OPA MCP
NPM · @ORYGN/OPA-MCP · 2 COMPONENTS · SCANNED SEP 20
Author, validate, debug, and explain OPA Rego policies through any MCP-compatible client.
Available components
How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. How we score → Why this is hard to score →
Supply Chain Security98
- No malware found by supply-chain analysis.Pass
- No known CVEs affecting this package version or its production dependencies.Pass
- No install/post-install scripts declared.Pass
- 32 of 104 dependencies flagged as unhealthy. View diagnostics → Partial
Provenance & Transparency100
- Source repository is publicly reachable at the declared URL. View diagnostics → Pass
- Cryptographically verified build provenance (signed, bound to OrygnsCode/opa-mcp-server). View diagnostics → Pass
- Clear OSI-approved license (MIT).Pass
- Actively maintained (last published 12 days ago).Pass
- Publishes a security disclosure policy (SECURITY.md).Pass
Schema Quality & AI Usability79
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Pass
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 12867 tokens (~233/item across 55 items; 52 tools + 3 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management83
- Stability observed for 25 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety81
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- 2 of 8 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation; "rego_eval" implies "eval" and declares no destructiveHint at all, which the MCP spec reads as destructive by default. See how to fix → Partial
- An AI judge read all 54 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
How do I install the OPA MCP server?
OPA MCP runs locally as an npm package, launched with npx -y @orygn/opa-mcp. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
npm · @orygn/opa-mcp
claude mcp add orygnscode-opa-mcp -- npx -y @orygn/opa-mcp
{
"mcpServers": {
"orygnscode-opa-mcp": {
"command": "npx",
"args": [
"-y",
"@orygn/opa-mcp"
]
}
}
} {
"servers": {
"orygnscode-opa-mcp": {
"command": "npx",
"args": [
"-y",
"@orygn/opa-mcp"
]
}
}
} codex mcp add orygnscode-opa-mcp -- npx -y @orygn/opa-mcp
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"orygnscode-opa-mcp": {
"type": "local",
"command": [
"npx",
"-y",
"@orygn/opa-mcp"
],
"enabled": true
}
}
} openclaw mcp add orygnscode-opa-mcp --command npx --arg -y --arg @orygn/opa-mcp
mcp_servers:
orygnscode-opa-mcp:
command: "npx"
args: ["-y", "@orygn/opa-mcp"] {
"McpServers": {
"orygnscode-opa-mcp": {
"Transport": "stdio",
"Command": "npx",
"Arguments": [
"-y",
"@orygn/opa-mcp"
]
}
}
} assistant mcp add orygnscode-opa-mcp -t stdio -c npx -a -y @orygn/opa-mcp
{
"mcpServers": {
"orygnscode-opa-mcp": {
"command": "npx",
"args": [
"-y",
"@orygn/opa-mcp"
]
}
}
} Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 19 Sept 26 −2
- Stability: pass → 0.80 functional
- 18 Sept 26 0
- Stability: 0.97 → pass security
- 16 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.
- 14 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 83 to 87. That category is still filling its 30-day observation window: 25 days of observed history at the previous scan, 26 at this one. The score rises as the window fills, whether or not the server changes.
- 12 Sept 26 −2
- Stability: pass → 0.80 functional
- 11 Sept 26 0
- Stability: 0.97 → pass security
- 9 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.
- 7 Sept 26 +1
- Tool safety: pass → unverified ▼ security
- Stability: 0.83 → unverified ▼ security
- Schema quality: 100 → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- Capabilities: pass → unverified ▼ functional
- Package version: 0.5.0 → 0.6.0 functional
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 20 Sept 2026 · Analysed npm/@orygn/opa-mcp@0.6.0
Provenance Verified
A signed build attestation was found and verified, binding this exact artifact to the source repository it claims to come from.
