Portable Agent Manifests with Host-Controlled Infrastructure Clear Ideas has released an open-source Agent Runtime that decouples agent definitions from execution infrastructure via portable Agent Manifests. The runtime allows host-controlled credential resolution, tool access, and authorization, while supporting multiple execution boundaries including local, remote, and sandboxed environments. AI agents often begin as application code: a prompt, a model call, a few tools, and enough control flow to make the first example run. As the agent grows, the definition and the environment tend to collapse into each other. Model configuration lives beside credentials. Tool access is mixed with prompts. Persistence assumes a particular process. Deployment choices become part of the agent itself. That coupling makes an agent harder to inspect, test, move, and recover. We built Clear Ideas Agent Runtime https://github.com/clearideas/agent-runtime around a different boundary: the agent definition should be portable, while the infrastructure that executes it should remain under host control. An Agent Manifest is a versioned YAML or TypeScript definition. It can describe: A separate Agent Run Manifest supplies the values and execution choices for one invocation. That keeps the reusable agent definition distinct from the inputs and operational decisions associated with a particular run. Here is a small example: schemaVersion: "1.0" name: research-brief variables: topic: type: string researchNotes: type: string briefDraft: type: string steps: - id: research type: prompt prompt: | Research {{ topic }} and return concise notes. outputVariable: researchNotes - id: draft type: prompt prompt: | Draft a brief using these notes: {{ researchNotes }} outputVariable: briefDraft The manifest describes the agent. It does not contain the credentials, infrastructure account, or persistence implementation that happens to run it. The host application supplies and controls: This is more than configuration hygiene. It prevents a portable agent definition from granting itself broader access. The host resolves credentials, exposes approved tools, narrows connection modes, and can authorize individual tool calls against application policy. Authorization is therefore part of the runtime boundary, not a feature supplied only by a hosted service. Agent Runtime supports three execution boundaries through one client contract: The Agent Manifest does not change when the execution boundary changes. The included Modal https://modal.com/ adapter implements remote submission, status, ordered events, result retrieval, resume, and cancellation. Docker and Modal Sandboxes https://modal.com/docs/guide/sandboxes implement the runtime's native sandbox contract for isolated code execution and generated artifacts. Applications can supply different compute or sandbox implementations through the same adapter interfaces. A multi-step agent needs more than a final response. Agent Runtime checkpoints run state, step outputs, transcripts, generated files, and continuation data. Suspended or interrupted runs can resume in a fresh process. Attempt fencing prevents an older worker from committing after another process has resumed the run. Runs also emit ordered lifecycle, model, tool, checkpoint, artifact, and text-delta events. A CLI, embedded application, remote worker, or OpenTelemetry integration can consume the same event stream. This gives the runtime a stable execution history around model calls that are inherently non-deterministic. Many orchestration frameworks ask the developer to define a sequence, write routing code, or maintain nodes and edges. Agent Runtime can instead read the variables each eligible step produces and consumes. From those data dependencies, it derives an execution plan. Independent prompt branches can run concurrently. Dependent steps wait for their inputs. Tool-enabled and stateful operations remain ordered. Results commit in manifest order. The graph does not become a second definition maintained beside the agent. It is resolved from the Agent Manifest. This can reduce elapsed time when an agent contains independent model calls, while preserving ordered checkpoints and state transitions. A mostly linear agent remains mostly sequential. The execution-graph article https://clearideas.com/blog/2026-07-28-agent-runtime-execution-graphs includes a complete example, scheduling rules, timing model, and visualization. Models connect through the AI SDK. Tools can be supplied directly by the application or through Model Context Protocol https://modelcontextprotocol.io/docs/getting-started/intro connections. Memory, file, and SQLite stores cover common persistence needs. Separate packages provide model, persistence, compute, sandbox, artifact, condition, and OpenTelemetry adapters, allowing an application to install the infrastructure it actually uses. Agent Runtime is available under Apache 2.0 and does not require a hosted Clear Ideas service. npm install @clearideas/agent-runtime Start with the five-minute quickstart https://agent-runtime.clearideas.com/quickstart , review the manifest documentation https://agent-runtime.clearideas.com/manifests , or inspect the source on GitHub https://github.com/clearideas/agent-runtime . The broader release announcement is available at Clear Ideas Agent Runtime 0.1.0 https://clearideas.com/blog/2026-07-28-clear-ideas-agent-runtime .