weave-cli 0.6.1

Entity-level semantic merge CLI. Resolves conflicts at the function/class level instead of lines.
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
> **Part of the [Ataraxy Labs](https://ataraxy-labs.com) stack**, agent-native infrastructure for software development. See also: [sem](https://ataraxy-labs.com/sem) (semantic version control) · [inspect](https://github.com/Ataraxy-Labs/inspect) (semantic code review) · [opensessions](https://github.com/Ataraxy-Labs/opensessions) (tmux sidebar for coding agents).
>
> Read the manifesto: https://ataraxy-labs.com/#thesis · Essays: https://ataraxy-labs.com/blogs · LLMs: https://ataraxy-labs.com/llms.txt

<p align="center">
  <img src="assets/banner.svg" alt="weave" width="600" />
</p>

<p align="center">
  <strong>Entity-level semantic merge for Git.</strong><br>
  Resolves merge conflicts that Git can't by parsing code into functions, classes, and keys with tree-sitter, then merging those entities instead of lines.
</p>

<p align="center">
  <a href="#how-weave-land-works">How weave land works</a> ·
  <a href="#install">Install</a> ·
  <a href="#quickstart">Quickstart</a> ·
  <a href="#how-weave-fixes-this">How It Works</a> ·
  <a href="#mcp-server">MCP Server</a> ·
  <a href="#cli-commands">CLI</a> ·
  <a href="https://github.com/Ataraxy-Labs/weave/releases/latest">Releases</a>
</p>

<p align="center">
  <a href="https://github.com/Ataraxy-Labs/weave/releases/latest"><img src="https://img.shields.io/github/v/release/Ataraxy-Labs/weave?color=blue&label=release" alt="Release"></a>
  <a href="https://formulae.brew.sh/formula/weave"><img src="https://img.shields.io/badge/homebrew-weave-orange" alt="Homebrew"></a>
  <img src="https://img.shields.io/badge/rust-stable-orange" alt="Rust">
  <img src="https://img.shields.io/badge/tests-441_passing-brightgreen" alt="Tests">
  <a href="LICENSE-MIT"><img src="https://img.shields.io/badge/license-MIT_OR_Apache--2.0-yellow" alt="License"></a>
  <img src="https://img.shields.io/badge/languages-38-blue" alt="Languages">
</p>

<p align="center">
  <img src="assets/merge-animation.gif" alt="Weave merge animation: two branches add different functions, git conflicts, weave merges cleanly" width="700" />
</p>

## How weave land works

`weave land` merges code and checks the result for structural problems. Add `--onto` to integrate and publish, and `--verify-cmd` or `--check sem` to validate the final tree before publishing.

[Usage and safety](#landing-an-agents-merge-weave-land)

## Quickstart

```bash
weave setup                 # this repo now merges through weave; git merge/rebase/cherry-pick unchanged
git merge <branch>          # real conflicts land as markers with a `refused_by:` line stating why
weave explain <file>        # per-hunk detail for one conflicted file, read off the actual git stages
#  ...edit to resolve...
weave check                 # verify the working tree against the three merge stages; exits 1 on findings, 2 if it could not verify
weave land --resolver <cmd> # or: land it, each conflicted file labelled PROVEN / VERIFIED / REFUSED
```

See [Setup](#setup) for `--global`/`--local` variants, [CLI Commands](#cli-commands) for the rest of the
`weave` binary, and [MCP Server](#mcp-server) for agent-framework integration.

## The Problem

Git merges by comparing **lines**. When two branches both add code to the same file, even to completely different functions, Git sees overlapping line ranges and declares a conflict:

```
<<<<<<< HEAD
export function validateToken(token: string): boolean {
    return token.length > 0 && token.startsWith("sk-");
}
=======
export function formatDate(date: Date): string {
    return date.toISOString().split('T')[0];
}
>>>>>>> feature-branch
```

These are **completely independent changes**. There's no real conflict. But someone has to manually resolve it anyway.

