Proof - Collaborative Markdown Editor

Proof is a collaborative document editor for humans and agents. It supports two modes:

1. Web API - Create and edit shared documents via HTTP (no install needed)
2. Local Bridge - Drive the macOS Proof app via localhost:9847

Identity and Attribution

Every write to a Proof doc must be attributed. Two fields carry the agent's identity:

• Machine ID (by on every op, X-Agent-Id header): ai:compound-engineering — stable, lowercase-hyphenated, machine-parseable. Appears in marks, events, and the API response.
• Display name (name on POST /presence): Compound Engineering — human-readable, shown in Proof's presence chips and comment-author badges.

Set the display name once per doc session by posting to presence with the X-Agent-Id header; Proof binds the name to that agent ID for the session. These values are the defaults for any caller of this skill; callers running HITL review (references/hitl-review.md) may pass a different identity pair if a distinct sub-agent should own the doc. Do not use ai:compound or other ad-hoc variants — identity stays uniform unless a caller explicitly overrides it.

Human-in-the-Loop Review Mode

Human-in-the-loop iteration over an existing local markdown file: upload to Proof, let the user annotate in Proof's web UI, ingest feedback as in-thread replies and agreed edits, and sync the final doc back to disk. Two entry points, identical mechanics — load references/hitl-review.md for the full loop spec (invocation contract, mark classification, idempotent ingest passes, exception-based terminal reporting, end-sync atomic write) in either case:

• Direct user request — a bare user phrase naming a local markdown file and asking to iterate collaboratively via Proof: "share this to proof so we can iterate", "iterate with proof on this doc", "HITL this file with me", "let's get feedback on this in proof", "open this in proof editor so I can review". The file is whichever markdown the user just created, edited, or referenced; if ambiguous, ask which file. This is a first-class entry point — do not require an upstream caller.
• Upstream skill handoff — ce-brainstorm, ce-ideate, or ce-plan finishes a draft and hands it off for human review before the next phase, passing the file path and title explicitly.

Web API (Primary for Sharing)

Create a Shared Document

No authentication required. Returns a shareable URL with access token.

curl -X POST https://www.proofeditor.ai/share/markdown \
  -H "Content-Type: application/json" \
  -d '{"title":"My Doc","markdown":"# Hello\n\nContent here."}'

Response format:

{
  "slug": "abc123",
  "tokenUrl": "https://www.proofeditor.ai/d/abc123?token=xxx",
  "accessToken": "xxx",
  "ownerSecret": "yyy",
  "_links": {
    "state": "https://www.proofeditor.ai/api/agent/abc123/state",
    "ops": "https://www.proofeditor.ai/api/agent/abc123/ops"
  }
}

Use the tokenUrl as the shareable link. The _links give you the exact API paths.

Read a Shared Document

If you already have a shared Proof URL, no browser automation is needed. Fetch the URL directly with content negotiation:

curl -s -H "Accept: application/json" "https://www.proofeditor.ai/d/{slug}?token=<token>"
curl -s -H "Accept: text/markdown" "https://www.proofeditor.ai/d/{slug}?token=<token>"

The JSON response includes the markdown, API links, and agent auth hints. Use /state when you need mutation metadata, marks, or presence:

curl -s "https://www.proofeditor.ai/api/agent/{slug}/state" \
  -H "x-share-token: <token>"

For comment-ingest workflows, prefer the server-side filter:

curl -s "https://www.proofeditor.ai/api/agent/{slug}/state?kinds=comment" \
  -H "x-share-token: <token>"

state.marks is a union of comments, suggestions, and provenance/authorship marks. The ?kinds=comment filter avoids treating human-authored provenance marks as review comments.

Edit a Shared Document

Comment, suggestion, and rewrite operations go to POST https://www.proofeditor.ai/api/agent/{slug}/ops. Block edits use /api/agent/{slug}/edit/v2.

Note: Use the /api/agent/{slug}/ops path (from _links in create response), NOT /api/documents/{slug}/ops.

Authentication for protected docs:

• Header: x-share-token: <token> or Authorization: Bearer <token>
• Token comes from the URL parameter: ?token=xxx or the accessToken from create response
• Header: X-Agent-Id: ai:compound-engineering (required for presence; include on ops for consistent attribution)

Wire-format reminder. /api/agent/{slug}/ops uses a top-level type field; /api/agent/{slug}/edit/v2 uses an operations array where each entry has op. Do not mix — sending op to /ops returns 422.

