RUNTIME_API.md

Runtime API & Integration Contract

codewhale app-server is the canonical local runtime API and control plane. Local SDKs, mobile/remote-control clients, and editor integrations talk to it instead of screen-scraping terminal output. It serves the full HTTP/SSE runtime API (/v1/*), a JSON-RPC control transport over stdio, and the phone-friendly mobile page. codewhale doctor --json provides machine-readable health, and codewhale serve --acp speaks the Agent Client Protocol over stdio for editors such as Zed.

codewhale serve --http / serve --mobile remain as compatibility aliases for codewhale app-server --http / --mobile; both launch the identical server. New integrations should target app-server.

codewhale exec is the separate one-shot headless worker path (stream-json, fleet worker subprocess, CI primitive). It is not part of this API, but it shares the same runtime, provider/model resolution, permission profiles, and event vocabulary.

This document is the stable integration contract for native workbench applications (and other local supervisors) that embed the Codewhale engine.

Architecture

local supervisor / SDK / automation harness
        │
        ├─ codewhale app-server --http     → HTTP/SSE runtime API (/v1/*)        [canonical]
        ├─ codewhale app-server --mobile   → runtime API + mobile control page
        ├─ codewhale app-server --stdio    → JSON-RPC control transport over stdio
        ├─ codewhale app-server --socket   → same JSON-RPC over a unix domain socket (desktop daemon)
        ├─ codewhale doctor --json         → machine-readable health & capability
        ├─ codewhale serve --acp           → ACP stdio agent for editors such as Zed
        ├─ codewhale serve --mcp           → MCP stdio server
        ├─ codewhale serve --http/--mobile → legacy aliases for `app-server --http/--mobile`
        └─ codewhale exec [args]           → one-shot headless worker (stream-json)

The engine runs as a local-only process. All APIs bind to localhost by default. No hosted relay, no provider-token custody, no secret leakage.

For a proposed read-only audit export over completed turns, see docs/RECEIPTS.md. That document is a protocol note; the receipt CLI/API surfaces are not implemented yet.

Runtime API entrypoints

Entry	Transport	Use
codewhale web [--port 7878]	HTTP/SSE on 127.0.0.1:7878 + embedded client	First-class loopback-only browser client; opens the default browser
codewhale app-server --http	HTTP/SSE on 127.0.0.1:7878	Full /v1/* runtime API (canonical)
codewhale app-server --mobile	HTTP/SSE on loopback + /mobile	Runtime API + local mobile control page
codewhale app-server --stdio	JSON-RPC 2.0 over stdio	Local SDK / control probe (no listener)
codewhale app-server --socket [--socket-path P]	JSON-RPC 2.0 over a 0600 unix domain socket	Desktop daemon: multi-client, peer-uid checked, daemon/attach claim handshake (macOS/Linux; Windows named pipe reserved, not implemented)
codewhale app-server	HTTP on 127.0.0.1:8787	Legacy in-process app-server (/healthz, /thread, /app, /prompt, /tool, /jobs); /prompt and /thread messages execute real turns via the runtime bridge
codewhale serve --http / --mobile	same server as app-server --http/--mobile	Compatibility aliases

app-server --http and --mobile launch the same mature runtime API server historically reached through serve --http — no routes or behavior changed, so every endpoint documented below is identical across both entrypoints. The runtime API token is read from --auth-token, then CODEWHALE_RUNTIME_TOKEN, then DEEPSEEK_RUNTIME_TOKEN; use --insecure-no-auth only with a loopback bind. The serve compatibility aliases keep their --insecure flag. The legacy in-process codewhale app-server also requires an explicit --auth-token or CODEWHALE_APP_SERVER_TOKEN before binding a non-loopback host; its generated one-time cwapp_* token is loopback-only.

Workspace file suggestions

GET /v1/workspace/files/search?query=runtime&limit=20 returns {"paths":["src/runtime.rs"]} through the existing authenticated /v1/* router. It searches only the server's configured workspace, not a thread's workspace or the process's current directory. No workspace/path override is accepted. The response contains workspace-relative file paths with / separators, never file contents, absolute paths, or directories.

• query is a literal partial filename/path, without an @ prefix, at most 256 UTF-8 bytes. Missing, empty, or whitespace-only queries return an empty list without walking the filesystem. No match also returns an empty list.
• limit defaults to 20; accepted values are 1–100. Invalid limits, oversized queries, and unknown query parameters return HTTP 400.
• Matching reuses TUI fuzzy @file discovery/ranking: case-insensitive path prefix matches first, then substring matches, alphabetically within each group. This is not glob, subsequence, content, or semantic search, and does not apply the TUI's personal frecency boosts.
• Discovery shares the composer's ignore policy, including .ignore and .deepseekignore, always-discoverable AI directories, and the bounded hidden/gitignored local-reference fallback. The special .agents, .claude, .cursor, and .deepseek walks intentionally bypass ignore rules, as in the TUI. Ignore files are not confidentiality boundaries.
• Directory symlinks are not traversed. Files are canonicalized and filtered for containment in the workspace before applying the result limit; external and broken file symlinks are omitted. In-workspace file symlinks may appear by their relative names. Suggestions are a filesystem snapshot, not authorization to read a file later; consumers must revalidate when opening it.

Discovery runs off the async executor, with the shared default depth of 10, at most 20,000 candidates, and a cooperative two-second discovery budget. Results are best-effort, not an exhaustive listing; a slow filesystem operation can finish after that budget. Each request scans anew; there is no new index or cache. This read-only endpoint does not alter sessions or the pinned model prompt/tool prefix.

Runtime and account identity

GET /v1/runtime/info reports codewhale_version plus the full 40-character codewhale_commit embedded by the shared CLI/TUI build. A source archive that cannot provide an exact commit reports unknown, allowing compatibility clients to fail closed rather than accepting an ambiguous binary pair.

The same response advertises capabilities.account_session: true and capabilities.turn_operation_idempotency: true. A client must require the latter before relying on operation_key; do not infer support from a 2xx turn response because an older tolerant reader may ignore an unknown request field. capabilities.turn_operation_lookup: true separately advertises the read-only operation lookup below; clients must require it before relying on GET-based recovery of a lost turn response. The response also includes a token-free account receipt:

{
  "account": {
    "schema_version": 1,
    "state": "authenticated",
    "api_base": "https://api.codewhale.net",
    "account_id": "acct_...",
    "session_id": "session_...",
    "scopes": [],
    "expires_at": "2026-08-01T20:00:00Z"
  }
}

The Runtime reads this receipt from the exact profile- and API-origin-scoped secure record written by codewhale account login; it does not run a second login flow. States are signed_out, authenticated, offline_cached, expired, or revoked. Scopes are copied only from explicit stored session grants and are never inferred from account identity. Access/refresh tokens, email, provider profile, and provider credentials are never returned. account_id and session_id are included only for a request authorized with the Runtime token (or an explicitly insecure loopback server); the public bootstrap response remains usable but reports signed_out. Signed-out local Work remains supported and never allocates cloud compute implicitly.

The --stdio control transport is newline-delimited JSON-RPC 2.0. Probe it without spending model tokens:

printf '%s\n' \
  '{"jsonrpc":"2.0","id":1,"method":"healthz"}' \
  '{"jsonrpc":"2.0","id":2,"method":"capabilities"}' \
  '{"jsonrpc":"2.0","id":3,"method":"shutdown"}' \
  | codewhale app-server --stdio

capabilities returns the advertised method families (thread/*, app/*, prompt/*) and the full method list; thread/capabilities, app/capabilities, and prompt/capabilities scope it per family. The method set is pinned by a drift test in crates/app-server/src/lib.rs, so SDK and local integration clients can rely on it not changing silently.

Daemon socket: codewhale app-server --socket

The desktop shell (DESKTOP-APP-BRIEF §2) attaches to a long-lived daemon over a unix domain socket. The wire is the --stdio transport verbatim — the same newline-delimited JSON-RPC 2.0 methods, dispatched by the same code — with one handshake in front of it.

Endpoint. --socket-path if given; else $CODEWHALE_HOME/run/daemon.sock when CODEWHALE_HOME is set (an explicit home is an isolation boundary); else $XDG_RUNTIME_DIR/codewhale/daemon.sock; else ~/Library/Application Support/codewhale/daemon.sock on macOS or ~/.codewhale/run/daemon.sock elsewhere. The directory is created 0700, the socket is 0600, and every accepted peer must present the daemon's own uid. On start, a socket file nobody answers on is removed; a live one makes the new daemon exit with a live listener already answers on <path>; refusing to replace it; a non-socket file at the path is never touched. On Windows --socket fails with a typed UnsupportedPlatform error naming the reserved pipe \\.\pipe\codewhale-daemon — there is no silent TCP fallback. The daemon prints codewhale daemon: listening on <path> to stderr once it is accepting.

