swaitsandClaude Opus 4.7
1c2007dcb5
Add a "Multipart ACK Usage Constraints" subsection making explicit what upstream enforces in code but the spec previously left implicit: - MULTIPART-wrapped ACKs MUST only be emitted on direct-routed return paths. When no direct path is known, the sender MUST fall back to a plain PAYLOAD_TYPE_ACK via flood. Matches sendAckTo() and routeDirectRecvAcks() in upstream. - All MULTIPART and plain copies of the same ACK carry an identical 4-byte ack_crc; receivers MUST dedup by CRC at the application layer (Section 16 packet-hash dedup does not catch them because the wrapper byte makes each copy hash-distinct). - Typical inter-copy delay ~300 ms plus the direct retransmit delay; exact count via getExtraAckTransmitCount() (reference default 0). Validated against upstream meshcore-dev/MeshCore @ 1a7b361 (Mesh::routeDirectRecvAcks, BaseChatMesh::sendAckTo). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
MeshCore Spec
A comprehensive specification and conformance test suite for the MeshCore mesh networking protocol.
MeshCore Spec aims to be the authoritative, machine-readable definition of the MeshCore wire format — much like RubySpec became the definitive specification of the Ruby language. Any implementation that passes the full test corpus can claim bit-perfect MeshCore compatibility.
What's Here
spec/— RFC-style protocol specification in Markdown, covering every layer from packet framing to cryptographic operations.corpus/— JSON test vectors organized by protocol layer. Each vector pairs a structured representation with its exact binary encoding, enabling any implementation to verify encode and decode correctness.tools/— Validation and generation utilities.
Test Vector Format
Test vectors are JSON files. Binary data is represented as uppercase hex strings (whitespace allowed for readability). Each file contains an array of vectors in one of three modes:
encode_decode— Structured input paired with expected binary output. Implementations MUST produce the given binary when encoding, and MUST recover the given structure when decoding.decode_only— Binary input with expected structured output. Used for alternate valid encodings that an encoder need not produce but a decoder MUST accept.invalid— Binary input that MUST be rejected by a conforming decoder.
See corpus/schema/test-vector.schema.json for the full schema.
Using the Corpus
- Parse each JSON file in
corpus/. - For
encode_decodevectors: encode thestructuredform and compare tobinary; decodebinaryand compare tostructured. - For
invalidvectors: attempt to decodebinaryand verify failure.
No special tooling is required — just a JSON parser and your MeshCore implementation.
Project Status
This project is under active development. The specification and corpus are being built from the official MeshCore firmware source code.
Protocol Versions
The corpus covers all known MeshCore protocol versions. Each test vector file
includes a protocol_version field. Version 1 (the current production version)
has the most comprehensive coverage.
License
MIT — see LICENSE.
Contributing
See CONTRIBUTING.md.
Acknowledgments
Based on the MeshCore firmware by the MeshCore developers. Protocol documentation derived from the official MeshCore docs.