b43d735d97
receive-opportunistic-lxmf.md mirrors the send flow on the recipient side: KISS/HDLC deframe -> Transport.inbound -> packet_filter dedup -> DATA/SINGLE branch -> Destination.receive -> Identity.decrypt with the ratchet ring + long-term-key fallback -> LXMRouter.delivery_packet (which fires the PROOF receipt before parsing) -> LXMessage.unpack_from_bytes with msgpack stamp-strip -> ticket/stamp/dedup checks -> __delivery_callback to the app. Notes upstream's narrower variant tolerance vs SPEC.md §5.6 and the missing clockless-sender fix-up vs §9.6. send-link-lxmf.md walks the DIRECT method end-to-end: process_outbound DIRECT branch decides reuse-vs-establish, RNS.Link.__init__ builds the unencrypted LINKREQUEST body (initiator_X25519_pub || initiator_Ed25519_pub || optional signalling), link_id derived from get_hashable_part, LRPROOF arrives back and validate_proof verifies signature against the responder's long-term Ed25519 pub recalled from a prior announce, handshake() does ECDH+HKDF over the shared secret with salt=link_id, lxmessage.send sends the full LXMF body (with dest_hash, per §5.2) over the link with Token encryption that omits the eph_pub prefix per §3.1, mandatory PROOF receipts per §6.5 resolve the PacketReceipt. Sketches the RESOURCE representation for oversize bodies and the backchannel-identify trick that makes the link bidirectional. flows/README.md status table updated. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> |
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| test-vectors | ||
| tools | ||
| agent.md | ||
| LICENSE | ||
| README.md | ||
| SPEC.md | ||
| todo.md | ||
Reticulum Specifications
Byte-level interoperability specifications for the Reticulum Network Stack and LXMF — the parts that aren't in the upstream manuals but are needed to build a working client from scratch.
Upstream Reticulum has excellent operator-facing documentation (config, deployment, design philosophy). What's missing — and what every alternative implementation has had to reverse-engineer from the Python source — is an authoritative wire-level spec: header bit layouts, msgpack field types, signature input formats, the exact behavior of Transport.outbound, and the long list of "would never guess from reading the manual" gotchas that cost hours of debugging each.
This repo collects those findings in one place. The hope is that future client authors (Kotlin, Swift, Rust, Go, embedded C — pick your stack) can read this instead of re-deriving everything from RNS/Transport.py.
Status
Early days, contributions welcome. Current content was bootstrapped from the working notes of two reverse-engineering efforts:
- The web-based Reticulum client at
reticulum-lora-webclient - The native Android client at
reticulum-mobile-app
Each finding is grounded in upstream source citations (file + line) so it can be re-verified as RNS evolves.
What's here
SPEC.md— the single combined spec document, organized by protocol layerflows/— chronological end-to-end narratives (e.g. "send a message"), cross-referencing SPEC.md sectionstools/— self-contained Python verifier scripts that test SPEC.md claims against upstream RNS / LXMFtest-vectors/— known-good byte sequences each implementation should be able to round-trip (intent: grow into a compliance suite)
As content grows, SPEC.md will be split into per-layer files (packet header, identity, announce, token-crypto, LXMF, link, resource, transport).
Scope
In scope:
- Wire formats: byte layouts, field encodings, framing
- Signing inputs and what's hashed where
- Cross-cutting behaviors required for interop (path requests, ratchet rotation, retransmit semantics)
- "Gotchas" — things upstream code does that aren't obvious from the manual or RFC-style sketches
- Test vectors that any implementation must be able to round-trip
Out of scope:
- Operator/user documentation — see the official manual
- API design choices for any specific implementation
- Networking layer config (interfaces, transport modes) — already well documented
Source citations
Where a finding cites upstream Python code, the path is relative to a standard pip install rns lxmf installation, e.g. RNS/Transport.py, LXMF/LXMF.py. Where the bundled umsgpack is referenced, the path is RNS/vendor/umsgpack.py.
When upstream code changes such that a citation no longer matches, file an issue or PR — the goal is to track the de-facto wire spec as it actually behaves, not as it was at any single snapshot.
Contributing
If you've debugged a Reticulum interop problem and the answer wasn't in the upstream docs, please add it. Format:
### N.M Short description of the finding
**Symptom:** what you observed that prompted the investigation.
**What's happening:** the actual mechanism, ideally with upstream source citation (file + line).
**Implication / fix:** what an implementation must do to interop.
**Source:** upstream file paths and approximate line numbers.
Add a worked test vector to test-vectors/ if the finding is byte-level.
License
CC BY 4.0 — use freely, attribution appreciated.