> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ixo.world/llms.txt
> Use this file to discover all available pages before exploring further.
# Prompt anatomy
> How the runtime assembles the system prompt — 16 sections, what's automatic, what you configure.
## Overview
Every time the main agent is invoked, the runtime compiles a system prompt from up to 16 sections. Most sections are automatic — the runtime builds them from env state, loaded plugins, and live session data. You are only responsible for four fields in `config.prompt`. Everything else is handled for you.
## The 16 sections
Sections appear in this fixed order. "Always present" means the section is included on every turn regardless of configuration; "conditional" means the section only appears when a specific condition is met.
| # | Section | Present |
| -- | -------------------------------------------------------------------------------------- | ----------- |
| 1 | **Oracle section** — identity preamble | Always |
| 2 | **Capabilities note** — `config.prompt.capabilities` text | Conditional |
| 3 | **Capability block** — Tier-1 plugin manifest list | Conditional |
| 4 | **Operating principles** — fixed bullets + optional communication style | Always |
| 5 | **Custom instructions** — `config.prompt.customInstructions` + loaded operating guides | Conditional |
| 6 | **Working with files** — file-handling guidance | Always |
| 7 | **What you know about the user** — memory context (6 slots) | Conditional |
| 8 | **Current time** — `{currentTime}` (`{timezone}`) | Always |
| 9 | **Current entity** — `{DID}` | Conditional |
| 10 | **Available user secrets** | Conditional |
| 11 | **User preferences** | Conditional |
| 12 | **Operational mode** — general (default) or editor variants | Always |
| 13 | **Composio context** — Composio tool context | Conditional |
| 14 | **Editor section** — editor plugin state | Conditional |
| 15 | **Slack formatting constraints** — Slack output rules | Conditional |
| 16 | **Degraded services** — failed-init notices | Conditional |
### Section details
**1. Oracle section**
The identity preamble. If `config.prompt.opening` is set, it is used verbatim. Otherwise the runtime generates a fallback from the other top-level fields: `"You are {name}, an AI agent operated by {org}. {description}."` (shorter variants when `org` or `description` are absent). See the [`createOracleApp` config reference](/build-an-oracle/reference/createoracleapp) for the exact fallback logic.
**2. Capabilities note**
Rendered if `config.prompt.capabilities` is non-empty. Appears immediately above the plugin capability block. No header is added by the runtime — include your own heading in the field value if you want one.
**3. Capability block**
Auto-generated list of all loaded plugins with `visibility='always'` (Tier-1). Each entry is more than a one-liner: the plugin name and summary, then up to three sub-bullets pulled from the manifest — `When to use:` (first two `whenToUse` triggers), `Avoid for:` (first `whenNotToUse`), and `Example:` (the first `examples` entry). Manifest quality therefore drives prompt size. You never write this section; the runtime builds it from the loaded plugin set. See [the 5,000-token capability-block budget](#the-5000-token-capability-block-budget) below — it is a warn-only soft budget, not an auto-trim.
**4. Operating principles**
Always present. Contains a fixed set of operating-principle bullets (currently nine) covering discovery-first tool use, clarifying questions, reporting results, surfacing failures, delegating with context, and completing-then-stopping. If `config.prompt.communicationStyle` is non-empty, it is injected here as an additional paragraph after those bullets. If `communicationStyle` is absent, the section still appears — just without the custom style block.
**5. Custom instructions**
Conditional. Rendered as a `## Custom Instructions` section when there is anything to put in it. Its body is your `config.prompt.customInstructions` field plus any operating guides contributed by on-demand capabilities the agent has loaded for this thread (e.g. the Flow Builder guide). When nothing contributes, the whole section is omitted and costs zero tokens.
**6. Working with files**
Always present. Hardcoded guidance on how the agent should handle file uploads, attachments, and generated file output.
**7. What you know about the user**
Conditional on the memory plugin being loaded and at least one context slot being populated. Contains up to 6 slots fetched by `UserContextFetcher` before the agent is compiled: `identity`, `work`, `goals`, `interests`, `relationships`, `recent`. See [How memory reaches the prompt](/build-an-oracle/reference/bundled-plugins/memory) for the pre-fetch details.
**8. Current time**
Always present. Stamped at agent-compile time with the user's wall-clock time and resolved timezone.
**9. Current entity**
Conditional on `state.currentEntityDid` being set in the agent state. Surfaces the active entity DID so the agent can route entity-aware tool calls correctly.
**10. Available user secrets**
Conditional on the secrets service having entries for the current user. Lists secret names (not values) so the agent can reference them by name in tool calls.
