Agents

In Flow, agents are governed AI personas for chat and automation. You configure each one as a filesystem package under AI → Agents (AGENT.md with YAML frontmatter plus a Markdown system prompt, optional schedules.json, optional avatars/ image pointed at by frontmatter avatar, and sibling files). Every tool call is audited; every agent runs inside the permissions you set.

Agent definitions follow the open AGENTS.md pattern. The Agents explorer opens the correct editor card for each path; saving re-ingests the derived runtime catalog.

Shipped defaults

Fontana ships ready-to-use agents you can tailor for your organisation:

Fontana agent (system/fontana-agent) - the assistant on every page, including /ai/chat, unmapped routes, and general routing (including agent schedules). When you start a chat on a Flow surface such as Dashboard, Files, Knowledge Graph, Skills, or an Admin route, Fontana agent activates that page’s skill, so one agent carries the page-specific tools without a separate agent per page.
Workflow agent (system/workflow-agent) - the agent on /workflow; the workflow canvas is the one surface with its own agent. The new-chat picker selects it there. You can change the agent before the first send; your choice sticks until you navigate again.
Canvas agent - specialist for building and editing workflow graphs (nodes, edges, ports, and canvas config). It remains a sub-agent of system/workflow-agent, typically invoked by delegation.

On AI → Agents with no agent selected, Flow shows a welcome plus your last three chats that belong to an agent. Each tile reopens that thread; the overflow menu copies the link, opens a new tab, marks unread as read, or deletes the chat. The expanded left-sidebar AI list opens that agent’s chat on Agents (/agents?agent=). Admin → Agents remains the package explorer.

When you send a message on an existing thread from a different page than the thread’s current owner, Flow switches the thread to that page’s agent automatically. Intentional non-page transfers still use handoff (chat_handoffThread) to allowlisted agents. Chat history is per-user across pages (not siloed by workflow).

On Skills, the Skills page skill lets Fontana agent manage namespaces, packages, and files with the same RBAC as the Skills UI. Page selection (namespace, folder, file) is sent as structured chat context. When you ask to open a named skill, Fontana agent resolves it via the skill catalog and navigates to that skill’s SKILL.md (not only the Skills home page).

On Agents, the Agents page skill lets Fontana agent create and manage portable agent packages the same way: it picks a non-reserved namespace (users when only Fontana system exists; otherwise it asks), writes AGENT.md with role-ready system prompts and defaults that include handoff to system/fontana-agent for Fontana product requests, and opens the package in the explorer. It does not author into the reserved system namespace (or legacy default if present).

Fontana-shipped agents and abilities live under system/, and every platform update reconciles that namespace: a package Fontana no longer ships is removed, and moving your own agent package into system or creating a skill there is refused. Keep your own packages in your own namespaces.

You can clone these defaults, adjust prompts, and switch abilities and Skills on or off as your operating model requires.

For recurring scheduled prompts on a persistent chat thread, see Agent schedules. For mailboxes and send/receive tools, see Agent email.

Configure each agent

In AI → Agents, you edit the package files that define each persona:

Setting	What you control
Id and display name	Stable identity and the label users see in chat
Avatar	Roster head on an accent ring (the same catalog face in the Agents sidebar, chat bubbles, hover tooltips, and pickers). Optional raster under the package `avatars/` folder; frontmatter `icon` points at the file. Upload or remove from the agent card header.
Description and system prompt	Short summary plus Markdown instructions that define tone, scope, and operating rules
Language model	Approved model override; leave empty to use the deployment default
Skills and abilities	One list of everything the agent can do. Abilities are Fontana’s own packages (Email, Messaging, Knowledge Graph, Agent memory, Data, Files, Workflows, Workflow documents, Agents, System One, Fontana Browser, Coding, MCP connections, Skill authoring, plus one per MCP connection you add); Skills are the packages you author. Switch one Enabled or Off, and expand it to configure its settings and whether it loads on the first turn. Related packages collapse into one row — the page skills appear together as Fontana pages, showing how many are on; expand it to switch them individually. See Skills and Tools and MCP
Auto-load on first LLM turn	Inside an enabled ability or skill. On: its instructions and tools are there from the first message, and the agent can close it later when the job is done. Off (the default for most): the agent activates it when the task needs it, so its tools cost nothing until then. Knowledge Graph is the one ability that auto-loads by default
Available in	Under Advanced settings. Tiles for where you can pick the agent: Chat (chat pickers, your default agent, handoff targets, chat channels, schedules), AI node (workflow AI nodes), KG extract (Knowledge Graph ontology agent), and Internal (background workers Fontana calls itself, hidden from every picker). Hover a tile to see what it covers. An agent needs at least one; a new agent starts in Chat.
Vector source	Keywords that help route and discover this agent and related workflow templates
Call settings	Optional JSONC for `generateText` fields (`temperature`, `maxOutputTokens`, `topP`, `topK`, `presencePenalty`, `frequencyPenalty`, `stopSequences`, `seed`). Uncomment a key to set it. Unused keys are stored as `_temperature`-style placeholders in AGENT.md so the raw frontmatter stays a parseable mapping. Runtime calls use only unprefixed keys.
Reasoning effort	Off through Max segmented control under Language model (gray to purple). Per-thread chat controls can override.
Context strategy	Auto uses platform defaults; Custom sets token limit, compress target, minimum recent user messages, tool-result retention (rounds), and KG body retention (turns). Stale file reads and KG bodies are evicted deterministically; conversation is summarised when still over budget.
KB injection score threshold	Minimum similarity score for automatic Knowledge Graph injection on each turn; per-thread overrides available

