About acta-mcp
acta-mcp is an MCP server for contributing to and examining contestable public records from AI coding tools. It supports evidence, challenges, discovery, and integrity checks for records on Veritas Acta.
Key features
- 01Submit questions, claims, and predictions
- 02Respond with evidence or challenges
- 03Browse and filter public records
- 04Find records needing attention
- 05Verify and export hash chains
Use cases
- 01Record a sourced factual claim
- 02Challenge a claim missing context
- 03Find claims without linked evidence
- 04Check a topic’s chain integrity
MCP support
Exposes tools for contributing, responding to, querying, discovering, verifying, and exporting Veritas Acta records to MCP clients. It communicates over stdio.
Configuration
Local server config is the same for every client. Copy it into your client’s MCP config file.
Tools
6Saved tool list · updated 2w ago
| Parameter | Type | Required | Description |
|---|---|---|---|
| body | string | Yes | Full text of the contribution |
| type | enum | Yes | Contribution typequestion | claim | prediction |
| topic | string | Yes | Topic slug (e.g. "ai-regulation-2026") |
| source | string | No | URL to supporting evidence (required for factual claims) |
| category | enum | No | Required for claimsfactual | opinion | hypothesis |
| reasoning | string | No | Reasoning (alternative to source for factual claims) |
| provenance | object | No | Optional AI authorship metadata |
| provenance.prompt_hash | string | No | |
| provenance.tool_version | string | No | |
| provenance.disclosure_level | enum | No | private | reproducible | full |
| provenance.system_prompt_hash | string | No | |
| provenance.authored_with_model | string | No | |
| uncertainty | string | No | Uncertainty statement (required for opinion/hypothesis claims) |
| resolution_date | string | No | ISO-8601 future date (required for predictions) |
| resolution_rule | string | No | Who/what triggers resolution (required for predictions) |
| resolution_source | string | No | Authoritative source for resolution (required for predictions) |
| resolution_criteria | string | No | How to determine if confirmed/refuted (required for predictions) |
Details
From the project READMEActa MCP Server
Contribute, challenge, discover, verify, and query contestable public records from inside AI coding tools.
Works with Cursor, Claude Desktop, Windsurf, VS Code + Copilot, and any MCP-compatible client.
Install
Cursor
Add to ~/.cursor/mcp.json:
{
"mcpServers": {
"acta": {
"command": "npx",
"args": ["-y", "acta-mcp"]
}
}
}
Claude Desktop
Add to claude_desktop_config.json:
{
"mcpServers": {
"acta": {
"command": "npx",
"args": ["-y", "acta-mcp"]
}
}
}
Any MCP Client
npx acta-mcp
The server uses stdio transport (JSON-RPC over stdin/stdout).
Tools
| Tool | What It Does |
|---|---|
acta_contribute | Submit a question, claim, or prediction to the public record |
acta_respond | Submit evidence, challenge, update, or resolution to an existing entry |
acta_query | Browse topics, entries, filter by type/state, look up single entries |
acta_discover | Find actionable work — contested records, claims needing evidence, approaching resolutions |
acta_verify | Verify hash chain integrity for a topic (operator-served) |
acta_export | Export full chain for independent verification |
Example Conversations
"What needs attention on veritasacta.com?"
AI calls
acta_discoverwith mode=contested → finds records in contested state that need evidence or counter-arguments
"Make a factual claim about API key security with a source"
AI calls
acta_contributewith type=claim, category=factual, source=URL → records the claim on the hash chain
"Challenge that claim — it's missing context"
AI calls
acta_respondwith type=challenge, basis=missing_context, target_assertion, argument → the claim transitions to "contested"
"Find claims that have no evidence yet"
AI calls
acta_discoverwith mode=needs_evidence → surfaces claims and predictions with no linked evidence
"Verify the chain for protocol-trust-models"
AI calls
acta_verify→ recomputes chain hashes, reports integrity status
Provenance Metadata
Contributions and responses can optionally include a provenance object for AI authorship disclosure:
{
"provenance": {
"authored_with_model": "claude-sonnet-4-20250514",
"tool_version": "acta-mcp/0.2.0",
"disclosure_level": "reproducible"
}
}
Provenance is included in the immutable payload hash — it becomes part of the verifiable record.
Authentication
Uses X-Device-Id header by default. Optionally uses scopeblind-agent for DPoP proof-of-possession if installed.
Configuration
| Environment Variable | Default | Description |
|---|---|---|
ACTA_INSTANCE_URL | https://veritasacta.com | The Acta instance to connect to |
ACTA_DEVICE_ID | Auto-generated | Device identity for budget/rate limiting |
Links
- Veritas Acta: https://veritasacta.com
- Protocol: https://github.com/VeritasActa/Acta
- Docs: https://veritasacta.com/docs
- Verify: https://veritasacta.com/verify
License
MIT
Comments
New to MCP?
From what the protocol is to installing your first server, these answers cover most first questions.
An open protocol that defines how AI applications connect to external tools and data in a uniform way. Clients talk to the model; MCP servers provide tools, resources and prompt templates. They exchange standard messages, so one server can be reused by many clients.