Local, evidence-backed security for Python packages and SCA alerts.
Your SCA tool (Snyk, Dependabot, Trivy, pip-audit, OSV, or another scanner) flags every CVE in your dependency tree. You get 60 alerts. Your team scrambles. But many of those CVEs are in code your application never imports, never calls, and never executes.
You're patching vulnerabilities in functions you don't use, in packages you didn't know you had, in code paths your app will never reach.
That's wasted engineering time. That's alert fatigue. That's how real vulnerabilities get ignored.
ca9 is a local-first security layer for Python packages and open-source dependency risk. Today, its strongest path turns CVE alerts into evidence-backed fix, suppress, or investigate decisions. The newer inventory path normalizes packages, artifacts, lockfile evidence, and dependency edges so ca9 can grow beyond CVE-only reachability without making any resolver or package manager a required dependency.
It takes your CVE list and answers one question per vulnerability: is this code actually reachable from your application?
pip install ca9[cli]
ca9 scan --repo . --coverage coverage.jsonFor package inventory and supply-chain evidence, ca9 can read project manifests natively
and uses fyn.lock when present:
ca9 inventory --repo . -f json
ca9 vet --repo . -f jsonCVE ID Package Severity Verdict
--------------------------------------------------------------
GHSA-cpwx-vrp4-4pq7 Jinja2 high REACHABLE
GHSA-frmv-pr5f-9mcr Django critical UNREACHABLE (static)
GHSA-mrwq-x4v8-fh7p Pygments medium UNREACHABLE (dynamic)
--------------------------------------------------------------
Total: 61 | Reachable: 25 | Unreachable: 36 | Inconclusive: 0
59% of flagged CVEs are unreachable — only 25 of 61 require action
36 CVEs eliminated. No manual triage. No guessing.
ca9 combines repository evidence with advisory metadata to determine whether vulnerable code is reachable:
1. Static analysis (AST import tracing) — Parses every Python file in your repo and traces import statements. If a vulnerable package is never imported, it's unreachable.
2. Dependency inventory — Uses declared dependencies, report metadata, local package metadata, and fyn.lock when available to separate direct, transitive, imported, and unused packages.
3. Dynamic analysis (coverage.py) — Checks whether vulnerable code was actually executed during your test suite. A package might be imported but the specific vulnerable function might never be called.
4. Advisory normalization — Preserves source, aliases, CWE/CPE IDs, timestamps, and cache freshness where input data provides them, so evidence can be traced back to the alert.
For each CVE:
Is the affected version installed or declared?
├── NO → UNREACHABLE (static)
└── YES → Is the package, affected submodule, or known vulnerable API used?
├── NO, with enough graph/import evidence → UNREACHABLE (static)
├── YES, and runtime/coverage confirms execution → REACHABLE
├── YES, but coverage shows no affected execution → UNREACHABLE (dynamic)
└── Not enough evidence → INCONCLUSIVE
ca9 is conservative — it only marks something unreachable when it can prove it. Every verdict comes with an evidence trail and a confidence score so you can see exactly why ca9 reached its conclusion.
ca9 does not replace your SCA tool. It adds local, evidence-first reachability analysis to the vulnerability data you already have.
| ca9 | Alert-only SCA output | Hosted reachability platforms | |
|---|---|---|---|
| Local analysis | Runs in your repo/CI | Varies | Often requires source upload or hosted project import |
| Direct OSV scan | Yes — ca9 scan queries OSV.dev directly |
Not always | Varies |
| SCA report parsing | Snyk, Dependabot, Trivy, pip-audit | Native to each tool | Platform-specific |
| Package inventory | Native manifests plus optional fyn.lock artifacts and dependency edges |
Varies | Varies |
| Static + dynamic evidence | Imports, dependency graph, coverage, API usage | Usually package-level alerts | Varies by vendor and integration |
| Open outputs | JSON, SARIF, OpenVEX, Markdown, HTML, remediation, action plan | Vendor-specific | Platform-specific |
| Confidence/evidence trail | Structured evidence per verdict | Limited | Varies |
| Runtime dependencies | packaging core dependency; optional CLI/MCP extras |
Varies | Hosted service |
Use ca9 when you want an open, local Python reachability layer for CVE triage, CI gates, SARIF upload, OpenVEX generation, or SBOM enrichment.
