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fork of Kludex/zigai, ported to zig 0.17
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pub const Content = messages.Content;pub const ContentSource = messages.ContentSource;pub const CapabilityLoadCall = messages.CapabilityLoadCall;pub const CapabilityLoadResult = messages.CapabilityLoadResult;pub const CapabilitySnapshot = capability_types.Snapshot;pub const CompactionPart = messages.CompactionPart;pub const InstructionPart = messages.InstructionPart;pub const FinishReason = messages.FinishReason;pub const Message = messages.Message;pub const Metadata = messages.Metadata;pub const Part = messages.Part;pub const PromptPart = messages.PromptPart;pub const ProviderFile = messages.ProviderFile;pub const ProviderPart = messages.ProviderPart;pub const ProviderDetails = messages.ProviderDetails;pub const RequestMessage = messages.RequestMessage;pub const RequestPart = messages.RequestPart;pub const RequestState = messages.RequestState;pub const ResponseMessage = messages.ResponseMessage;pub const ResponsePart = messages.ResponsePart;pub const ResponseState = messages.ResponseState;pub const SpeechPart = messages.SpeechPart;pub const SystemPromptPart = messages.SystemPromptPart;pub const TextContent = messages.TextContent;pub const TextPart = messages.TextPart;pub const Thinking = messages.Thinking;pub const ToolCall = messages.ToolCall;pub const ToolResult = messages.ToolResult;pub const ToolOutcome = messages.ToolOutcome;pub const ToolPartKind = messages.ToolPartKind;pub const ToolSearchCall = messages.ToolSearchCall;pub const ToolSearchMatch = messages.ToolSearchMatch;pub const ToolSearchResult = messages.ToolSearchResult;pub const ToolAvailabilityDeltaPart = messages.ToolAvailabilityDeltaPart;pub const UploadedFile = messages.UploadedFile;pub const Usage = messages.Usage;pub const RequestUsage = usage_types.RequestUsage;pub const RunUsage = usage_types.RunUsage;pub const UsageDetail = usage_types.Detail;pub const UsageCost = usage_types.Cost;pub const UsageCostSource = usage_types.CostSource;pub const UserContent = messages.UserContent;pub const dupeContent = messages.dupeContent;pub const dupeMetadata = messages.dupeMetadata;pub const dupeRequestPart = messages.dupeRequestPart;pub const dupeResponsePart = messages.dupeResponsePart;pub const dupeProviderDetails = messages.dupeProviderDetails;pub const dupeUserContent = messages.dupeUserContent;
pub const CancellationToken = struct { cancelled: std.atomic.Value(bool) = std.atomic.Value(bool).init(false),
pub fn cancel(self: *CancellationToken) void { self.cancelled.store(true, .seq_cst); }
pub fn isCancelled(self: *const CancellationToken) bool { return self.cancelled.load(.seq_cst); }};
/// Shared cancellation and monotonic deadline state for one agent invocation./// A deadline is created once and downstream operations consume its remaining/// time instead of restarting a timeout.pub const RunControl = struct { io: ?std.Io = null, cancellation: ?*const CancellationToken = null, deadline: ?std.Io.Clock.Timestamp = null,
/// Creates a control using the awake monotonic clock. A deadline requires /// an I/O runtime because every consumer must observe the same clock. pub fn init(io: ?std.Io, cancellation: ?*const CancellationToken, timeout_ms: ?u64) !RunControl { const runtime = if (timeout_ms != null) io orelse return error.RunControlRequiresIo else io; const deadline = if (timeout_ms) |milliseconds| blk: { const maximum: u64 = @intCast(std.math.maxInt(i64)); break :blk std.Io.Clock.Timestamp.fromNow(runtime.?, .{ .raw = .fromMilliseconds(@intCast(@min(milliseconds, maximum))), .clock = .awake, }); } else null; return .{ .io = runtime, .cancellation = cancellation, .deadline = deadline }; }
/// Fails when cancellation was requested or the deadline has elapsed. pub fn check(self: RunControl) !void { if (self.cancellation) |token| if (token.isCancelled()) return error.Cancelled; _ = try self.remainingMilliseconds(); }
