Declarative AI Agents: Spec Once, Generate Everywhere with ACEL
Most agent frameworks still force you to write imperative code: wire tools, manage memory, hard-code oversight logic, and re-implement the same patterns for every new runtime. The result is brittle agents that are hard to review, version, audit, or port. A cleaner path is emerging: treat the agent as a declarative contract . What is ACEL? ACEL (Agent Capability Expression Language) is a small,…
Declarative AI agents can now be defined through ACEL (Agent Capability Expression Language), a small language for specifying agents as declarative contracts. ACEL, built on the Rectified Pentachoron Framework, models an agent with five aspects plus autonomy, which is a modal that qualifies each aspect. The language enforces clean separations, such as read-only percepts, write-only effects, and bound reflection, and produces a conformance report against the five-aspect basis.
ACEL is designed to be the single source of truth for agents, versionable, reviewable, and enforceable in CI. The .acel file becomes the contract that drives CI gates, runtime policy, and interoperability. The ACEL generator, inspired by OpenAPI-Generator, turns the contract into concrete artifacts, including LangGraph Python packages, markdown agent cards, OSSA-style YAML contracts, pytest invariant test suites, Agent2Agent cards, MCP tool manifests, and more.
Governance details such as autonomy level, oversight, grounding, and retention shape are emitted as named extensions. ACEL is not a runtime but a contract that binds the layers already in use, shifting validation left and enforcing autonomy and oversight in runtime generation. The projects are currently in alpha, but they offer a practical step toward governable, auditable, and portable agents.
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