hashline-editing

An OpenCode plugin that edits files by line number instead of search and replace.

Search and replace breaks when the same code appears twice. Plain line numbers break when an earlier edit shifts the lines below. Hashline avoids both: every read returns a [PATH#TAG] header that pins the exact version you saw, and edit checks that tag before writing anything.

[src/a.ts#A1B2]
replace 2-3
+new line two
+new line three

Operations: replace N-M, replace N, insert before N, insert after N, append. New lines are prefixed with +. One patch can cover several files — everything is validated first, then written. If the file changed on disk since your read, the tag won't match and nothing is written: read again and retry.

Install

OpenCode v2 (2.x) — version 1.0.0:

opencode plugin add @glaicer/supercode-hashline-editing

OpenCode v1 (1.x) — version 0.1.0. Add it to the plugin array of your opencode.json:

{
  "plugin": ["@glaicer/supercode-hashline-editing@0.1.0"]
}

Restart OpenCode either way — running sessions don't pick up config changes. To uninstall, remove the plugin entry and restart again.

Options

v2 reads options from the plugins entry in the global config:

{
  "plugins": [
    {
      "package": "@glaicer/supercode-hashline-editing",
      "options": { "enforceSeenLines": true }
    }
  ]
}

v1 reads the same values from a hashline section of the config.

option	default	meaning
enforceSeenLines	true	refuse to edit lines a read never showed
roots	[]	additional Snapshot Roots besides the project root
maxPaths	256	tracked-file limit of the snapshot store
maxVersionsPerPath	4	remembered versions per file
maxTotalBytes	67108864	total snapshot budget in bytes
maxTaggedReadBytes	40960	byte budget of one tagged text read before truncation

roots takes absolute paths (or paths relative to the project root). Files outside the Snapshot Root can still be read natively, but edit stays unavailable there — to hashline-edit dotfiles outside the project, add their directory:

{
  "plugins": [
    {
      "package": "@glaicer/supercode-hashline-editing",
      "options": { "roots": ["/home/me/.config/opencode"] }
    }
  ]
}

Warning: edit permissions are not enforced

Hashline edit writes directly — the plugin API has no way to ask OpenCode for approval at write time. edit: ask rules won't prompt, and path-scoped edit: deny rules won't block it (measured on OpenCode 2.0.18). Only a blanket edit: deny * stops it, and only because the tool is then hidden from the model entirely. Reads are unaffected — they go through the native read tool and honor read permissions.

If you rely on edit approvals, don't use this plugin for those files. Edits are still confined to the project root and configured roots, and a stale tag still refuses to write — but that's drift protection, not an approval policy.

Differences from the native edit tools

• Existing files only. Creating files is the native write tool's job.
• No formatting. Hashline writes exactly the lines you sent and never runs a formatter.
• No approval prompt. See the warning above.