Every mutation requires a baseToken. Reuse the mutationBase.token from the most recent /state or /snapshot read, then update it from successful mutation responses (.mutationBase.token). On BASE_TOKEN_REQUIRED or STALE_BASE, re-read and retry once. Only do a pre-mutation read if no prior read has happened in this session or you need fresh document/comment/snapshot content. See the baseToken recipe in references/hitl-review.md.

/edit/v2 block refs are a separate concern: they can drift across revisions, so re-fetch /snapshot for fresh refs before a block edit if any writes have landed since your last snapshot.

Edit Strategy: Avoid Whole-Doc Rewrite

Do not default to full-document replacement. Pick the narrowest edit primitive that matches the requested change:

1. Literal repeated change: use /edit/v2 with find_replace_in_doc (optionally constrained by fromRef, toRef, or block_filter). This is the fastest and least error-prone path for terminology renames, punctuation/style sweeps, and other exact text substitutions.
2. Known block or section change: use /edit/v2 block operations from a fresh /snapshot: replace_block, insert_before, insert_after, delete_block, replace_range, or find_replace_in_block.
3. Visible track-changes desired: use /ops suggestion.add (pending or status: "accepted") when the user should see a suggestion mark and reject/revert affordance for that specific edit.
4. Whole-doc replacement: use rewrite.apply only as a last resort when the user explicitly asks to replace the entire document, when the intended change is genuinely global and cannot be expressed as block/range/find-replace operations, and when no live clients are present. Before rewriting, read current state, preserve comments/marks expectations, and mention that the rewrite is broad.

When in doubt, start with /snapshot and build a small /edit/v2 batch. A narrow failed edit is easier to inspect and retry than a broad rewrite, and it avoids clobbering concurrent human work.

Retry discipline after mutation errors — verify before retrying. An error response is not proof that nothing was written.

• STALE_BASE, BASE_TOKEN_REQUIRED, MISSING_BASE, INVALID_BASE_TOKEN — pre-commit, token-related. Re-read /state, rebuild the request body with a fresh baseToken, and retry once with a new Idempotency-Key.
• ANCHOR_NOT_FOUND, ANCHOR_AMBIGUOUS — pre-commit, but the quote no longer uniquely matches content. Re-reading does not help by itself; the caller must tighten or regenerate the anchor before retrying. Do not auto-retry blindly.
• INVALID_OPERATIONS, INVALID_REQUEST, INVALID_REF, INVALID_BLOCK_MARKDOWN, INVALID_RANGE, INVALID_MARKDOWN, 422 — pre-commit, but the payload is wrong. Do not retry blindly; fix the payload first.
• COLLAB_SYNC_FAILED, REWRITE_BARRIER_FAILED, PROJECTION_STALE, INTERNAL_ERROR, 5xx, network timeout, and any 202 with collab.status: "pending" — the canonical doc may have been written even though the call looks like a failure. Before any retry, re-read /state and check whether the intended mark/edit is already present; only retry if it isn't.
• Idempotency-Key (see below) protects against double-apply on the same request (e.g., TCP-level retry). It does not help if you build a new request body and send a second call — that is a new logical write with a new key.

Duplicate-mark incidents usually come from retrying a comment.add or suggestion.add after a timeout without verifying. When in doubt: re-read, diff, then decide.

Idempotency-Key header is recommended on every mutation for safe automation retries; required when /state.contract.idempotencyRequired is true. Use the same key only when resending the exact same serialized request body. If the body changes — including because you replaced baseToken after STALE_BASE — mint a new key or Proof will reject it as key reuse with a different payload.

Comment on text:

{"type": "comment.add", "quote": "text to comment on", "by": "ai:compound-engineering", "text": "Your comment here", "baseToken": "<token>"}

Reply to a comment:

{"type": "comment.reply", "markId": "<id>", "by": "ai:compound-engineering", "text": "Reply text", "baseToken": "<token>"}

Reply and resolve in one mutation:

{"type": "comment.reply", "markId": "<id>", "by": "ai:compound-engineering", "text": "Fixed.", "resolve": true, "baseToken": "<token>"}

Batch existing-thread comment mutations:

{"by": "ai:compound-engineering", "baseToken": "<token>", "operations": [
  {"type": "comment.reply", "markId": "<id-1>", "text": "Fixed.", "resolve": true},
  {"type": "comment.reply", "markId": "<id-2>", "text": "Leaving this open because X."}
]}

Batch /ops supports comment.reply, comment.resolve, and comment.unresolve for existing threads. Use it for HITL ingest passes instead of issuing separate reply and resolve requests per thread.

