popcorn-temporal-anchorCAUTION
Signed temporal evidence for agents: trusted timestamp and proof-of-existence verification, authorization expiry, and an RFC 3161 / OpenTimestamps comparison. Free offline verifier; evidence, not authorization or proof of execution.
Overview
From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.
Looking for RFC 3161, FreeTSA, OpenTimestamps, a trusted timestamp, proof of existence, authorization expiry, a signed execution receipt, or independent verification? Start with Proving an action happened before an authorization expired.
Licensing: component boundaries and earlier grants · evaluation terms · receipt carry-and-use permission. The paid service is separate from code permissions.
Live pages: POPCORN homepage (source and SOS 1.2.0 notes) and Check the assumptions (source, build and verification checks). The assumptions page presents saved signed task checks in human language and machine-readable form. Its PROCEED and STOP results describe historical local policy, not current authorization or execution.
Run the verification checks yourself
Offline checker and instructions: 37 cases covering schedule boundaries, malformed input, exact bytes, and saved signed receipts. From this repository with Node.js 20+:
node examples/verification-checks/check.mjs
No wallet, payment, or network call. Expected results are separate from computation. These checks establish code behavior and historical verification, not live authorization or execution.
Here, try your free sample
Can I still cancel? Which side of the deadline am I on?
Inspect the page. Save and read sample.mjs, then run node sample.mjs with Node.js 20 or newer. No key, wallet, or payment for this offline sample.
Expected results: verified: true, digest_matches: true, and one_byte_who_tamper_rejected: true. This is a 305
74a6ad3478e8OBSERVED · 2026-10-08Connect
Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control. Replace the environment placeholders with a token scoped to the least it needs.
claude mcp add popcorn-mcp --env EVM_PRIVATE_KEY=${EVM_PRIVATE_KEY} -- npx -y @violetclaire/[email protected]Exposed tools (7)
7 read · 0 write · 0 destructive.
| Tool | Risk | Description |
|---|---|---|
popcorn_catalog | read | |
popcorn_hash | read | |
popcorn_sample | read | |
popcorn_time | read | |
popcorn_verify | read | |
popcorn_verify_v2 | read | |
popcorn_witness | read |
Trust audit
CAUTIONgrade B · trust 85/100 Install with care. The audit found things worth knowing before you trust its output.
| Layer | What it checks | Result |
|---|---|---|
| L0 | Provenance & inventory | PASS |
| L1 | Static analysis of the code | WARN |
| L2 | Instruction surface (what it tells the agent) | PASS |
| L3 | Class-specific surface | PASS |
| L4 | Behavioural (sandbox) | SKIPPED |
What the source does
- Filesystem
- none-observed
- Network
- declared (2 observation(s))
- Shell
- none-observed
- Dependencies
- not all pinned
- Secrets in source
- none-found
Findings (22)
http.createServer(async(req,res)=>{try{const r=await worker.fetch(new Request('http://127.0.0.1:8792'+req.url,{method:req.method}));res.writeHead(r.status,Object.fromEntries(r.headers));res.end(Bufferconst taskSamplePacket={"format":"TASK-SCHEDULE/1.0","origin":"https://767-2676.com","byte_length":305,"schedule_utf8":"need: Verify the public schedule packet at https://767-2676.com/schedule/exampleimport { verifyPopcornTemporalEvidence } from "../../verify/typescript/src/index.js";new URL("../../verify/test-vectors/popcorn-receipt-v1.json", import.meta.url),} from "../../../verify/typescript/src/index.js";
} from "../../../verify/typescript/src/index.js";
} from "../../../verify/typescript/src/v2.js";
The local preview is http://127.0.0.1:8792. The worksheet runs in the browser. Its optional save button downloads a local JSON file; it does not transmit notes. A refresh clears unsaved notes. Checks
export const evidence = freeze({"format":"POPCORN-ASSUMPTIONS/1.0","historical":true,"keyTrustDisclosure":"The archived public keys reproduce these saved signatures. Independent issuer trust, current</pre></div></div><h3 class="eyebrow">Received task / base64url</h3><pre id="received-base64">eyJzY2hlZHVsZV9pZCI6InBvcGNvcm4td2l0bmVzcy1ldmFsdWF0aW9uLTAwMiIsInRhc2siOiJ2ZXJpZnkgYSB0aW1lLWJvdW5kIGF2YW
"base64url": "eyJzY2hlZHVsZV9pZCI6InBvcGNvcm4td2l0bmVzcy1ldmFsdWF0aW9uLTAwMiIsInRhc2siOiJ2ZXJpZnkgYSB0aW1lLWJvdW5kIGF2YWlsYWJpbGl0eSBpbnF1aXJ5Iiwib3duZXIiOiJldmFsdWF0aW9uLWFnZW50IiwiZXh
"base64url": "eyJzY2hlZHVsZV9pZCI6InBvcGNvcm4td2l0bmVzcy1ldmFsdWF0aW9uLTAwMiIsInRhc2siOiJ2ZXJpZnkgYSB0aW1lLWJvdW5kIGF2YWlsYWJpbGl0eSBpbnF1aXJ5Iiwib3duZXIiOiJldmFsdWF0aW9uLWFnZW50IiwiZXh
const binary = atob(value.replace(/-/g, '+').replace(/_/g, '/'));
const decode = value => Uint8Array.from(atob(value.replace(/-/g, '+').replace(/_/g, '/')), char => char.charCodeAt(0));
const decode = value => Uint8Array.from(atob(value.replace(/-/g, '+').replace(/_/g, '/')), char => char.charCodeAt(0));
const binary = atob(value.replace(/-/g, '+').replace(/_/g, '/'));
const binary = atob(normalized.padEnd(Math.ceil(normalized.length / 4) * 4, "="));
cryptography
@types/node, tsx, typescript
Examples read secrets only from local environment variables. `.env` files and
examples/resource-simulation/grid.csv
worker/production/index.js
Gates applied: no_behavioural_pass.
74a6ad3478e8full audit observations/trust-audit/mcp-server/violetclaire__popcorn-temporal-anchor.json · Report an issue / request a re-scanAudit history
Every audit this server has had. A grade with a past is a grade somebody is still checking.
| Date | Source | Verdict | Grade | Score | Change |
|---|---|---|---|---|---|
| 2026-10-08 | 74a6ad3478e8 | CAUTION | B | 85 | first audit |
Questions
What is the popcorn-temporal-anchor MCP server?
Signed temporal evidence for agents: trusted timestamp and proof-of-existence verification, authorization expiry, and an RFC 3161 / OpenTimestamps comparison. Free offline verifier; evidence, not authorization or proof of execution.
What tools does popcorn-temporal-anchor expose?
7 in total: 7 read-only, 0 that write, and 0 that can delete or overwrite. Every one is listed on this page with its risk.
Is popcorn-temporal-anchor safe to connect to an agent?
With care. The audit graded it B (85/100) and found 22 things worth knowing before you trust this server, listed below with the exact line each was found on.
What credentials does popcorn-temporal-anchor need?
It reads EVM_PRIVATE_KEY from the environment. Give it a token scoped to the least it needs — an agent that can be talked into calling a tool can be talked into calling it with your credentials.
How does popcorn-temporal-anchor run?
It speaks stdio, so it runs as a local process your client starts. It is published on npm as @violetclaire/popcorn-mcp at 0.1.3.
How current is this page?
The grade is for one exact copy of the source (74a6ad3478e8), read on 2026-10-08. The repository is watched and re-audited when it changes.