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 ContextSnapshot.

ContextSnapshot is a point-in-time operating context: the facts an agent should know before it plans, answers, or acts.

Purpose

Use cel-context when you have multiple streams and want to make them useful to an agent without coupling the agent to each stream's native format.

metrics / logs / traces / tickets / DOM / APIs / database rows
        -> ContextElement[]
        -> ContextContribution
        -> ContextMerger
        -> ContextSnapshot
        -> agent, planner, brief builder, monitor, or evaluator

The crate does not collect the streams for you. It defines the portable contract they can emit.

What's Included

• ContextElement — one source-derived fact: UI control, log line, metric, alert, ticket, row, or event.
• ContextSnapshot — 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.

Status: v0.2.0 on crates.io.

Upgrading from 0.1.x

The deprecated ScreenContext alias was removed in 0.2.0 — use ContextSnapshot. See the 0.2 migration guide.

Example

cargo run --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

Apache-2.0