Resolve / unresolve a comment:

{"type": "comment.resolve", "markId": "<id>", "by": "ai:compound-engineering", "baseToken": "<token>"}
{"type": "comment.unresolve", "markId": "<id>", "by": "ai:compound-engineering", "baseToken": "<token>"}

Suggest a replacement (pending — user must accept/reject):

{"type": "suggestion.add", "kind": "replace", "quote": "original text", "by": "ai:compound-engineering", "content": "replacement text", "baseToken": "<token>"}

Suggest and immediately apply (tracked but committed — user can reject to revert):

{"type": "suggestion.add", "kind": "replace", "quote": "original text", "by": "ai:compound-engineering", "content": "replacement text", "status": "accepted", "baseToken": "<token>"}

status: "accepted" creates the suggestion mark and commits the change in one call. The mark persists as an audit trail with per-edit attribution and a reject-to-revert affordance. Works with kind: "insert" | "delete" | "replace".

Accept or reject an existing suggestion:

{"type": "suggestion.accept", "markId": "<id>", "by": "ai:compound-engineering", "baseToken": "<token>"}
{"type": "suggestion.reject", "markId": "<id>", "by": "ai:compound-engineering", "baseToken": "<token>"}

suggestion.resolve is not supported — use accept or reject instead.

Whole-doc rewrite (last resort):

{"type": "rewrite.apply", "content": "full new markdown", "by": "ai:compound-engineering", "baseToken": "<token>"}

Prefer find_replace_in_doc or block-level /edit/v2 operations first. rewrite.apply is broad, disruptive, and blocked while live clients are connected.

Block-level edits via /edit/v2 (separate endpoint, separate shape):

curl -X POST "https://www.proofeditor.ai/api/agent/{slug}/edit/v2" \
  -H "Content-Type: application/json" \
  -H "x-share-token: <token>" \
  -H "X-Agent-Id: ai:compound-engineering" \
  -H "Idempotency-Key: <uuid>" \
  -d '{
    "by": "ai:compound-engineering",
    "baseToken": "mt1:<token>",
    "operations": [
      {"op": "replace_block", "ref": "b3", "block": {"markdown": "Updated paragraph."}},
      {"op": "insert_after", "ref": "b3", "blocks": [{"markdown": "## New section"}]}
    ]
  }'

Per-op body shape (singular block vs plural blocks is load-bearing — sending the wrong one returns 422):

Read /snapshot to get block ref IDs and mutationBase.token. ref values are opaque request tokens tied to the snapshot/baseToken; re-read /snapshot before follow-up block edits if writes have landed. operations commits atomically — either every op lands or none do — so one /edit/v2 call can batch dozens of block edits safely and efficiently (see the bulk-sweep guidance in references/hitl-review.md Phase 2.4). Successful full responses include the next mutationBase.token and fresh snapshot.blocks[].ref values for chaining.

For literal doc-wide sweeps, prefer find_replace_in_doc over many block replacements or a whole-doc rewrite. Validate large batches with ?dryRun=1 or ?validate=1; use ?return=minimal when you only need ok, revision, appliedCount, and the next mutationBase.

Editing while a client is connected is fine. /edit/v2, suggestion.add (including status: "accepted"), and all comment ops work during active collab. Only rewrite.apply is blocked by LIVE_CLIENTS_PRESENT — it would clobber in-flight Yjs edits.

When the loop breaks. If a mutation keeps failing after a fresh read and one retry, or state across reads looks inconsistent, call POST https://www.proofeditor.ai/api/bridge/report_bug with the failing request ID, slug, and raw response. The server enriches and files an issue.

Known Limitations (Web API)

• Bridge-style endpoints (/d/{slug}/bridge/*) require client version headers (x-proof-client-version, x-proof-client-build, x-proof-client-protocol) and return 426 CLIENT_UPGRADE_REQUIRED without them. Use /api/agent/{slug}/ops instead.

Local Bridge (macOS App)

Requires Proof.app running. Bridge at http://localhost:9847.

