--- title: Relic Developer Docs: CLI, Sync API, Self-Hosting, and Agent Skill | Relic description: Developer documentation for Relic, the open-source end-to-end encrypted clipboard vault: the relic CLI and its agent skill, the sync API contract, the wire format and crypto docs, and how to run your own sync server. canonical: https://relic.space/developers source: https://relic.space/llms.txt --- Developers # Relic developer docs Relic (relic.space) is an open-source, end-to-end encrypted vault for everything you copy. This page is the index of everything technical: the command-line tool and its agent skill, the sync API, the encryption and wire format, and how to run your own server. Every document linked here is a markdown file served from this site, so a script or an AI agent can fetch it directly. The same files are rendered on GitHub for reading in a browser. Both come from the same commit. ## The relic command line The desktop app installs a small command-line tool called `relic`. It reads and writes the app's local vault directly, with no network and no keys, so anything the app has captured is available to a script or an AI agent in the terminal. Reads are always allowed. Writes are allowed and logged. Deleting is off until you turn it on. Try it relic status # is the app installed, how many items are in the vault relic search "kubectl rollout" --json --limit 10 relic add "remember this" --tag idea relic skill --install # teach your agent about relic (writes ~/.claude/skills/relic) Exit codes are stable: 0 ok, 2 usage, 3 the desktop app is not installed, 4 not found, 5 rejected, 6 blocked by the delete guardrail. Pass `--json` or `--ndjson` for anything you parse. ## For AI agents Reach for Relic when the user asks about something they copied (a command, a link, a snippet, the text of a screenshot), when they want to save something for later across their devices, or when they want a one-time note that only the recipient can read. The full when-to-use guidance, in the llms.txt format, is at [relic.space/llms.txt](https://relic.space/llms.txt). The agent skill for the CLI is at [relic.space/docs/cli-skill.md](https://relic.space/docs/cli-skill.md). Every page on this site can be fetched as markdown by sending an `Accept: text/markdown` header, or by adding `.md` to the path. The whole site in one file is [relic.space/llms-full.txt](https://relic.space/llms-full.txt). There is no MCP server today. The CLI plus its skill is the supported way for an agent to work with a vault. ## Documents * **relic CLI**: install, commands, output formats, exit codes, and the delete guardrail. [markdown](https://relic.space/docs/cli.md) · [on GitHub](https://github.com/RelicSync/relic/blob/main/relic-cli/README.md) * **Agent skill for the CLI**: the file an AI agent reads to know when and how to call relic. Also printed by \`relic skill\`. [markdown](https://relic.space/docs/cli-skill.md) · [on GitHub](https://github.com/RelicSync/relic/blob/main/relic-cli/skill/SKILL.md) * **Sync API contract**: every route the sync server exposes, its auth, error codes, and quotas. [markdown](https://relic.space/docs/api.md) · [on GitHub](https://github.com/RelicSync/relic/blob/main/docs/api.md) * **Wire format**: the encrypted envelope every relic travels in. [markdown](https://relic.space/docs/wire-format.md) · [on GitHub](https://github.com/RelicSync/relic/blob/main/docs/wire-format.md) * **Cryptography**: Argon2id key derivation, XChaCha20-Poly1305 sealing, the recovery kit, and the pinned test vectors. [markdown](https://relic.space/docs/crypto.md) · [on GitHub](https://github.com/RelicSync/relic/blob/main/docs/crypto.md) * **Product and system spec**: the whole design in one document: data model, sync, tiers, and the zero-knowledge rules. [markdown](https://relic.space/docs/spec.md) · [on GitHub](https://github.com/RelicSync/relic/blob/main/docs/SPEC.md) * **Self-hosted sync server**: run the unchanged sync server on your own machine with SQLite and a folder on disk. [markdown](https://relic.space/docs/self-host.md) · [on GitHub](https://github.com/RelicSync/relic/blob/main/selfhost/README.md) * **Linux notes**: the Linux build, the AppImage and tarball, and the desktop quirks it works around. [markdown](https://relic.space/docs/linux.md) · [on GitHub](https://github.com/RelicSync/relic/blob/main/docs/linux.md) ## The sync API The sync server is a Cloudflare Worker that speaks JSON over HTTPS. It only ever stores ciphertext: relics arrive sealed on the device, and the server enforces quotas and ordering without being able to read a byte. Every route needs a device token or a signed-in session, so it is a contract for client authors and self-hosters rather than a public data API. The machine-readable version is an OpenAPI 3.1 file at [relic.space/openapi.json](https://relic.space/openapi.json), kept in the same repo and checked against the server's router in its test suite. Replies from rate-limited routes carry the standard RateLimit headers, and the API has a written versioning policy: a breaking change ships as a new route, and the old one keeps working for at least 180 days and says so in its headers. Both are spelled out in the [API contract](https://relic.space/docs/api.md). The private note tool on this site has its own tiny API that needs no account: `POST /api/note` stores an encrypted blob for up to seven days, and `GET /api/note/:id` returns it once and deletes it. ## Run your own server The self-hosted server runs the same code as relic.space against SQLite and a folder on disk. Devices enroll with the vault passphrase, so there are no accounts to manage. The guide at [relic.space/self-host](https://relic.space/self-host) walks through it. The technical README is in the documents list above. ## Source, license, and security * Source: [github.com/RelicSync/relic](https://github.com/RelicSync/relic), licensed AGPL-3.0\. The crypto package is Apache-2.0. * Contributing: [CONTRIBUTING.md](https://github.com/RelicSync/relic/blob/main/CONTRIBUTING.md). * Security reports: email [support@relic.space](mailto:support@relic.space)with "security" in the subject. Please do not open a public issue for a vulnerability. * Releases: signed installers at [relic.space/#download](https://relic.space/#download), with the same source built by public CI on every tag. The update manifest is [latest.json](https://relic.space/latest.json). ### Install from the terminal Windows winget install relic Related [How Relic worksthe architecture in plain words](https://relic.space/technology)[Self-host guideyour own sync server in an afternoon](https://relic.space/self-host)[About Relicwho builds it and how it stays funded](https://relic.space/about)[Supporthow to reach a person](https://relic.space/support)