This happens constantly when multiple AI agents work on the same codebase. Agent A adds a function, Agent B adds a different function to the same file, and Git halts everything for a human to intervene.

## How Weave Fixes This

Weave replaces Git's line-based merge with **entity-level merge**, a 3-way merge that compares base, ours, and theirs at the level of individual functions, classes, and keys instead of individual lines. That lets it tell where the two branches actually drifted apart, rather than just where their edits happen to land on the same line numbers. It works like this:

1. Parses all three versions (base, ours, theirs) into semantic entities: functions, classes, JSON keys, etc., using [tree-sitter](https://tree-sitter.github.io/)
2. Matches entities across versions by identity (name + type + scope), including renames
3. Merges at the entity level:
   - **Different entities changed** → auto-resolved, no conflict
   - **Same entity changed by both** → attempts intra-entity merge, conflicts only if truly incompatible
   - **One side modifies, other deletes** → flags a meaningful conflict

Run the same scenario above through weave, and it merges cleanly with zero conflicts: both functions end up in the output.

This merge algorithm is deterministic and stateless: it reads three file revisions and writes one result, the same way `git merge-file` does. It is not a CRDT. (Weave separately ships a CRDT-backed coordination layer, `weave-crdt`, for tracking *live* multi-agent edits before they hit Git; see [Architecture](#architecture).)

## Weave vs Git Merge

| Scenario | Git (line-based) | Weave (entity-level) |
|----------|-----------------|---------------------|
| Two agents add different functions to same file | **CONFLICT** | Auto-resolved |
| Agent A modifies `foo()`, Agent B adds `bar()` | **CONFLICT** (adjacent lines) | Auto-resolved |
| Both agents modify the same function differently | CONFLICT | CONFLICT (with entity-level context) |
| One agent modifies, other deletes same function | CONFLICT (cryptic diff) | CONFLICT: `function 'validateToken' (modified in ours, deleted in theirs)` |
| Both agents add identical function | **CONFLICT** | Auto-resolved (identical content detected) |
| Both agents add different properties to same object | **CONFLICT** | Auto-resolved |
| Different JSON keys modified | **CONFLICT** | Auto-resolved |

The key difference: Git produces false conflicts on **independent changes** because they happen to be in the same file. Weave only conflicts on **actual semantic collisions** when two branches change the same entity incompatibly.

## Weave vs Mergiraf

31 hand-crafted merge scenarios across 7 languages, comparable to [mergiraf](https://mergiraf.org/)'s own test corpus. Run `weave stats --bench` to reproduce:

Two of the 31 **must not** merge. When both sides add different decorators to the same Python or TypeScript function, decorator application is function composition, so the stack order is a semantic decision neither side made — `@cache` outside `@auth` serves cached responses without ever running the auth check. Weave refuses rather than fabricate an order, and a tool that merges those cleanly is wrong, not better. Annotations in Java, C# and Kotlin are unordered metadata, so weave still set-unions those.

| Tool | Clean merges (of 29 mergeable) | Correct outcomes (of 31) |
|------|-------------------------------|--------------------------|
| **Weave** | **29/29** (100%) | **31/31** (100%) |
| Mergiraf (v0.16.3) | 26/29 (90%) | 28/31 (90%) |
| Git | 15/29 (52%) | 17/31 (55%) |

All three tools correctly refuse the two decorator scenarios. Mergiraf fails on both-add-at-end-of-file and insert-between-existing; weave resolves those because it operates at entity granularity (functions, classes, methods) rather than AST node level. Full breakdown at [ataraxy-labs.github.io/weave](https://ataraxy-labs.github.io/weave/benchmarks.html).

## Real-World Benchmarks

Replayed against real merge commits from five long-lived open-source repositories. For each of the first 500 merge commits per repo, weave re-runs the merge (base/ours/theirs from the actual git history) and compares its output to both Git's line merge and the human-authored merge commit. Reproduce with `weave stats --repo <path-to-clone> --limit 500`; full per-repo breakdown, including which files disagree and why, is at [ataraxy-labs.github.io/weave/benchmarks.html](https://ataraxy-labs.github.io/weave/benchmarks.html).

