Memfault

Technical Preview

Overview

Memfault is a device reliability platform for MCU, Linux and Android fleets: it collects crashes, metrics and logs from devices through the Memfault SDKs and runs OTA updates by cohort. These connectors connect the Coreflux broker to the Memfault REST API, so plant logic can check a device’s health and release, move devices between cohorts, roll out firmware and react to new crash issues over MQTT.

MemfaultRestApi (MemfaultRestApi.lot) is a client connector on https://api.memfault.com with 32 events.
MemfaultWebhookReceiver (cloud-iot_memfault_webhook.lot, opt-in, server mode) receives Memfault issue and alert webhooks, so new or regressed issues reach MQTT without polling.

The events follow Memfault’s published OpenAPI definition.

Authentication

An Organization Auth Token has project-manager access to every project in the organization, and a user API key acts as that user. Keep the credential in a Hub secret, map it in with GET SECRET, and never publish it on a topic other clients can read.

Every event takes "authorization" in its MQTT payload and sends it as the whole Authorization header, so you can use either Memfault credential:

Credential	Where to create it	`authorization` value
Organization Auth Token (recommended)	Admin → Organization Auth Tokens (organization admins). The only option when the organization enforces SSO.	`Bearer oat_...`
User API key	Project Settings → User API Key. Stops working when the user leaves the organization.	`Basic <base64 of email:api_key>`

Store the full value as the secret MEMFAULT_AUTHORIZATION.
Every project event also takes "organization_slug" and "project_slug", as shown in the Memfault app URL.
GetLatestReleaseForDevice is the device-side check and sends "project_key" in the Memfault-Project-Key header instead. Project keys aren’t secret, but they let anyone send data into the project.

A missing or wrong credential returns 401 with {"error": {"message": "Unauthorized", "http_code": 401, "type": "UnauthorizedError", "code": 1004}}.

Payload conventions

Path ids (device_serial, cohort_slug, release_version, deployment_id, issue_id, task_id, software_type_slug, version) go at the top level of the MQTT payload.
Events marked ?{query} take the query string already URL-encoded, for example page=1&per_page=100 (default 20, max 100) or status=open&sort=-created_date. Timestamps in filters must be ISO 8601 with Z. Send "query": "" when there is nothing to add.
Request bodies come from "body" and are sent as JSON.

Projects and tasks

Event	Request	Topic	Notes
GetMe	`GET /auth/me`	`cloud-iot/memfault/me/get`	Auth smoke (user API key, Basic): the logged-in user and their organizations; with an org token use ListProjects instead
ListProjects	`GET /api/v0/organizations/{organization_slug}/projects?{query}`	`cloud-iot/memfault/project/list`	Auth smoke (org token or user key): projects in the organization; query page=1&per_page=100 \| sort=-created_date (send "" for none)
GetProject	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}`	`cloud-iot/memfault/project/get`	One project by slug: name, slug, platform, os, count_devices (the response also carries the project key)
GetTaskStatus	`GET /api/v0/queue/{task_id}`	`cloud-iot/memfault/task/get`	Status of an asynchronous task, e.g. {“status”: “SUCCESS”}

Devices

Event	Request	Topic	Notes
ListDevices	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/devices?{query}`	`cloud-iot/memfault/device/list`	Devices in the project (paged, max 100 per page); query page=1&per_page=100 \| sort=-created_date (send "" for none)
GetDevice	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/devices/{device_serial}`	`cloud-iot/memfault/device/get`	Catalog: one device by serial: cohort, hardware_version, last_seen, last_seen_release, latest_install, latest_trace
CreateDevice	`POST /api/v0/organizations/{organization_slug}/projects/{project_slug}/devices`	`cloud-iot/memfault/device/create`	Write. Create a device; body {“device_serial”: “ABCD1234”, “hardware_version”: “proto”} (409 if it already exists)
UpdateDevice	`PATCH /api/v0/organizations/{organization_slug}/projects/{project_slug}/devices/{device_serial}`	`cloud-iot/memfault/device/update`	Write. Update a device, e.g. move it to a cohort; body {“cohort”: “beta”} (cohort slug)
GetDeviceAttributes	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/devices/{device_serial}/attributes?{query}`	`cloud-iot/memfault/device-attributes/get`	Device attributes; query q=line_* filters by string_key (wildcard *), send "" for all
UpdateDeviceAttributes	`PATCH /api/v0/organizations/{organization_slug}/projects/{project_slug}/devices/{device_serial}/attributes`	`cloud-iot/memfault/device-attributes/update`	Write. Update one or more device attributes (attribute must exist in Settings > Metrics); request body shape is not in the published spec, confirm on unblock

