GitLab Transcend Hackathon 2026 · Path B Target: Sherlock Project Rule: DEF-104

Supervised Incident-to-Immunity System

ANTIBODY demonstrates how a production defect in sherlock_project/sites.py (Incident #104: unbounded outbound HTTP requests breaching canary latency thresholds) is converted into an AST-validated structural defense (DEF-104), discovering 6 latent sibling sites across 4 verbs, and deterministically halting held-out recurrence attacks in GitLab CI.

Stage 1 · Proof PROVEN

RED → GREEN

Pre-fix: Exit 1 (2 failed)
Post-fix: Exit 0 (3 passed)

Stage 2 · Siblings 6 SITES

6 Confirmed

Across 4 modules & 4 HTTP verbs
(8 safe counterparts preserved)

Stage 3 · Validation 7 / 7 MUTANTS

100% Class A

3/3 negative controls rejected
0 False Positives on clean code

Stage 4 · Gate BLOCKED

BLOCKED

Held-out recurrence attack halted
Hash-bound receipt emitted

The Closed Immunity Loop (Incident to Defense)

Automated sequence turning ephemeral alerts into durable architectural defenses

Deterministic Oracle

Step 01

Production Defect

Unbounded HTTP call in sites.py triggers latency breach.

diagnosis.json

Step 02

Regression Proof

Focused test proves defect before patch (RED) and resolves post-patch (GREEN).

proof.json

Step 03

Sibling Discovery

AST & Semgrep sweep discovers 6 latent sibling sites across verbs & files.

siblings.json

Step 04

Structural Defense

Semgrep rule DEF-104 tested against 7 AST mutants and 3 negative controls.

DEF-104.validation.json

Step 05

Recurrence Gate

Held-out recurrence attack is deterministically BLOCKED in GitLab CI.

recurrence_receipt.json

Five Authoritative Lifecycle Stages

Interactive execution receipts, AST rules, and machine verifications

Select stage to inspect receipts

Authoritative Consolidated Receipt PROVEN_DEFENDED

Consolidated execution receipt generated by demonstrate_e2e.py and formally validated against antibody/schemas/e2e_evidence.schema.json.

Scenario	INC-104: Outbound HTTP Timeout Recurrence Prevention
Defense ID	`DEF-104`
Rule SHA256	`dbee6e133c320fc0619903b83c885319cceb7cbc484f01aa5564a20319bb1e26`
Execution Verdict	PROVEN_DEFENDED
Schema Validation	Draft2020-12 Valid

Stages Summary Snapshot 5 / 5 Stages Verified

1. Regression Proof	PROVEN RED (Exit 1) → GREEN (Exit 0)
2. Sibling Discovery	PASSED 6 confirmed sibling sites discovered
3. Structural Defense	PASSED 7/7 AST mutants caught · 3 negative controls
4. Recurrence Gate	PASSED Held-out attack BLOCKED · 0 False Positives
5. Consolidated Receipt	PASSED Schema valid output emitted

incidents/INC-104/e2e_evidence.json

{
  "scenario": "INC-104: Outbound HTTP Timeout Recurrence Prevention",
  "timestamp": "2026-10-13T09:42:17.162877+00:00",
  "duration_seconds": 128.61,
  "status": "PROVEN_DEFENDED",
  "defense": {
    "defense_id": "DEF-104",
    "rule_sha256": "dbee6e133c320fc0619903b83c885319cceb7cbc484f01aa5564a20319bb1e26",
    "integrity_verified": true
  },
  "stages": {
    "stage_1_regression_proof": {
      "status": "PROVEN",
      "reg_01": "PASSED",
      "reg_02": "PASSED",
      "pre_fix_exit": 1,
      "post_fix_exit": 0
    },
    "stage_2_sibling_discovery": {
      "confirmed_siblings": 6,
      "files_affected": 4,
      "out_of_scope_cases": 3
    },
    "stage_3_structural_defense": {
      "validation_status": "passed",
      "mutations_caught": 7,
      "mutations_total": 7,
      "good_corpus_flagged": 0
    },
    "stage_4_recurrence_gate": {
      "gate_status": "passed",
      "recurrence_attack_blocked": true,
      "recurrence_findings": 1,
      "siblings_defended": 6,
      "known_good_control_clean": true
    }
  },
  "evidence_references": {
    "regression_proof": "incidents/INC-104/proof.json",
    "siblings_report": "incidents/INC-104/siblings.json",
    "defense_validation": "defenses/DEF-104.validation.json",
    "recurrence_receipt": "defenses/DEF-104.recurrence_receipt.json"
  }
}

