Threat Modeler (/mantis-threat-model)

System Goal

Security Architect. Synthesizes trust boundaries, attack surfaces, and attacker profiles into THREAT_MODEL.md based exclusively on the entities and architecture defined in the Knowledge Base (KB).

Command Definition

• Command: /mantis-threat-model
• Description: Evaluates architectural perimeters, entry points, and trust boundaries to construct the threat model.
• Arguments (all optional; absent → today's behavior):
  • --state_root <dir>: parent of workspace/. If absent, use ./workspace/... relative to the current directory. Locates .mantis_state.json, the KB, and the archive directory.
  • --snapshot_id <id>: the SNAPSHOT_ID this pass is pinned to. Used ONLY as the provenance value stamped into THREAT_MODEL.md (the KB_SNAPSHOT: line). If absent, fall back to active_snapshot.snapshot_id from state; if that is also absent or snapshot_pinned is false, the stamp is the literal UNPINNED.
  • --snapshot_root <dir>: accepted for interface uniformity but NOT used — this stage never reads target source (Block A step 0, findings-only role).

Input/Output Contract

• Reads:
  • workspace/.mantis_state.json — pass_number (to archive per pass) and, for provenance only, active_snapshot ({root, snapshot_id, snapshot_pinned}). Both optional; absent → degraded (see Backward-compat).
  • workspace/kb/architecture.md.
  • workspace/kb/entities/*.md.
  • The EXISTING workspace/kb/THREAT_MODEL.md from the previous pass, if present — only its first KB_SNAPSHOT: line, for the freshness check in step 0.
• Writes:
  • workspace/kb/THREAT_MODEL.md (first line is a KB_SNAPSHOT: provenance header).
  • Archives the previous workspace/kb/THREAT_MODEL.md (if any) to workspace/archive/kb/THREAT_MODEL_pass_${N}.md BEFORE overwriting.
• Preconditions:
  • Knowledge Base files must exist and be populated.
• Idempotency Guarantee:
  • Copies the prior THREAT_MODEL.md (if any) to the pass archive, then deterministically overwrites workspace/kb/THREAT_MODEL.md in-place. Re-running a pass with an unchanged snapshot reproduces an equivalent model plus a STALE banner (see step 0 and the final save step).

Instructions

LOCATOR RESOLUTION (before reading ANY target code or artifact):
0. ROLE: If this skill NEVER reads target source (report, calibrate, reflect),
   you are a FINDINGS-ONLY stage: skip steps 2-6; still read active_snapshot from
   state for provenance/annotation; NEVER stop merely because a code root is unset.
1. Determine CODE_ROOT, in this priority order:
   a. If --target_root is passed on THIS invocation, CODE_ROOT = --target_root.
      It is AUTHORITATIVE and OVERRIDES SNAPSHOT_ROOT and the state fallback
      (used when a caller hands you a prepared tree, e.g. a patched shadow).
   b. Else if --snapshot_root (or SNAPSHOT_ROOT) is passed, use it.
   c. Else read state_root/workspace/.mantis_state.json (state_root from
      --state_root if passed, else ./workspace/... relative to the current dir)
      -> active_snapshot.root / .snapshot_id / .snapshot_pinned.
   d. Else (no arg AND no readable active_snapshot): CODE_ROOT = current directory,
      treat snapshot_pinned = false (MODE-OFF). Do NOT stop.
2. SENTINEL CHECK (only if snapshot_pinned is true AND you did NOT take path 1a):
   verify CODE_ROOT/.mantis_snapshot_id exists and equals SNAPSHOT_ID. If missing
   or different -> STOP "snapshot sentinel mismatch". (A --target_root tree (1a) is
   deliberately mutated and is sentinel-EXEMPT.)
3. PATH FIELDS:
   - SNAPSHOT-RELATIVE (read under CODE_ROOT): code_paths entries; plan target_files
     that are file paths. Strip ONLY a trailing ":<digits>". A code_paths entry
     containing "://" is a URL/endpoint, NOT a file read. A code_paths entry that is
     NOT of the form <existing-path>:<integer> is a non-source LOCATOR
     (symbol/offset/endpoint): only check that the artifact/symbol exists; skip ALL
     line-range and line-existence logic.
   - STATE-RELATIVE (read/write under state_root/workspace, NEVER prefix CODE_ROOT):
     kb_references, repro_file_path, reattack_file_path, helper scripts, report
     files, and all state/findings JSON.
4. Never WRITE under CODE_ROOT when snapshot_pinned is true. Any command that
   compiles, generates, or writes artifacts MUST run in a PRIVATE SHADOW copy
   (mktemp -d from CODE_ROOT), never with cwd=CODE_ROOT. Read-only inspection may
   cd into CODE_ROOT.
5. VCS-METADATA CARVE-OUT: history-log extraction and any VCS diff/blame command
   run in the LIVE repository root (which still has .git/.hg/.repo), NOT CODE_ROOT
   (the snapshot copy strips VCS metadata). Do NOT stop merely because CODE_ROOT
   lacks .git/.hg/.repo.
6. Every shell command uses ABSOLUTE paths and sets its own working directory on
   that call. Do NOT assume the working directory persists between calls.

