minimal working version of backend and cli

backend/cli.py

@@ -0,0 +1,434 @@
+#!/usr/bin/env python3
+"""
+MIND CLI (v0) — supports Ops 1–8 via REST calls to the Go backend.
+
+Assumptions:
+  - API base: http://localhost:8080 (change with \\set api ...)
+  - llama.cpp server: http://localhost:8081 (change with \\set llama ...)
+  - Auth: dev token ("Bearer dev"). Adjust as needed.
+
+Core usage model:
+  - Free text (no leading '\\') calls /completion (Op 2 helper) on the active conversation/branch.
+  - Backslash commands perform explicit ops.
+
+Operations → Commands mapping
+  1) Start conversation            → \\new <title> <owner_id>
+  2) Commit (prompt/answer or node)→ free text → /completion; or \\node <user|assistant> <content> [parent_id]
+  3) Fork branch                   → \\branch <name> [head_node_id]
+  4) Delete branch or node         → \\delbranch <name>   |  \\delnode <node_id>
+  5) Extract subset as new tree    → \\extract <title> <node_id ...>
+  6) Merge two branches            → \\merge <left> <right> <left-first|right-first>
+  7) Detach branch to new convo    → \\detach <branch>
+  8) Append/copy tree to another   → \\append-tree <src_conv> <src_branch> [dst_conv [dst_branch]]
+
+Helpful extras:
+  - \\listconvs <owner_id>
+  - \\listbranches <conversation_id>
+  - \\linearize (active conv/branch)
+  - \\llama <prompt> (debug llama-server directly)
+  - \\useconv <id> ; \\usebranch <name> ; \\who ; \\quit
+"""
+
+import json
+import os
+import shlex
+import sys
+from typing import Dict, Any, List
+
+import requests
+
+DEFAULT_API = os.environ.get("MIND_API", "http://localhost:8080")
+DEFAULT_LLAMA = os.environ.get("LLAMA_API", "http://localhost:8081")
+
+auth_headers = lambda: {"Authorization": "Bearer dev", "Content-Type": "application/json"}
+
+class State:
+    def __init__(self):
+        self.api = DEFAULT_API.rstrip('/')
+        self.llama = DEFAULT_LLAMA.rstrip('/')
+        self.conversation_id = None  # int
+        self.branch = None           # str
+
+    def as_dict(self):
+        return {
+            "api": self.api,
+            "llama": self.llama,
+            "conversation_id": self.conversation_id,
+            "branch": self.branch,
+        }
+
+
+def pretty(obj: Any) -> str:
+    try:
+        return json.dumps(obj, indent=2, ensure_ascii=False)
+    except Exception:
+        return str(obj)
+
+
+def post_json(url: str, payload: Dict[str, Any]) -> Dict[str, Any]:
+    r = requests.post(url, headers=auth_headers(), data=json.dumps(payload), timeout=60)
+    r.raise_for_status()
+    if r.text.strip() == "":
+        return {}
+    return r.json()
+
+
+def delete_json(url: str, payload: Dict[str, Any] | None = None) -> Dict[str, Any]:
+    r = requests.delete(url, headers=auth_headers(), data=json.dumps(payload) if payload else None, timeout=60)
+    r.raise_for_status()
+    return r.json() if r.text.strip() else {}
+
+
+def get_json(url: str, params: Dict[str, Any]) -> Dict[str, Any] | List[Any]:
+    r = requests.get(url, headers=auth_headers(), params=params, timeout=60)
+    r.raise_for_status()
+    ct = r.headers.get('Content-Type','')
+    if 'application/json' in ct:
+        return r.json()
+    return {"raw": r.text}
+
+
+# ---------- Commands ----------
+
+def cmd_help():
+    print(__doc__)
+
+
+def cmd_set(st: State, args):
+    if len(args) < 2:
+        print("usage: \\set <api|llama> <URL>")
+        return
+    key, val = args[0], args[1]
+    if key == 'api':
+        st.api = val.rstrip('/')
+    elif key == 'llama':
+        st.llama = val.rstrip('/')
+    else:
+        print("unknown key; use 'api' or 'llama'")
+        return
+    print("ok:", pretty(st.as_dict()))
+
+
+# (1) Start conversation
+
+def cmd_new(st: State, args):
+    if len(args) < 2:
+        print("usage: \\new <title> <owner_id>")
+        return
+    title = args[0]
+    try:
+        owner_id = int(args[1])
+    except ValueError:
+        print("owner_id must be an integer")
+        return
+    out = post_json(f"{st.api}/conversations", {"title": title, "owner_id": owner_id})
+    cid = out.get("id")
+    st.conversation_id = cid
+    print("created conversation:", cid)
+
+
+def cmd_listconvs(st: State, args):
+    if not args:
+        print("usage: \\listconvs <owner_id>")
+        return
+    owner_id = int(args[0])
+    out = get_json(f"{st.api}/conversations", {"owner_id": owner_id})
+    print(pretty(out))
+
+
+# (3) Fork branch
+
+def cmd_branch(st: State, args):
+    if st.conversation_id is None:
+        print("set a conversation first: \\useconv <id> or \\new <title> <owner_id>")
+        return
+    if len(args) < 1:
+        print("usage: \\branch <name> [head_node_id]")
+        return
+    name = args[0]
+    head = int(args[1]) if len(args) > 1 else 0
+    payload = {
