GLP Audit Proxy

mcp-name: io.github.antonio-castellon/mcp-glp-audit-proxy

mcp-glp-audit-proxy

Local MCP proxy that sits between an MCP host and your MCP servers and writes a tamper-evident audit trail. Community edition, v0.1.0.

It is designed to support GLP, ALCOA+, 21 CFR Part 11 and EU GMP Annex 11 traceability. Data stays on the customer's infrastructure. This package is the open core. Signed checkpoints, WORM storage, Part 11 electronic signatures, PDF/CSV reports, the IQ/OQ pack and SSO/OAuth are Pro features and are not in this repository.

host (Claude, Cursor, Grok, self-hosted LLM)
        |  stdio JSON-RPC
        v
mcp-glp-audit-proxy
  policy (allow / deny, reason, human approval)
  audit  (append-only JSONL, RFC 8785, SHA-256 chain)
        |  stdio or HTTPS (TLS 1.3)
        v
upstream MCP servers (Excel, ELN, LIMS, databases, instruments)

Install

Requires Python 3.11 or newer.

pip install mcp-glp-audit-proxy

From a checkout:

pip install -e ".[dev]"

The mcp dependency is pinned to >=2.2.0,<3. That floor is outside GHSA-84m7-p3x7-pcfv (affected ranges are mcp >=1.8.0,<1.30.0 and >=2.0.0,<2.2.0). The process refuses to start on an older SDK.

Run

export GLP_PRINCIPAL_ID=operator-1
export GLP_PRINCIPAL_NAME="Ada Analyst"
export GLP_PRINCIPAL_ROLE=operator
mcp-glp-audit-proxy --config config.json

Stdio identity comes from the environment. There is no HTTP listener in 0.1.0. A Cursor snippet is in mcp.json. A full config is in config.example.json.

Verify a chain and write a searchable JSON export (the export is skipped when the chain does not verify):

mcp-glp-audit-proxy-verify data/audit.jsonl --json-export exports/audit.json
mcp-glp-audit-proxy-verify data/audit.jsonl --tool excel__write_cell --status ok
mcp-glp-audit-proxy-verify data/audit.jsonl --print-head

--print-head prints seq and entry_hash. Copy that line into a ticket, an email or a LIMS record. The sidecar data/audit.jsonl.head makes a cut of whole trailing lines fail verification. Someone who can edit both the log and the sidecar can move them together; the external copy is the control. Signed checkpoints and WORM storage are Pro.

What is recorded

Every mediated call, including denials and failures, is one JSON object on an append-only JSONL file. Each line is RFC 8785 canonical JSON. entry_hash is the SHA-256 of that object with entry_hash removed. prev_hash is the previous entry (64 zero digits for the first). hash_algo and canonicalization are stored on the entry. The open schema is schema/audit-record.schema.json. Cross-language vectors are in schema/jcs-test-vectors.json.

Fields include who (principal id, name, role), which tool, inputs, outputs, UTC timestamp plus utc_offset, protocol version, optional session id, record class (gxp_data, access, technical, config), reason for writes, and the previous hash.

The GxP trail is that file. The Python logging logger mcp_glp_audit_proxy.technical writes method, status and record class to stderr. It is not the record. Arguments are not written there.

Policy

• Allow list and deny list use shell-style globs on the exposed tool name (excel__write_cell). Deny wins. An empty allow list denies every upstream tool.
• Roles are operator, approver, qa and admin. Only operator may call upstream tools. qa is read-only on the trail (glp_verify_chain, glp_search_audit, glp_export_audit). approver may record an approval and read the trail. admin may change policy and read the trail, and cannot call upstream tools.
• Auditing cannot be switched off. glp_update_policy with audit_enabled: false is denied and logged.
• Write tools (names matching write_tools) require a reason by default. The reason is _meta["io.github.antonio-castellon/reason"] or the argument _glp_reason (stripped before the upstream call).
• Optional human approval holds the write until a different person in the approver role records meaning approved. reviewed is stored and does not authorise the write. rejected rejects it. An approval is single-use, bound to the SHA-256 of the canonical {tool, arguments}, and expires (default 3600 seconds). The record label is approval. It is not an electronic signature.
• Fail closed is the default. The store is checked before a call is forwarded. If the append after a successful upstream call fails, the upstream payload is not returned to the host. Denied and failed calls are still logged. If the upstream may already have applied a write, follow docs/RECONCILIATION_SOP.md.

Protocol

The proxy speaks both handshake-era MCP revisions (2024-11-05, 2025-03-26, 2025-06-18, 2025-11-25, with initialize) and spec 2026-07-28 (server/discover, no initialize, no session). A session id is recorded only when that revision has one. Upstream protocol auto tries server/discover and falls back to initialize at 2025-11-25.

Exposed tool names are server__tool. Resource URIs are prefixed server:. Credential-bearing _meta keys are stripped, their names are logged, and their values are neither stored nor forwarded. Upstream stdio receives a safe environment allow-list from the MCP SDK, plus the env block in the config.

Regulatory coverage

mcp-glp-audit-proxy is designed to support the audit-trail requirements below. Meeting them still depends on your validated use, SOPs and reviews. The clause-by-clause matrix is docs/COVERAGE.md. The norms and the verification log are docs/STANDARDS.md.