Deterministic Regression Proof PROVEN

CI script antibody/scripts/regression_proof.py proves defect reproduction before code fix and verifies resolution post-fix.

Target Function	`sherlock_project/sites.py:check_target_connection`
Regression Test	`tests/regression/test_timeout_regression.py`
Pre-Fix Status	RED (Exit 1) 2 tests failed
Post-Fix Status	GREEN (Exit 0) 3 tests passed
Check REG-01 / REG-02	PASSED

Code Remediation Diff Bounded Timeout

Patch applied to sherlock_project/sites.py establishing explicit connect/read timeout:

sherlock_project/sites.py

@@ -145,3 +145,5 @@
- response = requests.get(url, headers=headers)
+ # DEF-104: Enforce explicit connect/read timeout
+ response = requests.get(url, headers=headers, timeout=(3.05, 10.0))

incidents/INC-104/proof.json

{
  "incident_id": "104",
  "target": "sherlock_project/sites.py:check_target_connection",
  "regression_test": "tests/regression/test_timeout_regression.py",
  "pre_fix": {
    "ref": "9e612429ec5c55b53983630fd863ff8392948087:sherlock_project/sites.py",
    "exit_code": 1,
    "status": "RED",
    "tests_passed": 1,
    "tests_failed": 2
  },
  "post_fix": {
    "ref": "HEAD",
    "exit_code": 0,
    "status": "GREEN",
    "tests_passed": 3,
    "tests_failed": 0
  },
  "proof_status": "PROVEN",
  "reg_01": "PASSED",
  "reg_02": "PASSED",
  "reg_03": "PASSED",
  "timestamp": "2026-10-13T09:40:11.856372+00:00"
}

AST & Semgrep Sibling Sweep 6 SIBLINGS FOUND

antibody/scripts/discover_siblings.py scans for the same defect pattern across different modules, files, and HTTP verbs.

Total Candidates Examined	17 sites evaluated
Confirmed Sibling Sites	6 confirmed (requiring defense)
Safe Counterparts Preserved	8 safe (existing timeouts)
Explicit Scope Limits	3 out of scope (documented boundary)
HTTP Verbs Covered	`GET` (3), `POST` (1), `PUT` (1), `DELETE` (1)

Confirmed Sibling Sites Breakdown 4 Files

ID	Module	Symbol	Verb	Confidence
SIB-104-001	`fixture_direct_sibling.py`	`fetch_site_manifest`	`GET`	High
SIB-104-002	`fixture_incident_104.py`	`check_target_connection`	`GET`	High
SIB-104-005	`fixture_renamed_sibling.py`	`retrieve_remote_metadata`	`GET`	High
SIB-104-009	`fixture_verb_sibling.py`	`send_telemetry_beacon`	`POST`	High
SIB-104-010	`fixture_verb_sibling.py`	`update_remote_state`	`PUT`	High
SIB-104-011	`fixture_verb_sibling.py`	`purge_remote_record`	`DELETE`	High

incidents/INC-104/siblings.json (Summary & First Confirmed Sites)

