{"id":37107467,"url":"https://github.com/dotpostcard/postcards-go","last_synced_at":"2026-01-14T12:55:00.609Z","repository":{"id":60696605,"uuid":"531813368","full_name":"dotpostcard/postcards-go","owner":"dotpostcard","description":"A CLI \u0026 library for creating digital representations of postcards. The current reference implementation of this filetype.","archived":true,"fork":false,"pushed_at":"2024-11-08T07:08:20.000Z","size":23946,"stargazers_count":0,"open_issues_count":0,"forks_count":0,"subscribers_count":1,"default_branch":"main","last_synced_at":"2025-12-19T20:22:25.814Z","etag":null,"topics":["fileformat","postcards"],"latest_commit_sha":null,"homepage":"","language":"Go","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"mit","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/dotpostcard.png","metadata":{"files":{"readme":"README.md","changelog":"CHANGELOG.md","contributing":"CONTRIBUTING.md","funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2022-09-02T06:47:28.000Z","updated_at":"2024-11-08T07:08:34.000Z","dependencies_parsed_at":"2023-01-22T13:30:36.109Z","dependency_job_id":"2018fe92-6019-4ce7-9944-0aca7069a113","html_url":"https://github.com/dotpostcard/postcards-go","commit_stats":{"total_commits":113,"total_committers":2,"mean_commits":56.5,"dds":"0.17699115044247793","last_synced_commit":"ad37bfabf0f2a669f9826ff98300a1079aec0345"},"previous_names":["jphastings/postcard-go","jphastings/postcarder","jphastings/postcards-go"],"tags_count":24,"template":false,"template_full_name":null,"purl":"pkg:github/dotpostcard/postcards-go","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/dotpostcard%2Fpostcards-go","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/dotpostcard%2Fpostcards-go/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/dotpostcard%2Fpostcards-go/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/dotpostcard%2Fpostcards-go/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/dotpostcard","download_url":"https://codeload.github.com/dotpostcard/postcards-go/tar.gz/refs/heads/main","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/dotpostcard%2Fpostcards-go/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":28420814,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-01-14T10:47:48.104Z","status":"ssl_error","status_checked_at":"2026-01-14T10:46:19.031Z","response_time":107,"last_error":"SSL_connect returned=1 errno=0 peeraddr=140.82.121.6:443 state=error: unexpected eof while reading","robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":false,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["fileformat","postcards"],"created_at":"2026-01-14T12:54:59.240Z","updated_at":"2026-01-14T12:55:00.601Z","avatar_url":"https://github.com/dotpostcard.png","language":"Go","funding_links":[],"categories":[],"sub_categories":[],"readme":"# Archival\n\nMy plans for the .postcard format changed significantly in ealry 2024; please visit [jphastings/dotpostcard](https://github.com/jphastings/dotpostcard) to learn about the significantly simpler tool \u0026 ecosystem I switched to building!\n\n# Postcard\n\nA **work in progress** CLI \u0026 library for interacting with `.postcard` files, and the current reference implementation of the structure of this filetype.\n\nA `.postcard` file represents a physical postcard digitally; a double-sided image with metadata like: URLs referencing to the sender(s) and receiver(s), the date it was sent on, the lat/long of where it was sent from, transcriptions of any written text on the front/back, and image descriptions of the front/back.\n\nThe contained CLI tool, `postcards`, is able to compile front \u0026 back images, and a metadata file into a `.postcard` file:\n\n```bash\nbrew install dotpostcard/tools/postcards\npostcards compile fixtures/hello-front.jpg\n```\n\n## Implementation notes\n\nThe package at the root of this repo handles the 'steady state' interaction with postcard files — eg. readinging \u0026 writing — and have extremely limited dependencies. The packages one level deeper (eg. `compile` and `validate`) hold functionality that needs complex dependencies (eg. a capable image processing library), except for `internal`, which holds packages that are common dependencies.\n\n## File format notes\n\nA `.postcard` file contains 4 sections, organised to provide maximum compatibility with web-browsers:\n\n1. A WebP image file representing the front of the postcard, placed at the beginning of the file, so application sunable to read a `.postcard` file can process it as a standard WebP file.\n  - Ideally with a transparent background, if any non-postcard pixels are included.\n    - Hopefully the `postcarder` tool will one day help with auto-removal of the background of scanned postcards\n2. The string `postcard`, followed by three uint8 bytes representing the `X.Y.Z` of the version number of the library that created the postcard (in that order).\n3. (a uint32 defining the length of this section and) JSON for the postcard metadata (see `types.go` for spec)\n4. A WebP image for the back of the postcard (identical in format to 1)\n  - The physical dimensions should be within 1% of physical dimensions of the front of the postcard. This allows for different resolutions on front \u0026 back\n  - Ideally co-registered, so flipping about the verical or horizontal axis (for homoriented postcards) or about one of the diagonal axes (for heteroriented postcards) have the same or extremely similar outlines\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdotpostcard%2Fpostcards-go","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fdotpostcard%2Fpostcards-go","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdotpostcard%2Fpostcards-go/lists"}