Purpose
Mantyl is a local-first command-line tool (CLI) for AI code handover. It addresses the problem that software built with coding agents often has its knowledge concentrated in fragile corners—session logs, discarded prompts, and the operator's memory. When such a project needs to change hands, the recipient usually gets only the source code and verbal assurances. Mantyl replaces those assurances with inspectable records, producing a project passport that the recipient can independently verify.
Main capabilities
- Reads the repository and its coding agent history (Claude Code, Cursor, OpenAI Codex CLI), extracting claims and decisions.
- Generates a passport that describes: what the software contains, how to run it, what decisions were made during the build, what has been proven by execution, and what remains unknown.
- Every claim, decision, risk, and setup step carries one of eight statuses, with the underlying rule being: explanation can never be upgraded to proof. The LLM can explain, but must never mark anything as verified; claims that contradict the code are presented as contradictions, with the evidence identified, and never hidden.
- Outputs are stored in the .mantyl/ directory: passport.json (the canonical, digest-stamped contract), readable HTML and Markdown reports, and the evidence files behind each statement.
- All processing is done locally. Nothing is uploaded unless a publish command is explicitly run; all transcripts undergo fail-closed secret redaction before storage or analysis.
- Provides recipient verification commands: recompute the passport digest, fingerprint the delivered files, compare commits, and re-execute the recorded checks in the recipient's own sandbox. Any deviation is pinpointed precisely and exits with a non-zero status.
Usage
Requires Node 20.12+. Docker Desktop is a prerequisite for full results: it drives sandbox verification, from which the passport's strongest evidence comes; without Docker, checks are honestly recorded as skipped. Reading Cursor history requires Node 22.13+. The repository contains the complete CLI, and everything running on the local machine is publicly auditable. The hosted passport service and Mantyl Verified signing infrastructure are in a separate private codebase, and signing keys are not distributed with any client. The passport format itself is open, with the schema at mantyl.dev/schemas/passport-v1.json.
Full documentation is at mantyl.dev/docs, including quick start, supported agents, real models, command reference with stable exit codes, and publishing. The reasoning behind the tool is at mantyl.dev/manifesto. Details of the storage layout for supported agents are at mantyl.dev/guides.
Applicable scenarios
Suitable for scenarios where AI-built software is delivered to others and verifiable handover materials are needed. Both the producer and the recipient can verify independently. The repository itself is proof that it generates its own passport and is verified by independent re-execution. The test suite includes a determinism gate (two runs must produce a byte-for-byte identical passport) and a secret leakage gate (credentials planted in fixtures must never reach any artifact). Sandbox integration tests are automatically skipped when there is no Docker daemon and run in CI.
Limitations
- Full sandbox verification depends on Docker Desktop; without Docker, checks are recorded as skipped.
- Reading Cursor history requires Node 22.13+.
- The hosted passport service and signing infrastructure are a private codebase and are not in this repository.
- Mantyl output is evidence-backed, not a certification.
- This material does not provide specific pricing information and only states that it uses the MIT license.