- **Win**: the line-based 3-way merge conflicted, weave resolved cleanly
- **Regression**: the line-based 3-way merge resolved cleanly, weave conflicted
- **Human match**: of weave's wins, how many are byte-identical (whitespace-normalized) to what the developer actually wrote

> **Note (0.5.3):** regenerated on the 0.5.3 engine on 2026-09-01 (`weave stats --repo <clone>
> --limit 500`, fresh full clones). Read against the previous table with three caveats, stated
> rather than smoothed over. First, 0.5.3 conflicts on purpose where 0.5.2 sometimes resolved
> silently (divergent same-name additions, tightened same-entity and gap verdicts) — most of the
> regression increase is that tightening doing its job; on CPython, whose tested window is
> identical between runs, all of it is. Second, the earlier run's exact commit window was not
> recorded, and `stats --repo` walks the most recent N merges — for git, Go, and TypeScript the two
> runs replay substantially different commit sets, so cross-run rate comparisons there are
> indicative, not exact; this run's windows are current as of the date above. Third, audited
> details: the "clean line merge" baseline is a diff3 implementation (`diffy`), which disagrees
> with `git merge-file` on a small number of cases; 3 of the 86 regressions are a known guard
> false-positive (files whose *source code contains conflict-marker string literals* — e.g.
> TypeScript's own scanner); and in 2 regressions the line merge's "clean" result differs from
> what the human actually committed, i.e. weave's refusal was arguably the safer verdict.

| Repository | Language | File merges tested | Wins | Regressions | Human match |
|------------|----------|--------------------:|-----:|-------------:|-------------:|
| [git/git](https://github.com/git/git) | C | 1,701 | 183 | 23 | 72% |
| [Flask](https://github.com/pallets/flask) | Python | 67 | 15 | 1 | 33% |
| [CPython](https://github.com/python/cpython) | C / Python | 256 | 11 | 10 | 45% |
| [Go](https://github.com/golang/go) | Go | 1,667 | 120 | 37 | 33% |
| [TypeScript](https://github.com/microsoft/TypeScript) | TypeScript | 1,280 | 15 | 15 | 53% |

Across all five repos: 344 wins on 4,971 file merges (0.5.2 measured 83 wins on 4,517), with 86 total
regressions spread across every repo (0.5.2 measured 3, all on TypeScript). The jump in regressions is
expected and by design, not a quality drop we're hiding: 0.5.3 now conflicts on genuinely divergent
concurrent additions that 0.5.2 silently merged, and no longer resolves a case that could resurrect a
deleted JSON key — both changes move cases from "weave resolves" into "weave conflicts" under this
benchmark's own regression definition (git resolves cleanly, weave doesn't). Wins also rose substantially
on every repo. File-merge counts and human-match rates shifted too, partly because "first 500 merge
commits" is a moving window and all five repos have advanced since the 0.5.2 run. See the per-repo
breakdown on the benchmarks page before relying on weave for large merges in any of these languages.

## Testing

The open test suite in this repository, 441 unit and integration tests plus a five-scenario
sweep per supported language in `crates/weave-core/tests/language_coverage.rs`, covers the
documented merge properties and runs in CI (`cargo fmt --check`, `cargo clippy -D warnings`,
`cargo test --workspace`) on Linux and Windows on every push and PR.

## Conflict Markers

When a real conflict occurs, weave gives you context that Git doesn't: which
entity, what type, and, on the line inside the box, which internal guard
declined to auto-merge and exactly which lines both sides disagree about.

```
<<<<<<< ours — function `process` (T, confidence: high)
// refused_by: statement_fold · collision: `    return data.upper()` +1 more
export function process(data: any) {
    return JSON.stringify(data);
}
=======
export function process(data: any) {
    return data.toUpperCase();
}
>>>>>>> theirs — function `process` (T, confidence: high)
```

Run `weave explain <file>` for more detail on every conflicted entity in the
file, and `weave check` after editing to verify your resolution against the
three merge stages; see [Quickstart](#quickstart).