Cohorts

Event	Request	Topic	Notes
ListCohorts	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/cohorts?{query}`	`cloud-iot/memfault/cohort/list`	Cohorts in the project (paged); send query "" for none
GetCohort	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/cohorts/{cohort_slug}`	`cloud-iot/memfault/cohort/get`	One cohort: name, slug, count_devices, last_deployment
CreateCohort	`POST /api/v0/organizations/{organization_slug}/projects/{project_slug}/cohorts`	`cloud-iot/memfault/cohort/create`	Write. Create a cohort; body {“name”: “Beta”, “slug”: “beta”} (409 if it already exists)
UpdateCohort	`PATCH /api/v0/organizations/{organization_slug}/projects/{project_slug}/cohorts/{cohort_slug}`	`cloud-iot/memfault/cohort/update`	Write. Update a cohort; body {“name”: “Beta line 1”} (fields from the Cohort schema)
ListCohortDevices	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/cohorts/{cohort_slug}/devices?{query}`	`cloud-iot/memfault/cohort-device/list`	Devices in one cohort (paged); query page=1&per_page=100 (send "" for none)
MoveDevicesToCohort	`PATCH /api/v0/organizations/{organization_slug}/projects/{project_slug}/cohorts/{cohort_slug}/devices`	`cloud-iot/memfault/cohort-device/move`	Write. Bulk: move devices to the cohort (removes them from their previous cohort, async, 202); request body shape is not in the published spec, for one device prefer UpdateDevice

OTA: releases and deployments

A release is a firmware version with its payloads. A deployment activates a release for one cohort, and the devices in that cohort pick it up the next time they ask for the latest release. A staged_rollout deployment only offers it to a share of the cohort.

Event	Request	Topic	Notes
ListReleases	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/releases?{query}`	`cloud-iot/memfault/release/list`	Releases in the project (paged); query page=1&per_page=20 \| sort=-created_date (send "" for none)
GetRelease	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/releases/{release_version}`	`cloud-iot/memfault/release/get`	One release by version: artifacts, count_devices, min_version, notes, revision
CreateRelease	`POST /api/v0/organizations/{organization_slug}/projects/{project_slug}/releases`	`cloud-iot/memfault/release/create`	Write. Create a release record; body {“version”: “1.2.0”, “revision”: “g31cffde”, “notes”: “Line 1 fix”} (fields from the Release schema; binaries go through the CLI upload flow)
UpdateRelease	`PATCH /api/v0/organizations/{organization_slug}/projects/{project_slug}/releases/{release_version}`	`cloud-iot/memfault/release/update`	Write. Update a release; body {“notes”: “Line 1 fix”} (fields from the Release schema)
GetLatestReleaseForDevice	`GET /api/v0/releases/latest?{query}`	`cloud-iot/memfault/release-latest/get`	Device-side check (Memfault-Project-Key, not secret): latest release a device should install; query hardware_version=evt&software_type=main&current_version=1.0.0&device_serial=ABCD1234; 204 = up to date; 100 calls per device per day
ListDeployments	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/deployments?{query}`	`cloud-iot/memfault/deployment/list`	Deployments (paged); query cohort=beta&release=1.2.0 (send "" for none)
GetDeployment	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/deployments/{deployment_id}`	`cloud-iot/memfault/deployment/get`	One deployment: cohort, release, status, type, rollout_percent, deployer
CreateDeployment	`POST /api/v0/organizations/{organization_slug}/projects/{project_slug}/deployments`	`cloud-iot/memfault/deployment/create`	Write. Catalog: deploy a release to a cohort (devices in the cohort start updating); body {“type”: “normal”, “release”: “1.2.0”, “cohort”: “beta”} or {“type”: “staged_rollout”, “release”: “1.2.0”, “cohort”: “beta”, “rollout_percent”: 10}
UpdateDeployment	`PATCH /api/v0/organizations/{organization_slug}/projects/{project_slug}/deployments/{deployment_id}`	`cloud-iot/memfault/deployment/update`	Write. Update a deployment, e.g. widen a staged rollout; body {“rollout_percent”: 50} (fields from the Deployment schema)
ListSoftwareTypes	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/software_types?{query}`	`cloud-iot/memfault/software-type/list`	Software types (firmware components) in the project; send query "" for none
GetSoftwareType	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/software_types/{software_type_slug}`	`cloud-iot/memfault/software-type/get`	One software type
ListSoftwareVersions	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/software_types/{software_type_slug}/software_versions?{query}`	`cloud-iot/memfault/software-version/list`	Software versions of one software type (paged); send query "" for none
GetSoftwareVersion	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/software_types/{software_type_slug}/software_versions/{version}`	`cloud-iot/memfault/software-version/get`	One software version (also tells whether a version exists before deploying)