Automatic and agentic context

Agents receive Knowledge Graph context in two ways, described fully on Knowledge Graph:

Automatic pre-turn injection - hybrid search over assigned namespaces before each message when you turn on auto-search for the agent, gated by its KB injection score threshold, so likely-relevant approved documents are already in context.
Agentic search - during the work, agents can call Knowledge Graph retrieval directly: hybrid search (full-text, vector, and relationship expansion), outline navigation over long structured documents, and entity navigation, each returning path citations back to the exact source section.

You assign namespaces per agent so regulated corpora stay segregated and retrieval stays least-privilege.

Long threads use a layered context model: durable goals and completed task summaries sit in a compact block after your latest message; stale file reads and KG evidence bodies are evicted automatically or when the agent calls evict context; only conversation text is summarised when the thread is still over budget. Compaction failures appear as failed tool rows in the transcript (no silent pruning).

Workflow-aware assistance

Agents can search community workflow templates by semantic similarity and, with user consent, read workflow configuration from the canvas. That lets assistants help you design and refine pipelines with awareness of graph structure, node types, and connections.

Runtime execution data is queried separately from canvas configuration, so design assistance and live run results stay strictly separated. With the Workflow capability assigned, an agent can also list, read, and update Exception Management tickets for a workflow you can access.

Diagrams in chat

When an agent (or any other markdown surface in Flow) includes a fenced Mermaid diagram, you can zoom, pan, fit, export SVG or PNG, copy the diagram, and open it fullscreen from the hover controls on the preview. Inline previews do not zoom on mouse wheel (the page keeps scrolling); fullscreen keeps wheel zoom. Raw shows the Mermaid source in the same preview box; the control then reads Diagram to return to the chart. Language-less ASCII pipeline trees (box-drawing lines with pipeline arrows) render as the same interactive flowchart.

Sending while the agent is busy

The composer decides how a message you send lands while a reply or tool run is in progress. The cog beside the prompt sets the send mode, and Auto is the default: it interrupts while the agent is writing its reply and steers while tools are running. Enter and the purple button always use the mode you picked.

Steer lands your message in the thread right away; the agent answers it as soon as the current step settles.
Interrupt cancels the running turn and any pending tools, then answers your new message immediately.
Queue holds the message until the current turn finishes. Queued messages appear in a drawer on top of the prompt box where you can drag to reorder, edit, remove, or send one now. One queued message is sent each time the agent goes idle. Stop pauses the queue; the next completed turn resumes it.

The same cog holds the composer preferences: auto-apply canvas suggestions, auto-read replies, and clearing every message in the thread.

If the server restarts in the middle of a turn, the thread recovers on its own: unanswered tool calls are closed with a visible error and any message you sent meanwhile is answered once the thread is idle again.

Delegation and handoff

Complex work can span multiple agents without losing governance:

Sub-agents run delegated tasks in child threads while the parent conversation continues under audit.
Handoff transfers the same thread to another in-app agent when the task surface changes (for example from planning to canvas editing).

Peer-agent federation with external platforms uses separate interop protocols. See Agent Interop for A2A, ACP, and related patterns.