Real interop bug found while checking what the
thatSFguy/reticulum-lora-repeater stack does with the random_hash
field. The repeater is a thin wrapper around attermann/microReticulum,
which emits 10 fully-random bytes for random_hash rather than the
upstream Python form of 5 random bytes + 5 bytes of big-endian uint40
unix_seconds. The Python form is preserved as a comment in
microReticulum src/Destination.cpp:270-272, with a "CBA TODO add in
time to random hash" next to the random-only implementation.
Effect: Python RNS receivers parse random_hash[5:10] as an emission
timestamp via Transport.timebase_from_random_blob (RNS/Transport.py:
3100-3101), and use it for path-table replacement decisions in the
equal-or-greater-hop branch (RNS/Transport.py:1721-1745). A
uniformly-random uint40 has median ~5.5e11 ≈ year 19403 AD, so
microReticulum announces look "far-future" to Python receivers and
permanently win replay-ordering comparisons until the path TTL
expires.
First-contact path-table population is unaffected — the bug only
surfaces on path replacement, which makes it a quiet failure mode
in mixed-vendor meshes (microReticulum repeater + Python rnsd).
Symmetry: microReticulum receivers don't consult the timestamp half,
so microReticulum-to-microReticulum traffic is unaffected. The
asymmetry is what makes the symptom show up only when a Python
relay is also in the mesh.
The repeater's pre_build.py aggressively patches FIVE other
microReticulum protocol bugs (ratchet announce parsing, identity
hash length 16→32, validate_announce/announce diagnostics, DATA/
PROOF forwarding for transport-mode, path-table write dedup) — but
not this one. Filed as an outreach todo to upstream the fix to
attermann/microReticulum.
SPEC.md §4.1 — adds an UNVERIFIED callout naming the deviation,
citing the exact source location and explaining
the propagation path through Python's path-table
logic.
SPEC.md §9.10 — gotcha entry making the bug findable from the
gotchas list, with a suggested clean-room
workaround (emit the timestamp half yourself,
even just seconds-since-boot).
todo.md — outreach entry to file an issue on
attermann/microReticulum proposing the fix.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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| flows | ||
| 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.