Interface inventory

Contract revision: 337c5858c33bc7f8f6dfd391a2c279fa0f7e4d17 (upstream source). Captured 2026-11-05. This SDK covers the pinned wire operations through named helpers and generic transports. It does not guarantee server-version support, credential permissions or a T3 agent context. Payloads retain the original JSON/string-keyed format; TypeScript schemas are enforced by T3, not duplicated as Elixir structs.

Use mix t3.interfaces --json for the programmatic inventory. Generic calls also permit new operation names absent from the static catalogs.

MCP

71 known tools: 66 advertised to the development agent and five additional upstream definitions. Use T3.discover(client) to inspect a connected external client's actual surface. MCP protocol 2025-06-18; ConduitMCP manages transport and OAuth. A category helper and T3.Tools.<wire_name>/2 exist for every entry.

Permission and context checks remain on the server. Browser/device/UI rendering, worktree handoff and delegated-agent operations generally require agent context; adding a wrapper does not make an external OAuth client an agent session.

HTTP JSON

All 38 routes in EnvironmentHttpApi are represented. Group modules live under T3.HTTP; T3.HTTP.call/3 routes an endpoint identifier and request/4 handles new same-origin paths. HTTP credentials are separate from MCP credentials. JSON, form and raw body encodings are preserved. The app starts a Finch pool; caller options can select another. Responses expose status, headers and decoded/raw body.

The body limit is 16 MiB by default, with bounded pool/request/receive timeouts. Redirects and automatic retries are disabled. Cookie storage and renewal are not automatic; caller-supplied cookie headers or tokens must have appropriate scopes. DPoP proofs may be supplied; proof generation and signing remain caller-owned.

Named helper and endpoint identifiers are available from T3.HTTP.endpoints/0. Attachment upload URLs can include signed query strings; T3.HTTP.upload/4 preserves them and refuses cross-origin destinations.

WebSocket RPC

211 methods, including 27 streams, use orchestration protocol 2 over /ws. T3.RPC.Methods provides named wrappers; arbitrary names work through T3.RPC.call/4 or subscribe/4. Each stream delivers chunks to its subscriber, which calls ack/2 after consumption. unsubscribe/2 sends an interrupt. The transport handles Effect Request/Chunk/Ack/Exit/Ping/Pong/Interrupt framing, server-originated replies, deadlines and disconnect cleanup without replay.

Use a permitted environment access token or a single-use RPC ticket from T3.HTTP.Auth.web_socket_ticket_for(http, "rpc"). MCP OAuth client tokens are rejected by T3 on this surface. TLS/loopback policy and token redaction apply. Subscriptions may be long-lived; supply a total timeout when desired. Unary calls have finite defaults and the pending-request limit is bounded.

Additional HTTP routes and streaming

45 additional operations cover the raw routes outside EnvironmentHttpApi. Their methods, patterns and authentication audiences are listed below. Device proxy methods/payloads may be further constrained by the installed upstream hub. HEAD and other supported proxy methods can use the generic request interface.

T3.HTTP.Raw.call/3 buffers a bounded result; Raw.stream/4, HTTP.stream/5 and HTTP.start_stream/5 consume bytes with callback backpressure and cancellation. SSE uses Conduit's incremental decoder. The stream deadline applies even to a blocked callback, and finite byte/event/per-event limits apply. Binary MJPEG, AVCC and downloads remain unchanged. T3.HTTP.multipart/2 delegates MIME encoding to Multipart. Cookies, media tickets, Range and proof headers are explicit.

Raw WebSocket media routes

These four routes are distinct from Effect RPC. T3.WebSocket.Routes provides helpers for each; T3.WebSocket.start_link/1 accepts new route paths. Text and binary data stay unchanged. A local delivery reference must be acknowledged to release bounded backlog memory. Preview's preview_ack/2 also sends the server's JSON ACK. A raw frame API is not a video codec, WebRTC stack or PTY renderer.

Use a media-bound ticket or permitted environment/media credential, not an MCP OAuth token. The adapter does not follow redirects or reconnect automatically. Frame bytes, incomplete fragments and unacknowledged deliveries are bounded; idle and total lifetime limits are configurable. Owner death closes the transport.

Local CLI

T3.CLI.run/2 accepts every command implemented by the installed executable, passing an argument vector without a shell. commands/2 discovers the actual version's help tree; it does not assume the pinned upstream CLI matches your host. Named family helpers are available for start, serve, app, pair, auth, browser, project, service, update, uninstall, theme, trace, doctor, triage, connect and thread. The installed snapshot is priv/t3/cli.json (t3 v0.1.1); it lacks newer thread commands. There is no automatic upgrade or mutation during discovery.

Exile supplies native subprocess IO and lifecycle on Linux/macOS. A C compiler and make are required to build it. The SDK supports finite stdin and interactive stdin write/EOF, merged stdout/stderr, deadlines and output limits. It is not a PTY and does not expose arbitrary inherited file descriptors. Cancellation kills the directly invoked executable; detached descendant processes are outside the SDK's ownership. As with any process, cleanup cannot survive killing the entire VM.

Validation boundaries

The catalog completeness tests check typed HTTP routes against the pinned contract and MCP/RPC helpers against their source inventories. Actual local HTTP and WebSocket fixtures test protocol behavior and errors; subprocess fixtures test OS IO and termination. This is transport/contract coverage, not proof that every operation's business semantics work against a live T3 installation. No destructive T3 command was run for validation. Authenticated HTTP/RPC live workflows need appropriate credentials and remain distinct from the successful external MCP sign-in.

Included source snapshots are MIT-licensed T3 Tools Inc. code; see priv/t3/UPSTREAM_LICENSE. They document the upstream contract and are not compiled or executed by this package.