## Supported Languages

TypeScript, TSX, JavaScript, Python, Go, Rust, Java, C, C++, Ruby, C#, PHP, Swift, Kotlin, Scala, Dart, Elixir, Bash, Fish, Fortran, Perl, OCaml, Zig, Elm, Clojure, EDN, D, Lua, Nix, SQL, HCL/Terraform, LaTeX, XML, JSON, YAML, TOML, CSV, Markdown. Falls back to standard line-level merge for everything else.

`weave setup` derives its `.gitattributes` rules directly from the parser
registry: every extension the tree-sitter grammars recognize gets a
`merge=weave` line automatically, with no hand-maintained list to fall
behind. Each language on it passes a five-scenario merge sweep (two sides
adding different definitions merges clean, two sides rewriting the same
definition conflicts, and nothing is dropped) in
`crates/weave-core/tests/language_coverage.rs`, and a separate parity test
(`crates/weave-core/tests/setup_extension_coverage.rs`) fails the build if a
newly added grammar is ever left unclaimed and undeclined.

INI files (`*.ini`, `*.cfg`) have no grammar but are claimed too
(`weave_core::LINE_RULE_EXTENSIONS`): they take Git's line merge, plus the
rule that unites keys two sides added to one section.

Vue, Svelte, ERB and Haskell are parsed but deliberately **not** claimed:
weave declines exactly these four (`weave_core::DECLINED_EXTENSIONS`), and
nothing else. Their entity model treats a whole `<script>` block, template,
or type signature as a single unit, so two people adding two different
definitions conflict where they should merge cleanly, and the conflict
marker can land mid-definition. Those files get Git's line-level merge
instead, which is the better answer until the parser gains a real
per-definition model for them. They're excluded from `weave setup`
automatically; nothing to opt out of by hand.

## Install

```bash
brew install weave
```

Or build from source (requires Rust). Two binaries, both required: `weave`
(the CLI you run: `setup`/`explain`/`check`/...) and `weave-driver` (the one
git itself invokes on every merge; `weave setup` fails without it on `PATH`):

```bash
git clone https://github.com/Ataraxy-Labs/weave
cd weave
cargo install --path crates/weave-cli      # the `weave` binary
cargo install --path crates/weave-driver   # the `weave-driver` binary git calls
```

Upgrading an existing source install? `cargo install` refuses to overwrite a
binary it didn't put there itself, so add `--force` to either command above.

## Setup

In any Git repo:

```bash
weave setup
```

This configures Git to use weave for all supported file types. Then use `git merge` as normal.

To revert back to normal git merging:

```bash
weave setup --off
```

To set up for just yourself (without modifying `.gitattributes`), write the same supported file type rules to `.git/info/attributes` instead:

```bash
weave setup --local
```

### Global (every repo)

To make weave the default merge driver for **all** your repos at once (no per-repo setup, like [mergiraf](https://mergiraf.org/usage.html#registration-as-a-git-merge-driver)):

```bash
weave setup --global
```

This writes the driver to your `~/.gitconfig` and the supported file-type rules to git's global attributes file (`~/.config/git/attributes`, or your `core.attributesfile` if set). No git repo required. Make sure `weave-driver` is on your `PATH` (it ships next to the `weave` binary).