Handshake. The first request on a connection must be daemon/attach (healthz is also allowed beforehand, so a shell can probe liveness). Every other method is refused with -32010 attach_required until then.

{"jsonrpc":"2.0","id":1,"method":"daemon/attach","params":{
  "client":{"name":"codewhale-desktop","version":"1.2.3","pid":4242},
  "mode":"claim",
  "expect_daemon_version":"0.9.11"}}

mode is "claim" (this client spawned the daemon and manages its lifetime) or "attach" (default: a guest that found a healthy daemon). A claim while another connection owns the daemon fails with -32011 daemon_already_claimed (data.owner names the holder) and the client should retry with attach. expect_daemon_version, when present, must equal the daemon's crate version or the attach fails with -32013 daemon_version_skew (the bundle-skew guard). The reply reports the granted role (owner / attached), the daemon's pid, version, socket_path, and uptime_ms, the current owner, and the live connections count. A second daemon/attach on an attached connection is -32014 already_attached.

Capabilities. On this transport capabilities.methods is the pinned stdio set plus daemon/attach (second entry, after healthz); transport reads unix-socket. shutdown is advertised to every connection because the method exists, but only the owner may call it (below).

Ownership. Only the owner may shutdown; a guest's shutdown is refused with -32012 not_daemon_owner and does not interrupt anyone's turn. When the owner disconnects the slot frees, so a relaunched shell re-claims the daemon it left running. The owner's shutdown stops the listener, closes every connection, and removes the socket file. Journal replay from a client's last-seen seq is not part of this transport yet.

Interrupting a turn

thread/message streams until the turn reaches a terminal state, which can take minutes. The read loop keeps polling stdin while a turn streams, so a client can send:

{"jsonrpc":"2.0","id":9,"method":"thread/interrupt","params":{"thread_id":"thr_..."}}

and the runtime is asked to interrupt that turn (POST /v1/threads/{id}/turns/{turn_id}/interrupt). The reply carries interrupted: false when no turn is streaming for that thread — this is not an error, just nothing to stop. The interrupted thread/message then fails with a turn interrupted error, and its reply is written before the interrupt's own reply, since the turn owns the writer until it unwinds.

shutdown sent during a live turn also interrupts first: it needs the same bridge that the turn holds, so without that it would wait for the very turn it was meant to stop. Other requests that arrive mid-turn are queued and run in order once the turn finishes.

Running a prompt

prompt/request and prompt/run (byte-identical aliases) and the legacy HTTP POST /prompt all execute a real turn on the runtime, through the same bridge thread/message uses. There is no local fallback: nothing else in the app-server can produce model output, so a prompt either runs or fails.

• params.prompt is required and must be non-empty (-32602 otherwise).
• params.thread_id is optional. With one, the prompt runs on that thread and its history. Without one, the runtime gets a fresh thread for that single turn; the mapping is dropped when the turn ends, so a one-shot prompt is not addressable by thread/interrupt. Use thread/message when you need to be able to interrupt.
• params.model selects the model only when the call is the one that creates the runtime thread; an existing thread keeps the model it was created with.
• The response carries what the model actually said: output is the concatenated agent_message text, model is the model the runtime reports for the thread that ran it, and events are the real response_start/response_delta/response_end frames. Over stdio the same frames are also streamed to stdout while the turn runs, exactly as for thread/message.
• If the runtime cannot be reached, the call fails with -32005 (runtime_unavailable) on stdio, or HTTP 503 with {"error":{"code":"runtime_unavailable", ...}} on POST /prompt. Failures are never shaped like a successful PromptResponse.

POST /thread with a Message body behaves the same way — it runs the turn and replies status: "completed" with the streamed frames in events — where it previously replied accepted without doing anything.

Answering a clarification question

When a headless turn calls request_user_input, the runtime emits a user_input.required event carrying a request_id. Reply on the runtime API:

POST /v1/user-input/{thread_id}/{request_id}

The app-server control transport cannot accept that reply. app/request with SubmitUserInput returns ok: false and error: "user_input_reply_unsupported". This is a property of the transport, not an omission: while a turn is streaming, the stdio loop executes only thread/interrupt and queues everything else, so an answer sent there would wait on the very turn that is waiting for it.

SDK contract

The app-server exists so an external SDK can answer — without scraping TUI output — what route ran, which provider/model/reasoning/permission profile was effective, what events happened, how many tokens were used, and how the run finished. The durable Thread/Turn/Item data model already carries most of this; the table maps each integration need to where a local client reads it.

Integration need	Where it comes from	Status
Route / effective model / billing surface	TurnRecord + thread model; per-run --provider/--model overrides	available
Permission / sandbox / approval profile	thread auto_approve, sandbox + approval policy	available
Run / thread / turn IDs	thread_id, turn_id, SSE event envelope	available
Event stream	GET /v1/threads/{id}/events (replay + live SSE)	available
Turn status / terminal classification	TurnRecord.status + error summary	available
Token usage	TurnRecord.usage; aggregate via GET /v1/usage	available
Single-read run receipt (route + usage + cost)	GET /v1/threads/{id}/turns/{turn_id}/receipt	proposed (RECEIPTS.md)

For one-shot/headless automation, prefer codewhale exec with explicit --provider <id> --model <id> so a failure identifies the exact provider/model pair. Use app-server when a local integration needs to start, resume, steer, or interrupt turns, list models/capabilities, follow the event stream, or read usage. Both paths share the same runtime, so route-effective model resolution and the event vocabulary match.

Release smoke

scripts/release/app-server-smoke.sh is the committed pre-release check:

scripts/release/app-server-smoke.sh                 # stdio health/capabilities probe (no tokens)
scripts/release/app-server-smoke.sh --matrix        # + print the configured provider/model matrix
scripts/release/app-server-smoke.sh --matrix --real # + exec a cheap sentinel per provider

The stdio probe runs against a throwaway config, so it never reads real keys. The matrix discovers configured providers from codewhale auth list, skips unconfigured providers, and maps a provider to a cheap sentinel model only when it has a built-in cheap default. That built-in set is deliberately conservative (currently deepseek, zai, moonshot, and openai); every other provider — including arcee, openrouter, xiaomi-mimo, and openai-codex — is left unmapped on purpose and must be given a model per run via SMOKE_MODEL_<SLUG> rather than a guessed default (#3205). Any configured-but-unmapped provider fails loudly in --real mode. auth list reports presence flags only and exec output is passed through a redactor, so secrets are never printed. The parser is covered by scripts/release/app-server-smoke.test.sh against a fake codewhale binary.

ACP stdio adapter: codewhale serve --acp

codewhale serve --acp speaks JSON-RPC 2.0 over newline-delimited stdio for ACP-compatible editor clients. The initial adapter implements the ACP baseline:

• initialize
• session/new
• session/prompt
• session/cancel

Prompt requests are routed through the configured Codewhale client and current default model. Responses are emitted as session/update agent message chunks followed by a session/prompt response with stopReason: "end_turn".

The adapter is intentionally conservative: it does not yet expose shell tools, file-write tools, checkpoint replay, or session loading through ACP. Use codewhale serve --http for the full local runtime API and codewhale serve --mcp when another client needs Codewhale's tools as MCP tools.

Capability endpoint: codewhale doctor --json

Returns a JSON object describing the current installation's readiness state. Suitable for health-check polling from a macOS workbench. This command is strictly structural and offline: it does not load workspace credential .env files, inspect credential environment values, open secret/OAuth files, probe an OS keyring, contact providers, or start MCP processes.

codewhale doctor --json

Response schema (key fields)