+        "conversation_id": st.conversation_id,
+        "name": name,
+        "head_node_id": head
+    }
+    out = post_json(f"{st.api}/branches", payload)
+    st.branch = out.get("name", name)
+    print("active branch:", st.branch, pretty(out))
+
+
+def cmd_usebranch(st: State, args):
+    if not args:
+        print("usage: \\usebranch <name>")
+        return
+    st.branch = args[0]
+    print("active branch:", st.branch)
+
+    
+def cmd_listbranches(st: State, args):
+    if not args:
+        if st.conversation_id is None:
+            print("usage: \\listbranches <conversation_id> (or set active with \\useconv)")
+            return
+        conv = st.conversation_id
+    else:
+        conv = int(args[0])
+    out = get_json(f"{st.api}/branches", {"conversation_id": conv})
+    print(pretty(out))
+
+
+def cmd_useconv(st: State, args):
+    if not args:
+        print("usage: \\useconv <conversation_id>")
+        return
+    st.conversation_id = int(args[0])
+    print("active conversation:", st.conversation_id)
+
+
+# (2) Commit helpers
+
+def cmd_node(st: State, args):
+    """Create a single node (explicit Op 2). usage: \\node <user|assistant> <content> [parent_id]"""
+    if st.conversation_id is None:
+        print("set active conversation first")
+        return
+    if len(args) < 2:
+        print("usage: \\node <user|assistant> <content> [parent_id]")
+        return
+    author = args[0]
+    content = args[1]
+    parent_id = int(args[2]) if len(args) > 2 else None
+    payload = {
+        "conversation_id": st.conversation_id,
+        "author_kind": author,
+        "content": content
+    }
+    if parent_id is not None:
+        payload["parent_id"] = parent_id
+    out = post_json(f"{st.api}/nodes", payload)
+    print(pretty(out))
+
+
+def send_prompt(st: State, line: str):
+    # Free text → /completion (with auto-branch-create retry)
+    if st.conversation_id is None or not st.branch:
+        print("need active conversation and branch (\\new/\\useconv and \\branch/\\usebranch)")
+        return
+    payload = {
+        "conversation_id": st.conversation_id,
+        "branch": st.branch,
+        "prompt": line.strip(),
+    }
+    try:
+        out = post_json(f"{st.api}/completion", payload)
+    except requests.HTTPError as e:
+        body = e.response.text if e.response is not None else ""
+        # If branch doesn't exist yet, create it and retry once
+        if e.response is not None and e.response.status_code in (400, 404, 500) and "branch" in body.lower():
+            _ = post_json(f"{st.api}/branches", {
+                "conversation_id": st.conversation_id,
+                "name": st.branch,
+                "head_node_id": 0
+            })
+            out = post_json(f"{st.api}/completion", payload)
+        else:
+            raise
+    print("assistant:\n", out.get("answer"))
+
+    
+# (4) Delete branch / node
+def cmd_delbranch(st: State, args):
+    if st.conversation_id is None:
+        print("set active conversation first")
+        return
+    if not args:
+        print("usage: \\delbranch <name>")
+        return
+    name = args[0]
+    out = delete_json(f"{st.api}/branches", {"conversation_id": st.conversation_id, "name": name})
+    if st.branch == name:
+        st.branch = None
+    print("deleted branch:", name, pretty(out))
+
+
+def cmd_delnode(st: State, args):
+    if not args:
+        print("usage: \\delnode <node_id>")
+        return
+    node_id = int(args[0])
+    out = delete_json(f"{st.api}/nodes/{node_id}")
+    print(pretty(out))
+
+
+# (5) Extract selected nodes to new conversation
+
+def cmd_extract(st: State, args):
+    if len(args) < 2:
+        print("usage: \\extract <title> <node_id ...>")
+        return
+    title = args[0]
+    node_ids = [int(x) for x in args[1:]]
+    payload = {"conversation_id": st.conversation_id, "title": title, "node_ids": node_ids}
+    out = post_json(f"{st.api}/extract", payload)
+    new_cid = out.get("new_conversation_id")
+    print("extracted to conversation:", new_cid, pretty(out))
+
+
+# (6) Merge two branches (concat order)
+
+def cmd_merge(st: State, args):
+    if st.conversation_id is None:
+        print("set active conversation first")
+        return
+    if len(args) < 3:
+        print("usage: \\merge <left_branch> <right_branch> <left-first|right-first>")
+        return
+    left, right, order = args[0], args[1], args[2]
+    payload = {"conversation_id": st.conversation_id, "left_branch": left, "right_branch": right, "order": order}
+    out = post_json(f"{st.api}/merge", payload)
+    print("merge result:", pretty(out))
+
+
+# (7) Detach branch → new conversation
+
+def cmd_detach(st: State, args):
+    if st.conversation_id is None:
+        print("set active conversation first")
+        return
+    if not args:
+        print("usage: \\detach <branch>")
+        return
+    payload = {"conversation_id": st.conversation_id, "branch": args[0]}
+    out = post_json(f"{st.api}/detach", payload)
+    print("detached to:", pretty(out))
+
+
+# (8) Append/copy tree
+
+def cmd_append_tree(st: State, args):
+    if len(args) < 2:
+        print("usage: \\append-tree <src_conv> <src_branch> [dst_conv [dst_branch]]")
+        return
+    src_conv = int(args[0])
+    src_branch = args[1]
+    dst_conv = int(args[2]) if len(args) > 2 else st.conversation_id
+    dst_branch = args[3] if len(args) > 3 else st.branch
+    payload = {"src_conversation_id": src_conv, "src_branch": src_branch, "dst_conversation_id": dst_conv, "dst_branch": dst_branch}
+    out = post_json(f"{st.api}/append-tree", payload)
+    print("append-tree result:", pretty(out))
+
+
+# Linearize & llama & misc
+
+def cmd_linearize(st: State):
+    if st.conversation_id is None or not st.branch:
+        print("need active conversation and branch (\\useconv / \\usebranch)")
+        return
+    out = get_json(f"{st.api}/linearize", {"conversation_id": st.conversation_id, "branch": st.branch})
+    if isinstance(out, dict):
+        print("==== Transcript ====")
+        print(out.get("text", ""))
+    else:
+        print(pretty(out))
+
+
+def cmd_llama(st: State, args):
+    if not args:
+        print("usage: \\llama <prompt>")
+        return
+    prompt = " ".join(args)
+    payload = {"prompt": prompt}
+    try:
+        r = requests.post(f"{st.llama}/completion", headers={"Content-Type": "application/json"}, data=json.dumps(payload), timeout=60)
+        r.raise_for_status()
+        data = r.json()
+        text = None
+        if isinstance(data, dict):
+            if 'completion' in data:
+                text = data['completion']
+            elif 'content' in data and isinstance(data['content'], list) and data['content']:
+                seg = data['content'][0]
+                if isinstance(seg, dict) and 'text' in seg:
+                    text = seg['text']
+        print("llama says:", text or pretty(data))
+    except Exception as e:
+        print("llama error:", e)
+
+
+def cmd_who(st: State):
+    print(pretty(st.as_dict()))
+
+
+# ---------- REPL ----------
+
+def repl():
+    st = State()
+    print("MIND CLI — type \\help for commands. Free text sends /completion.")
+    while True:
+        try:
+            line = input("> ").strip()
+        except (EOFError, KeyboardInterrupt):
+            print()
+            break
+        if not line:
+            continue
+        if line.startswith("\\"):
+            parts = shlex.split(line[1:])
+            if not parts:
+                continue
+            cmd, *args = parts
+            cmd = cmd.lower()
+            try:
+                if cmd == 'help':
+                    cmd_help()
+                elif cmd == 'set':
+                    cmd_set(st, args)
+                elif cmd == 'new':
+                    cmd_new(st, args)
+                elif cmd == 'listconvs':
+                    cmd_listconvs(st, args)
+                elif cmd == 'listbranches':
+                    cmd_listbranches(st, args)
+                elif cmd == 'useconv':
+                    cmd_useconv(st, args)
+                elif cmd == 'branch':
+                    cmd_branch(st, args)
+                elif cmd == 'usebranch':
+                    cmd_usebranch(st, args)
+                elif cmd == 'node':
+                    cmd_node(st, args)
+                elif cmd == 'delbranch':
+                    cmd_delbranch(st, args)
+                elif cmd == 'delnode':
+                    cmd_delnode(st, args)
+                elif cmd == 'extract':
+                    cmd_extract(st, args)
+                elif cmd == 'merge':
+                    cmd_merge(st, args)
+                elif cmd == 'detach':
+                    cmd_detach(st, args)
+                elif cmd in ('append-tree', 'appendtree', 'append'):
+                    cmd_append_tree(st, args)
+                elif cmd == 'linearize':
+                    cmd_linearize(st)
+                elif cmd == 'llama':
+                    cmd_llama(st, args)
+                elif cmd == 'who':
+                    cmd_who(st)
+                elif cmd in ('quit', 'exit', 'q'):
+                    break
+                else:
+                    print("unknown command, try \\help")
+            except requests.HTTPError as e:
+                try:
+                    print("HTTP", e.response.status_code, e.response.text)
+                except Exception:
+                    print("HTTP error:", e)
+            except Exception as e:
+                print("error:", e)
+        else:
+            send_prompt(st, line)
+
+
+if __name__ == '__main__':
+    repl()