The equivalent manual config, if you prefer:

```bash
git config --global merge.weave.name "Entity-level semantic merge"
git config --global merge.weave.driver "weave-driver %O %A %B %L %P"
# then add `*.ts merge=weave` (etc.) to ~/.config/git/attributes
```

### Declaring a container a set (`weave-set`)

When two branches each add an entry at the same point of one container,
weave unites them only if the container's order carries no meaning: a
Python dict or JS/TS object literal with constant keys, `__all__`, an
`import`/`export` name list, the keys of one INI section, TOML/JSON/YAML
keys. The union never depends on which side is "ours", and in a Python,
JS/TS or INI container it is merged by key, so a fleet of branches that
each add one entry lands on one tree whatever order they merge in (an entry
under its own comment keeps its run together instead).

A list, a statement sequence, match/switch arms, an INI multi-line value or
a YAML sequence is ordered in general (the first matching arm wins, a
parametrize list names test ids by position), so two insertions at one point
stay a conflict. So do the entries two branches add to one section of a
changelog: two differently worded bullets can describe one change, and
telling them apart is not a set's job. If you know one of yours is really a
set, say so with the `weave-set` gitattribute:

```gitattributes
setup.cfg              weave-set=console_scripts
tests/test_*.py        weave-set=parametrize
src/cli.py             weave-set=build_parser
.pre-commit-hooks.yaml weave-set
CHANGELOG.md           weave-set=Unreleased
```

A bare `weave-set` makes every container in the file a set; a value is a
comma-separated list of container names: the variable a literal is assigned
to, the key it is the value of, the function it is an argument of
(`parametrize`), the function whose body or match arms it is, the INI key of
a multi-line value, the YAML/JSON/TOML key of an array, the title of a
changelog section or of a heading above it (brackets off, or its first word:
`## [Unreleased]` is `Unreleased`, `## 1.2.0 - 2026-01-01` is `1.2.0`). The driver reads the
attribute with `git check-attr` only when such a container is what stands
between a conflict and a union. Every union is still checked: an entry
edited, deleted or moved beside the insertion, one key with two values, or
an answer that does not parse stays a conflict.

## Jujutsu (jj)

Add to your jj config (`jj config edit --user`):

```toml
[merge-tools.weave]
program = "weave-driver"
merge-args = ["$base", "$left", "$right", "-o", "$output", "-l", "$marker_length", "-p", "$path"]
merge-conflict-exit-codes = [1]
merge-tool-edits-conflict-markers = true
conflict-marker-style = "git"
```

Resolve conflicts with `jj resolve --tool weave`, or set as default:

```bash
jj config set --user ui.merge-editor "weave"
```

## Preview

Dry-run a merge to see what weave would do:

```bash
weave preview feature-branch
```

```
  src/utils.ts — auto-resolved
    unchanged: 2, added-ours: 1, added-theirs: 1
  src/api.ts — 1 conflict(s)
    ✗ function `process`: both modified

✓ Merge would be clean (1 file(s) auto-resolved by weave)
```

After a real conflict, `weave explain <file>` and `weave check` are the
next two commands; see [Quickstart](#quickstart).

## Landing an agent's merge: `weave land`

Resolve a merge in progress, check its result, and stage accepted files:

```bash
weave land
weave land --resolver '<resolver-command>' --certificate land.json
```

A resolver is optional. It receives merge inputs as JSON on stdin and returns a resolved file. Rejected answers are not written; unresolved files remain conflicted.

| Result | Meaning |
|---|---|
| **PROVEN** | The result satisfies the supported structural proof rules. |
| **VERIFIED** | The result passed the merge gate, without a structural proof. |
| **REFUSED** | The result was not accepted; resolve the reported findings. |

These labels describe merge checks, not proof that the program behaves correctly. The gate checks individual files for problems such as lost changes, duplicates, and invalid syntax; it does not establish cross-file or runtime correctness.

### Integrate and publish

`--onto` merges the target branch, gates the result, runs configured validation, and publishes fast-forward only. If the target moves, it retries against the new tip.

```bash
weave land --onto origin/main --verify-cmd 'go build ./... && go test ./...'
# Or use Sem's project checkers:
weave land --onto origin/main --check sem
```

**Configure validation before publishing.** A failed gate or configured validation refuses publication. Without `--onto`, `weave land` does not publish.

