# Etchd > Etchd is a timestamp calendar in the OpenTimestamps style that anchors to Ethereum Classic. You send a hash, the calendar folds it into a Merkle tree with the other hashes of the same UTC minute, and one ETC transaction puts the root on chain. The proof is a standard .ots file that any ETC node can check without Etchd. Each tick also commits to the newest blocks of about 35 other chains and to hashes of witness captures such as news front pages. Every docs page has a markdown copy at its address plus .md, listed below, and https://etchd.app/llms-full.txt holds all of them in one file. The explorer and the JSON API share https://etchd.app. The calendar URI inside proofs is https://a.etc.calendar.etchd.app, which serves the OpenTimestamps calls only. The API needs no key. Byte layouts, attestation tags and test vectors are in SPEC.md. ## Docs - [About Etchd](https://etchd.app/about.md): What Etchd is, where the code and the specification live, and the anchor contract on ETC mainnet. - [Why Etchd](https://etchd.app/docs/why.md): What timestamp proofs are for, the public record kept each minute, OpenTimestamps and the case for Ethereum Classic. - [Architecture](https://etchd.app/docs/architecture.md): The Workers, Durable Objects, storage and Workflows behind the calendar, and what keeps going without Cloudflare. - [Stamping](https://etchd.app/docs/stamping.md): How a hash leaves your machine, joins a one-second round and comes back as a pending proof. - [Worked Example](https://etchd.app/docs/example.md): One real stamp of hello.txt, byte by byte, from the digest to an ETC transaction and back through verify. - [Ticks](https://etchd.app/docs/ticks.md): The tick root sealed each UTC minute, what goes into it and the beacon chains it records. - [The ETC Anchor](https://etchd.app/docs/anchor.md): Three Merkle trees, one ETC transaction a minute and the open contract it calls. - [Verifying](https://etchd.app/docs/verifying.md): When the calendar serves a proof, what the verifier checks, including the sender and the confirmation count, and what a reorg does to it. - [The Bitcoin Bridge](https://etchd.app/docs/bitcoin.md): Bitcoin heads go into every tick, and every hour the ticks go into Bitcoin. - [What a Proof Proves](https://etchd.app/docs/proofs.md): What a proof shows and leaves open, how precise its time is, and the quantum argument for proof of work. - [What We Publish](https://etchd.app/docs/what-we-publish.md): The calendar records, every witness capture with its normalized form, the raw bytes we keep, and what we never publish. - [Signers](https://etchd.app/docs/signers.md): Which key signed which anchors, the window each key is accepted in, and how we rotate to a new one. - [Daily Bundles](https://etchd.app/docs/data.md): One CAR file per UTC day, the export index, and single blocks by CID from our own gateway. - [Mirrors](https://etchd.app/docs/mirrors.md): Keeping a checked copy of the daily bundles with etchd mirror, on disk, a Kubo node or a pinning service. - [The Etchd CLI](https://etchd.app/docs/cli.md): Stamp, upgrade and verify from a terminal or a script, with JSON output and fixed exit codes. - [Self Hosting](https://etchd.app/docs/self-hosting.md): Running a calendar of your own on your own Cloudflare account, with your domain, your anchor key and your gas. - [Trust Model](https://etchd.app/docs/trust.md): Which claims rest on a chain and which on Etchd, the anchor key, and running on one vendor. - [Credits](https://etchd.app/docs/credits.md): Fonts, icons and logos, where they come from and their licences. ## API - [GET /v1/status](https://etchd.app/v1/status): Health of the calendar, its configuration, the anchor state, the signer epoch and the ETC RPCs the anchor reads with their quorum. - [GET /v1/ticks](https://etchd.app/v1/ticks): Ticks newest first, with ?before= and ?limit= up to 100. /v1/ticks/ is one tick with its roots, anchor tx and beacon heads. - [GET /v1/chains](https://etchd.app/v1/chains): The beacon chains each tick records, with the newest head of each. /v1/chains//history lists recent heads. - [GET /v1/sources](https://etchd.app/v1/sources): The witness sources, their schedules and whether new captures keep the raw body. - [GET /v1/captures](https://etchd.app/v1/captures): Witness captures since ?since= (Unix seconds, 6 h back at most). /v1/captures/ is one capture, with /raw and /normalized for its bytes. - [GET /v1/exports](https://etchd.app/v1/exports): The export index of daily CAR files, with CID, sha256, size and the Filebase IPFS copy. - [POST /digest](https://etchd.app/digest): The OpenTimestamps submit call. The body is a raw digest of 1 to 64 bytes and the answer is a pending .ots timestamp. - [GET /timestamp/](https://etchd.app/timestamp/): The OpenTimestamps upgrade call. 200 with the ETC attestation once the anchor tx is mined, 404 with x-etchd-state before that. - [POST /v1/digests](https://etchd.app/v1/digests): JSON stamping for scripts, a list of hex digests and an optional hashOp of sha256 or keccak256. - [GET /v1/proofs/](https://etchd.app/v1/proofs/): The state of one proof as JSON, its tick, confirmations and Bitcoin branch. ## Data - [Daily CAR exports](https://etchd.app/v1/exports): One CAR file per UTC day at /v1/exports/.car and .car.gz, holding every tick body, anchor record and capture of that day. - [Trustless IPFS gateway](https://etchd.app/docs/data.md): Single blocks by CID at /ipfs/?format=raw or ?format=car. The daily CARs are also pinned on IPFS through Filebase. - [Mirrors](https://etchd.app/docs/mirrors.md): Keeping a checked copy of the daily bundles with etchd mirror. ## Code - [GitHub repository](https://github.com/classix-dev/etchd): The Workers, the explorer, the CLI and the contract, MIT licensed. - [SPEC.md](https://raw.githubusercontent.com/classix-dev/etchd/main/SPEC.md): The proof format, commitments, tick body, beacon, witness and export layouts. - [README](https://raw.githubusercontent.com/classix-dev/etchd/main/README.md): Install, use and self hosting in short. ## Optional - [llms-full.txt](https://etchd.app/llms-full.txt): All docs pages as markdown in one file. - [Design notes](https://raw.githubusercontent.com/classix-dev/etchd/main/docs/design.md): The reasoning behind the calendar. - [Sitemap](https://etchd.app/sitemap.xml): Every static page of the explorer.