backend/cmd/main.go

@@ -26,7 +26,7 @@ func main() {
 	}
 	repo := db.NewRepo(database)
 
-	g := glue.NewGlue(repo)
+	g := glue.NewGlue(repo, cfg)
 	r := httpapi.NewRouter(logger, cfg, g)
 
 	srv := &http.Server{ 

backend/internal/config/config.go

@@ -5,10 +5,11 @@ import (
 )
 
 type Config struct {
-	DSN        string // e.g. mysql: "user:pass@tcp(127.0.0.1:3306)/mind?parseTime=true"; sqlite: "file:mind.db?_pragma=busy_timeout(5000)"
+	DSN        string
 	Driver     string // "mysql" or "sqlite"
 	JWTSecret  string
-	Port       string // default 8080
+	Port       string
+	LlamaURL   string 
 }
 
 func getenv(k, def string) string { v := os.Getenv(k); if v == "" { return def }; return v }
@@ -19,5 +20,6 @@ func Load() Config {
         Driver:    getenv("DB_DRIVER", "sqlite"),
         JWTSecret: getenv("JWT_SECRET", "devsecret"),
         Port:      getenv("PORT", "8080"),
+        LlamaURL:  getenv("LLAMA_URL", "http://localhost:8081"),
     }
 }

backend/internal/db/repo.go

@@ -86,3 +86,29 @@ func (r *Repo) LatestParent(ctx context.Context, childID int64) (models.Node, bo
 	}
 	return n, true, nil
 }
+
+func (r *Repo) DeleteBranch(ctx context.Context, convID int64, name string) error {
+    _, err := r.db.ExecContext(ctx, `DELETE FROM branches WHERE conversation_id=? AND name=?`, convID, name)
+    return err
+}
+
+// ListBranches returns all branches for a conversation, newest first.
+func (r *Repo) ListBranches(ctx context.Context, convID int64) ([]models.Branch, error) {
+	rows, err := r.db.QueryContext(ctx, `
+		SELECT id, conversation_id, name, head_node_id
+		FROM branches
+		WHERE conversation_id=?
+		ORDER BY id DESC`, convID)
+	if err != nil { return nil, err }
+	defer rows.Close()
+
+	var out []models.Branch
+	for rows.Next() {
+		var b models.Branch
+		if err := rows.Scan(&b.ID, &b.ConversationID, &b.Name, &b.HeadNodeID); err != nil {
+			return nil, err
+		}
+		out = append(out, b)
+	}
+	return out, nil
+}

backend/internal/glue/branches.go

@@ -5,8 +5,20 @@ import (
 	"mind/internal/models"
 )
 