Field	Type	Description
version	string	Installed version (e.g. "0.8.9")
config_path	string	Resolved config file path
config_present	bool	Whether the config file exists
paths	object	Canonical config, settings, state, sessions, logs, automations, and secrets paths
secret_backend	object	Metadata-only file-store shape, or literal unknown / not_probed for system and unsupported backends
workspace	string	Default workspace directory
legacy_state.primary_root	string	Primary Codewhale state root inspected for known state paths
legacy_state.legacy_root	string	Legacy .deepseek state root inspected for known state paths
legacy_state.needs_attention	bool	Whether known ~/.deepseek state paths need review or the read-only session recovery diagnostic found missing destination filenames / could not complete
legacy_state.legacy_only_count	number	Count of known state paths present only under the legacy root
legacy_state.dual_present_count	number	Count of known state paths present under both primary and legacy roots
legacy_state.entries	array	Per-path migration status: {name, primary_present, legacy_present, status}
legacy_state.session_recovery.status	string	isolated, no_legacy_sessions, migration_pending, migration_incomplete, migration_complete, or scan_failed
legacy_state.session_recovery.read_only	bool	Always true; doctor never invokes session migration or modifies either session directory
legacy_state.session_recovery.chat_contents_read	bool	Always false; comparison is based only on top-level .json filenames and filesystem metadata
legacy_state.session_recovery.checkpoint_internals_scanned	bool	Always false; sessions/checkpoints/ and all other directories are skipped
legacy_state.session_recovery.recoverable_files	array	Bounded sample of up to 100 missing destination filenames with source and destination paths; no chat payloads
legacy_state.session_recovery.recoverable_file_count	number	Total missing destination filename count, including entries beyond the bounded sample
legacy_state.session_recovery.recoverable_files_truncated	bool	Whether more than 100 recoverable filenames were found
legacy_state.session_recovery.recovery_command	string or null	codewhale sessions when additive automatic recovery is available; null for isolated, complete, empty, or failed scans
api_key.source	string	Structural source state: config_declared, env_declared, external_auth_declared, secret_store_unprobed, secret_store_unavailable, oauth_unprobed, external_consent, none, local_runtime, or unknown; declarations are not availability proof
api_key.availability	string	Literal present, not_required, not_probed, unavailable, or unknown; only present and not_required certify structural Setup/Fleet credential readiness
base_url	string	Provider URL authority only (scheme://host[:explicit-port]); userinfo, path, query, and fragment are omitted
default_text_model	string	Default model
memory.enabled	bool	Whether the memory feature is on
memory.path	string	Path to memory file
memory.file_present	bool	Whether memory file exists
mcp.config_path	string	MCP config file path
mcp.present	bool	Whether MCP config exists
mcp.probe_scope	string	configuration; doctor does not start MCP servers
mcp.live_health_checked	bool	Always false for doctor JSON
mcp.servers	array	Per-server structural result and counts plus separate checks; URL userinfo/path/query/fragment and command argv, environment, header, and token values are never emitted, and all live stages are not_checked
skills.selected	string	Resolved skills directory
skills.global.path / .present / .count	—	Codewhale global skills dir (~/.codewhale/skills, with legacy ~/.deepseek/skills support)
skills.agents.path / .present / .count	—	Workspace .agents/skills/ dir
skills.agents_global.path / .present / .count	—	agentskills.io global skills dir (~/.agents/skills)
skills.local.path / .present / .count	—	skills/ dir
skills.opencode.path / .present / .count	—	.opencode/skills/ dir
skills.claude.path / .present / .count	—	.claude/skills/ dir
tools.path / .present / .count	—	Global tools directory
plugins.path / .present / .count	—	Global plugins directory
sandbox.available	bool	Whether sandbox is supported on this OS
sandbox.kind	string or null	Sandbox kind (e.g. "macos_seatbelt")
storage.spillover.path / .present / .count	—	Tool output spillover dir
storage.stash.path / .present / .count	—	Composer stash

Example

{
  "version": "0.8.9",
  "config_path": "/Users/you/.codewhale/config.toml",
  "config_present": true,
  "workspace": "/Users/you/projects/codewhale-tui",
  "api_key": {
    "source": "secret_store_unprobed",
    "availability": "not_probed"
  },
  "base_url": "https://api.deepseek.com",
  "default_text_model": "deepseek-v4-pro",
  "memory": {
    "enabled": false,
    "path": "/Users/you/.codewhale/memory.md",
    "file_present": true
  },
  "mcp": {
    "config_path": "/Users/you/.codewhale/mcp.json",
    "present": true,
    "servers": [
      {"name": "filesystem", "enabled": true, "transport": "stdio", "args_count": 2, "env_count": 0, "status": "ok"}
    ]
  },
  "sandbox": {
    "available": true,
    "kind": "macos_seatbelt"
  }
}

HTTP/SSE runtime API: codewhale app-server --http

codewhale app-server --http [--host 127.0.0.1] [--port 7878] [--workers 2] [--auth-token TOKEN] [--insecure-no-auth]
codewhale app-server --mobile [--host 127.0.0.1] [--port 7878] [--auth-token TOKEN]
codewhale app-server --mobile --host ::1 [--port 7878] [--insecure-no-auth]
codewhale web [--port 7878]

# Compatibility aliases — identical server, serve flag names:
codewhale serve --http   [...] [--insecure]
codewhale serve --mobile [...] [--insecure]

Defaults: host 127.0.0.1, port 7878, 2 workers (clamped 1–8).

The server binds to localhost by default. Configuration is via CLI flags — there is no [app_server] config section.

/v1/* routes require a bearer token unless codewhale app-server is started with --insecure-no-auth on a loopback bind such as 127.0.0.1. Mobile mode is loopback-only: non-loopback hosts are rejected until Runtime has a TLS or verified-overlay transport boundary. The codewhale serve compatibility aliases use --insecure for the same loopback escape hatch. Pass --auth-token TOKEN or set CODEWHALE_RUNTIME_TOKEN=TOKEN before starting the server; DEEPSEEK_RUNTIME_TOKEN remains a compatibility alias. If neither is set, the process generates a Runtime token for that process and does not print it. /health, /v1/runtime/info, and an enabled static client shell remain public; Runtime mutations and thread data stay behind /v1/* authentication. /mobile returns 404 when mobile mode is disabled and serves the unchanged static shell when it is enabled.

Authenticated clients can provide the token as Authorization: Bearer TOKEN, X-Codewhale-Runtime-Token: TOKEN, the legacy X-DeepSeek-Runtime-Token: TOKEN. Query-string and raw Runtime-token cookie authentication are not supported.

Local browser client

codewhale web starts the canonical Runtime API on 127.0.0.1, serves dependency-free assets embedded in the binary, prints a single-use launch URL, and asks the operating system to open that URL in the default browser. If the browser does not open, the printed URL remains usable for ten minutes. The command cannot bind to a non-loopback host and cannot run with Runtime auth disabled.

The browser-launch URL contains a random, short-lived, one-time bootstrap capability, never the Runtime token. A loopback request exchanges that capability for a codewhale_web_session=…; HttpOnly; SameSite=Strict; Path=/ cookie backed by a single process-local server session that expires 12 hours after the server process starts, consumes the capability immediately, and redirects to /. Reused, expired, malformed, or non-loopback bootstrap attempts fail closed. The Runtime bearer token is not placed in rendered HTML, browser storage, logs, URL queries/fragments, or browser-launch arguments. The one-time bootstrap capability is printed in the local terminal and transits the OS browser launcher's argument list. A same-user process could race the browser to the exchange, which is why the capability is single-use, loopback-only, and expires after ten minutes — and why a same-user attacker has strictly easier local avenues than this race. Existing bearer/header/cookie authorization for /v1/* is unchanged outside web mode. In web mode, cookie-authenticated unsafe requests must also carry the exact local web origin, and Fetch Metadata identifying a cross-origin cookie request is rejected. Explicit bearer and Runtime-token header clients keep their existing behavior.

The embedded client provides a responsive thread/search rail, Runtime-owned session facts, transcript and tool receipts, and a bottom composer. It can create, select, rename, and archive threads; choose a provider and model for a new thread without changing Runtime defaults; start or steer turns; interrupt work; resolve approvals; and answer Runtime user-input requests. Selection loads GET /v1/threads/{id} first, then opens the replayable event stream with since_seq=latest_seq; reconnection advances from the newest accepted sequence and drops duplicates or events from a stale selection. The thread detail snapshot includes pending_approvals, pending_user_inputs, and pending_dynamic_tool_calls; clients must hydrate those fields before subscribing so a reload cannot strand work whose request event is at or before latest_seq. Resolution is also published as approval.decided, user_input.answered, user_input.canceled, tool_call.resolved, tool_call.canceled, or tool_call.timeout for already-connected clients.

An existing thread's model, mode, permission posture, workspace, and branch are display-only in this client. Files/Changes, PTY/terminal, preview, artifacts, provider login or global-default switching, Fleet creation, and undo/retry/restore controls are intentionally absent until the Runtime publishes explicit contracts for them.

Mobile control page

codewhale serve --mobile starts the same HTTP/SSE runtime API and serves a phone-friendly control page at /mobile. It binds only to loopback (127.0.0.1 or ::1); a non-loopback host is rejected because this Runtime surface does not yet provide TLS or a verified overlay transport. The static HTML page contains no Runtime bearer and is not itself token-gated. When Runtime auth is enabled, the CLI prints a short-lived, single-use loopback bootstrap URL. That capability creates a 30-minute, process-local Max-Age=1800; HttpOnly; SameSite=Strict mobile session cookie plus origin-scoped browser proofs. A sibling port that receives the host-scoped cookie cannot use it by itself. The page can also exchange an explicitly entered bearer once, then clears it rather than storing it in browser storage or a cookie. EventSource connections use separate short-lived, single-use stream tickets.

The mobile page can list/create threads, send prompts, follow live SSE events, steer or interrupt an active turn, and resolve normal tool approvals through POST /v1/approvals/{approval_id}. It is a local-only convenience surface; do not expose it directly to another device or public network until Runtime has a TLS or verified transport boundary.

