Mattermost (mattermost)

Category: io | Form: | Symbol: Mm

Connect to Mattermost — receive messages and send to channels

Bidirectional Mattermost integration. Configure spec.server_url, spec.bot_token_ref, and spec.team_id. When wired as a flow entry point (trigger input exposed), the element listens for incoming posts via outgoing webhook. When driven from another element (request input wired), it sends messages to a channel via Mattermost API v4 /api/v4/posts. The channels operation lists team channels (requires team_id). Mattermost is self-hostable — ideal for on-premise deployments. Common mistake: missing team_id causes the channels operation to fail. Same credentials serve both receive and send.

Guide

Connect to Mattermost — receive messages and send to channels

What It Does

Mattermost is an IO connector that bridges your Triform flows with Mattermost teams and channels. It can receive incoming messages via webhooks or WebSocket and send messages to channels. Mattermost is an open-source, self-hosted messaging platform.

Element Definition

Property	Value
Type	mattermost
Category	io
Form	atom

Key Properties

Field	Type	Default	Description
server_url	string	—	Mattermost server URL
bot_token_ref	string	—	Reference to secret containing bot token
team_id	string	—	Team to connect to
channel_ids	array	—	Channels to listen in
event_types	array	[posted]	Mattermost event types to listen for

Usage

1. Create a bot account in your Mattermost instance
2. Create a secret element for the bot token
3. Configure with server URL, team ID, and channel IDs
4. Wire to an automation or action to process messages

Relationships

• Attaches to: rate-limit, auth-policy
• Uses: variable

Capabilities

• mattermost-webhook: Receive messages via Mattermost outgoing webhook
• mattermost-send: Send messages to Mattermost channels via REST API
• channel-filtering: Filter received messages by channel type
• threading: Reply in Mattermost threads via root_id

Properties

Property	Type	Default	Description
server_url	string	—	Mattermost server URL
bot_token_ref	string	—	Reference to secret element containing bot token
team_id	string	—	Mattermost team ID (required for channels operation)
channel_types	array	["direct","public","private"]	Channel types to listen for when receiving messages
default_channel_id	string	—	Default channel ID to send messages to when none is specified
message_format	string	"markdown"	Default message format for outbound messages

Operations

activity

Get /ops/activity | Auth: Read

Get activity events for this element

Scope depends on element capabilities: individual elements query by element_id, project-form elements with activity-scope-members include member activities, circle-level elements with activity-scope-all query the entire circle. Gracefully returns empty list if activities table is missing (old circles).

attachments

Get /ops/attachments | Auth: Read

List all modifiers and resources attached to this element

Returns both modifiers (policy enforcement) and resources (data injection) with is_modifier flag to distinguish. Items in the generated MODIFIER_TYPES list are modifiers; everything else is a resource. Includes cascade_policy and version pin info.

batch_stats

Get /ops/batch_stats | Auth: Read

Get per-element statistics for all children of this element

Returns per-child stats plus an aggregate. Most meaningful on compound or manifest form elements (repositories, circles, projects); atoms have no children so the result is an empty children array with a zeroed aggregate. Uses efficient GROUP BY SQL. Weighted averages for eval scores.

channels

Get /ops/channels | Auth: Read

List Mattermost channels the bot has access to

Calls Mattermost API v4 /users/me/teams/{team_id}/channels with the configured bot token. Requires spec.server_url, spec.bot_token_ref, and spec.team_id. Returns channel id, name, display_name, type, and header. team_id must be set in element spec or the call fails.

compose

Post /ops/compose | Auth: Execute

Batch add and remove modifiers on this element in a single call

Declarative composition: add modifiers by ref path (slug or path@version) and remove by attachment ID, all in one atomic call on the target element. Each ‘add’ entry resolves the source element, validates topology, attaches with optional priority and cascade policy. Each ‘remove’ entry deletes the attachment row. Returns a summary of what was added and removed. Example: compose({ add: [{ref: “my-prompt”}, {ref: “rate-limit/api@v2”, priority: 50}], remove: [{attachment_id: “uuid”}] })

context

Get /ops/context | Auth: Read

Get connected elements (graph traversal)

Graph traversal showing all connected elements with their relationship type (contains, contained_by, references, referenced_by, attaches, etc.). Use ?depth=N to control traversal depth (default 1) and ?types=actor,data to filter by element types.