{
  "incident_id": "104",
  "rule_id": "DEF-104",
  "summary": {
    "total_candidates": 17,
    "confirmed_siblings": 6,
    "safe_counterparts": 8,
    "out_of_scope": 3,
    "files_affected": 4,
    "modules_affected": 4,
    "by_module": {
      "fixture_direct_sibling": 1,
      "fixture_incident_104": 1,
      "fixture_renamed_sibling": 1,
      "fixture_verb_sibling": 3
    },
    "by_http_verb": {
      "get": 3,
      "post": 1,
      "put": 1,
      "delete": 1
    }
  },
  "sites_sample": [
    {
      "path": "antibody/corpus/siblings/fixture_direct_sibling.py",
      "symbol": "fetch_site_manifest",
      "line": 12,
      "confidence": "high",
      "classification": "confirmed_sibling",
      "http_verb": "get",
      "rule_id": "DEF-104",
      "reason": "Outbound HTTP call without explicit timeout parameter matching DEF-104 structural pattern",
      "requires_validation": false,
      "scope_limit": null,
      "id": "SIB-104-001"
    },
    {
      "path": "antibody/corpus/siblings/fixture_incident_104.py",
      "symbol": "check_target_connection",
      "line": 13,
      "confidence": "high",
      "classification": "confirmed_sibling",
      "http_verb": "get",
      "rule_id": "DEF-104",
      "reason": "Outbound HTTP call without explicit timeout parameter matching DEF-104 structural pattern",
      "requires_validation": false,
      "scope_limit": null,
      "id": "SIB-104-002"
    },
    {
      "path": "antibody/corpus/siblings/fixture_renamed_sibling.py",
      "symbol": "retrieve_remote_metadata",
      "line": 13,
      "confidence": "high",
      "classification": "confirmed_sibling",
      "http_verb": "get",
      "rule_id": "DEF-104",
      "reason": "Outbound HTTP call without explicit timeout parameter matching DEF-104 structural pattern",
      "requires_validation": false,
      "scope_limit": null,
      "id": "SIB-104-005"
    }
  ]
}

Defense Validator Oracle PASSED

antibody/scripts/validate_defense.py subjects rule DEF-104 to an adversarial mutation oracle and negative controls.

Rule Identifier	`DEF-104` (Severity: ERROR)
Class A Mutants (M1-M7)	7 / 7 Caught (100%)
Good Code Corpus	9 / 9 Preserved (0 FP)
Negative Controls	3 / 3 Rejected (Overbroad, Narrow, Regex)
Class B Boundaries	1 / 3 (Honest scope limits disclosed)

Semgrep Rule Definition YAML AST

Declarative structural pattern in defenses/DEF-104.yaml:

defenses/DEF-104.yaml

rules:
  - id: antibody-def-104-http-no-timeout
    languages: [python]
    severity: ERROR
    message: "Outbound HTTP call without explicit timeout. Prevented by defense DEF-104 generated from Incident #104."
    metadata:
      incident: "104"
      defense: "DEF-104"
      incident_url: "https://gitlab.example.com/antibody/sherlock/-/issues/104"
    pattern-either:
      - patterns:
          - pattern: requests.$M(...)
          - metavariable-regex:
              metavariable: $M
              regex: '^(get|post|put|patch|delete|head|options|request)$'
          - pattern-not: requests.$M(..., timeout=$T, ...)
      - pattern: requests.$M(..., timeout=None, ...)
      - pattern: urllib.request.urlopen($U)
      - patterns:
          - pattern-inside: |
              $S = requests.Session()
              ...
          - pattern: $S.$M(...)
          - metavariable-regex:
              metavariable: $M
              regex: '^(get|post|put|patch|delete|head|options|request)$'
          - pattern-not: $S.$M(..., timeout=$T, ...)

defenses/DEF-104.validation.json

{
  "defense_id": "DEF-104",
  "rule_sha256": "dbee6e133c320fc0619903b83c885319cceb7cbc484f01aa5564a20319bb1e26",
  "checks": {
    "lint": true,
    "original": true,
    "siblings": true,
    "mutants_A": {
      "total": 7,
      "caught": 7
    },
    "mutants_B": {
      "total": 3,
      "caught": 1
    },
    "good": {
      "total": 9,
      "flagged": 0
    },
    "repo_clean": true
  },
  "status": "passed",
  "attempt": 1
}

Recurrence Gate Enforcement ATTACK BLOCKED

Authoritative CI gate antibody/scripts/recurrence_gate.py evaluates whether a held-out attack is blocked and siblings protected.