Required headers:

• X-Agent-Id: ai:compound-engineering (identity for presence; keep aligned with by)
• Content-Type: application/json
• X-Window-Id: <uuid> (when multiple docs open)

Key Endpoints

Presence Statuses

thinking, reading, idle, acting, waiting, completed

Workflow: Review a Shared Document

When given a Proof URL like https://www.proofeditor.ai/d/abc123?token=xxx:

1. Extract the slug (abc123) and token from the URL
2. Read the document via content negotiation on the shared URL or via /api/agent/{slug}/state when you need marks/mutation metadata
3. For content edits, prefer /edit/v2 find_replace_in_doc or block operations; use /ops for comments, suggestions, and comment replies/resolution
4. The author sees changes in real-time

SHARE_URL="https://www.proofeditor.ai/d/abc123?token=xxx"
curl -s -H "Accept: application/json" "$SHARE_URL"
curl -s -H "Accept: text/markdown" "$SHARE_URL"

# Read once for content + the initial baseToken.
# After each successful mutation, update BASE from the response's mutationBase.token.
STATE=$(curl -s "https://www.proofeditor.ai/api/agent/abc123/state" \
  -H "x-share-token: xxx")
BASE=$(printf '%s' "$STATE" | jq -r '.mutationBase.token')
# Inspect doc fields as needed: printf '%s' "$STATE" | jq '.markdown, .revision'

# Comment
OP_RESP=$(curl -s -X POST "https://www.proofeditor.ai/api/agent/abc123/ops" \
  -H "Content-Type: application/json" \
  -H "x-share-token: xxx" \
  -H "X-Agent-Id: ai:compound-engineering" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d "$(jq -n --arg base "$BASE" '{type:"comment.add",quote:"text",by:"ai:compound-engineering",text:"comment",baseToken:$base}')")
NEXT_BASE=$(printf '%s' "$OP_RESP" | jq -r '.mutationBase.token // empty')
[ -n "$NEXT_BASE" ] && BASE="$NEXT_BASE"

# Suggest edit (tracked, pending)
OP_RESP=$(curl -s -X POST "https://www.proofeditor.ai/api/agent/abc123/ops" \
  -H "Content-Type: application/json" \
  -H "x-share-token: xxx" \
  -H "X-Agent-Id: ai:compound-engineering" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d "$(jq -n --arg base "$BASE" '{type:"suggestion.add",kind:"replace",quote:"old",by:"ai:compound-engineering",content:"new",baseToken:$base}')")
NEXT_BASE=$(printf '%s' "$OP_RESP" | jq -r '.mutationBase.token // empty')
[ -n "$NEXT_BASE" ] && BASE="$NEXT_BASE"

# Suggest and immediately apply (tracked, committed)
OP_RESP=$(curl -s -X POST "https://www.proofeditor.ai/api/agent/abc123/ops" \
  -H "Content-Type: application/json" \
  -H "x-share-token: xxx" \
  -H "X-Agent-Id: ai:compound-engineering" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d "$(jq -n --arg base "$BASE" '{type:"suggestion.add",kind:"replace",quote:"old",by:"ai:compound-engineering",content:"new",status:"accepted",baseToken:$base}')")
NEXT_BASE=$(printf '%s' "$OP_RESP" | jq -r '.mutationBase.token // empty')
[ -n "$NEXT_BASE" ] && BASE="$NEXT_BASE"

# Direct content edit (preferred when visible suggestion marks are not needed)
SNAPSHOT=$(curl -s "https://www.proofeditor.ai/api/agent/abc123/snapshot" \
  -H "x-share-token: xxx")
EDIT_BASE=$(printf '%s' "$SNAPSHOT" | jq -r '.mutationBase.token')
curl -X POST "https://www.proofeditor.ai/api/agent/abc123/edit/v2?return=minimal" \
  -H "Content-Type: application/json" \
  -H "x-share-token: xxx" \
  -H "X-Agent-Id: ai:compound-engineering" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d "$(jq -n --arg base "$EDIT_BASE" '{by:"ai:compound-engineering",baseToken:$base,operations:[{op:"find_replace_in_doc",find:"old",replace:"new",occurrence:"all"}]}')"

Workflow: Create and Share a New Document

# 1. Create
RESPONSE=$(curl -s -X POST https://www.proofeditor.ai/share/markdown \
  -H "Content-Type: application/json" \
  -d '{"title":"My Doc","markdown":"# Title\n\nContent here."}')

# 2. Extract URL and token
URL=$(echo "$RESPONSE" | jq -r '.tokenUrl')
SLUG=$(echo "$RESPONSE" | jq -r '.slug')
TOKEN=$(echo "$RESPONSE" | jq -r '.accessToken')