A focused library that genuinely uses most of its deps. Even here, ca9 found 7 CVEs in packages that are installed but never imported (redis, sentry-sdk, pip):
$ ca9 scan --repo /path/to/drf -v
GHSA-g92j-qhmh-64v2 sentry-sdk low UNREACHABLE (static)
-> 'sentry-sdk' is not imported and not a dependency of any imported package
GHSA-8fww-64cx-x8p5 redis high UNREACHABLE (static)
-> 'redis' is not imported and not a dependency of any imported package
...
Total: 37 | Reachable: 0 | Unreachable: 7 | Inconclusive: 30
A Flask app that imports 4 packages but has 19 pinned in requirements.txt (Django, tornado, Pygments added "just in case"):
$ ca9 scan --repo demo/ --coverage demo/coverage.json
Total: 61 | Reachable: 25 | Unreachable: 36 | Inconclusive: 0
59% of flagged CVEs are unreachable — only 25 of 61 require action
Django alone brought 21 CVEs that were pure noise.
The pattern: ca9's value scales with how bloated your dependency list is — which in enterprise codebases is typically very.
pip install ca9[cli]
ca9 scan --repo .This resolves exact dependency versions from the target repository and queries
OSV.dev. ca9 does not use the ambient Python environment unless
you explicitly pass --allow-env-fallback, which keeps CI scans tied to repository
evidence. No Snyk, no Dependabot, no config files.
ca9 inventory --repo . -f jsonWhen fyn.lock is present, ca9 reads it directly and includes package versions,
direct/transitive dependency edges, dependency groups, markers, artifact URLs, hashes,
upload times, and source evidence. If there is no fyn.lock, ca9 falls back to native
manifest readers for pyproject.toml, requirements*.txt, Pipfile, uv.lock, and
poetry.lock.
ca9 vet --repo .
ca9 vet --repo . --malware-query
ca9 vet --repo . --scan-artifacts
ca9 vet --repo . --internal-package 'acme-*' --private-index https://packages.acme.internal/simple
ca9 vet --repo . --deny-license AGPL-3.0 --deny-license GPL-3.0ca9 vet evaluates the normalized package inventory for local supply-chain risk signals:
untrusted package indexes, missing artifact hashes, missing artifact metadata, source-only
install risk, and mutable package sources. With --malware-query, ca9 also queries OSV
for known malicious-package advisories such as MAL-* records. Direct dependencies from
untrusted indexes and known malicious packages are blocking findings; weaker local signals
are warnings by default.
With --scan-artifacts, ca9 downloads only lockfile artifacts with hashes by default,
verifies the hash, safely unpacks wheels/sdists without executing code, and runs
GuardDog-style static heuristics for suspicious .pth startup execution, install-time
setup.py execution, startup customization hooks, credential/network exfiltration,
import-time risky behavior, silent process execution, and encoded payload execution.
python scripts/incident_replay.py --strict --format tableca9 keeps real incident fixtures for npm package compromise, PyPI import-time malware, and GitHub-token compromise scenarios. The current matrix is intentionally honest: unsupported npm and GitHub Actions attack surfaces are reported as gaps instead of passing demo cases.
For dependency-confusion controls, use --internal-package with one or more private
package name patterns and --private-index for the indexes those packages are allowed to
resolve from. For license policy, use --deny-license; ca9 reads wheel/sdist metadata and
blocks denied direct dependencies while warning or investigating weaker cases.
Use the local demo fixture when you need a report screenshot or a JSON artifact without depending on a live suspicious repository:
bash demo/supply_chain/run_demo.shThe fixture generates a fyn.lock with local, hash-pinned wheel artifacts and then runs
ca9 vet with artifact scanning, dependency-confusion policy, and denied-license policy.
The underlying gate exits 1 because the findings are intentionally blocking; the wrapper
still writes demo/supply_chain/ca9-vet.json for screenshots and CI artifact examples.
ca9 supply-chain report for .../demo/supply_chain/repo
Packages: 4 | Edges: 3 | Findings: 3 | Block: 3 | Warn: 0
Artifact scans: 3 | Skipped artifacts: 0
Findings:
[BLOCK] dependency_confusion critical acme-internal@1.0.0
Possible dependency confusion for acme-internal
[BLOCK] python-startup-pth-exec critical startup-hook@1.0.0
Python startup file executes suspicious code in startup-hook
[BLOCK] denied_license high license-risk@1.0.0
Denied license for license-risk
coverage run --source=.,$(python -c "import site; print(site.getsitepackages()[0])") -m pytest
coverage json -o coverage.json
ca9 scan --repo . --coverage coverage.jsonca9 check snyk.json --repo . --coverage coverage.json
ca9 check dependabot.json --repo .Format is auto-detected. Supports Snyk, Dependabot, Trivy, and pip-audit:
ca9 check snyk.json --repo .