Endpoints

Health

• GET /health

Sessions (durable session manager)

• GET /v1/sessions?limit=50&search=<fuzzy>&include_archived=false&archived_only=false&workspace=<path>&sort=recent|name|size
• GET /v1/sessions/summary?… (same query params; projected row shape)
• GET /v1/sessions/{id} (add ?peek=true&entries=12 for a bounded, redacted read-only peek instead of the full transcript)
• PATCH /v1/sessions/{id} ({ "title"?: string, "archived"?: bool })
• DELETE /v1/sessions/{id}
• POST /v1/sessions/{id}/resume-thread

Sessions and threads answer the same include_archived / archived_only pair with the same meaning, and search is the same fuzzy match (title, id, workspace — substring, then subsequence) the TUI session picker and the workbar Sessions list use. All three surfaces run one projection (crates/tui/src/session_projection.rs), so a listing cannot differ between the terminal and the dashboard.

GET /v1/sessions/summary returns rows that are field-compatible with GET /v1/threads/summary — id, title, preview, model, mode, workspace, archived, updated_at — plus message_count, total_tokens, created_at, parent_session_id, and is_current. One caveat stated plainly: preview is the session's recorded title, not its last message. Session metadata does not store a last message, and reading every transcript to synthesise one would make a list view an unbounded read. Full transcript preview lives in the TUI session picker, which reads one selected session.

PATCH /v1/sessions/{id} renames and/or archives a saved session and returns a lifecycle receipt shaped like the thread patch receipt:

{
  "session": { "id": "…", "title": "Renamed", "archived": true, "…": "…" },
  "changes": { "title": "Renamed", "archived": true }
}

changes lists only what actually moved, so a no-op patch is distinguishable from an applied one. Archiving is durable and reversible: an archived session stays on disk and stays loadable, disappears from default listings, and is never chosen by --continue or by auto-resume. The route is the same writer the TUI picker (e) and /sessions archive <id> use — there is no second archive notion.

While a session is open in an interactive Codewhale process, that process holds the authoritative copy in memory and rewrites the whole document on its next autosave. PATCH therefore fails closed on it with 409 Conflict rather than writing something that would be silently reverted. Change it in the terminal instead. A standalone codewhale web holds nothing open and is never blocked.

GET /v1/sessions/{id}?peek=true returns a bounded, redacted, read-only view instead of the transcript: at most 12 entries of at most 400 characters each (&entries=N lowers the budget, never raises it past the cap), tool calls and results summarised to a name and a size rather than inlined, and credential-shaped substrings masked. omitted_before reports how many earlier messages were dropped. The payload carries "live": false and deliberately has no turn status, running, or active field — a saved session is a recording, and live state comes only from a resumed thread's SSE stream.

Threads (durable runtime data model)

• GET /v1/threads?limit=50&include_archived=false&archived_only=false
• GET /v1/threads/summary?limit=50&search=<optional>&include_archived=false&archived_only=false
• POST /v1/threads
• GET /v1/threads/{id}
• PATCH /v1/threads/{id} (see body shape below)
• POST /v1/threads/{id}/resume
• POST /v1/threads/{id}/fork

POST /v1/threads accepts optional execution defaults in addition to the provider, model, workspace, and permission fields:

{
  "model_provider": "openai-codex",
  "model": "gpt-5.6",
  "reasoning_effort": "high",
  "allowed_tools": ["read_file", "search"]
}

reasoning_effort uses the canonical Runtime vocabulary (auto, off, low, medium, high, xhigh, ultra, or max; documented compatibility aliases are accepted and persisted canonically). allowed_tools is a model-visible allowlist. Omitting it keeps the normal configured catalog; an explicit empty array ("allowed_tools": []) exposes no tools to the model. Both fields are additive: older thread records and clients that omit them retain their previous behavior.

GET /v1/threads/summary is the read-only summary surface used by the VS Code Agent View. search matches thread id, title, and model (and, when the title is unset, the latest turn's input summary — the displayed title). It does not scan turn or item bodies: preview is filled only after a match, so a dashboard keystroke is not a whole-store read per thread. Each item includes id, title, preview, model, mode, archived, updated_at, latest_turn_id, latest_turn_status, plus workspace metadata:

{
  "id": "thread_...",
  "title": "Implement MCP status count",
  "preview": "The TUI footer should count project MCP servers...",
  "model": "deepseek-v4-pro",
  "mode": "agent",
  "branch": "feature/runtime-api",
  "head": "abc1234",
  "dirty": false,
  "workspace": "/Users/you/projects/codewhale",
  "archived": false,
  "updated_at": "2026-06-06T05:43:00Z",
  "latest_turn_id": "turn_...",
  "latest_turn_status": "completed"
}

branch is resolved from the thread workspace at request time and may be null when the workspace is not a Git repository or the branch cannot be read. head is the current short Git commit for that workspace when available. dirty is true when the workspace has staged, unstaged, or untracked changes. workspace is included so editor clients can show when an agent lane is working outside the current VS Code folder.

Thread forks are sibling runtime threads, not an in-place tree projection. thread.forked events include source_thread_id; internal backtrack-aware forks may also include backtrack_depth_from_tail and dropped_turn_id. Thread list and summary responses remain flat in v0.8.40, so clients that need a graph should reconstruct it from events instead of assuming list order is a complete tree.

archived_only=true returns archived threads only (mutually overrides include_archived). Default behavior is unchanged: include_archived=false and archived_only=false returns active threads. Added in v0.8.10 (#563).

PATCH /v1/threads/{id} body — every field is optional, missing means "no change". At least one field must be present. title and system_prompt accept an empty string to clear a previously-set value. Added in v0.8.10 (#562):

{
  "archived": true,
  "allow_shell": false,
  "trust_mode": false,
  "auto_approve": false,
  "model": "deepseek-v4-pro",
  "mode": "agent",
  "title": "User-set thread title",
  "system_prompt": "You are a useful assistant."
}

Turns (within a thread)

• POST /v1/threads/{id}/turns
• POST /v1/threads/{id}/turns/{turn_id}/steer
• POST /v1/threads/{id}/turns/{turn_id}/interrupt
• POST /v1/threads/{id}/compact (manual compaction)
• POST /v1/threads/{id}/undo - fork the thread with the last N turns removed ({"depth": N}, default 0 = last turn only); returns the forked thread plus original_user_text so a GUI can pre-populate the input box
• POST /v1/threads/{id}/patch-undo - snapshot-based whole-workspace rollback followed by the same fork ({"depth": N}); returns patch_result (files_restored, summary, snapshot_label) alongside the forked thread. See Workspace restore endpoints for the trust, admission and abort rules.
• POST /v1/threads/{id}/file-revert - restore exactly one file from one named snapshot ({"path", "snapshot_id", "expected_hash"}); never forks the conversation. See Workspace restore endpoints.
• POST /v1/threads/{id}/retry - fork with the last N turns removed and immediately start a new turn ({"depth": N, "prompt": "..."}; prompt overrides the original user text, which is re-used when omitted)

POST /v1/threads/{id}/turns accepts the same optional reasoning_effort and allowed_tools fields as per-turn overrides:

{
  "prompt": "Review this change without running tools.",
  "operation_key": "cwc-request-01J7Y6Q9W4",
  "reasoning_effort": "max",
  "allowed_tools": []
}

Resolution is deterministic: a turn override wins over the thread default, which wins over the Runtime's normal configuration. For tools, reaching normal configuration means the ordinary configured catalog; [] is never treated as missing. Reasoning is normalized only after the exact provider/model route is resolved, and auto remains a per-prompt reasoning decision even when the thread uses a fixed model. The request still enters the existing Op::SendMessage path and the single Engine::run_turn loop.

Image input uses the same turn path: "images": [{"mime": "image/png", "dataBase64": "..."}]. Clients must first observe capabilities.turn_image_inputs: true in /v1/runtime/info (or the isolated Runtime Chat relay catalog). Older HTTP runtimes ignore unknown fields, so a successful text response is not evidence that an attachment was accepted. The field is omitted when empty. It is also accepted by app-server thread/message, thread/request messages, and prompt requests; that bridge checks the underlying Runtime capability before forwarding image bytes. Legacy remote Work commands do not support images and explicitly refuse them.

New inline images require a named model whose exact resolved route reports image_input: "supported"; Auto and unknown/unsupported image routes are refused before classifier or provider dispatch. This does not change the existing trusted-local attachment behavior for routes with unknown capability. A nonempty prompt is required. Inputs are limited to 10 images, 4 MiB decoded bytes per image, 5 MiB total, and an 8 MiB JSON body. PNG, JPEG, GIF and WebP must have matching MIME, canonical padded base64 and valid bounded image content: at most 8192 pixels per dimension, 33,554,432 pixels total and 64 MiB decoder allocation. The Runtime does not fetch paths or URLs from this field. Malformed images refuse the whole turn; callers can retain the draft for correction. Relay command polling uses an 8 MiB response budget; the sender must paginate by serialized bytes without advancing past unserved commands.