Issues

Event	Request	Topic	Notes
ListIssues	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/issues?{query}`	`cloud-iot/memfault/issue/list`	Issues (crash / trace groups, paged); query status=open&cohort=beta&sort=-created_date (send "" for none)
GetIssue	`GET /api/v0/organizations/{organization_slug}/projects/{project_slug}/issues/{issue_id}`	`cloud-iot/memfault/issue/get`	One issue: title, reason, status, device_count, trace_count, first / last release, last_trace stack
UpdateIssue	`PATCH /api/v0/organizations/{organization_slug}/projects/{project_slug}/issues/{issue_id}`	`cloud-iot/memfault/issue/update`	Write. Set the issue state; body {“status”: “open”} (spec example; UI states are Unresolved, Resolved, Muted, the API strings for resolve / mute are unconfirmed)

Webhook receiver

Deploy cloud-iot_memfault_webhook.lot only if you want Memfault to push notifications to the broker. It opens HTTP port 9004. Put a reverse proxy or tunnel with a public TLS certificate in front of it, and have it verify the X-Signature-SHA256 header (HMAC-SHA256 of the raw body with the target’s signing secret), because the connector itself doesn’t.

In Memfault, open Settings → Notifications → External Targets and add a Webhook target with the public URL https://<public host>/memfault/webhook/issues. Keep the signing secret it shows for your proxy.
Add a second target for https://<public host>/memfault/webhook/alerts and pick it in your alerts.
Use the target’s test notification to check the path: it arrives with "type": "test_notification.dispatched".

Path	Topic	Memfault event types
`POST /memfault/webhook/issues`	`cloud-iot/memfault/webhook-issue/received`	`issue.created`, `issue.reopened`, `issue.regressed`, `issue.resolved`, `issue_comment.created`
`POST /memfault/webhook/alerts`	`cloud-iot/memfault/webhook-alert/received`	`device_threshold_alert.summary`, `device_threshold_alert.incident_started`, `device_threshold_alert.incident_ended`, `fleet_threshold_alert.triggered`

The body is {"type": "<event type>", "project": {"id": "...", "slug": "..."}, ...}. The Memfault-Delivery header stays the same on retries, so your proxy can use it to drop duplicates. Memfault marks generic webhooks as experimental, so payload fields beyond type and project may change.

Golioth chunk forwarding

If your devices connect through Golioth, Golioth forwards their Memfault chunks itself with the memfault pipeline destination and the project key. Nothing extra runs on the broker. This connector then reads the resulting devices, issues and releases from Memfault. Chunk upload (chunks.memfault.com) isn’t packaged, because chunks are binary.

Examples

Read one device:

{"authorization": "Bearer <MEMFAULT_ORG_TOKEN>", "organization_slug": "coreflux", "project_slug": "porto-line-1", "device_serial": "ABCD1234"}

Move a device to the beta cohort:

{"authorization": "Bearer <MEMFAULT_ORG_TOKEN>", "organization_slug": "coreflux", "project_slug": "porto-line-1", "device_serial": "ABCD1234", "body": {"cohort": "beta"}}

Deploy release 1.2.0 to 10% of the beta cohort:

{"authorization": "Bearer <MEMFAULT_ORG_TOKEN>", "organization_slug": "coreflux", "project_slug": "porto-line-1", "body": {"type": "staged_rollout", "release": "1.2.0", "cohort": "beta", "rollout_percent": 10}}

