meticulous-agent-security-invariants

name	meticulous-agent-security-invariants
description	Use when changing agent enrollment, join tokens, controller–agent trust, per-job secrets delivery, revocation, OIDC-style provider auth, or supported agent platforms for Meticulous.

Meticulous agent security invariants

Overview

Agents are untrusted executors until enrolled. Secrets must stay scoped, revocable, and encrypted in transit for the relevant hop. Join and job flows must preserve egress-only agent networking assumptions described in meticulous-system-architecture.

Non-negotiables (summary)

• No access to secrets outside the active pipeline/job scope.
• Agents revocable from the control plane (kill/disable enrollment).
• Join tokens scoped (e.g. pipeline, project, or broader group semantics as implemented).
• OIDC-style identity patterns for secrets providers where applicable (JWT claims / subject), comparable in intent to GitHub Actions OIDC.
• Per-job cryptographic handling for secret material (see reference): generate or exchange job keys, encrypt on server, agent decrypts and verifies integrity.
• NTP required for sane TLS and audit timelines; environment validation (host, OS, network posture) is a first-class concern for join policy.
• Operator pattern for Kubernetes: controller/operator-style deployment similar in spirit to GitHub Actions Runner Controller.

Product expectations

• Dry / test modes for developer iteration without full production side effects.
• Live log streaming to the control plane for debugging (exact attachment points evolve with code).
• Long-lived agents (e.g. Windows/macOS runners) may need JWT lifetime and approval/renewal workflows.

Platforms

Target agents: Linux amd64/arm64, macOS arm64, Windows amd64. BSD is an explicit future possibility (likely without container execution parity).

Provisioning flow (high level)

1. Controller issues join token.
2. Agent starts with token; builds security bundle and X.509 public key; sends to controller.
3. Controller validates bundle, stores pubkey with agent metadata.
4. Controller issues JWT (renewable or not per policy).
5. Agent connects to job queue / messaging fabric after success.

PKI / secret delivery (high level)

Job published → agent accepts work → ephemeral keypair for the job → server validates pubkey → server resolves secrets → encrypt per key with agent pubkey, attach integrity digests → agent decrypts and verifies digests.

Full notes

Historical bullets and numbered flows: references/agent-security-notes.md. Design folder mirror: design/agents.md (pointer only; this skill is canonical).

Keywords

join token, JWT, revocation, per-job PKI, X.509, OIDC, secrets scope, NTP, security bundle, met-agent, met-controller, operator.