Role for this stage (findings-only / KB-only). /mantis-threat-model NEVER reads target source. Every input it uses — architecture.md, entities/*.md, the prior THREAT_MODEL.md, and .mantis_state.json — is STATE-RELATIVE (read under state_root/workspace, NEVER under CODE_ROOT). This stage therefore takes Block A step 0's FINDINGS-ONLY path: SKIP Block A steps 2–6, but STILL read active_snapshot from state for provenance, and NEVER stop merely because a code root is unset or unpinned.

Maintain a high-level Threat Model that explicitly defines who the attackers are and where they can interact with the system, relying on the pre-processed entities in the KB.

Execute the threat modeling process as follows:

0. Resolve Snapshot Provenance, Freshness, and Archive the Prior Model:

   a. Compute CUR (the snapshot this threat model is stamped against):

   • If --snapshot_id was passed → CUR = that value.
   • Else if state active_snapshot.snapshot_pinned is true → CUR = active_snapshot.snapshot_id.
   • Else → CUR = the literal UNPINNED (degraded / today's behavior).

   b. Compute PREV_TM (what the last model was stamped against): read the FIRST line matching ^KB_SNAPSHOT: in the existing workspace/kb/THREAT_MODEL.md; its value (trimmed) is PREV_TM. If the file is absent, has no such line, or the value is empty → PREV_TM = the empty string "".

   c. SYNC-DELTA DECISION (mechanical; exact string equality, no fuzzy compare):

   • CUR == "UNPINNED" → SYNC_OCCURRED = true (degraded: always re-derive).
   • else PREV_TM == "" → SYNC_OCCURRED = true (first run / legacy KB).
   • else PREV_TM != CUR → SYNC_OCCURRED = true (a sync or dirty edit advanced the snapshot).
   • else (PREV_TM == CUR) → SYNC_OCCURRED = false (snapshot unchanged since the last model).

   d. Archive the prior model (per pass), so overwrite is non-destructive:

   • Resolve N: read "pass_number" from workspace/.mantis_state.json. If missing or invalid, scan workspace/archive/ for folders matching findings_pass_N or loopN_findings and set N = max_found + 1, defaulting to 1 if no archives exist. (Same rule the architecture stage uses.)
   • If workspace/kb/THREAT_MODEL.md exists: ensure workspace/archive/kb/ exists (mkdir -p workspace/archive/kb/) and COPY (do NOT move) the file to workspace/archive/kb/THREAT_MODEL_pass_${N}.md. You will overwrite the live file in step 3. If the file does not exist, skip the copy.
   • All paths in this step are STATE-RELATIVE (under state_root/workspace); NEVER prefix CODE_ROOT.

   Carry CUR, SYNC_OCCURRED, and N forward into steps 1–3 and the final save.

1. Read the Synthesized KB:

   • Read workspace/kb/architecture.md to understand the system's data flows and high-level design.
   • Read the files inside workspace/kb/entities/ to understand the individual components and any historical constraints or vulnerability patterns mapped to them by the /mantis-architecture stage.

2. Analyze Trust Boundaries:

   • Evaluate the entities to determine where trust boundaries lie. Where does untrusted data cross into a trusted context? Which components are exposed to external input?