Use `--dry-run` to inspect without writing, `--json` for structured output, and `weave land --help` for resolver inputs, revision selection, timeouts, and other options. Exit codes: `0` accepted, `1` refused, `2` execution error.

## CLI Commands

Seven commands. Each `--help` line says which question the command answers, and every flag has an example (`weave <command> --help`).

| Command | The question it answers |
|---|---|
| `weave setup [--global] [--local] [--off]` | Make `git merge` use weave here (`--global`: every repo; `--off`: stop) |
| `weave land [--resolver <cmd>] [--onto <remote>/<branch>] [--verify-cmd <cmd>] [--check sem] [--queue]` | Can this merge land? Merge, gate every file (PROVEN / VERIFIED / REFUSED), verify, publish; see [above](#landing-an-agents-merge-weave-land). `--queue` is experimental |
| `weave explain <file> [--summary] [--json]` | Why did this file conflict? `--summary`: a structured summary of the weave markers in any file |
| `weave check [--json]` | Is my conflict resolution right? Lost lines, duplicates, leftover markers, dangling names |
| `weave preview <branch> [--file <path>]` | What would merging this branch look like? Nothing is written |
| `weave patch extract <base-file> <changed-file>` / `weave patch apply <ops-file> <target-file>` | Apply an edit to a file that drifted: typed entity ops, merged three-way against the ops' base |
| `weave stats [--bench] [--repo <path> --limit N]` | How has weave done? Lifetime counters if you opted in with `WEAVE_STATS=1`; `--bench` runs the 31-scenario synthetic benchmark; `--repo` replays real merge commits from a clone (see [Real-World Benchmarks](#real-world-benchmarks)) |

Every earlier command name still works, with the same output. At a terminal weave prints a one-line note on stderr with the new spelling; in `--json` mode or when output is piped it prints nothing extra.

| Old | New |
|---|---|
| `weave unsetup` | `weave setup --off` |
| `weave summary <file>` | `weave explain <file> --summary` |
| `weave bench` | `weave stats --bench` |
| `weave bench-repo <path>` | `weave stats --repo <path>` |
| `weave claim`, `release`, `status`, `apply` | `weave experimental claim`, `release`, `status`, `apply` |

The `weave experimental` group (hidden from `--help`) is the live-editing prototype: it claims and releases entities and applies edits held in the `.weave/state.automerge` CRDT document, the same document the MCP coordination tools below use. Claims are advisory. That document lives in the repo's working tree but is never repo content: the first time weave writes it, it adds `.weave/` to the repo's local `.git/info/exclude` (never your own `.gitignore`), so it never shows up in `git status` or gets swept into `git add -A`.

## MCP Server

For agent frameworks that speak [MCP](https://modelcontextprotocol.io):

```bash
# Claude Code
claude mcp add --scope user weave -- weave-mcp

# Any MCP client, via stdio (~/.config/claude/claude_desktop_config.json etc.)
{ "mcpServers": { "weave": { "command": "weave-mcp" } } }
```

The server discovers the repo from the first tool call's file path, the
`WEAVE_REPO` env var, or its working directory. It lists five tools, one per
`weave` command (each tool's own description states when to call it and what an
empty result means):

- `weave_preview`: dry-run a merge of two branches, as per-file verdicts, a
  findings document, or the strategy weave used on each entity.
- `weave_edit`: change code by entity, written straight to disk: replace an entity, edit
  text inside it, add one before or after it, delete it, or create a file. A batch is all or
  nothing, and an edit that breaks the parse or quietly renames an entity is refused.
- `weave_explain`: why a file conflicted, from the merge's three stages.
- `weave_check`: is the resolution right, plus the cross-file breakage a per-file
  merge driver can't see (a rename in `a.py` whose surviving caller lives in `b.py`).
- `weave_land`: label every file of a stopped merge PROVEN, VERIFIED or REFUSED, and
  write the ones that pass.
- `weave_patch`: carry an edit to a file that drifted, as a three-way entity merge.

