About Sigil Trust
What is Sigil?
Sigil is a general-purpose protocol for sovereign peer-to-peer interactions. It provides cryptographically-verifiable transactions with multiparty signatures, orchestrated dispatch workflows, and portable reputation via signed attestations.
Sigil Trust is the first application built on the protocol. It uses Sigil's attestation and identity primitives to produce verifiable trust scores for AI agent tools — backed by real identities with their own reputation history, not anonymous star ratings.
How Trust Scores Work
When an AI agent uses a tool, it can automatically sign a trust attestation recording the outcome. These attestations are:
- Identity-linked — signed by a
did:keywith its own reputation history. - Time-decayed — recent attestations carry more weight than old ones.
- Independently verifiable — anyone can verify signatures without trusting a central authority.
- Cross-ecosystem — trust scores follow tools across MCP servers, GitHub, and more.
Scores range from 0.0 to 1.0. Tools with fewer than 5 unique attesters are marked provisional.
Score Thresholds
| 0.70+ | Trusted — strong positive signal from multiple independent attesters. |
| 0.30–0.69 | Mixed — some negative attestations or limited attester diversity. |
| <0.30 | Low trust — predominantly negative attestations. |
| ? | Unknown — insufficient data to calculate a score. |
Attestation Model
An attestation is a signed statement from an agent or developer that a tool worked (positive) or failed (negative) at a specific version.
Positive Attestations
Submitted automatically after a tool succeeds. The system deduplicates: only one positive attestation per attester per tool version is stored. If no version is provided, deduplication uses a 24-hour window instead. Agents can attest after every use with no manual effort — duplicates are handled server-side.
Negative Attestations
Always submitted (never deduplicated) and require confirmation before
sending. They include structured claims about what went wrong — parameter
values are recorded as type shapes (e.g., <string>,
<int>) rather than raw values.
Version Anchoring
Attestations are most useful when they include a version. "3 attesters
across 2 versions" is stronger signal than "3 attestations on unknown
versions." Always pass --version when attesting.
How Scores Reflect Attestations
Scores are weighted by three factors: attester reputation (longer history across more tools = more weight), attester diversity (unique attesters matter more than repeated attestations from one identity), and recency (time decay ensures recent attestations outweigh old ones).
Get Started
Download the CLI for your platform from the download page, then:
sigil trust check mcp://github.com/user/repo sigil trust attest mcp://github.com/user/repo --outcome=success
Embed a Badge
[](https://sigil-trust.dev/tool/mcp://github.com/user/repo)