Overplane vs SIMD Agent

Overplane and SIMD Agent are both cli coding agents tracked by AIDiveForge. Below is a side-by-side comparison of pricing, capabilities, platforms, and ownership — sourced from each tool's live website and verified before publishing.

Overplane

Overplane is a free, open-source CLI binary that wraps Claude Code, Codex, or OpenCode in container isolation, spec-driven builds, and Z3 formal verification before a single line of code is written. Every agent run executes in a locked-down container with a restricted view of the host system, so a bad outcome means deleting a sandbox, not restoring a backup. Builds are content-hashed and content-addressable, which means you can replay any build down to a single spec and see the normalized dollar cost attached to that run. The ceiling appears early in teams who need the tool to also do its own code generation — Overplane is a build wrapper around agents you already own, not a coding agent itself.

SIMD Agent

Orbit is an MIT-licensed open-source harness that wraps any JSON-speaking CLI agent — Claude, Codex, Cursor, or otherwise — in a bounded loop: select one task from a dependency-aware backlog, run the agent, gate on real validation (tests, lint, type checks), and write inspectable artifacts before closing the orbit. Every run produces four JSON/markdown files recording what the agent returned, how the output scored against a rubric, whether to accept or iterate, and a human-readable mission log. The harness is intentionally small, so there is precious little abstraction to hide behind — what you see is what runs. Teams with strict audit requirements get durable, reviewable evidence without instrumenting the agent itself. The trade-off is that Orbit is a harness framework, not a turnkey product: you bring the agent, the backlog structure, and the validation suite.

Attribute	Overplane	SIMD Agent
Pricing	Free	Free
Free trial	No	No
Open source	Yes	Yes
Has API	No	No
Self-hosted option	Yes	Yes
Platforms	Linux, macOS, Windows (local binary)	Python 3, Linux, macOS
Pros	Every agent run executes in a locked-down container with a restricted view of the host system, so a compromised or misbehaving agent destroys a sandbox rather than your local environment or production credentials. Z3 runs on per-spec and merged Intermediate Representation models before any code is generated, which means logical contradictions in your spec surface as a pre-build error rather than a 4,000-line diff you have to reverse-engineer. Content-hashed images and content-addressable outputs make builds cacheable and replayable down to a single spec, so audit requests or incident investigations do not require reconstructing what the agent did from memory. Agent-agnostic design with per-project or per-run agent selection and normalized cost tracking across runs, which means you can benchmark Claude Code against Codex on the same spec without re-architecting anything. Apache-2.0 licensed with no hosted offering and no subscription, which means the tool introduces no vendor lock-in and no data leaving your infrastructure beyond what the agent API calls require.	Agent-neutral adapter contract, so you can swap Claude for Codex or any other JSON-speaking CLI behind the same harness without rewriting your validation logic or losing artifact continuity. Validation gates block task completion until tests, lint, and type checks pass, which means 'the agent said it worked' is never the acceptance criterion — proof is. Dependency-aware backlog selection keeps each orbit scoped to one task at a time, so the agent cannot drift into adjacent work and leave the codebase in a half-finished state. Structured artifact output per run — four files covering result, evaluation, review recommendation, and progress log — so audit trails and agent comparison experiments run on inspectable data rather than stdout logs. MIT-licensed and self-hostable with no commercial dependency, so the harness can run inside air-gapped or regulated environments where a SaaS agent platform is a non-starter.
Cons	Overplane does not include a coding agent — it drives Claude Code, Codex, or OpenCode, which means a team that does not already have those agents installed and API keys configured faces a multi-tool setup before a single build runs. Teams without an existing agent subscription hit this wall immediately and often reach for an integrated hosted tool instead. The tool is described as v0.0.8, which the vendor page does not present as production-stable. Teams evaluating it for a compliance-sensitive production pipeline face the specific problem of building internal policy around a binary that carries no stated stability guarantee — they document the version, pin it, and own the upgrade path. Formal spec verification with Z3 adds value only when specs are written to the schema Overplane expects. Teams migrating existing informal or prose-heavy spec documents spend the migration time rewriting specs before they see any verification benefit — the workflow does not adapt to how specs were written before.	Orbit produces no UI — review artifacts are JSON and markdown files on disk. Teams where product managers or compliance officers need to review agent work without opening a terminal hit this wall immediately and end up building a separate reporting layer. The validation gates are only as strong as the suite you bring: a codebase with no tests, no lint config, and no type checks gives Orbit nothing to gate on, which means the bounded-loop guarantee collapses to 'the agent returned output' — the same problem Orbit exists to solve. Backlog and task structure require manual definition in a format the harness expects; there is no backlog ingestion from issue trackers, project management tools, or CI systems. Teams running high-velocity sprints from Jira or Linear spend engineering time on a translation layer, and when that overhead compounds, they switch to an agent platform with native integrations. There is no API surface — the tool is CLI-only — so embedding Orbit into a larger automated pipeline (CI/CD, event-driven triggers, multi-repo workflows) requires shell scripting around the harness rather than programmatic control.

Bottom line

Overplane and SIMD Agent are closely matched on pricing model, openness, and API availability — pick by feature set and platform support in the table above.

Frequently asked questions

What is the difference between Overplane and SIMD Agent?

Overplane is Free and open source, while SIMD Agent is Free and open source. Compare pricing, free trial, API, platforms, and pros/cons in the table above on AIDiveForge.

Is Overplane better than SIMD Agent?

It depends on your workflow. Use the side-by-side attributes (pricing, open source, API, self-hosted, platforms) to decide. AIDiveForge does not rank a universal winner — we publish verified facts so you can choose.