---
title: "ETR Possession-Chain Receipt Builder"
method: POST
path: "/v1/tools/build_etr_possession_chain"
tags: ["TODO_TAGS_REVIEW", "TODO_AP2_EXPORT_REVIEW"]
---

# ETR Possession-Chain Receipt Builder

`POST /v1/tools/build_etr_possession_chain`

## Request

- Base URL: `https://ainumbers.co`
- URL: `https://ainumbers.co/v1/tools/build_etr_possession_chain`
- Auth: none declared

Builds a hash-chained possession-receipt evidence pack for an electronic transferable record (ETR) under UNCITRAL MLETR Art. 10/11: given the ETR's own document digest and an ordered set of control-transfer events (from_holder, to_holder, timestamp, signature -- all as supplied), each receipt binds the prior receipt's hash, so reordering, inserting, or deleting a transfer breaks the chain. Also checks holder-to-holder continuity and timestamp ordering, and computes a SHA-256 Merkle root over the chain -- a portable evidence pack a holder can present to a bank or court. Does not itself assess MLETR Art. 10/11 singularity/exclusive-control legal elements; that verdict is check_etr_control_evidence (art-352).

**Tool URL:** https://ainumbers.co/chaingraph/art-353-etr-possession-chain-builder.html

## Request body

- object
  - `control_transfer_events` unknown[], required
    - unknown
  - `document_digest` unknown, required
  - `initial_holder` unknown, required

## Response `200`

Successful tool execution result

- object
  - `chain_continuous` boolean
  - `continuity_breaks` unknown[]
    - unknown
  - `document_digest` string
  - `event_count` integer
  - `final_holder` string
  - `merkle_root` string
  - `note` string
  - `possession_receipts` string
  - `timestamp_order_valid` boolean

---

[API](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite.md) · [All operations](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/llms.txt) · [OpenAPI document](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/revisions/b462e4f5bb28?raw)