**11. User preferences**
Conditional on the user-preferences plugin being loaded and the user having saved preferences. May include `agentName`, `language`, `tone`, `formality`, and `customInstructions`.
**12. Operational mode**
Always present, but content varies. The runtime ships a `general` default (`DEFAULT_OPERATIONAL_MODE`) and editor-mode variants supplied by the editor plugin. Any other mode arrives through `hooks.operationalMode` — a plugin or host override — not a built-in runtime selection. See [Model resolution & hooks](/build-an-oracle/understand/architecture#model-resolution-and-hooks).
**13. Composio context**
Conditional on the Composio plugin loading successfully. Auto-injected Composio account and connection context so the agent knows which third-party integrations are available for the current user.
**14. Editor section**
Conditional on the editor plugin being active in the current session. Describes the active document, cursor position, and editor affordances.
**15. Slack formatting constraints**
Conditional on the session client being Slack. Appends Slack-specific formatting rules to prevent the agent from using markdown that Slack does not render correctly (e.g. tables).
**16. Degraded services**
Appended after the main prompt when one or more plugins fail their init. Lists the failed services and tells the agent not to attempt their tools for this turn.
## The 5,000-token capability block budget
Section 3 (the Tier-1 capability block) is the only section with a token budget — and it is a **warn-only soft budget, not a cap**. If the combined manifest text of all `visibility='always'` plugins exceeds 5,000 tokens, the runtime logs a warning naming the largest manifests so you can decide what to mark `on-demand`. Nothing is trimmed automatically: the full block is always emitted with every `always` plugin in it. Degrading verbosity is an operator decision, not a runtime guess — so keep manifest text (`summary`, `whenToUse`, `examples`) concise to keep the block small.
## What you actually need to write in config.ts
Only four things — all optional:
| Field | What to write | What happens if you skip it |
| ---------------------------------- | ---------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------- |
| `config.prompt.opening` | A paragraph describing the oracle's identity, purpose, and domain expertise. | Runtime generates a generic fallback from `name`, `org`, `description`. |
| `config.prompt.communicationStyle` | One or two paragraphs on tone, vocabulary, and response style. | The operating-principles section appears without a custom style block. |
| `config.prompt.capabilities` | A short section (with your own heading) listing what the oracle can do. | The capability-notes section is omitted; only the auto-generated plugin list appears. |
| `config.prompt.customInstructions` | Standing guidance that should hold across every turn (house rules, escalation policy, domain constraints). | The `## Custom Instructions` section is omitted unless a loaded capability contributes a guide. |
Time, memory, user preferences, Composio context, entity DID, secrets, editor state, Slack constraints, and degraded-service notices are all injected automatically. You do not need to mention them in `config.ts`, instruct the agent to fetch them, or account for them in your opening paragraph.
Because memory context is pre-fetched and already in the system prompt by turn 1, you do not need to write instructions like "recall the user's context before responding" in `config.prompt`. The agent already has the user's identity, goals, and recent history before it processes the first message.
## Minimal config.ts example
```ts theme={"system"}
// src/config.ts
import type { OracleConfig } from '@ixo/oracle-runtime';
export const config: OracleConfig = {
name: 'Aria',
org: 'Acme Climate',
description: 'Carbon-project advisory oracle for portfolio managers.',
prompt: {
opening: `You are Aria, the carbon-project advisory oracle operated by Acme Climate.
You help portfolio managers track project status, assess compliance, and draft
stakeholder communications across Verra VCS, Gold Standard, and REDD+ frameworks.`,
communicationStyle: `Be precise and data-driven. Lead with numbers and deadlines.
Use plain English — avoid jargon unless the user demonstrates familiarity.
When something is uncertain, say so explicitly.`,
capabilities: `## What Aria can do
- Retrieve live project status and registry issuance data.
- Draft verification reports, CORSIA letters, and board summaries.
- Search and cite methodology documents from the oracle knowledge base.`,
customInstructions: `Always cite the registry framework (Verra VCS, Gold Standard, REDD+)
behind any compliance claim. Never approve a credit issuance on the user's behalf —
draft it and ask them to confirm.`,
},
};
```
Everything else in the 16-section prompt — plugin tools, current time, user memory, preferences, Composio context — is assembled by the runtime from the loaded plugins and session state.
## Related
Full reference for config.prompt fields and fallback logic.
How UserContextFetcher pre-loads memory into section 6.
What controls which plugins appear in the capability block.
How plugins declare the manifest text that feeds section 3.