provider-observation time, shipment data, provider data, and archive provenance. The record concerns posting. It is not itself the recipient's receipt, a signature, deadline compliance, or the legal effect of the letter.

During an archive upgrade path, a clearly labeled FrankKi-synthesized record based on provider status may appear before an original provider artifact. It is not represented as a provider original. The source derives the court_grade archive tier only for German LetterXPress registered mail, provider_attestation for defined provider cases, and none for raw international delivery. A tier label does not decide legal sufficiency.

Status, cancellation, and evidence retrieval

order_status is authoritative for fulfillment state, tracking number, timeline, and whether cancellation is still available. Call order_cancel immediately when requested, but never promise success. Once printing starts, physical mail cannot be recalled.

Evidence can arrive at different times. A missing posting record is not proof that no order exists, and a tracking status is not a substitute for the requested record. Preserve the order ID, selected product, quote, approval decision, and returned provenance in the case audit trail.

Questions to ask before using registered mail

Can every destination receive registered mail?
No. Registered mail is destination-dependent and requires a real named registered product. Validate and quote the exact destination.

Does tracking prove delivery?
No. Tracking is the carrier timeline. A delivery record or signature exists only where the selected service returns it.

Does proof of posting prove the contents?
No. It records posting and provenance, not by itself the legal sufficiency, contents, authority, form, deadline, or intended legal effect.

Can the agent approve its own send?
No. The authorized human must review the frozen preview, recipient, delivery type, and exact price and explicitly approve dispatch.

Continue with the canonical controls

• Physical mail for AI agents
• Physical-mail MCP providers compared
• Human-approval architecture
• Worldwide destination and quote policy
• Canonical safe-send workflow
• Status and proof tool contracts
• Errors and recovery
• Service status