Accepted image bytes and order are retained in the existing turn records and reconstructed after restart, import and fork. Retry retains those images even when its optional prompt changes the text; undo responses include original_user_images when present. Image-bearing records require schema v3, which older readers refuse. Text-only records and operation fingerprints retain their prior representation. Validated stored local images retain the existing 5 MiB per-image ceiling and prior aggregate/count semantics on import/retry; this internal storage authority does not relax exact model or permission checks. Image bytes, MIME and order participate in request identity, so changing an image under the same operation key conflicts. Compaction can summarize older context; retaining the original attachment does not promise that every later model request includes it. Image pixels are not subject to text-secret redaction.

operation_key is an optional idempotency key for clients that may lose an HTTP response after the Runtime accepted a turn. It is scoped to the current Runtime store and thread, may contain at most 128 UTF-8 bytes, and may not be empty or contain surrounding whitespace or control characters. Omitting it preserves the legacy create-a-new-turn behavior.

The first accepted request durably binds a SHA-256 fingerprint of the key to the Runtime turn id and a canonical request fingerprint before sending the existing Op::SendMessage. An exact retry returns that original turn in the normal { "thread": ..., "turn": ... } response and emits no second engine operation, item, or lifecycle sequence. Reusing the key on the same thread with a different provider/model, prompt, reasoning policy, tool allowlist or dynamic-tool schema, environment, or permission policy fails closed with 409 Conflict. The same caller key may be used independently on another thread.

Only the scoped key fingerprint, request fingerprint, thread id, and turn id are stored in the Runtime's private turn-operation index. The raw key is never persisted or logged, and request bodies, credentials, and attachments are not copied into that index. Existing thread/turn persistence remains the source of the returned turn after a process restart.

Exact accepted-turn lookup

GET /v1/threads/{id}/turn-operations/{operation_key} uses the same Runtime authentication as turn submission. URL-encode each path segment. It returns 200 OK with the existing bare TurnRecord (the turn object in the POST response), identified by that exact thread and operation key. It does not use the thread's latest turn or require the original request body or current route settings to match.

• 404 Not Found: no binding exists for that thread/key, or persisted identities do not match. These cases share a generic response.
• 409 Conflict: admission holds the operation claim, or its durable binding is incomplete. Retry the lookup; this response does not authorize another turn.
• 400 Bad Request: the thread ID or operation key is malformed. The key uses the same 128-byte and whitespace/control-character rules as POST.
• 500 Internal Server Error: storage or the existing claim lock cannot be checked safely. This is not evidence that the operation is absent.

The lookup holds a shared read lock on the existing operation claim while reading the binding and turn. It creates no files, starts no engine, emits no events, and performs no replay or recovery. Normal Runtime startup may recover an incomplete admission before a later lookup, but GET itself never does so.

Approvals

• POST /v1/approvals/{approval_id} with body { "decision": "allow" | "deny", "remember": false }

approval_id is minted by the Runtime, not by the model or the provider. It is an opaque approval_<32 hex> capability, unique per prompt, bound to the thread that raised it, and single-use: the Runtime removes it when the decision is delivered, when the prompt times out, or when the turn abandons it. Clients echo the value they were given and must not construct, derive, or guess one.

It is deliberately not the provider's tool-call ID. Providers restart their call-ID counters per response, so two threads can gate calls whose raw IDs are byte-equal; keying approvals by that value let one thread's decision settle another thread's call. The endpoint therefore performs one exact match on the minted ID and has no fallback: a raw tool-call ID, an expired ID, or a replayed ID that has already been settled all return 404 and reach no engine. A 404 means the capability is not pending — it is not evidence about how the approval was resolved; read approval.decided for that.

The raw provider call ID travels separately as tool_call_id on pending_approvals[] and on the approval events. It is a correlator for attaching a prompt to the tool row it gates, and never accepted as a decision. Each thread-detail pending_approvals[] entry is { "id", "turn_id", "tool_name", "description", "intent_summary"?, "tool_call_id"? }, where id is the capability above.

User input

• POST /v1/user-input/{thread_id}/{input_id} with body { "answers": [{ "id": "question-id", "label": "Choice", "value": "Choice" }] }

Submitted values are delivered to the active model turn but are deliberately excluded from durable Runtime items and events. The settled tool item contains only a neutral receipt and a machine-readable response_redacted marker. The Runtime accepts only an exact pending (thread_id, input_id) request; an unknown, concurrently settling, or already settled id returns 404 and is never placed in the engine mailbox. It commits the secret-free user_input.answered receipt before removing the snapshot-authoritative prompt or delivering the answer to the engine. That settlement runs independently of the HTTP connection, so disconnecting after submission cannot leave a prompt half accepted. Terminal-turn cancellation follows the same receipt-before- removal ordering through user_input.canceled.

Client-executed dynamic tools

• POST /v1/threads/{thread_id}/turns/{turn_id}/tool-calls/{call_id}/result

The thread and turn in the result route must match the pending call. A call is settled at most once; wrong-route and duplicate results return 404. Terminal lifecycle events carry identifiers and status only, never tool result content. The Runtime commits the terminal lifecycle event before making a submitted result available to the model. Result delivery, timeout, and terminal-turn cancellation race through one settlement owner, so exactly one of these events is durable for a call:

• tool_call.requested — the typed client-executed call became pending;
• tool_call.resolved — a result was durably accepted by the Runtime (result_accepted: true; success is result metadata, but result content is excluded);
• tool_call.timeout — no result won before the bounded wait expired;
• tool_call.canceled — the turn terminated before a submitted result won.

HTTP 202 Accepted and tool_call.resolved share that durable-acceptance meaning. Neither claims that the model consumed the result: a concurrent turn shutdown may close the model receiver after acceptance. Once the Runtime has accepted the result, that call is terminal and a duplicate result returns 404.

Events (SSE replay + live stream)

• GET /v1/threads/{id}/events?since_seq=<u64>

Durable history parsing runs off the async server workers and reaches SSE in bounded batches of at most 256 events through a backpressured channel. Broadcast delivery is only a wake-up optimization: a lagged receiver opens the same bounded durable replay from its last accepted cursor. Optional replay_limit returns the newest requested tail and may not exceed 4096; previous_seq on the first returned event advances past exactly the omitted history.

Snapshots (side-git restore point listing + restore)

• GET /v1/snapshots?limit=20
• POST /v1/snapshots/{id}/restore

/v1/snapshots lists recent side-git restore points for the runtime workspace. limit defaults to 20 and must be between 1 and 100. POST /v1/snapshots/{id}/restore restores workspace files from the snapshot and returns {"restored": "<snapshot-id>"}. It is the direct operator surface for the server's own workspace (the same action as the TUI's /restore <N>): it is gated by the Runtime API bearer token, not by any thread's trust flag, and it is refused with 409 while a turn is active in an overlapping workspace (see below). A pre-restore: safety snapshot is taken first.

[
  {
    "id": "snap_...",
    "label": "post-turn:1",
    "timestamp": 1780730580
  }
]

Workspace restore endpoints

Three routes mutate workspace files from side-git snapshots. They share one admission rule and one safety net, and they differ in scope and trust.

Route	Scope	Trust	Forks the thread
POST /v1/snapshots/{id}/restore	whole server workspace	bearer token only (operator action)	no
POST /v1/threads/{id}/patch-undo	whole thread workspace	thread trust_mode or auto_approve when files would change	yes
POST /v1/threads/{id}/file-revert	exactly one regular file	thread trust_mode or auto_approve, always	no

Admission. A restore reserves the same admission the Runtime uses for config reloads and session checkpoints, so no new turn starts and no saved history changes while files are being rewritten. If any thread already has an active turn in the same workspace, a nested checkout of it, or a parent of it, the request is refused with 409 and the message already has an active turn. The reservation is owned by the worker performing the Git mutation, so a client that disconnects mid-request cannot release it early; the operation completes or fails as a whole. Concurrent restores serialize. The reservation is runtime-wide: while a restore's safety snapshot and checkout run, new turns, steering, compaction and user-input delivery on every thread wait for it to finish, so a large workspace can add seconds of latency elsewhere during a restore. A thread whose workspace directory is not available (unmounted volume, disconnected share, missing directory) is refused with 409 rather than treated as having nothing to restore.