-type ForkReq struct { ConversationID int64; Name string; HeadNodeID int64 }
+type ForkReq struct {
+    ConversationID int64  `json:"conversation_id"`
+    Name           string `json:"name"`
+    HeadNodeID     int64  `json:"head_node_id"`
+}
 
 func (g *Glue) ForkBranch(ctx context.Context, fr ForkReq) (models.Branch, error) {
 	return g.repo.CreateOrGetBranch(ctx, fr.ConversationID, fr.Name, fr.HeadNodeID)
 }
+
+func (g *Glue) DeleteBranch(ctx context.Context, conversationID int64, name string) error {
+    return g.repo.DeleteBranch(ctx, conversationID, name)
+}
+
+func (g *Glue) ListBranches(ctx context.Context, conversationID int64) ([]models.Branch, error) {
+	return g.repo.ListBranches(ctx, conversationID)
+}

backend/internal/glue/completion.go

@@ -1,9 +1,34 @@
 package glue
 
 import (
+	"bytes"
 	"context"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"time"
+
+	"mind/internal/config"
+	"mind/internal/db"
+	"mind/internal/models"
 )
 
+type Glue struct {
+	repo *db.Repo
+	cfg  config.Config
+}
+
+// NewGlue now receives cfg
+func NewGlue(r *db.Repo, cfg config.Config) *Glue { return &Glue{repo: r, cfg: cfg} }
+
+func (g *Glue) CreateConversation(ctx context.Context, ownerID int64, title string) (int64, error) {
+	return g.repo.CreateConversation(ctx, ownerID, title)
+}
+
+func (g *Glue) ListConversations(ctx context.Context, ownerID int64) ([]models.Conversation, error) {
+	return g.repo.ListConversations(ctx, ownerID)
+}
+
 type CompletionReq struct {
 	ConversationID int64  `json:"conversation_id"`
 	BranchName     string `json:"branch"`
@@ -16,24 +41,73 @@ type CompletionResp struct {
 	Answer       string `json:"answer"`
 }
 
-// For v0 we stub the answer as a simple echo with a prefix.
+// llama request/response (support two common shapes)
+type llamaReq struct {
+	Prompt string `json:"prompt"`
+}
+type llamaResp struct {
+	Content string `json:"content"`
+}
+
+func (g *Glue) callLlama(ctx context.Context, prompt string) (string, error) {
+	if g.cfg.LlamaURL == "" {
+		return "", errors.New("LLAMA_URL not set")
+	}
+	body, _ := json.Marshal(llamaReq{Prompt: prompt})
+	url := g.cfg.LlamaURL + "/completion"
+
+	httpc := &http.Client{Timeout: 45 * time.Second}
+
+	req, _ := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := httpc.Do(req)
+	if err != nil {		
+		return "", err
+	}
+	defer resp.Body.Close()
+	
+	dec := json.NewDecoder(resp.Body)
+	var a llamaResp
+	if err := dec.Decode(&a); err == nil && a.Content != "" {
+		return a.Content, nil
+	}
+
+	return "", errors.New("unexpected llama response")
+}
+
 func (g *Glue) AppendCompletion(ctx context.Context, req CompletionReq) (CompletionResp, error) {
 	b, err := g.repo.GetBranch(ctx, req.ConversationID, req.BranchName)
-	if err != nil { return CompletionResp{}, err }
+	if err != nil {
+		return CompletionResp{}, err
+	}
 
-	// 1) create user prompt node
+	// 1) user prompt node
 	promptID, err := g.repo.CreateNode(ctx, req.ConversationID, "user", req.Prompt)
-	if err != nil { return CompletionResp{}, err }
-	if err := g.repo.Link(ctx, b.HeadNodeID, promptID); err != nil { return CompletionResp{}, err }
+	if err != nil {
+		return CompletionResp{}, err
+	}
+	if err := g.repo.Link(ctx, b.HeadNodeID, promptID); err != nil {
+		return CompletionResp{}, err
+	}
+
+	// 2) real llama call (fallback to stub if it fails)
+	answerText, err := g.callLlama(ctx, req.Prompt)
+	if err != nil {
+		answerText = "(stub) You said: " + req.Prompt
+	}
 