For callers, dependencies and blast radius, use [sem](https://github.com/Ataraxy-Labs/sem)'s
MCP server. The live multi-agent CRDT tools (`weave_claim_entity`,
`weave_update_entity_content`, ...) are listed only with `WEAVE_EXPERIMENTAL=1`. Every
older tool name still answers when called, so existing clients keep working.

## Architecture

```
weave-core       # Library: entity extraction, entity-level 3-way merge, reconstruction
weave-driver     # Git merge driver binary (called by git via %O %A %B %L %P)
weave-cli        # CLI: `weave setup`, `weave explain`, `weave check`, `weave patch`, ...
weave-crdt       # Automerge-backed CRDT: live multi-agent coordination state only
weave-mcp        # MCP server exposing weave to agent frameworks (one tool per command)
weave-github     # GitHub webhook service behind the hosted PR-comment integration
                 #   (publish = false, not a binary you install; runs weave's merge
                 #   analysis on pull_request events and posts the result as a comment)
```

Uses [sem-core](https://github.com/Ataraxy-Labs/sem) for entity extraction via tree-sitter grammars.

The merge algorithm (`weave-core`) and the coordination state (`weave-crdt`) are
deliberately separate concerns with different data models: the merge is a pure
function over three file revisions, run fresh on every `git merge`/`weave preview`/
`weave check` call. The CRDT is the thing that persists; it's what lets two live
agents see each other's claims and in-flight edits *before* either one commits,
via `weave_claim_entity`/`weave_update_entity_content` or `weave experimental claim`/`weave experimental apply`.
Nothing in the merge path depends on the CRDT ever having run.

## How It Works

```
         base
        /    \
     ours    theirs
        \    /
       weave merge
```

1. **Parse** all three versions into semantic entities via tree-sitter
2. **Extract regions**, alternating entity and interstitial (imports, whitespace) segments
3. **Match entities** across versions by ID (file:type:name:parent), detecting renames
4. **Resolve** each entity: one-side-only changes win, both-changed attempts intra-entity 3-way merge
5. **Reconstruct** file from merged regions, preserving ours-side ordering
6. **Fallback** to line-level merge for files >1MB, binary files, or unsupported types

## Limitations

- **Vue, Svelte, ERB, Haskell** parse, but their per-file entity model is too coarse to merge
  well, so they take Git's line merge, always (see [Supported Languages](#supported-languages)).
- **Files over 1MB, binary files, and file types with no parser** fall back to Git's line-level
  merge automatically.
- **Entity claims are advisory, not enforced.** `weave_claim_entity` and `weave experimental claim` are
  cooperative locks inside the CRDT coordination layer; weave does not stop a second agent
  (or you) from editing a claimed entity anyway.
- **Crashed agents aren't reaped.** `weave_agent_heartbeat`'s liveness timestamp is informational;
  weave does not currently expire or release a claim automatically when an agent stops
  heartbeating, so a crashed agent's claims stay visible until another call to
  `weave_release_entity`/`weave release`.
- **`weave stats` is empty until you opt in.** Lifetime merge counters are off by default; set
  `WEAVE_STATS=1` in the environment your git/jj merges run in to start accumulating them.

## Contributing

Bug reports and issues are welcome. This is a small team maintaining a merge engine that
runs inside other people's git workflows: incoming PRs get read, but are reviewed and
adapted before merge rather than merged as-is. Open an issue first for anything beyond a
small, obviously-correct fix, so the approach can be agreed on before you write the code.

## License

Dual-licensed under [MIT](LICENSE-MIT) or [Apache 2.0](LICENSE-APACHE), at your option.

## Star History

[![Star History Chart](https://api.star-history.com/svg?repos=Ataraxy-Labs/weave&type=Date)](https://star-history.com/#Ataraxy-Labs/weave&Date)