ca9 check dependabot.json --repo .
ca9 check trivy.json --repo .
ca9 check pip-audit.json --repo .| Verdict | What it means | What to do |
|---|---|---|
REACHABLE |
Evidence shows the vulnerable package, component, or known API is reachable | Fix this |
UNREACHABLE (static) |
Package is never imported — not even transitively | Suppress with confidence |
UNREACHABLE (dynamic) |
Package is imported but vulnerable code was never executed | Likely safe — monitor |
INCONCLUSIVE |
Imported but no coverage data to prove execution | Add coverage or review manually |
Every verdict is backed by structured evidence. Use --show-confidence to see scores in table output, or inspect the evidence object in JSON/SARIF output.
| Signal | What it checks |
|---|---|
advisory |
Advisory source, ecosystem, aliases, CWE/CPE IDs, and cache freshness metadata when available. |
version_in_range |
Is the installed version within the affected range (PEP 440)? |
package_imported |
Is the package imported anywhere in the repo? |
submodule_imported |
Is the specific vulnerable submodule imported? |
coverage_seen |
Was the vulnerable code executed during tests? |
api_call_sites_covered |
Were specific vulnerable API call sites executed in tests? |
coverage_completeness_pct |
Overall test coverage percentage — weights dynamic absence signals |
affected_component_source |
How was the vulnerable component identified (commit analysis, curated mapping, regex, class scan)? |
Confidence scoring is verdict-directional — evidence that supports the verdict boosts the score, evidence that contradicts it lowers it. A high confidence UNREACHABLE is different from a high confidence REACHABLE.
| Bucket | Score | Meaning |
|---|---|---|
| High | 80-100 | Strong evidence supports the verdict |
| Medium | 60-79 | Moderate evidence, reasonable certainty |
| Low | 40-59 | Weak evidence, treat with caution |
| Weak | 0-39 | Very little evidence, manual review recommended |
ca9 scan [OPTIONS] Scan repository dependency versions via OSV.dev
ca9 check SCA_REPORT [OPTIONS] Analyze a Snyk/Dependabot/Trivy/pip-audit report
ca9 inventory [PATH] [OPTIONS] Show normalized package inventory
ca9 vet [PATH] [OPTIONS] Run package supply-chain risk checks
Common options:
-r, --repo PATH Path to the project repository [default: .]
-c, --coverage PATH Path to coverage.json for dynamic analysis
-f, --format [table|json|sarif|vex|remediation|action-plan|markdown|html]
Output format [default: table]
-o, --output PATH Write output to file instead of stdout
-v, --verbose Show reasoning trace for each verdict
--no-auto-coverage Disable automatic coverage discovery
--show-confidence Show confidence score in table output
--show-evidence-source Show evidence extraction source in table output
--proof-standard [strict|balanced]
Proof policy for suppressions
--capabilities Attach AI capability blast radius
--runtime-context PATH Deployment-aware severity adjustment
--trace-paths Trace exploit paths
--threat-intel Enrich with EPSS and CISA KEV data
--otel-traces PATH Production runtime evidence from OTLP JSON
--accepted-risks PATH Accepted-risk TOML/JSON file
--baseline PATH Previous ca9 JSON report for new-only gating
--new-only Only gate on new reachable/inconclusive findings
Scan-only options:
--offline Use only cached OSV data, no network requests
--refresh-cache Clear OSV cache before fetching
--allow-env-fallback Use installed package versions when repo versions cannot be resolved
--max-osv-workers N Max concurrent OSV detail fetches [default: 8]
Inventory-only options:
-f, --format [table|json] Output format [default: table]
Vet-only options:
--trusted-index URL Trusted Python package index; repeatable
--private-index URL Private index allowed for internal packages
--internal-package PATTERN Internal package glob, e.g. acme-*; repeatable
--malware-query Query OSV for known malicious packages
--scan-artifacts Hash-verify, unpack, and statically inspect artifacts
--allow-unhashed-downloads Allow artifact downloads without lockfile hashes
--max-artifact-mb N Max artifact download size [default: 100]
--deny-license ID Denied license identifier; repeatable
--require-known-license Warn when artifact metadata has no known license
--offline Use cached OSV data only for malware query
Exit codes:
0 Clean — no reachable CVEs
1 Reachable CVEs found — action needed
2 Inconclusive only — need more coverage data
Create a .ca9.toml in your project root to set defaults:
repo = "src"
coverage = "coverage.json"
format = "json"
verbose = true
accepted_risks = "accepted-risks.toml"
baseline = "ca9-baseline.json"
new_only = trueConfig is auto-discovered from the current directory upward. CLI flags override config values. Accepted-risk and baseline options keep ignored findings visible in report output while excluding them from exit-code decisions.
