AI Systems & Agent Reliability Engineer · Founder, Rumbo

Public surfaces: RUMBO IA · 90-second agent state-drift video · @RumboAGI on X

I build agentic systems where intent, authority, execution, observed effect, and promotion are separate, testable states.

INTENT → AUTHORITY → PREFLIGHT → EXECUTION → READBACK → FALSIFICATION → CLOSURE

My focus is failure-boundary engineering: async resource ownership, cancellation safety, fail-closed execution, tool and permission routing, deterministic evaluation, canonical-state recovery, and verifiable effects.

An installable, runtime-dependency-free Python reference implementation for fail-closed agent execution with exact-state binding, deterministic revalidation, effect readback, replay prevention, and hash-bound receipts.

The test suite covers stale-state rejection, duplicate intent rejection, action allowlisting, secret-like payload rejection, readback mismatch, receipt-chain verification, tamper detection, and replay prevention.

Developer quickstart: 5-minute Reliability Quickstart walks through INTENT → AUTHORITY → MATERIALIZATION → READBACK → RECEIPT → VERIFICATION.

Technical deep dive: An accepted agent action is not necessarily executable explains DECISION_ACCEPTED != EXECUTION_SAFE and the exact pre-effect state-drift guard.

90-second video: An Accepted Agent Action Is Not Necessarily Executable demonstrates the same fail-closed state-drift boundary and the negative observation blocked_target_mutated=False.

Current verification: repository main is e54f48a5117c9c10b60f15f6941d8fc7f909d7e1, tree a0f37f103d87b5fa762a7cc1f15bdf26861ca5dc. PR #12 ran the 72-test suite successfully on Python 3.11/3.12/3.13 in GitHub Actions run 34054304431; the merged main tree is exactly the audited candidate tree.

Release evidence: v0.2.0 is tagged at ed3bb2684743376fdf2769ee378ca614c913e3d4; that exact release tag passed source installation, the 16-test suite, and outside-checkout import verification on Python 3.11, 3.12, and 3.13 in GitHub Actions run #11.

Boundary: sanitized reference implementation; no private production state, credentials, provider IDs, or deployment configuration.

All engineering work recorded below is part of the Rumbo public engineering portfolio. Each issue, PR, implementation, regression, audit result, and limitation is tracked as a Rumbo engineering artifact unless explicitly identified as third-party work. This does not imply OpenAI employment, affiliation, endorsement, or maintainer status.

Independent public engineering activity. These links do not imply OpenAI employment, affiliation, endorsement, or maintainer status. Authorship and merge state are stated explicitly per item.

• Authored PR #730 — optionally consume task prompt files, implementing the smallest opt-in fix proposed in issue #622.
• The patch adds --prompt-file-consume with READ → DELETE → DISPATCH ordering, preserves ordinary --prompt-file behavior, and rejects consume mode without a prompt file.
• Validation on the exact upstream base: RED 1/3 → GREEN 3/3 focused runtime regressions, 28/28 non-runtime tests, Node syntax check, TypeScript compile, version check, and git diff --check PASS. Upstream workflow execution is currently gated on maintainer approval for fork Actions; I do not claim merge or acceptance.
• An independent public reviewer later endorsed the READ → DELETE → DISPATCH ownership order and the three regressions. I classify that only as independent technical review; formal maintainer/OpenAI status was not verified.

• Authored PR #885 — clarify Bedrock Mantle model-family API roots, a documentation-only upstream contribution tied to issue #812. The change preserves the existing /openai/v1 default and documents the explicit BaseURL path for model families whose AWS model card requires /v1.
• I do not claim merge or maintainer endorsement unless the upstream PR state later proves it.

• RUMBO IA engineering record: PR #4925 — introduce no-replace move capability, arising from issue #4924 and the earlier #4919 overwrite finding. The work introduces a BaseSandboxSession.move_no_replace() capability boundary, explicit AtomicMoveUnsupportedError, Unix-local no-replace handling, a temporary-file transfer path in WorkspaceEditor, and an explicit distinction between native atomic semantics and portable non-replace-safe fallback. The upstream PR remains open; no merge or endorsement is claimed.

• RUMBO IA engineering record: PR #4922 — fail closed on existing move destinations, implementing the application-level protection for the destination-overwrite defect plus shared-session concurrency regression coverage. The upstream PR remains open; no merge or endorsement is claimed.

