A notation for transferring reasoning between AI systems that leaves an auditable record of the transfer.
Reasonledger encodes model-to-model messages as named blocks, each carrying an explicit instruction for how the receiver should process the enclosed content — activate this as a premise, enforce this as a constraint, verify this derivation step by step. Across a multi-hop chain of agents, those blocks and a three-way epistemic status accumulate into an inspectable record of what each model claimed, what it verified, and what it accepted on trust. That record is the ledger.
Reasonledger is a payload format. It rides inside a transport such as MCP or A2A; it does not replace one. It is not a blockchain and involves no tokens, chain, or consensus — "ledger" refers to the audit trail the format produces, nothing more.
Multi-agent systems are easy to run and hard to inspect. When a planner hands work to an executor, and that output feeds a third agent, the reasoning that produced the final answer is scattered across opaque messages. Plain prose loses structure at each hop; plain JSON carries data but no record of what was checked versus assumed. Reasonledger keeps the structure and adds the record: which agent asserted what, which steps were verified, which were trusted, and where a claim's status changed along the way.
The intended use is governance and observability for agentic pipelines — a reasoning ledger you can read after the fact to see how a conclusion was reached and how much of it was actually verified.
- Content blocks —
@FORMAL,@LOGIC,@DERIVE,@TAXONOMY,@ANCHOR— typed reasoning with per-block processing instructions. - Exchange blocks —
@STATE,@VERIFY,@OUTPUT— state handoff, per-step verification reporting, response shaping. - Transfer-protocol blocks —
@PROVENANCE,@TRANSFER_REPORT,@DERIVATION_TRACE,@SCOPE,@CONFIDENCE,@TRUST_TRANSFORMATION— chain-of-custody, per-hop integrity, and trust calibration for multi-hop chains. - Three-way epistemic status —
confirmed/open/denied, preserved across model boundaries rather than collapsed.
Full grammar and processing rules are in SPEC.md.
@FORMAL [kepler_third]
T² = (4π² / GM) · a³
@DERIVE [circular_velocity]
(1) For a circular orbit, gravity supplies the centripetal force
(2) G·M·m / r² = m·v² / r
(3) From (2): v² = G·M / r
→→ v = sqrt(G·M / r)
@TAXONOMY [orbit_properties]
bound_orbit: confirmed
exact_eccentricity: open
parabolic_escape: denied
After a transfer hop, the receiver's record carries the audit trail:
@PROVENANCE [chain]
hop_1: model_A → model_B | loaded+full_verify
@VERIFY [§circular_velocity]
(1): holds
(2): holds
(3): holds
→→: holds
A small, dependency-free Python validator checks a document against the v1.0 grammar (recognized block types, the required basis attribute on @LOGIC, valid status markers, reference syntax):
python reference/validator.py examples/orbital.rl
It exits non-zero and prints line-referenced errors on any violation. The validator is reference code under Apache 2.0.
The format has been exercised in author-run experiments across five model architectures, where all five adopted the notation in their own output and preserved the three-way epistemic status across multi-hop transfer. These are author-run results; independent replication is invited and has not yet been performed. Reasonledger makes no claim about model cognition.
This repository is dual-licensed:
- Specification and documentation (SPEC.md, grammar, prose docs) — Creative Commons Attribution 4.0 International (CC BY 4.0), see
LICENSE-CC-BY-4.0. - Code (reference checker, evaluation harness, scripts) — Apache License 2.0, see
LICENSE.
Reasonledger is an open, royalty-free standard, freely implementable by anyone, including in commercial products.
See CITATION.cff. Short form:
Aiello, M. P. (2026). Reasonledger: Specification v1.0. Zenodo. https://doi.org/10.5281/zenodo.19874728
Reasonledger was developed and first disclosed as AI-Native Notation (ANN). The earlier name is retained in the provenance record for citation and priority; see NOTICE and the specification's "Version lineage" section.