create

Post /ops/create | Auth: Write

Create child element

POST to the parent path — element_type goes in the request body, NOT the URL. Both element_type and slug are required and must be non-empty. Name is derived from slug if omitted. Writes to both Git and PostgreSQL. All elements are stored flat under the circle — no intermediate library wrapper rows.

delete

Delete /ops/delete | Auth: Admin

Delete element (soft delete)

Soft delete — sets state to ‘deleted’ but retains the record. Cannot delete elements that have children (has_no_bond precondition) or active runs. Requires admin auth and confirmation.

disable

Post /ops/disable | Auth: Admin

Disable element (hides and prevents use)

Idempotent — safe to call on already-disabled elements. Optionally pass a reason string. Disabled elements cannot be invoked or executed. Inverse of enable.

enable

Post /ops/enable | Auth: Admin

Enable element (makes usable and visible)

Idempotent — safe to call on already-enabled elements. Transitions element to ready/enabled state. Cannot enable deleted elements. Inverse of disable.

export_bundle

Get /ops/export/bundle | Auth: Read

Export element as downloadable git bundle

On non-root-namespace elements, returns a binary git bundle. On root-namespace (circle) elements, dispatch hands off to the circle’s own export_bundle op, which returns a multi-element JSON envelope with one base64 bundle per child element — this is intentional, not an error.

get

Get /ops/get | Auth: Read

Get element details

Element is already resolved by the routing layer — this returns the cached element, not a fresh DB query. Use the path /api/{circle}/{slug} to address elements.

import_bundle

Post /ops/import/bundle | Auth: Write

Import git bundle into element

Accepts a base64-encoded git bundle in the JSON bundle_base64 field. Use overwrite=true to replace existing elements with same slug (default skips duplicates). Imported elements get new UUIDs. Returns counts of imported/skipped elements and any errors.

intention

Get /ops/intention | Auth: Read

Get element intention with full inheritance chain

Returns three levels: direct (this element’s intention), inherited (from category and root), and resolved (final merged intention). Useful for understanding an element’s purpose in context of its hierarchy.

promote

Post /ops/promote | Auth: Admin

Promote element configuration to a target environment

Only for manifest-form elements (projects). Environments advance: dev → demo → live. dev→demo requires member+ role, demo→live requires admin. Freezes member versions at promotion time (creates snapshot). Persists environment config to spec.environments.

readme

Get /ops/readme | Auth: Read

Get element README.md content

Reads README.md from the element’s git repository. Returns empty content (not an error) if no README exists. Always returns markdown format.

readme_update

Post /ops/readme_update | Auth: Write

Update element README.md content

Creates or overwrites README.md in the element’s git repo. Commits to the draft branch. Content must be provided as a markdown string.

receive

Post /ops/receive | Auth: None

Receive incoming external traffic

Entry point for external traffic reaching this IO element. Declared auth: none to bypass platform auth — element-level auth is enforced by IoReceiveExecutor before dispatching into the flow graph. The flow/app that wires this element as an entry point determines what happens next.

remove-modifier

Post /ops/remove-modifier | Auth: Execute

Remove an attached modifier from this element by attachment ID

Removes a modifier/resource attachment by its row ID. The ID comes from the attachments or context API. This is the reverse of attach — called on the target element, not the source.

restore

Post /ops/restore | Auth: Admin

Restore element to a specific version

Automatically snapshots the current state before restoring (creates a ‘Before restore to vN’ version entry). Writes restored spec to git as .triform/spec.yaml. Git failures warn but don’t fail the operation — DB state is authoritative. Cannot restore deleted elements.

schema

Get /ops/schema | Auth: Read

Get element input/output schema (MCP tools/list compatible)

Returns type-level port schemas from the TypeRegistry — not instance-specific overrides. Includes direction (input/output), required flag, and JSON schema per port. Useful for understanding what data an element accepts and produces.

send

Post /ops/send | Auth: Write

Send a message to a Mattermost channel

Posts a message to a Mattermost channel via POST {server_url}/api/v4/posts using the configured bot token. Requires spec.server_url and spec.bot_token_ref. Both channel_id and message are required in input — the executor returns InvalidInput if either is missing. Use the channels op to discover channel_id values.