Check which release a device would get:

{"project_key": "<MEMFAULT_PROJECT_KEY>", "query": "hardware_version=evt&software_type=main&current_version=1.1.0&device_serial=ABCD1234"}

LoT actions that wire these events to plant topics:

DEFINE ACTION MemfaultDeployToCohort
ON TOPIC "porto/ota/memfault/deploy" DO
    SET "auth" WITH GET SECRET "MEMFAULT_AUTHORIZATION"
    SET "org" WITH GET SECRET "MEMFAULT_ORG_SLUG"
    SET "proj" WITH GET SECRET "MEMFAULT_PROJECT_SLUG"
    SET "rel" WITH GET JSON "release" IN PAYLOAD AS STRING
    SET "coh" WITH GET JSON "cohort" IN PAYLOAD AS STRING
    PUBLISH TOPIC "cloud-iot/memfault/deployment/create" WITH { "authorization": {auth}, "organization_slug": {org}, "project_slug": {proj}, "body": { "type": "normal", "release": {rel}, "cohort": {coh} } }

DEFINE ACTION MemfaultPollOpenIssues
ON EVERY 5 MINUTES DO
    SET "auth" WITH GET SECRET "MEMFAULT_AUTHORIZATION"
    SET "org" WITH GET SECRET "MEMFAULT_ORG_SLUG"
    SET "proj" WITH GET SECRET "MEMFAULT_PROJECT_SLUG"
    PUBLISH TOPIC "cloud-iot/memfault/issue/list" WITH { "authorization": {auth}, "organization_slug": {org}, "project_slug": {proj}, "query": "status=open&sort=-created_date&per_page=20" }

DEFINE ACTION MemfaultWebhookToPlant
ON TOPIC "cloud-iot/memfault/webhook-issue/received" DO
    SET "kind" WITH (GET JSON "type" IN PAYLOAD AS STRING)
    PUBLISH TOPIC "plant/memfault/issues/" + {kind} WITH PAYLOAD

Writes

11 events change data in Memfault, and each one is marked Write above. CreateDeployment, UpdateDeployment, UpdateDevice and MoveDevicesToCohort decide which firmware devices in the field install, so test them on a lab cohort first. No DELETE operation is packaged, so this connector can’t deactivate a deployment or delete devices, cohorts, releases or issues.

Memfault’s published spec has no request schemas for most writes. The CreateDevice, UpdateDevice, CreateCohort and CreateDeployment bodies above come from the Memfault docs and CLI. Check the other bodies (CreateRelease, UpdateRelease, UpdateCohort, UpdateDeployment, UpdateDeviceAttributes, MoveDevicesToCohort, and the UpdateIssue values for resolved or muted) against your project before you rely on them.

Not packaged

User API key management, project create, update and delete, project and client keys, data uploads (chunks, events, traces, coredumps, bug reports, symbols and release artifacts on the chunks, ingress and files hosts), software type and version create, installs (listed in the spec, but the live API returns 404 for them), SBOMs, nRF Cloud bulk device creation and every DELETE are left out of this template.

Status

Technical preview, and blocked on a live test. The events were checked against Memfault’s published OpenAPI, and all 32 events reach the real api.memfault.com host and are rejected without a valid credential as expected. An authenticated read and write with a real Memfault organization token is still pending.

Quick Start

Coreflux MQTT Broker

LoT Language

Coreflux HUB

VS Code - LoT Notebooks

Coreflux Portal

Using AI with Coreflux

Product Updates

Overview

Authentication

Payload conventions

Projects and tasks

Devices

Cohorts

OTA: releases and deployments

Issues

Webhook receiver

Golioth chunk forwarding

Examples

Writes

Not packaged

Status

​Overview

​Authentication

​Payload conventions

​Projects and tasks

​Devices

​Cohorts

​OTA: releases and deployments

​Issues

​Webhook receiver

​Golioth chunk forwarding

​Examples

​Writes

​Not packaged

​Status

Overview

Authentication

Payload conventions

Projects and tasks

Devices

Cohorts

OTA: releases and deployments

Issues

Webhook receiver

Golioth chunk forwarding

Examples

Writes

Not packaged

Status