Framework	What the proxy helps with	Edition
OECD GLP No. 17 (3.4) / Swiss GLPV Annex 2	Always-on, append-only audit trail; who/what/when/why; admin-only settings; QA read-only role; 10-year Swiss retention profile	Community core; WORM retention and PDF reports in Pro
FDA 21 CFR Part 11	Computer-generated, time-stamped, hash-chained audit trail (11.10(e)); tamper detection; complete copies; authority checks. Part 11 approval e-signatures (11.50, 11.70, 11.200) are Pro only: the Community approval is not an electronic signature	Community core; e-signatures (Pro only), reports, signing, SSO in Pro
EU GMP Annex 11 (2011; 2025 draft)	Audit trail of changes with reason; role, time zone; locked audit trail; searchable complete export; access log	Community core; review tooling and inactivity logout in Pro
MHRA / PIC/S PI 041-1 / WHO TRS 1033	ALCOA+ data integrity, segregation of duties, metadata with each record, true-copy exports	Community core; signed manifests and validation pack in Pro
ISPE GAMP 5 / FDA CSA	Supplier documentation, proposed Cat. 4 configured components, machine-readable test evidence	Pro (validation pack)
EU AI Act Art. 12, 19, 26(6)	Automatic event logging, minimum 6-month retention	Community
Crypto and time (RFC 8785, SHA-256, Ed25519/ECDSA, RFC 3161, eIDAS/ZertES, TLS 1.3)	Canonical hashing and encrypted transport	Hash chain and TLS in Community; signing and timestamps in Pro
MCP authorization, OWASP LLM/Agentic	No token passthrough, tool allowlist/denylist, approval before write tools, OAuth 2.1	Allowlist and no-passthrough in Community; OAuth/SSO in Pro
ISO/IEC 42001, NIST AI RMF	Event-log evidence for AI governance and monitoring	Community (supporting evidence only)

Default retention is the Swiss GLP profile: 10 years after study completion, with a floor of 6 months. The minimum profile may use a shorter year count but cannot go under 6 months. A legal-hold flag refuses disposal. The JSONL backend has no delete. Retention-period WORM enforcement is a Pro backend.

Community and Pro

This repository is the Community edition. Pro is available as a licensed / paid service - contact antonio@castellon.ch.

Pro adds SQL and S3 WORM backends, Ed25519 and ECDSA signing, RFC 3161 timestamps, Part 11 e-signatures, PDF and CSV auditor reports, an IQ/OQ validation pack, and SSO. It also includes the GLP Lab Data Pack for mcp-advanced-excel, unlocked by the same offline licence key. The free mcp-advanced-excel server reads and writes lab spreadsheets. The Data Pack adds what a GLP lab needs on top: provenance hashes that tie every result back to its source file, instrument templates for common lab exports, advanced LOD/LOQ calculations and molar unit conversions, batch processing of many files in one run, and Ed25519 signed output.

Capability	Community (this repo)	Pro (licensed service)
Proxy core, both protocol eras	yes	plugs in, does not fork
Append-only JSONL hash chain	yes
PostgreSQL / MSSQL append-only		yes
S3 Object Lock		yes
Verify CLI and searchable JSON export	yes
Plain-text verify listing	yes
PDF / CSV auditor reports		yes
Audit-trail review tooling (flags, reviewer sign-off)	search, filter, export	yes
DE / FR / EN report templates		later
Old/new value capture for write tools	planned	change highlighting in reports
Tool allowlist / denylist	yes
Local roles (operator, approver, qa, admin)	yes
Human approval before writes	yes (label: approval)
Part 11 electronic signatures		yes
Ed25519 / ECDSA signed checkpoints	unsigned checkpoints only	yes
RFC 3161 timestamps		yes
IQ/OQ validation pack		yes
SSO / OAuth		yes
Syslog (RFC 5424) / SIEM export		yes
Key management (KMS/HSM), field-level encryption and redaction		yes
FIPS 140-3 mode		on request
Merkle log with inclusion / consistency proofs		later
OpenTelemetry spans (technical telemetry, not the audit record)	planned
GLP Lab Data Pack for mcp-advanced-excel (provenance hashes, instrument templates, advanced LOD/LOQ and molar units, batch processing, Ed25519 signed output)		yes
TLS 1.3 to remote upstreams, no token passthrough	yes
Offline licence file, no phone-home	yes	reads the same file

Plugin entry points, the AuditStore / Signer / Reporter contracts, and the licence file are described in docs/PLUGINS.md.

Local tools

Tool	Who	What
glp_verify_chain	qa, approver, admin	Check chain integrity. Still returns the report if the chain is broken.
glp_search_audit	qa, approver, admin	Filter entries. The audit of the search stores the filter and the count, not a second copy of every row.
glp_export_audit	qa, approver, admin	JSON electronic export with a hash manifest. A filtered export is marked complete: false. A broken chain is not exported.
glp_approve	approver	Record meaning approved, reviewed or rejected.
glp_update_policy	admin	Append a config event. Policy is replayed from the log.

Safety

Read SAFETY.md. Short version: fail closed, no token passthrough, secrets are stripped from _meta, stdio children do not inherit the parent environment, an approval is not an electronic signature, and the JSONL file is tamper-evident, not a WORM store.

Development

pip install -e ".[dev]"
python -m pytest -q

CI runs the same suite on Python 3.11, 3.12 and 3.13 (.github/workflows/ci.yml).

MCP registry

server.json names this server io.github.antonio-castellon/mcp-glp-audit-proxy for the official MCP Registry. The marker on the first line of this file is the registry check.

Licence

MIT. Copyright (c) 2026 Antonio Castellon / Castellon.CH. See LICENSE.