-	// 2) create assistant answer node (stub)
-	answerText := "(stub) You said: " + req.Prompt
 	answerID, err := g.repo.CreateNode(ctx, req.ConversationID, "assistant", answerText)
-	if err != nil { return CompletionResp{}, err }
-	if err := g.repo.Link(ctx, promptID, answerID); err != nil { return CompletionResp{}, err }
+	if err != nil {
+		return CompletionResp{}, err
+	}
+	if err := g.repo.Link(ctx, promptID, answerID); err != nil {
+		return CompletionResp{}, err
+	}
 
 	// 3) move branch head
-	if err := g.repo.MoveBranchHead(ctx, b.ID, answerID); err != nil { return CompletionResp{}, err }
+	if err := g.repo.MoveBranchHead(ctx, b.ID, answerID); err != nil {
+		return CompletionResp{}, err
+	}
 
 	return CompletionResp{PromptNodeID: promptID, AnswerNodeID: answerID, Answer: answerText}, nil
 }

backend/internal/glue/conversations.go

@@ -1,19 +0,0 @@
-package glue
-
-import (
-	"context"
-	"mind/internal/db"
-	"mind/internal/models"
-)
-
-type Glue struct { repo *db.Repo }
-
-func NewGlue(r *db.Repo) *Glue { return &Glue{repo: r} }
-
-func (g *Glue) CreateConversation(ctx context.Context, ownerID int64, title string) (int64, error) {
-	return g.repo.CreateConversation(ctx, ownerID, title)
-}
-
-func (g *Glue) ListConversations(ctx context.Context, ownerID int64) ([]models.Conversation, error) {
-	return g.repo.ListConversations(ctx, ownerID)
-}

backend/internal/http/handlers.go

@@ -30,13 +30,51 @@ func (s *server) conversations(w http.ResponseWriter, r *http.Request) {
 }
 
 // POST /branches {conversation_id, name, head_node_id}
+// GET  /branches?conversation_id=...
+// DELETE /branches {conversation_id, name}
 func (s *server) branches(w http.ResponseWriter, r *http.Request) {
-	if r.Method != http.MethodPost { w.WriteHeader(405); return }
-	var in glue.ForkReq
-	if err := json.NewDecoder(r.Body).Decode(&in); err != nil { writeJSON(w, 400, map[string]string{"error":"bad json"}); return }
-	b, err := s.glue.ForkBranch(r.Context(), in)
+	switch r.Method {
+	case http.MethodPost:
+		var in struct {
+			ConversationID int64  `json:"conversation_id"`
+			Name           string `json:"name"`
+			HeadNodeID     int64  `json:"head_node_id"`
+		}
+		if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
+			writeJSON(w, 400, map[string]string{"error": "bad json"}); return
+		}
+		b, err := s.glue.ForkBranch(r.Context(), glue.ForkReq{
+			ConversationID: in.ConversationID,
+			Name:           in.Name,
+			HeadNodeID:     in.HeadNodeID,
+		})
 		if err != nil { writeJSON(w, 500, map[string]string{"error": err.Error()}); return }
 		writeJSON(w, 200, b)
+
+	case http.MethodGet:
+		qs := r.URL.Query().Get("conversation_id")
+		if qs == "" { writeJSON(w, 400, map[string]string{"error":"conversation_id required"}); return }
+		convID, _ := strconv.ParseInt(qs, 10, 64)
+		out, err := s.glue.ListBranches(r.Context(), convID)
+		if err != nil { writeJSON(w, 500, map[string]string{"error": err.Error()}); return }
+		writeJSON(w, 200, out)
+
+	case http.MethodDelete:
+		var in struct {
+			ConversationID int64  `json:"conversation_id"`
+			Name           string `json:"name"`
+		}
+		if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
+			writeJSON(w, 400, map[string]string{"error":"bad json"}); return
+		}
+		if err := s.glue.DeleteBranch(r.Context(), in.ConversationID, in.Name); err != nil {
+			writeJSON(w, 500, map[string]string{"error": err.Error()}); return
+		}
+		writeJSON(w, 200, map[string]string{"ok":"true"})
+
+	default:
+		w.WriteHeader(405)
+	}
 }
 
 // POST /completion {conversation_id, branch, prompt}