Held-Out Attack Fixture	`held_out_recurrence.py`
Attack Execution Result	BLOCKED (1 finding)
Safe Counterpart Twin	ALLOWED (0 findings)
Sibling Defense Coverage	6 of 6 Defended
Cryptographic Hash Binding	Verified SHA256

CI Blocking Diagnostic Output Authoritative

Terminal diagnostic emitted during recurrence gate evaluation in CI pipeline:

recurrence-gate stdout

[RECURRENCE BLOCKED]
File: antibody/corpus/recurrence/held_out_recurrence.py:27
Rule: DEF-104 (Incident #104)
Message: Outbound HTTP call without explicit timeout.
Prevented by defense DEF-104 generated from Incident #104.

defenses/DEF-104.recurrence_receipt.json

{
  "defense_id": "DEF-104",
  "incident_id": "104",
  "rule_sha256": "dbee6e133c320fc0619903b83c885319cceb7cbc484f01aa5564a20319bb1e26",
  "recurrence": {
    "fixture_path": "antibody/corpus/recurrence/held_out_recurrence.py",
    "blocked": true,
    "findings": 1
  },
  "sibling_defense": {
    "evaluated": 6,
    "defended": 6,
    "safe_preserved": 8,
    "out_of_scope": 3
  },
  "checks": {
    "lint": true,
    "original": true,
    "siblings": true,
    "mutants_A": {
      "total": 7,
      "caught": 7
    },
    "mutants_B": {
      "total": 3,
      "caught": 1
    },
    "good": {
      "total": 9,
      "flagged": 0
    },
    "repo_clean": true,
    "recurrence_blocked": true,
    "integrity_verified": true
  },
  "status": "passed",
  "attempt": 1
}

System Verification Matrix (Pipeline 2943123842)

Authoritative audit ledger distinguishing verified execution from honest boundaries

GitLab CI Verified

Job / Component	Stage	Status	Verification Evidence
`regression-proof`	`verify`	PASS	RED on unpatched source → GREEN on patched source (REG-01, REG-02 verified)
`unit-test`	`verify`	PASS	Full upstream Sherlock test suite passed on Python 3.12
`validate-defense`	`secure`	PASS	DEF-104 validated: 7/7 AST mutants caught, 3/3 negative controls rejected
`discover-siblings`	`secure`	PASS	6 confirmed sibling sites discovered across 4 files and 4 HTTP verbs
`recurrence-gate`	`secure`	PASS	Held-out recurrence attack deterministically blocked; receipt emitted
`build-image`	`package`	PASS (DinD)	Container built ephemeral in Docker-in-Docker runner (manual trigger; not published)
`static-analysis`	`secure`	FAIL (ALLOWED)	Ruff reported legacy debt (104 errors); configured with `allow_failure: true`
GitLab Duo Platform Execution	`agent`	UNVERIFIED	Flows authored per Flow Registry v1; simulated locally, unverified on remote Duo
Automated Canary Rollback	`release`	UNVERIFIED	Declarative policy in `canary-policy.yaml`; CI release jobs unexecuted

Platform Limitations & Non-Claims (Honest Engineering Boundaries)

No Live GitLab Duo Flow Claim Custom flow configurations (.gitlab/duo/flows/antibody-fix-prove.yaml and antibody-respond.yaml) are validated against official schemas and simulated offline via fix_prove_runner.py. We do not claim live remote Duo agent runner execution took place.

No Automated Canary Rollback Claim Canary thresholds in deploy/canary-policy.yaml are declarative specifications. The ci/release.yml and ci/monitor.yml jobs remain skeleton placeholders and were not executed during this deployment.

No Public Container Registry Publishing The build-image job in GitLab CI verified Docker packaging in an ephemeral DinD runner. The resulting image was not published to a public container registry.

Intra-Procedural AST Scope Limits Structural defense DEF-104 accurately catches intra-procedural calls and session wrappers. Complex inter-procedural taint flows (e.g. factory-instantiated sessions) are documented as known Class B boundary limits.