newsroom-mcp

Type-safe MCP server for investigative journalism. The sole, validating writer to an investigation's master-file.json — enforcing the evidentiary standards that prompt-based editing cannot guarantee.

Companion to newsroom-extension, the Claude Code / Gemini plugin that defines the investigation framework. The plugin teaches an LLM how to investigate; this server ensures the resulting evidence record is structurally correct.

Why

An LLM editing master-file.json directly will eventually:

• Mark a claim publishable without A1/A2 evidence
• Assign a non-existent DOC- id to a claim
• Overwrite a collection_log entry instead of appending
• Skip the Admiralty grade on a new evidence item

Any of these corrupts the chain of custody that protects the outlet in a libel proceeding. This server makes them impossible.

Enforced invariants

Rule	Enforcement
Admiralty grade required at intake	add_evidence rejects missing reliability/credibility or custody block
Publishable gate	publishable: true blocked unless corroborated (two independent sources) OR single-source with ≥1 A1/A2 item
Defamation gate	defamation_risk: "high" claim cannot be published without comment_requested: true
Referential integrity	Every entity_id and evidence_id reference must exist before write commits
Append-only log	collection_log entries are never edited or deleted; server owns the monotonic seq
Atomic writes	Serialize → temp file → rename() — a crash mid-write never leaves a partial file
Concurrent safety	In-process write queue serializes simultaneous tool calls

Installation

Requires Node 18+. No global install needed — use npx.

npx @ehurrn/newsroom-mcp

Setup

Each investigation is a directory with its own master-file.json. Point the server at it via NEWSROOM_WORKSPACE.

mkdir -p ~/investigations/city-hall-contracts
cd ~/investigations/city-hall-contracts
git init

# Install the evidence gate pre-commit hook
NEWSROOM_WORKSPACE=. npx @ehurrn/newsroom-mcp init-hook

Connecting to your AI client

Claude Code

Add to ~/.claude/settings.json (global) or .claude/settings.json (project):

{
  "mcpServers": {
    "newsroom-mcp": {
      "command": "npx",
      "args": ["@ehurrn/newsroom-mcp"],
      "env": {
        "NEWSROOM_WORKSPACE": "/absolute/path/to/investigation"
      }
    }
  }
}

Cursor (.cursor/mcp.json)

{
  "mcpServers": {
    "newsroom-mcp": {
      "command": "npx",
      "args": ["@ehurrn/newsroom-mcp"],
      "env": {
        "NEWSROOM_WORKSPACE": "/absolute/path/to/investigation"
      }
    }
  }
}

Antigravity / agy

{
  "mcpServers": {
    "newsroom-mcp": {
      "command": "npx",
      "args": ["@ehurrn/newsroom-mcp"],
      "env": {
        "NEWSROOM_WORKSPACE": "/absolute/path/to/investigation"
      }
    }
  }
}

Switch investigations by changing NEWSROOM_WORKSPACE and relaunching the server.

Tools

init_master_file

Initialize a new investigation. Fails if master-file.json already exists. Seeds collection_log entry #1.

{
  "id": "INV-2026-001",
  "title": "City Hall Contracts",
  "central_question": "Did Acme Corp receive preferential treatment?",
  "opened": "2026-06-21",
  "evidence_dir": "evidence/"
}

read_master_file

Return the full current state. No arguments.

upsert_entity

Create or update an entity. Omit id to create (server assigns the next ENT-NNN).

{
  "name": "Acme Corp",
  "type": "company",
  "roles": ["subject"],
  "jurisdictions": ["Delaware", "New York"],
  "identifiers": { "ein": "12-3456789" }
}

add_evidence

Add an evidence item. Admiralty grading and a full custody block are required. Returns the assigned DOC-NNN.

{
  "title": "Acme Corp 10-K (FY2025)",
  "source_type": "regulatory-filing",
  "reliability": "A",
  "credibility": "1",
  "custody": {
    "obtained_from": "https://sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=...",
    "obtained_date": "2026-06-21",
    "method": "public-registry",
    "hash": "sha256:abc123...",
    "local_path": "evidence/acme-10k-fy2025.pdf",
    "preservation_status": "preserved"
  },
  "summary": "Annual report disclosing related-party transactions with City vendor."
}

Admiralty scale:

Reliability	Meaning
A	Completely reliable (certified official record)
B	Usually reliable
C	Fairly reliable
D	Not usually reliable
E	Unreliable
F	Cannot be judged

Credibility	Meaning
1	Confirmed by independent sources
2	Probably true
3	Possibly true
4	Doubtful
5	Improbable
6	Cannot be judged

update_claim_status

Create or update a claim. The publishable gate is enforced at write time — the server computes whether the linked evidence actually supports the flag, rather than trusting the caller.

{
  "text": "Acme Corp received Contract C-2025-44 ($4.2M) without competitive bid, per City procurement records (DOC-001).",
  "entity_ids": ["ENT-001"],
  "evidence_ids": ["DOC-001"],
  "status": "single-source",
  "publishable": true,
  "defamation_risk": "medium"
}

append_collection_log

Manually append an audit entry. The log is append-only — entries cannot be edited or deleted.

{
  "actor": "reporter-jeh",
  "action": "comment-requested",
  "refs": ["ENT-001"],
  "notes": "Emailed Acme Corp comms director at press@acmecorp.com at 14:32 EST."
}

Pre-commit hook

The hook scans working/ and drafts/ in the investigation workspace for cited CLM-NNN IDs and blocks commits where a cited publishable claim lacks qualifying evidence.

# Install into the current investigation workspace
npx @ehurrn/newsroom-mcp init-hook

# Run manually at any time
npx @ehurrn/newsroom-mcp validate

Example gate failure:

✗ Evidence gate failed — commit blocked:

  CLM-003: publishable claim has no A1/A2 evidence and status is not 'corroborated'

Fix: update master-file.json via newsroom-mcp tools, or set publishable:false
until evidence meets the A1/A2 or corroborated standard.

Schema

master-file.json conforms to the schema defined in newsroom-extension. The vendored copy lives in schema/master-file.schema.json. To pull the latest:

node scripts/sync-schema.mjs /path/to/newsroom-extension
npm run codegen

Development

npm install          # installs deps and runs codegen
npm run typecheck    # tsc --noEmit
npm test             # vitest run
npm run build        # tsup → dist/

License

Unlicense