Safety net. Every restore first records a pre-restore:<target> snapshot of the current workspace. That label is never a /undo, patch-undo or file-revert candidate, so the net does not change what later undos select. For file-revert the backup is mandatory: if it cannot be written, or the requested file is excluded from it (for example by .gitignore), the request fails and nothing is changed.

patch-undo. Selects the newest tool:/pre-turn: snapshot owned by the thread's own session whose tree differs from the workspace, restores the whole tree from it, then forks the conversation exactly as /undo does. Ok means either files were restored or there was provably nothing to restore (no bound session, or no differing session-owned snapshot); files_restored says which. When there is something to restore and the thread is not trusted, the whole undo aborts with 409 and neither files nor conversation change. Snapshot repository, listing or comparison failures abort with 500, and an unavailable workspace directory aborts with 409; both preserve the conversation, so a turn is never dropped while its file changes stay on disk. Depth and history are validated before any file changes. If the fork cannot be persisted after files were restored, the response is a 500 that names the restored snapshot; the original thread still holds the turn and the pre-restore: snapshot holds the previous files.

file-revert. Request body:

{
  "path": "src/lib.rs",
  "snapshot_id": "3f2a…40-or-64 hex…",
  "expected_hash": "sha256:<64 lowercase hex digits>"
}

• path: workspace-relative, or absolute inside the thread workspace. The name is literal (brackets, spaces and glob characters are filename bytes; Git runs with --literal-pathspecs). It must name a regular file: directories, symlinks anywhere in the path, and .git components are 400.
• snapshot_id: the exact tool:<call_id> or pre-turn:<n> snapshot from the change the user selected. Clients obtain ids from GET /v1/snapshots (labels carry the tool call id) and must keep the selected change's identity; the server never picks "the newest snapshot that differs", because an unrelated newer snapshot can erase later user edits while leaving the tool's change.
• expected_hash: sha256: of the current file bytes the client displayed, or absent when the client saw the file as deleted. It is checked before the safety backup and again immediately before the mutation.

Responses:

• 200 {"path", "action", "snapshot_id", "snapshot_label"} — action is modified, recreated (file was missing) or removed (the snapshot does not contain the file, so the file the tool created is deleted; its parent directories are left in place).
• 400: malformed snapshot_id/expected_hash, path outside the workspace, or a path that is not a regular file on either side.
• 404: unknown thread.
• 409: thread not in trusted mode or Full Access; no bound session; active turn in an overlapping workspace; workspace directory not available; snapshot unknown, owned by another session or not a restore point (refresh the change record); file already matches the snapshot (nothing to revert); or the file changed after the reviewed expected_hash (refresh and review again). Nothing is changed in any of these cases.
• 422: missing or mistyped body fields.
• 500: Git or filesystem failure; a failure after the safety snapshot names that snapshot so the previous bytes can be recovered with POST /v1/snapshots/{id}/restore or /restore.

Capability probe: GET on the route returns 405 where the endpoint exists and 404 on an older engine; clients treat any non-404 as available and degrade with an explanation otherwise.

Receipts (future read-only audit export)

• Proposed only: GET /v1/threads/{thread_id}/turns/{turn_id}/receipt

Compatibility stream (one-shot, backwards-compatible)

• POST /v1/stream

Tasks (durable background work)

• GET /v1/tasks
• POST /v1/tasks
• GET /v1/tasks/{id}
• POST /v1/tasks/{id}/cancel

Automations (scheduled recurring work)

• GET /v1/automations
• POST /v1/automations
• GET /v1/automations/{id}
• PATCH /v1/automations/{id}
• DELETE /v1/automations/{id}
• POST /v1/automations/{id}/run
• POST /v1/automations/{id}/pause
• POST /v1/automations/{id}/resume
• GET /v1/automations/{id}/runs?limit=20

Create and update requests accept an optional model. When present, each scheduled or manually triggered run uses that model; omitting it keeps the runtime's default task model.

Operate (always-on named operation; same OperateRecord as CWC 20de981 / PR #284)

• GET /v1/operate — current operation + plan board
• POST /v1/operate — create (direction, optional burnRate)
• PATCH /v1/operate — steer direction, burnRate, or leadPlan
• PUT /v1/operate/plan — set leadPlan ({ slices: [...] })
• POST /v1/operate/keepalive — observe spend / burn; never stops
• POST /v1/operate/cancel — explicit cancel (/v1/operate/stop aliases); also pauses the cw-operate keepalive so nothing keeps spending after cancel
• POST /v1/operate/auto-merge/check — call landed scripts/check-auto-merge.py --repo --pr --agent (does not merge)

The operation record (current.json) is persisted under a cross-process file lock with atomic temp+rename writes; every PATCH / keepalive / plan save reloads the latest state inside the lock, so concurrent saves merge instead of losing writes. A PATCH that changes direction invalidates the recorded leadPlan (workers stop executing superseded slices) and pulls the keepalive lead run forward to re-plan. POST /v1/operate installs the hourly cw-operate keepalive and kicks its first lead-plan run immediately instead of waiting out the first recurrence; credentials resolve through the normal Z.ai provider resolution (config, api_key_env, secret store, or provider env vars — blank values count as missing).

burnRate is { "kind": "usd_per_hour", "amountUsdPerHour": number }, a positive number, or null (unbounded). Status is planning | running | idle_blocked | cancelled. Pace (unbounded | hold | throttle | widen) is not a status: over-target throttles, under-target widens, no wallet-cap stop. Idle-blocked only for empty direction, awaiting lead plan, missing credentials, or a human gate. Auto-merge is scripts/check-auto-merge.py --repo … --pr … --agent … from codewhale-ops origin/main (exit 0), then scripts/auto-merge-pr.py. Do not invent a second checker.

Introspection

• GET /v1/workspace/status
• GET /v1/workspace/files/search?query=<partial>&limit=<1-100> (see workspace file suggestions above)
• GET /v1/skills
• GET /v1/apps/mcp/servers
• GET /v1/apps/mcp/tools?server=<optional>

Skill activation toggles are persisted under a cross-process transaction lock. Each mutation reloads and merges the latest exact-name state before an atomic write, and GET /v1/skills refreshes that shared state so another Codewhale process's successful toggle is visible without restarting the Runtime API.

Usage (token/cost aggregation across threads)

• GET /v1/usage?since=<rfc3339>&until=<rfc3339>&group_by=<day|model|provider|thread>

since / until are inclusive RFC 3339 timestamps and may be omitted (no bound). group_by defaults to day. Buckets are sorted by ascending key. Empty time ranges produce empty buckets (never a 404). Cost is computed via the model→pricing map; turns whose model has no pricing entry contribute tokens but 0.0 cost. Added in v0.8.10 (#564).

{
  "since": "2026-04-01T00:00:00Z",
  "until": "2026-04-30T23:59:59Z",
  "group_by": "day",
  "totals": {
    "input_tokens": 12345,
    "output_tokens": 6789,
    "cached_tokens": 0,
    "reasoning_tokens": 0,
    "cost_usd": 0.012,
    "turns": 42
  },
  "buckets": [
    {
      "key": "2026-04-30",
      "input_tokens": 1234,
      "output_tokens": 678,
      "cached_tokens": 0,
      "reasoning_tokens": 0,
      "cost_usd": 0.001,
      "turns": 3
    }
  ]
}

Provider and model selection

These three routes are how a GUI renders a model picker whose contents are true for this runtime instead of guessed from a version snapshot. They were undocumented until 2026-08-04, which cost a desktop integration a day: the client probed /v1/models, /v1/runtime/models, and /v1/runtime/providers (all correctly 404) and concluded the capability did not exist.

GET /v1/providers

{
  "current": "modelstudio-token-plan",
  "providers": [
    {
      "id": "modelstudio-token-plan",
      "model_provider_id": "modelstudio-token-plan",
      "display_name": "Alibaba Cloud Model Studio",
      "default_model": "qwen3.8-max",
      "has_model_catalog": true,
      "credentialState": "configured"
    }
  ]
}

current is the active generic provider id. Only the active entry carries an exact identity: an active built-in normally repeats its canonical id in model_provider_id, while an active named custom route has current set to custom and the exact configured key there (for example lm-studio). Other entries have a null exact id; a null id on the active custom entry identifies the released legacy root-level custom route. Preserve both fields from the selected entry and send a non-null exact id back as POST /v1/threads's model_provider_id; dropping a named custom id would collapse the selection to the legacy root custom route. credentialState is a stable, non-secret projection of the Runtime's existing structural credential classification:

• configured: credential material is structurally available;
• login_required: the route needs login or a usable login capability;
• missing: an API-style credential is unavailable;
• no_auth: the route explicitly disables credential use;
• local: the exact route is local and keyless;
• legacy: the compatibility route cannot be classified more precisely.

For an active named custom provider, this state is calculated from the exact route named by model_provider_id, not from a generic custom-provider default. It deliberately collapses saved-key and imported-token details into configured, and login/consent-source details into login_required.

The response never includes endpoint URLs, credential environment-variable names, filesystem paths, credential values, consent-source details, or token metadata. credentialState is not a provider canary: configured does not prove endpoint reachability, credential validity, model entitlement, or a successful request. The models route below is also only a selection catalog; a non-empty list does not prove that the route can currently serve a request.

