Sequence three way merge

sequence-three-way-merge · version 1.0.0 · Sequences & diffs · free, no key needed

Three-way merge two sequence descendants against a shared base into clean or conflict regions.

Use when you need to: sequence three way merge · three-way merge two sequences against a base · sequence merge regions.

Supported

• sequence three way merge
• three-way merge two sequences against a base
• sequence merge regions

Not supported

• fuzzy matching
• text conflict markers
• RFC 7396 JSON merge patch
• RFC 6902 JSON Patch
• csv row diff
• patience merge

Behavior

• base, ours, and theirs are sequences of JSON null, boolean, string, or IEEE-754 safe integer items.
• Regions come from mergeRegions on the Myers SES of base→ours and base→theirs.
• Non-empty abutting ranges do not overlap. Empty spans at the same base index overlap. An insertion index inside another span overlaps.
• Identical overlapping replacements collapse to one ok region. Distinct overlapping replacements are a conflict.
• status is clean or conflict. result concatenates ok items when clean and is null when any conflict exists.
• A clean result must not exceed 1024 items.
• Ok regions are {type, items}. Conflict regions are {type, base, ours, theirs}.
• base ["A","B","C"], ours ["A","X","C"], theirs ["A","B","Y"] is clean with result ["A","X","Y"].
• ours ["A","X","C"] vs theirs ["A","Y","C"] is a conflict on B. The string "__proto__" is an ordinary item.

Input

• base (array of null or boolean or string or integer, required): max items 1024
• ours (array of null or boolean or string or integer, required): max items 1024
• theirs (array of null or boolean or string or integer, required): max items 1024

Output

• status (one of "clean", "conflict", required)
• regions (array of any, required)
• result (array or null, required)

Limits

• max sequence items: 1024
• max item string bytes: 4096
• max text bytes: 262144
• max output bytes: 1048576

Example

Request input:

{
  "base": [
    "A",
    "B",
    "C"
  ],
  "ours": [
    "A",
    "X",
    "C"
  ],
  "theirs": [
    "A",
    "B",
    "Y"
  ]
}

Response:

{
  "result": {
    "status": "clean",
    "regions": [
      {
        "type": "ok",
        "items": [
          "A",
          "X",
          "Y"
        ]
      }
    ],
    "result": [
      "A",
      "X",
      "Y"
    ]
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "sequence-three-way-merge",
  "version": "1.0.0",
  "input": {
    "base": [
      "A",
      "B",
      "C"
    ],
    "ours": [
      "A",
      "X",
      "C"
    ],
    "theirs": [
      "A",
      "B",
      "Y"
    ]
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/sequence-three-way-merge/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"base":["A","B","C"],"ours":["A","X","C"],"theirs":["A","B","Y"]}'

The machine-readable contract is at /v1/tools/sequence-three-way-merge/versions/1.0.0.

CLI

node cli.mjs run sequence-three-way-merge 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Sequence edit script: Compute the Myers shortest edit script between two bounded sequences, with keep/delete/insert counts.
• Sequence LCS: Compute the longest common subsequence of two bounded sequences from the Myers shortest edit script.
• Sequence longest common substring: Find the longest contiguous common subarray of two bounded sequences.
• Sequence apply edit script: Apply a keep/delete/insert edit script to a bounded sequence with exact value matching and no fuzz.
• Sequence compose edit scripts: Compose two sequence edit scripts into one per-item keep/delete/insert script.
• Sequence index map: Map each left-sequence index to a kept right index, or null if deleted, and list inserted right indices.