# 3. Bind display name via presence
curl -s -X POST "https://www.proofeditor.ai/api/agent/$SLUG/presence" \
  -H "Content-Type: application/json" \
  -H "x-share-token: $TOKEN" \
  -H "X-Agent-Id: ai:compound-engineering" \
  -d '{"name":"Compound Engineering","status":"reading","summary":"Uploaded doc"}'

# 4. Share the URL
echo "$URL"

# 5. Make comment/suggestion edits using the ops endpoint (baseToken required)
BASE=$(curl -s "https://www.proofeditor.ai/api/agent/$SLUG/state" \
  -H "x-share-token: $TOKEN" | jq -r '.mutationBase.token')
OP_RESP=$(curl -s -X POST "https://www.proofeditor.ai/api/agent/$SLUG/ops" \
  -H "Content-Type: application/json" \
  -H "x-share-token: $TOKEN" \
  -H "X-Agent-Id: ai:compound-engineering" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d "$(jq -n --arg base "$BASE" '{type:"comment.add",quote:"Content here",by:"ai:compound-engineering",text:"Added a note",baseToken:$base}')")
NEXT_BASE=$(printf '%s' "$OP_RESP" | jq -r '.mutationBase.token // empty')
[ -n "$NEXT_BASE" ] && BASE="$NEXT_BASE"

# For content edits, prefer /edit/v2 over rewrite.apply.
SNAPSHOT=$(curl -s "https://www.proofeditor.ai/api/agent/$SLUG/snapshot" \
  -H "x-share-token: $TOKEN")
EDIT_BASE=$(printf '%s' "$SNAPSHOT" | jq -r '.mutationBase.token')
curl -X POST "https://www.proofeditor.ai/api/agent/$SLUG/edit/v2?return=minimal" \
  -H "Content-Type: application/json" \
  -H "x-share-token: $TOKEN" \
  -H "X-Agent-Id: ai:compound-engineering" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d "$(jq -n --arg base "$EDIT_BASE" '{by:"ai:compound-engineering",baseToken:$base,operations:[{op:"find_replace_in_doc",find:"Content",replace:"Updated content",occurrence:"all"}]}')"

Workflow: Pull a Proof Doc to Local

Sync the current Proof doc state to a local markdown file. Used by:

• HITL review end-sync (references/hitl-review.md Phase 5) when the doc originated from a local file
• Ad-hoc snapshots of a Proof doc to disk (before closing the tab, archiving, handing off)
• Refreshing a local working copy against the live Proof version

SLUG=<slug>
TOKEN=<accessToken>
LOCAL=<absolute-path>

# One read to a temp file — avoids passing markdown through $(...), which would strip trailing newlines.
STATE_TMP=$(mktemp)
curl -s "https://www.proofeditor.ai/api/agent/$SLUG/state" \
  -H "x-share-token: $TOKEN" > "$STATE_TMP"
REVISION=$(jq -r '.revision' "$STATE_TMP")

# Atomic write: stream .markdown bytes directly to a temp sibling, then rename.
TMP="${LOCAL}.proof-sync.$$"
jq -jr '.markdown' "$STATE_TMP" > "$TMP" && mv "$TMP" "$LOCAL"
rm "$STATE_TMP"

jq -jr (-j no trailing newline, -r raw string) streams the markdown bytes straight to the temp file without going through a shell variable, so trailing newlines survive intact. mv within the same filesystem is atomic — a crashed write leaves the original untouched rather than a half-written file.

Confirm before writing when the pull isn't directly asked for. If a workflow ends up pulling as a side-effect of a different action (e.g., HITL review completion), surface the impending write with a short confirm like "Sync reviewed doc to <localPath>?" A silent overwrite is surprising — the user may have forgotten the local file exists in that session, or expected Proof to stay canonical until they explicitly asked to pull.

Safety

• Use /state content as source of truth before editing
• During active collab use edit/v2 (direct block changes) or suggestion.add (tracked changes); reserve rewrite.apply for no-client scenarios since it's blocked by LIVE_CLIENTS_PRESENT when anyone is connected
• Prefer find_replace_in_doc and block-level /edit/v2 edits before considering rewrite.apply
• Don't span table cells in a single replace
• Always include by: "ai:compound-engineering" on every op and X-Agent-Id: ai:compound-engineering in headers for consistent attribution
• Reuse baseToken from your most recent /state or /snapshot read; on STALE_BASE, re-read and retry once