source

Get /ops/source | Auth: Read

Get any file’s content from the element’s git repository

Reads an arbitrary file from the element’s CAS-backed git tree by its relative path. Same store as readme, just generalized. Path safety: rejects .. traversal, leading /, and null bytes. Use this to view main.py for action elements, asset files for SPAs, etc. Returns empty content (not an error) if the file doesn’t exist.

source_branches

Get /ops/source/branches | Auth: Read

List Source branches for this element

Returns the standard draft/demo/live Source branches, their current commits, and promotion relationships. Use GET /api/{element_path}/ops/source/branches.

source_promote

Post /ops/source/promote | Auth: Write

Promote Source branch forward

Promotes draft to demo or demo to live through the generated element op path. Direct Git pushes to demo/live are blocked by Source policy.

source_repair

Post /ops/source/repair | Auth: Write

Inspect or repair the element Source index

Runs Source repair through the element operation path. Defaults to dry_run=true; set dry_run=false only after reviewing a dry-run report.

source_status

Get /ops/source/status | Auth: Read

Get Source control status for this element

Returns the branch-aware clone URL, checkout commands, current draft commit, child source-link count, portable export summary, Source health, warnings, and auth hints for the addressed element. Use the element-first path: GET /api/{element_path}/ops/source/status.

source_validate

Post /ops/source/validate | Auth: Read

Validate Source branch contents

Validates a Source branch before accepting local Git workflow changes or promotion. Defaults to branch=draft and rejects runtime data, generated output, secret material, and unreadable CAS refs.

stats

Get /ops/stats | Auth: Read

Get aggregate statistics for this element

Health status is computed: error if errors_per_day > 5 or success_rate < 0.8, warning if errors_per_day > 0 or success_rate < 0.95. Firing alerts escalate health to error/warning. Default period is ‘day’. Returns runs_per_day, success_rate, avg_duration_ms, and more.

test_connection

Post /ops/test-connection | Auth: Execute

Test Mattermost configuration

Validates that the Mattermost element has the required spec fields configured (server_url, access_token). Does not call the Mattermost API — this is a configuration check only. Returns which fields are configured vs missing.

tree

Get /ops/tree | Auth: Read

Get the element’s position in the graph — ancestors, children, references, and subtree statistics

Uses per-circle ElementGraph cache for O(1) lookups. Returns ancestors (containment chain), children (direct), members (references), referenced_by (reverse refs), attachments, and subtree stats. Default depth is 3, max is 10. Pass ?include_metadata=true for name/state on each node.

update

Patch /ops/update | Auth: Write

Update element

Partial update — send only the fields you want to change. spec, name, and intention are all independently optional. spec MUST be a JSON object when present; deep-merged into the existing spec by default. Empty {"spec":{}} preserves existing spec content but still records a new version (no-op for content, not for version state). To clear/replace the entire spec wholesale send {"spec":{...},"deep":false}. List-typed spec fields use replace semantics (the patch list replaces the existing list, no array merging). Coordinates Git + DB writes. Slug cannot be changed after creation.

update_meta

Patch /ops/update_meta | Auth: Write

Update element metadata (lightweight merge — does NOT bump version or snapshot spec)

Shallow JSONB merge into element.meta. Top-level keys in the provided value replace existing meta values; other keys are preserved. Used for UI metadata like canvas positions, panel state, viewer preferences. Wire-shape op_name is update_meta (distinct from update) so SSE subscribers + the cache auto-invalidator can distinguish lightweight metadata changes from spec edits without inspecting the payload. The MutatingElementStore wrapper stamps this op_name on the lifecycle event emitted by update_element_meta storage calls.

version

Get /ops/version | Auth: Read

Get current version or full history

Returns current version by default. Pass ?history=true for full version history (up to ?limit=N, default 50). Versions are backed by the element_versions table. Every spec update creates a new version entry.

Error Codes

Code	Class	Retryable	Description
MATTERMOST_AUTH_FAILED	auth	no	Mattermost bot token invalid
MATTERMOST_TEAM_MISMATCH	auth	no	Message received from unexpected team
MATTERMOST_SEND_FAILED	internal	yes	Failed to send message to Mattermost
MATTERMOST_CHANNEL_NOT_FOUND	validation	no	Target channel not found