| Result | Verified |
|---|---|
| Ecosystem | npm |
| Reason | Verified |
| Discovered via | Registry attestation endpoint |
| Source repo | OrygnsCode/opa-mcp-server |
| Certificate issuer | https://token.actions.githubusercontent.com |
| Certificate SAN | https://github.com/OrygnsCode/opa-mcp-server/.github/workflows/release.yml@refs/tags/v0.6.0 |
| Rekor log index | 2752516785 |
| Predicate type | https://slsa.dev/provenance/v1 |
| Subject digest | sha512:6c5fa829f49da8cfa651a12169780b286000436febdafa92794e2dcfb5a9c8116b9ff97cfa6ebc000fd508700c82e5e36f46118f698d9ba4ede861d3f |
Background: How many MCP packages publish verified provenance →
Dependencies 104 packages
| Packages resolved | 104 |
|---|---|
| Stale | 32 |
| Tree resolution | Complete |
Background: SBOMs and build attestations, explained →
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
rego_test_multiroot Run Rego tests across multiple roots ~561
Run `opa test` once per root and aggregate results. Solves the package-conflict problem that occurs when `opa test .` is run on a repo with multiple independent package namespaces (OPA issue #4724). Two modes: `explicit` (supply root list with optional per-root `include` paths for shared libraries) and `scan` (auto-discover leaf test roots using the leaf rule -- a directory is a root only if it directly contains `*_test.rego` files and none of its eligible subdirectories do, preventing OPA's automatic recursion from double-running tests). Use `sharedPaths` in scan mode to add shared library directories to every root's invocation without including them in discovery. Coverage and threshold work per-root; `overallCoveragePct` is the mean across roots that have coverage data.
| Name | Type | Req | Description |
|---|---|---|---|
| coverage | boolean | – | Include per-line coverage data per root. Switches output to coverage-report mode: test record counts are not available, but `coverage`, `coveragePct`, and `overallCoveragePct` fields are populated. |
| ignorePatterns | array | – | Additional directory name patterns to skip during scan (e.g., ["vendor", "*.generated"]). Supports `*` wildcards. Only used with `scanDir`. |
| maxDepth | integer | – | Maximum directory depth to scan. Default: 10. Only used with `scanDir`. |
| maxRoots | integer | – | Maximum number of test roots allowed. Returns INVALID_INPUT if scan finds more. Default: 50. Only used with `scanDir`. |
| roots | array | – | Explicit list of test root directories. Use when roots are known upfront or when scan mode cannot determine the correct roots. Mutually exclusive with `scanDir`. |
| runPattern | string | – | Run only tests whose names match this regular expression (passed as `--run` to each root). |
| scanDir | string | – | Top-level directory to scan for test roots. Uses the leaf rule: a directory is a root only if it directly contains `*_test.rego` files and none of its eligible subdirectories do. Mutually exclusive w… |
| sharedPaths | array | – | Paths added to every root's `opa test` invocation and excluded from auto-discovery. Use for shared library directories that all roots import from. |
| threshold | number | – | Minimum coverage percentage required per root (0-100). Roots below threshold have `thresholdMet: false` in their result. Implicitly enables coverage-report output mode. |
| varValues | boolean | – | Include local variable bindings in trace output (`--var-values`). Only useful with `verbose: true`. |
| verbose | boolean | – | Emit per-test pass/fail details for each root. |
No output schema declared.
No examples provided.
rego_verify Formally verify a Rego policy rule ~299
Formally verify a property about a Rego rule using SMT solving (Microsoft Z3). Unlike testing, this checks ALL possible inputs and either proves the property holds or returns a concrete counterexample input that falsifies it. Supports equality, comparison, startswith, endswith, contains, and simple regex.match patterns (prefix: ^lit.*, suffix: .*lit$, exact: ^lit$, contains: .*lit.*, wildcard: .*). Complex regex patterns (character classes, quantifiers, alternation) return INCONCLUSIVE. Also reports INCONCLUSIVE for negation-as-failure (not), comprehensions, partial set and object rules (deny contains msg), functions, else chains, and any operand it cannot encode. A body that reads an absent field is undefined rather than true, so always_true holds only if the rule is also true for an empty input: a rule requiring input.x will be answered with the counterexample {}.
| Name | Type | Req | Description |
|---|---|---|---|
| kind | string | yes | Property to prove: always_true - rule is true for every possible input (finds inputs that violate this) never_true - rule is never true for any input (finds inputs that trigger it) satisfiab… |
| rule | string | yes | Name of the rule to verify (e.g. "allow", "deny"). |
| source | string | yes | Rego source to verify. |
No output schema declared.
No examples provided.
What is the OPA MCP server?
OPA MCP is listed in the public MCP registry as io.github.OrygnsCode/opa-mcp. Author, validate, debug, and explain OPA Rego policies through any MCP-compatible client. This page covers its npm package (@orygn/opa-mcp).
Is the OPA MCP server safe to use?
OPA MCP scores 92 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 20 September 2026. It declares no install or post-install scripts. Its build provenance is signed and verified. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the OPA MCP server expose?
OPA MCP exposes 52 tools: rego_format, rego_check, rego_check_schema, rego_lint, rego_parse_ast, and 47 more. Their descriptions and schemas cost roughly 12,361 tokens of context every time the server is loaded.
Is the OPA MCP server still maintained?
OPA MCP is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.
What licence is the OPA MCP server under?
OPA MCP declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.