• Authored PR #4868 — reset compaction response-chain state after a successful pop_item(), fixing issue #4867. Current head is f7b71a6dc704883cf5aa6ad5e6693dfed45cedb2, based directly on upstream main 02c205f9574c765a265ce102dc55da81cdd74b89; the PR remains limited to the compaction-session implementation and tests. The current branch adds deterministic coverage for destructive pop/clear invalidation, stale response-chain rejection, concurrent history races, deferred retry restoration after replacement failure, and backends that mutate while returning None from pop_item(). The latest author-side validation recorded on the prior exact head was 73 focused compaction-session tests and 223 memory tests passing, plus targeted Ruff, mypy, Pyright, and git diff --check; the new follow-up commits still require fresh runtime/CI verification. GitHub's exact-head Actions state is not currently available for the new follow-up head, so I do not label this CI PASS or FAIL, and no merge or acceptance is claimed.

• Authored #4747 — PTY teardown can be abandoned after registry removal, focused on cancellation-safe resource ownership after registry removal.

• Authored #4749 — PTY startup cancellation can leak unregistered resources, focused on the pre-registration ownership boundary.

• Reviewed PR #4750 and PR #4751 around cleanup ownership, cancellation propagation, and regression coverage.

• Reviewed PR #3780 around fail-closed CI dependency-gate ordering, scheduler semantics, and non-success dependency states.
• Publicly corrected a stale review blocker after re-reading the exact head revision.

• Revalidated the code-mode tool-output boundary reported in issue #42367, authored by another contributor.
• Published a concrete reference implementation in my fork: fscfede-beep/codex@9e70016.
• Published and merged RUMBO PR #28 — Codex thread scope evidence, a sanitized fail-closed scope-binding probe with 38/38 local regressions and exact-head privacy, scope-binding, and Vercel checks passing; no upstream mutation or root-cause claim.
• I do not claim upstream merge, endorsement, or Rust compile/test PASS for that reference commit.

Problema: una ejecución solicitada como “5 minutos” fue reportada incorrectamente como tal aunque duró aproximadamente 1 minuto y 11 segundos.

Solución registrada: no volver a etiquetar una ejecución por duración declarada. Cada ciclo debe usar únicamente tiempo realmente observado; si el entorno no permite mantener una ejecución activa durante 5 minutos, se debe reportar la duración real y la limitación operativa, sin sustituirla por una aproximación basada en cantidad de herramientas o trabajo realizado.

Regla de auditoría: DURACIÓN OBSERVADA ≠ DURACIÓN SOLICITADA implica FAIL de la métrica temporal, aunque el trabajo técnico realizado sea correcto.

Evidencia: la autoauditoría del 8 de septiembre de 2026 identificó el incumplimiento de la ventana temporal y corrigió el procedimiento para no volver a afirmar “5 minutos” sin medición verificable.

Estado: protocolo adoptado para las siguientes ejecuciones de RUMBO IA.

This registry is the attribution convention for engineering work produced by this account:

Attribution rule: future solutions are recorded as Rumbo engineering artifacts with repository, issue/PR, exact commit/head, validation status, and evidence boundaries. Upstream ownership, merge decisions, and endorsements remain with the respective projects.

• Async Resource Ownership Under Cancellation — ownership transfer, cancellation-settled teardown, exception precedence, attempt-all cleanup.
• Fail-Closed CI Gates — required-job scheduler semantics, dependency failure propagation, pre-checkout guards, reviewer self-correction.
• Tool Output Policy Boundaries — caller-requested budgets, model truncation policy, and context-safety boundaries.

• agent harnesses and long-running execution;
• async lifecycle and cancellation safety;
• MCP, plugins, connectors, and tool routing;
• permission and policy boundaries;
• deterministic evals and regression testing;
• canonical-state recovery and effect verification;
• verifiable control planes for consequential agent actions.

• RUMBO IA repository — human-controlled AI CRM and workflow automation with public privacy and verification gates.
• RUMBO Guardian — privacy-first, local-first security intelligence with explainable scoring and a tamper-evident SHA-256 Evidence Ledger.
• VAE Bindings — public privacy-preserving commitments and GitHub attestations for agent work-unit bindings.
• RUMBO IA website — product surface for small businesses in Latin America.
• @RumboAGI on X — public product, evidence, and engineering updates.
• Technical portfolio — selected work in AI workflow and agent reliability.

An agent is not reliable merely because it selected the right action. Reliability requires the authorized action, the executed action, the observed effect, and the evidence about that effect to remain consistent across failures.

I deliberately distinguish authored issues, reviews, reference implementations, upstream code authorship, merge state, endorsement, employment, and production status.

I am open to engineering roles and technical collaboration in agent reliability, developer tooling, applied AI, and agent infrastructure.