ca9 caches OSV vulnerability details (~/.cache/ca9/osv/, 24h TTL) and GitHub commit file lists (~/.cache/ca9/commits/, 7-day TTL) to reduce API calls.
ca9 scan --repo . --offline # use cached data only, no network
ca9 scan --repo . --refresh-cache # clear cache and re-fetchSet GITHUB_TOKEN to avoid GitHub API rate limits when ca9 fetches commit data for affected component analysis:
export GITHUB_TOKEN=ghp_...
ca9 check snyk.json --repo .ca9 does not require fyn. If a repository has fyn.lock, ca9 inventory parses it
natively and treats it as high-fidelity package evidence. This gives ca9 exact resolved
versions, direct/transitive edges, groups, markers, artifact hashes, artifact URLs, and
source registries without shelling out to fyn.
ca9 vet builds on that evidence for local supply-chain checks. For example, a direct
dependency resolved from a non-trusted index is treated as risky, and an internal package
matching --internal-package is blocked if it resolves outside the configured
--private-index values.
When --scan-artifacts is enabled, fyn's artifact URLs and hashes let ca9 verify and
inspect resolved wheels/sdists before applying malicious-package heuristics. This path
does not install packages or execute package code. The same artifact metadata powers
license checks through --deny-license and --require-known-license.
Future ca9 commands can use fyn as an optional provider for dependency-path and lock-diff context, but absence of fyn should not break scans or CI gates.
ca9 ships an MCP server so LLM-powered tools (Claude Code, Cursor, etc.) can run reachability analysis directly.
pip install ca9[mcp]Add to your MCP client config:
{
"mcpServers": {
"ca9": {
"command": "ca9-mcp"
}
}
}Available tools:
| Tool | What it does |
|---|---|
check_reachability |
Analyze an SCA report (Snyk, Dependabot, Trivy, pip-audit) |
scan_dependencies |
Scan repository dependency versions via OSV.dev |
check_coverage_quality |
Assess how reliable your coverage data is |
explain_verdict |
Deep-dive a specific CVE's verdict with full evidence |
generate_vex |
Generate OpenVEX exploitability statements |
generate_remediation_plan |
Generate prioritized remediation actions |
scan_capabilities |
Scan AI capabilities and emit an AI-BOM |
check_blast_radius |
Attach capability blast radius to reachable CVEs |
trace_exploit_path |
Trace paths to vulnerable API call sites |
lookup_threat_intel |
Look up EPSS and CISA KEV data |
enrich_sbom |
Enrich CycloneDX or SPDX SBOM JSON |
import json
from pathlib import Path
from ca9.parsers.snyk import SnykParser
from ca9.engine import analyze
data = json.loads(Path("snyk.json").read_text())
vulns = SnykParser().parse(data)
report = analyze(
vulnerabilities=vulns,
repo_path=Path("./my-project"),
coverage_path=Path("coverage.json"),
)
for result in report.results:
print(f"{result.vulnerability.id}: {result.verdict.value} (confidence: {result.confidence_score})")
print(f" reason: {result.reason}")
if result.evidence:
print(f" source: {result.evidence.affected_component_source}")ca9's core library depends on packaging for PEP 440/version normalization and uses the
Python standard library for TOML parsing on Python 3.11+. On Python 3.10, tomli is used
for lockfile parsing. The click package is optional — only needed if you use the CLI.
This means you can embed ca9 in CI pipelines, security toolchains, or other Python tools
without pulling in a large dependency tree.
- Static analysis traces
importstatements andimportlib.metadatadependency trees. Dynamic imports (importlib.import_module,__import__) are not detected. - Coverage quality directly impacts dynamic analysis. If your tests don't exercise a code path, ca9 can't detect it dynamically.
- Transitive dependency resolution requires packages to be installed. Without installed deps, ca9 falls back to direct-import-only checking.
fyn.locksupport currently powers inventory, the firstca9 vetlocal supply-chain checks, and optional artifact static analysis. Full attack detection still needs richer external intelligence for maintainer changes, release-age anomalies, typosquatting, provenance, and active malware analysis.- Python only (for now).
git clone https://github.com/duriantaco/ca9.git
cd ca9
python3 -m venv .venv && source .venv/bin/activate
pip install -e ".[dev]"
pytest tests/ -v