GET /v1/providers/{id}/models

{
  "provider": "deepseek",
  "models": [
    {
      "id": "deepseek-v4-flash-vision-exp",
      "image_input": "supported",
      "reasoning_effort": "unknown",
      "reasoning_effort_levels": [],
      "reasoning_effort_source": null
    }
  ]
}

For an exact configured route, supply ?model_provider_id=vision-work and require the response to echo that same model_provider_id. The Runtime resolves that identity under the requested provider kind before reading model support. Unknown or mismatched identities return 400. Named pagination cursors bind the configuration identity, endpoint and catalog snapshot; changing any of those requires restarting pagination. Omitting the query preserves the legacy catalog projection and omits the identity echo.

The catalog for one provider. Returns 400 for an unknown id, and for the legacy deepseek-cn alias, which has no provider metadata — use deepseek. An empty models array means the Runtime has no discoverable or configured model ids for that provider; it does not report credential presence.

The ids returned here are exactly the values accepted by POST /v1/threads's model field and by the switch route below. image_input is the exact resolved provider/model route's capability state: supported, unsupported, or unknown. Keep unknown unknown rather than inferring from the model name or wire protocol. supported describes the model route; it does not mean a given client implements an image-upload control.

reasoning_effort uses the same three capability states and describes whether the exact model's metadata publishes a selectable effort ladder. reasoning_effort_levels contains only canonical, recognized active effort levels from that metadata. Off and provider synonyms such as none are excluded: the Apps/Chat protocol treats off as omission, which does not prove support for an explicit provider disable command. A model capable of reasoning may still have an unknown active effort ladder. Codex levels are also excluded when native compatibility would change their wire value (currently minimal and auto). This projection does not change native compatibility behavior or advertise a tier the Runtime cannot send unchanged. No levels are inferred from a provider-wide default or a familiar model name on a custom endpoint. reasoning_effort_source identifies catalog, codex_cli_cache, or codex_app_server; missing, stale, and unrecognized model metadata stays unknown. Codex roster metadata describes the external CLI's roster, not proof that a separately configured Runtime credential belongs to the same account or that an authentication boundary is approved.

Pass ?model_provider_id=<exact configured id> when selecting a named route. The Runtime validates the provider kind and exact identity together, returns model_provider_id alongside that route's model list, and leaves the active configuration unchanged. An empty or unknown requested identity, or a mismatched kind, returns 400; it never falls back to another named route.

The Runtime Chat relay publishes the same effort fields in camelCase (reasoningEffort, reasoningEffortLevels, reasoningEffortSource). These model facts do not enable tool execution or establish account entitlement.

For a thread-scoped choice, send the provider fields from the selected entry alongside the selected model. Omit model_provider_id when it is null:

{
  "model_provider": "custom",
  "model_provider_id": "lm-studio",
  "model": "local-vision-model"
}

This creates one thread on the exact named custom route without changing the Runtime's provider or model defaults.

POST /v1/providers/{id}/switch

// request  (model is optional; omit to take the provider default)
{ "model": "qwen3.8-max" }

// response
{ "provider": "modelstudio-token-plan", "model": "qwen3.8-max",
  "message": "…", "persisted": true }

Use this rather than simulating a switch with repeated POST /v1/config writes plus a reload. Provider and model move together here, the change is validated against the provider's catalog before it is applied, and persisted reports whether it was written to config or applied to the live session only. Rejects an unknown provider id and the deepseek-cn alias with 400.

Runtime data model

The runtime uses a durable Thread/Turn/Item lifecycle.

• ThreadRecord — id, created_at, updated_at, model, model_provider (generic kind), model_provider_id (optional exact configured route), workspace, mode, task_id, system_prompt, latest_turn_id, latest_response_bookmark, archived
• TurnRecord — id, thread_id, status (queued|in_progress|completed| failed|interrupted|canceled), effective_provider, effective_model, effective_billing_surface, timestamps, duration, usage, error summary
• TurnItemRecord — id, turn_id, kind (user_message|agent_message| tool_call|file_change|command_execution|context_compaction|status|error), lifecycle status, metadata

Events are append-only with a global monotonic seq for replay/resume.

effective_billing_surface is a non-secret classification derived from the endpoint that served the turn. Recognized StepFun routes use stepfun-payg or stepfun-plan; unknown and custom endpoints leave it unset. The raw base URL is not persisted in TurnRecord.

Restart semantics

• If the process restarts while a turn or item is queued or in_progress, the recovered record is marked interrupted with an "Interrupted by process restart" error.
• The trailing newline is an event append's commit marker. On startup, a final JSONL fragment without that delimiter is truncated and fsynced even when its bytes form valid JSON; it is an uncommitted append, and its already-reserved sequence number is not reused. Newline-terminated malformed records are not identifiable crash debris and continue to fail closed during replay.
• If a terminal turn record reached disk but its terminal event sequence did not, the first async read reconciles any unresolved dynamic calls as tool_call.canceled and then emits one turn.completed. Existing terminal call and turn receipts are detected and never duplicated.
• Turn-operation bindings survive restart. Retrying the same operation_key and request returns the original recovered turn (including an interrupted turn recovered from an in-progress process exit); mismatched reuse remains a conflict. A crash-created binding that never acquired a turn is discarded at startup because engine submission happens only after both records are durable.
• Task execution performs its own recovery on top of the same persisted thread/turn store.

Approval model

• The auto_approve flag applies to the runtime approval bridge and engine tool context. When enabled for a thread/turn/task, approval-required tools are auto-approved in the non-interactive runtime path, shell safety checks run in auto-approved mode, and spawned sub-agents inherit that setting.
• When omitted, auto_approve defaults to false.
• Authorization order describes where typed rules, registered tool requirements, safety floors, repository law, approval transport, and sandbox enforcement sit relative to one another.

SSE event stream

The SSE event payload shape for /v1/threads/{id}/events:

{
  "schema_version": 1,
  "seq": 42,
  "previous_seq": 38,
  "event": "item.delta",
  "kind": "item.delta",
  "thread_id": "thr_1234abcd",
  "turn_id": "turn_5678efgh",
  "item_id": "item_90ab12cd",
  "timestamp": "2026-02-11T20:18:49.123Z",
  "created_at": "2026-02-11T20:18:49.123Z",
  "payload": {
    "delta": "partial output",
    "kind": "agent_message"
  }
}

Compatibility notes:

• schema_version is the HTTP/SSE envelope schema version. It is independent of the runtime store schema used for persisted thread/turn/event records.
• event remains the SSE event name in existing clients; it is preserved as-is.
• kind mirrors event in the stable envelope for typed clients.
• seq is allocated globally across all Runtime threads. Consequently, gaps between a thread's events are normal when other threads interleave. On this per-thread SSE stream, previous_seq is the sequence of the last event delivered for this thread (or the requested replay cursor for the first event); clients detect loss by comparing it with their accepted per-thread cursor, not by requiring seq == previous_seq + 1. Sequence allocation is also not rewound after an append is transactionally rolled back, so a retry can intentionally skip an unused value without implying a missing event.
• thread.started, turn.started, and turn.completed are emitted as SSE event names exactly as before.
• timestamp remains the canonical event time for schema version 1. created_at is an equivalent alias for clients that use created_at naming elsewhere; do not require both fields to be present.

Common event names: thread.started, thread.forked, turn.started, turn.lifecycle, turn.steered, turn.interrupt_requested, turn.completed, item.started, item.delta, item.completed, item.failed, item.interrupted, approval.required, approval.decided, approval.timeout, user_input.required, user_input.answered, user_input.canceled, tool_call.requested, tool_call.resolved, tool_call.timeout, tool_call.canceled, sandbox.denied, runtime.store_failure.

runtime.store_failure is the runtime reporting a fault in the operator's own on-disk state: a thread, turn, or item record under the session's runtime store could not be read, parsed, or written. The payload carries operation (read | parse | write), record_kind (thread | turn | item), record_id, path, the full error chain, the root-cause reason, a next_action (which file to move aside, or where to check free space and permissions), and a one-line message. When terminal is true, the turn's own record is unreadable or unwritable and no turn.completed will follow; clients waiting on that turn should treat it as failed.

Agent-message and reasoning deltas are materialized into the item projection before their corresponding item.delta event is sequenced. To avoid an fsync for every provider fragment, adjacent deltas are coalesced to configured bounds of at most 32 ms or approximately 16 KiB before publication (an indivisible upstream chunk can itself exceed the byte target). A process crash inside that unpublished window can lose the recent suffix; no durable event claims that suffix existed. Once an item.delta is durable, snapshots at or beyond its cursor include the same materialized prefix.

approval.required events may include a matched_rule string when an execution-policy rule caused the prompt. This field is explanatory metadata for clients and does not grant or persist permissions.

approval.required, approval.decided, and approval.timeout carry two distinct identifiers. approval_id is the Runtime-minted, single-use capability described under Approvals — the only value POST /v1/approvals/{id} accepts — and approval.required also repeats it in the legacy id field for older clients. tool_call_id is the provider's raw tool-call ID, present for correlation only. Automatically resolved prompts (thread auto_approve, and the Auto-Review posture, which never opens a modal) mint an approval_id as well, so the field has one meaning on every path; those IDs register no waiter and are inert against the endpoint. Clients must never treat tool_call_id as an approval capability or assume it is unique across threads.

