Developers

An API thatwrites to metal —carefully.

In brief

Weldeon's developer surface is deliberately narrow and deliberately bounded. You can read everything the platform senses and records, and you can act only inside the envelope your welding engineer qualified.

Next step

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Quickstart

Control a cell in a dozen lines

Connect to the edge, load the qualified envelope, and stream welds. Every write is clamped to the envelope and logged to genealogy — there is no path around it.

weldeon_cell.py

# Subscribe to a cell and hold heat input inside the qualified envelope.
from weldeon import Site, WeldEnvelope

site = Site.connect("edge://bay-3.local")      # factory edge, no cloud required
cell = site.cell("CELL-04")

envelope = WeldEnvelope.from_wps("D1.1-GMAW-3G-06")   # qualified range, enforced

for weld in cell.stream_welds():
    if weld.fitup.gap_mm > envelope.max_gap_mm:
        weld.hold(reason="gap outside qualified range")
        continue

    weld.control(
        heat_input_kj_mm=1.24,
        travel_mm_s=6.4,
        seam_tracking=True,
        envelope=envelope,          # writes are clamped to this
    )

    print(weld.id, weld.genealogy.heat_input_kj_mm, weld.ndt.status)

Surface

What the API exposes

Four resources, one schema, no hidden side effects.

Sites and cells: Connect to an edge appliance, enumerate cells, read health, latency and autonomy state.
Welds: Stream live welds; read fit-up, parameters, pass history, arc signature and NDT status.
Envelopes: Load qualified WPS envelopes; envelopes are read-only to the API and owned by your welding engineer.
Control: Issue bounded parameter and motion instructions; every call returns the clamped values actually applied.
Genealogy: Query and export complete weld records in open, documented formats.
Events: Subscribe to webhooks for indications, deviations, stops and scorecard metrics.

Events

Webhooks you will actually use

The defect agent calls an indication with a confidence figure and routes it to your inspector queue. Your systems hear about it at the same moment your inspector does.

indication.called.json

// Indication called by the defect agent — routed to your inspector queue.
{
  "event": "indication.called",
  "weld_id": "4471-A",
  "cell": "CELL-04",
  "pass": 3,
  "modality": "radiographic",
  "indication": {
    "type": "lack_of_fusion",
    "confidence": 0.91,
    "location_mm_from_root": 12,
    "length_mm": 8.4
  },
  "code": "AWS D1.1",
  "disposition": "awaiting_inspector",
  "model_version": "defect-2026.03.1"
}

$ weldeon site status --site bay-3
edge appliance    online   runtime 2026.03.1   uptime 41d
cells             6 connected   4 autonomous   2 advisory
loop latency      18 ms p50 · 27 ms p99
cloud sync        disabled (air-gapped)
pending export    0 records

$ weldeon weld show 4471-A --format genealogy
wps               D1.1-GMAW-3G-06        qualified
consumable        ER70S-6 lot 88214      verified
fit-up            gap 1.8 mm rev 07      in tolerance
heat input        1.24 kJ/mm             within WPS
passes            5 (root + 4 fill)      complete
ndt               RT + UT machine read   accepted by J. Okafor
distortion        2.1 mm out-of-plane    in tolerance

Adapters

Talking to the equipment

The adapter layer is where safety lives. It is also where most of the engineering is.

Power sources: Fronius, Lincoln Electric, Miller, ESAB, EWM, Kemppi digital interfaces.
Robot controllers: FANUC, ABB, KUKA, Yaskawa Motoman, Panasonic, Cloos.
Cutting and forming: Plasma, laser and oxy tables, press brakes and roll formers over OPC UA or vendor APIs.
Sensors: Laser seam trackers, structured light, thermal, through-arc sensing and shop vision.
NDT systems: Digital radiography and phased-array ultrasonic via DICONDE and vendor formats.
Business systems: SAP, Oracle, Plex, Tulip, Fabsuite and Tekla for work orders, WPS and traceability.

Design

Why the API is smaller than you expect

It would be straightforward to expose every parameter as a writable field. It would also be irresponsible. A welding API with unbounded authority is a way to produce non-conforming welds at machine speed.

So the control surface takes an envelope as a required argument, returns the clamped values actually applied, and writes a deviation record whenever your requested value differed from the applied one. There is no force flag, no override parameter, and no support ticket that will add one.

Everything else — sensing, history, genealogy, events — is as open as we can make it, because that is where integration value lives and where nothing can be damaged.

Environments

How teams build against Weldeon

Three environments, in the order you should use them.

01
Simulator
A local simulator replays recorded welds and synthetic joints so integrations can be built and tested without a cell.
02
Shadow cell
A real cell in read-only mode. Your code sees live sensing and issues control calls that are logged but not applied.
03
Bounded production
Write authority granted per cell, per agent scope, with the confidence and stop policy your site configured.

Practices

Conventions worth knowing

Six things that will save an integration team a fortnight.

Idempotent control

Control calls carry an intent key; a retried call never produces a second pass.

Clamped returns

Always read the returned value, not the requested one. They differ more often than you expect.

Versioned models

Every inference carries its model version. Pin it in your records if you need reproducibility.

Offline first

Assume the network is gone. Local buffering and reconciliation are part of the contract.

Time is shop time

All timestamps are site-local with an explicit offset, because shift boundaries matter in analysis.

Open export

Genealogy export formats are documented and stable; build reports on them, not on scraped screens.

Architecture

Where your code runs

SDK calls resolve against the edge appliance on the shop-floor network. Cloud APIs exist for fleet-level queries and are optional.

Architecture diagram showing perception, reasoning and control — Local by default; cloud only where latency does not matter. Weldeon studio diagram.

Limits

The numbers your integration will hit

18 ms

median control-loop latency at the edge on reference hardware

1 kHz

arc signature sampling available to the sensing API

90d

default local genealogy retention before archival policy applies

0

documented ways to write outside a qualified envelope

“Read broadly. Write narrowly. Log absolutely everything.”

WeldeonAPI design principle

Questions

Developer questions

Begin

Bring autonomy to thearc, the fit-up andthe inspection bay.

Book a pilot on one cell or line. We agree the scorecard before we start — first-pass yield, rework hours, defect escapes, takt — and we report against it in the open.

Book a pilot Read the pricing