CEL OSS

CEL is the open context and trust data plane for AI agents.

CEL gives agent builders reusable contracts for four things every serious agent runtime needs:

• fuse many sources into one canonical context snapshot
• persist cross-turn memory locally or behind your own backend
• assemble governed model briefs with receipts
• inspect what the agent saw, remembered, sent to the model, and later claimed

The open project is intentionally not the full Cellar runtime. The live cortex engine, policy enforcement, monitoring, compliance workflows, hosted workers, and GUI surfaces are the commercial Cellar/Dilipod operating layer built on these contracts.

OSS Crates

Each crate is published on crates.io and maintained in a standalone repository. This workspace (cellar-oss) mirrors them for integrated examples and shared docs.

Crate	Repository	Role	Start here
cel-context	crates.io	ContextElement / ContextSnapshot model and merge mechanics	docs/concepts/context.md
cel-memory	crates.io	Memory trait, sessions, scopes, write hooks	docs/concepts/memory.md · BACKENDS.md
cel-memory-sqlite	crates.io	Local SQLite + vector + FTS backend	docs/concepts/memory.md
cel-brief	crates.io	Brief assembly, budgeting, governance, receipts	docs/concepts/brief.md
cel-contracts	crates.io	Action, planning, and execution receipt schemas	docs/concepts/receipts.md
cel-summarizer	crates.io	LLM summarizers for session rollups (Anthropic + Ollama)	docs/migration-0.2.md

Current release line: 0.2.0 on crates.io. Upgrading from 0.1.x? See docs/migration-0.2.md.

See docs/crates.md for the full crate matrix.

Architecture

+------------------------------------------------------------+
| Agents       LangGraph | Mastra | Claude Code | Cursor     |
|              Codex | GPT | Gemini | n8n | MCP clients     |
+------------------------------------------------------------+
| Cellar       live cortex runtime, policy, monitoring,       |
| runtime      compliance, hosted execution, GUI workflows    |
+------------------------------------------------------------+
| CEL OSS      context snapshots, memory, brief assembly,     |
| contracts    transport schemas, receipts                    |
+------------------------------------------------------------+
| Sources      browser | desktop apps | logs | traces | APIs  |
+------------------------------------------------------------+

Quickstart

Use the OSS contracts without the full runtime. Clone a standalone crate repo, or run from this workspace:

# standalone repo (from repo root)
cargo run --example context_snapshot -- --json
cargo run --example basic
cargo run --example standalone
cargo run --features memory --example with_memory

# this workspace
cargo run -p cel-context --example context_snapshot -- --json
cargo run -p cel-memory --example basic
cargo run -p cel-memory-sqlite --example basic
cargo run -p cel-brief --example standalone
cargo run -p cel-brief --features memory --example with_memory

For a guided path, read docs/quickstart.md.

Examples

The top-level examples are organized by job-to-be-done:

• examples/merge-context — emit or capture multiple sources into one ContextSnapshot.
• examples/memory-provider — store and retrieve memory through the MemoryProvider trait.
• examples/build-brief — build a governed prompt bundle and inspect its receipt.
• examples/receipt-inspection — understand action and brief receipts.
• examples/context-to-brief — connect context, memory, and brief assembly end-to-end.

Commercial Boundary

Open CEL provides the contracts. Cellar/Dilipod operates those contracts in a live environment:

Open CEL	Commercial Cellar/Dilipod
Context schema and merge contracts	Live cortex runtime
Memory and SQLite backend	Policy enforcement and approvals
Brief assembly and brief receipts	Monitoring, alerting, audit timeline
Receipt and transport schemas	Compliance exports and hosted workers

See docs/oss-boundary.md and docs/commercial-model.md.

License

Open CEL crates and docs are Apache-2.0 unless a subdirectory states otherwise.