3. Synthesize the Threat Model:

   • Write a comprehensive, structured Markdown file and save it directly to workspace/kb/THREAT_MODEL.md (overwriting the old one).
   • Token Optimization: Use your file-writing tools to write the file directly to disk; do not output the threat model text in your chat response.

   Include the following sections to ensure downstream planning agents have sufficient context:

   • System Overview Summary: A concise summary derived from architecture.md.

   • Deployment Intent: State exactly one of Intent: PRODUCTION or Intent: SAMPLE_OR_TEST_ONLY. This verdict has a large blast radius: /mantis-critic marks EVERY finding SAMPLE_OR_TEST (dismissing the whole pass) the instant it reads Intent: SAMPLE_OR_TEST_ONLY. So SAMPLE_OR_TEST_ONLY is FAIL-CLOSED behind a mechanical checklist:

     PRODUCTION-SIGNAL CHECKLIST — you may write Intent: SAMPLE_OR_TEST_ONLY ONLY IF ALL five checks are TRUE. If ANY is FALSE, or the KB is silent on / you are unsure about any one of them, you MUST write Intent: PRODUCTION.

     1. NO entity in workspace/kb/entities/*.md is classified CRITICAL or STANDARD availability (either implies an operated/production service).
     2. architecture.md names NO externally-reachable service, daemon, server, API, or network endpoint, AND NO deployment/packaging descriptor (systemd, Dockerfile/docker, kubernetes/k8s/helm, load balancer, cloud/VPC/IaC, CI/CD publish or release).
     3. The KB describes NO installable/publishable package or runtime entrypoint (e.g., console_scripts/entry_points, a main()/service binary, a published library or package manifest).
     4. EVERY component/path referenced in the KB lies exclusively under test/sample directories — its path contains one of test, tests, example, examples, sample, samples, tutorial, demo, docs, fixtures — and NONE lie under production source roots such as src, lib, pkg, internal, cmd, app, server, or core.
     5. NO entity documents a real (non-mock, non-test) untrusted external input crossing a trust boundary into privileged/production logic.

     After a sync (SYNC_OCCURRED == true from step 0) you MUST re-run this checklist from scratch against the CURRENT KB and MUST NOT inherit a prior Intent: verdict — a sync can add production code to a tree that was previously sample-only, which would otherwise silently dismiss every new finding.

   • Trust Boundaries: Clear, rigorous definitions of where untrusted inputs meet internal trusted states. Reference the specific entities (e.g., [Auth Module](entities/auth_module.md)).

   • Threat Actors & Vectors: Define the profiles of potential attackers (e.g., Unauthenticated Network Attacker, Malicious Local User) and the specific boundaries they can reach.

   • High-Risk Assets: The data, execution privileges, or availability targets an attacker wants to compromise. For availability targets, classify them into one of these Availability Tiers based on the KB:

     • CRITICAL: 24/7 immediate operational impact if disrupted.
     • STANDARD: Important operations; short downtime is tolerable.
     • LOW_CRITICALITY: Non-blocking utilities; disruption is a mild annoyance.

Stamp and save the model:

• The FIRST line of workspace/kb/THREAT_MODEL.md MUST be the provenance stamp KB_SNAPSHOT: followed by CUR (from step 0) — e.g. KB_SNAPSHOT: <CUR>, or KB_SNAPSHOT: UNPINNED in degraded mode. The next pass reads this back as PREV_TM, and mantis-critic reads it as a KB freshness check.
• If SYNC_OCCURRED == false (snapshot unchanged since the last model): you MAY reuse the prior model's substance, but you MUST insert this STALE banner as the line immediately AFTER the KB_SNAPSHOT: line: > STALE: Threat model NOT re-evaluated this pass; carried unchanged from snapshot <CUR>. If SYNC_OCCURRED == true: do NOT emit the STALE banner — you re-derived every section fresh this pass, including the Deployment-Intent checklist.
• Save directly to workspace/kb/THREAT_MODEL.md (STATE-RELATIVE; the prior file was already copied to the pass archive in step 0d). Use your file-writing tools; do not print the model to chat. When complete, notify the user.