The thread event stream forwards these payloads intact. The compatibility turn stream carries approval_id, its id alias and tool_call_id; the pending snapshot carries the same capability and correlator so reconnecting clients can attach an approval prompt to its tool row.

Security boundary

• Localhost by default. The server binds to 127.0.0.1 by default. --mobile is also loopback-only and rejects a non-loopback host until a TLS or verified-overlay transport boundary exists. The runtime does not provide user isolation or TLS.
• Optional token guard. --auth-token or DEEPSEEK_RUNTIME_TOKEN requires a matching bearer token for /v1/* routes. This is a local convenience guard, not a replacement for TLS, VPN, or a trusted reverse proxy on public networks.
• No provider-token custody. The server never returns the API key. The api_key.source capability field reports env, config, or missing — never the key itself.
• No hosted relay. The app-server is a local process under the user's control. There is no cloud component.
• Capability responses never leak secrets, file contents, or session message bodies. They report metadata: presence, counts, status flags.

CORS allow-list

The runtime API ships with a built-in dev-origin allow-list: http://localhost:3000, http://127.0.0.1:3000, http://localhost:1420, http://127.0.0.1:1420, tauri://localhost. To add additional origins (e.g. when developing a UI on Vite's default :5173), use any of:

• CLI flag (repeatable): codewhale serve --http --cors-origin http://localhost:5173
• Env var (comma-separated): DEEPSEEK_CORS_ORIGINS="http://localhost:5173,http://localhost:8080"
• Config (~/.codewhale/config.toml):

  [runtime_api]
  cors_origins = ["http://localhost:5173"]

User-supplied origins stack on top of the built-in defaults; they do not replace them. Wildcard origins are not supported — the explicit allow-list model is preserved. Cross-origin preflights advertise only Authorization, Content-Type, Accept, X-Codewhale-Runtime-Token, and the compatibility X-DeepSeek-Runtime-Token request header; custom request headers are not allowed. Added in v0.8.10 (#561), tightened in v0.9.1 (#4454).

Managed Fleet Runtime and SDK helpers

The Runtime SDK lives in npm/runtime-sdk and is exposed as the @codewhale/runtime-sdk workspace package. It is deliberately thin: every helper calls the local Rust Runtime API and therefore cannot bypass Codewhale's sandbox, approval prompts, provider configuration, or fleet ledger authority.

import { createRuntimeClient } from "@codewhale/runtime-sdk";

const client = createRuntimeClient({
  baseUrl: "http://127.0.0.1:7878",
  token: process.env.CODEWHALE_RUNTIME_TOKEN,
});

const created = await client.createFleetRun({
  target: "this_computer",
  roles: [{ name: "reviewer" }, { name: "verifier" }],
  workflow: {
    id: "release-check",
    kind: "parallel",
    tasks: [
      { id: "review", name: "Review", instructions: "Review locally.", worker: { role: "reviewer" } },
      { id: "verify", name: "Verify", instructions: "Verify locally.", worker: { role: "verifier" } },
    ],
  },
});

// POST /runs only prepares durable work. This call crosses the launch gate.
await client.startFleetRun(created.run.id);

let cursor;
for await (const event of client.fleetEvents(created.run.id, { after: cursor })) {
  if (event.cursor) cursor = event.cursor;
  if (event.event === "fleet.replay.cursor_unavailable") {
    // Reload getFleetRun(created.run.id), then reconnect without the old cursor.
  }
}

The managed path is deliberately two-step. POST /v1/fleet/runs validates and persists the run and queue without starting a worker. A separate authenticated POST /start activates it and schedules the executor driver; its 202 response reports leased: 0 because the driver performs all leasing after it owns the run. Creation requires named roles, one task owner per role, a parallel Workflow, and an explicit Runtime target. v0.9.4 executes only this_computer; another_computer and cloud return 501 rather than silently executing locally. Worker IDs are generated per run; caller-assigned worker_specs return 501 until custom workers can be given collision-free managed identities. Parallel tasks with overlapping effective write roots are rejected before the run is journaled. Managed security_policy overrides also fail closed until that document can be enforced end to end; executable authority comes from each named role's tool posture and bounded task workspace scope.

Fleet helpers cover this HTTP surface:

Helper	Runtime API route
createFleetRun(spec)	POST /v1/fleet/runs
startFleetRun(runId)	POST /v1/fleet/runs/{run_id}/start
listFleetRuns()	GET /v1/fleet/runs
getFleetRun(runId)	GET /v1/fleet/runs/{run_id}
listFleetWorkers(runId)	GET /v1/fleet/runs/{run_id}/workers
getFleetWorker(workerId)	GET /v1/fleet/workers/{worker_id}
interruptWorker(workerId)	POST /v1/fleet/workers/{worker_id}/interrupt
stopWorker(workerId)	POST /v1/fleet/workers/{worker_id}/stop
restartWorker(workerId)	POST /v1/fleet/workers/{worker_id}/restart
stopFleetRun(runId)	POST /v1/fleet/runs/{run_id}/stop
replayFleetEvents(runId, options)	GET /v1/fleet/runs/{run_id}/events/replay
fleetEvents(runId, options)	GET /v1/fleet/runs/{run_id}/events (SSE)

stopWorker durably cancels that worker's active task and leaves the rest of the Fleet running. interruptWorker is the compatibility name for the same attempt-fenced cancellation transition. stopFleetRun cancels every queued or active task and marks the whole run cancelled.

Replay covers aggregate run/task transitions and privacy-bounded individual worker transitions. Event bodies omit prompts, tool call IDs, completion text, artifact paths/checksums, and cancellation identities; bounded failure reasons pass through secret redaction. cursor is opaque and stable across ordinary appends and Runtime restarts. Clients reconnect with after=<cursor>. A fresh request returns a bounded newest tail and marks history_truncated when older history exists. Ledger compaction can remove an old cursor; the JSON endpoint then returns 409, while the SSE endpoint emits fleet.replay.cursor_unavailable, so the client reloads the current run projection instead of accepting a silent gap.

GET /v1/runtime/info advertises fleet_run_create, fleet_run_start, fleet_event_replay, fleet_event_stream, and fleet_local_target. Older runtimes without a requested route still produce a typed SDK RuntimeCapabilityError.

Verification:

npm test --workspace @codewhale/runtime-sdk

Agent Run Receipts

Sub-agent lanes persist compact run receipts in .codewhale/state/subagents.v1.json. The Runtime API exposes those receipts as a read-only inspection surface:

Operation	Endpoint
List persisted agent runs	GET /v1/agent-runs
Inspect one run	GET /v1/agent-runs/{run_id}

The response is the same worker-record shape surfaced by agent receipts: spec.run_id, actor_kind, lifecycle status, bounded events, follow_up, takeover, artifacts, usage, and verification. run_id falls back to the worker id for older records, and {run_id} may be either the run id or the worker id.

These endpoints do not start, cancel, or steer sub-agents. The API surface exists so app/editor/headless clients can inspect the same handoff receipts that the TUI and parent model see.

Session lifecycle (native UI supervision)

Operation	Endpoint
List sessions	GET /v1/sessions
List session summaries	GET /v1/sessions/summary
Get session	GET /v1/sessions/{id}
Rename / archive session	PATCH /v1/sessions/{id}
Delete session	DELETE /v1/sessions/{id}
Resume into thread	POST /v1/sessions/{id}/resume-thread
Create thread	POST /v1/threads
List threads	GET /v1/threads
Attach to events	GET /v1/threads/{id}/events?since_seq=0
Send message	POST /v1/threads/{id}/turns
Steer	POST /v1/threads/{id}/turns/{turn_id}/steer
Interrupt	POST /v1/threads/{id}/turns/{turn_id}/interrupt
Compact	POST /v1/threads/{id}/compact

Compatibility tests

Contract snapshots live in crates/protocol/tests/. Run:

cargo test -p codewhale-protocol --test parity_protocol --locked

This validates that the app-server's event schema hasn't drifted from the documented contract. CI runs this on every push to main and on release tags.

The app-server stdio control surface has its own drift guard — the advertised capabilities method set is pinned in crates/app-server/src/lib.rs:

cargo test -p codewhale-app-server capabilities

Before a release, run the headless smoke (stdio probe + optional provider matrix, no secrets leaked):

scripts/release/app-server-smoke.sh --matrix        # dry-run plan
bash scripts/release/app-server-smoke.test.sh       # parser self-test (fake binary)