cel-context

Portable context snapshots for AI agents.

cel-context gives any stream a common shape an agent can consume. Browser DOM, accessibility trees, logs, traces, metrics, tickets, database rows, app events, OCR, and domain APIs can all emit ContextElements and merge into one ScreenContext.

Despite the historical name, ScreenContext is not limited to screens. Treat it as a point-in-time operating context: the facts an agent should know before it plans, answers, or acts.

What's Included

ContextElement — one source-derived fact: UI control, log line, metric, alert, ticket, row, or event.
ScreenContext — one point-in-time snapshot of normalized context elements.
ContextSource — source labels such as external stream, accessibility, CDP, native API, OCR, vision, merged.
ContentRole — prompt-injection-aware classification.
ContextReference — resilient targeting data that survives ephemeral IDs.
ContextContribution / ContextMerger — generic source contribution merge mechanics.

Out Of Scope

Capturing live desktop, browser, OCR, vision, network, log, trace, metric, ticket, or database streams.
Deciding freshness, anomaly, prioritization, or policy rules over time.
Dispatching actions back into an app or browser.
Hosting dashboards, audit timelines, or compliance exports.

Those responsibilities belong in whichever runtime, adapter, or product embeds the snapshot contract.

Example

cargo run -p cel-context --example context_snapshot -- --json

The example constructs a snapshot from caller-provided stream facts. Any source that can produce ContextElements can participate.

Minimal Element

use cel_context::{ContentRole, ContextElement, ContextSource};
use std::collections::HashMap;

let element = ContextElement {
    id: "incident:metric:error_rate".into(),
    label: Some("Checkout error rate is above threshold".into()),
    description: None,
    element_type: "metric".into(),
    value: Some("7.2%".into()),
    bounds: None,
    state: Default::default(),
    parent_id: None,
    actions: vec![],
    confidence: 0.88,
    source: ContextSource::External,
    content_role: ContentRole::Content,
    properties: HashMap::new(),
};

License