paltree breeding API

1What this API does

One endpoint. Post a target Pal on its own and it returns the breeding route to that Pal — the parent combinations that produce it, generation by generation. Add the passive or active skills you want and the Pals you already own that carry them, and the route also passes those skills down. Either way the answer is a tree plus an ordered list of breeding steps.

POST /api/solveJSON in, JSON out. Public, no key, no rate limit beyond ordinary abuse protection. Please send a descriptive User-Agent.

2Request

POST /api/solve
Content-Type: application/json

{
  "target":  "139.0",            // Pal id. Required.
  "want":    ["legend", "movespeed_up_3"], // target passives, max 4
  "act":     "",                 // one active (combat) skill, optional
  "groups":  [                   // the Pals you already own
    {"passives": ["legend"],         "pals": ["33.0"], "waza": "", "off": false},
    {"passives": ["movespeed_up_3"], "pals": ["22.0"], "waza": "", "off": false}
  ],
  "exclude": [],                 // Pal ids the plan may not use
  "lang":    "en"                // language of names and messages
}

A group is a set of Pals that all carry the same passives. Put the skills in passives (and at most one active in waza), put the Pal ids in pals. Set off to true to keep a group in the payload but leave it out of the search.

For the plain “how do I breed this Pal” question, send only target (optionally with groups for Pals you own). The answer comes back with "mode": "free" and up to three routes trading fewer generations against fewer wild catches.

3Response

{
  "ok": true,
  "url": "https://paltree.app/calc/5tzx0hzy19zx0kzy0t",  // opens this same plan on screen
  "results": [{
    "gens": 3,                    // generations deep
    "breeds": 5,                  // breeding operations
    "wild": ["121.0", "184.0"],   // Pals you must catch
    "totalEggs": 28.0,            // expected eggs over the whole plan
    "steps": [{
      "i": 1, "a": "184.0", "b": "22.0", "c": "91.0",
      "p": ["movespeed_up_3"],    // passives held at this point
      "prob": 28.57,              // worst-case inheritance chance, %
      "bestProb": 32.0,           // with junk passives cleared
      "eggsMin": 4, "eggsMax": 4
    }],
    "tree": { "id": "139.0", "children": [ ... ], "leaf": false }
  }],
  "unknown": [],                  // Pal ids we did not recognise
  "unknownSkills": []             // skill keys we did not recognise
}

Unrecognised skill keys are dropped, not rejected, and listed in unknownSkills. Check it: if every key in want is dropped, the request silently becomes the plain “how do I breed this Pal” question and comes back with "mode": "free".

That is the real answer to the request above. Leaves of the tree carry kind: wild for a Pal you must catch, carrier or owned for one you supplied.

4Failures

A failure is "ok": false with a machine-readable code and a translated error sentence.

noPathNo plan exists with the Pals allowed. A partial list shows which subsets of the passives are reachable.

ownedA Pal you already listed has every target passive, so no breeding is needed.

needTargetThe target id was missing or not a breedable Pal.

The warning selfOnly on a success means the target only breeds with itself, so wild catches were assumed.

5Ids

Pal ids look like "139.0"; the part after the dot separates variants, so "33.0" is Direhowl. Passive and active skills use string keys such as "legend" (Legend) and "movespeed_up_3" (Swift) — not their display names. The calculator page ships the full list of both in its bootstrap payload, so the simplest way to look an id up is to open https://paltree.app/ and read window.BOOT.