/// Returns the positive milliseconds left, rounded up so a live /// sub-millisecond deadline is not mistaken for an expired one. pub fn remainingMilliseconds(self: RunControl) !?u64 { const deadline = self.deadline orelse return null; const io = self.io orelse return error.RunControlRequiresIo; const now = std.Io.Clock.Timestamp.now(io, deadline.clock); const nanoseconds = now.durationTo(deadline).raw.nanoseconds; if (nanoseconds <= 0) return error.RunTimedOut; const unit: i96 = std.time.ns_per_ms; const rounded = @divFloor(nanoseconds + unit - 1, unit); return @intCast(@min(rounded, std.math.maxInt(u64))); }
/// Tightens an operation-local timeout to the remaining run deadline. pub fn timeoutMilliseconds(self: RunControl, local_timeout_ms: ?u64) !?u64 { if (self.cancellation) |token| if (token.isCancelled()) return error.Cancelled; const remaining = try self.remainingMilliseconds(); if (remaining) |run_timeout| { if (local_timeout_ms) |local| return @min(run_timeout, local); return run_timeout; } return local_timeout_ms; }
/// Invokes one fallible operation while racing cancellation and the /// absolute run deadline. Losing work is cancelled and drained before this /// function returns, so it cannot mutate caller-owned state afterward. /// Results that require cleanup should be allocated in the run-owned arena /// because a result completed at the cancellation boundary may be discarded. pub fn invoke( self: RunControl, comptime Result: type, comptime operation: anytype, args: anytype, ) !Result { try self.check(); if (self.cancellation == null and self.deadline == null) return @call(.auto, operation, args);
const io = self.io orelse { const result = try @call(.auto, operation, args); try self.check(); return result; }; const Outcome = InvocationOutcome(Result); var buffer: [3]Outcome = undefined; var select: std.Io.Select(Outcome) = .init(io, &buffer); defer select.cancelDiscard(); select.concurrent(.operation, operation, args) catch return error.RunControlConcurrencyUnavailable; if (self.deadline) |deadline| select.concurrent(.deadline, waitForDeadline, .{ io, deadline }) catch return error.RunControlConcurrencyUnavailable; if (self.cancellation) |token| select.concurrent(.cancelled, waitForCancellation, .{ io, token }) catch return error.RunControlConcurrencyUnavailable;
return switch (try select.await()) { .operation => |result| operation: { const value = try result; try self.check(); break :operation value; }, .deadline => |result| blk: { result catch return error.Cancelled; break :blk error.RunTimedOut; }, .cancelled => |result| blk: { result catch return error.Cancelled; break :blk error.Cancelled; // kcov-ignore }, }; }
fn InvocationOutcome(comptime Result: type) type { return union(enum) { operation: anyerror!Result, deadline: anyerror!void, cancelled: anyerror!void, }; }
fn waitForDeadline(io: std.Io, deadline: std.Io.Clock.Timestamp) !void { return deadline.wait(io); }
fn waitForCancellation(io: std.Io, token: *const CancellationToken) !void { const poll_delay = std.Io.Timeout{ .duration = .{ .raw = .fromMilliseconds(5), .clock = .awake, } }; while (true) { try poll_delay.sleep(io); if (token.isCancelled()) return; } }};
pub const ToolDefinition = struct { name: []const u8, description: []const u8, parameters_json_schema: []const u8, /// Schema for the encoded tool result. return_json_schema: ?[]const u8 = null, /// Controls whether adapters add the return schema to the model-visible /// description. Provider function-tool protocols have no portable native /// return-schema field. return_schema_visibility: ToolReturnSchemaVisibility = .application,};
pub const ToolReturnSchemaVisibility = enum { application, model_description,};
/// Application metadata carried with a tool and exposed to lifecycle hooks.pub const ToolMetadata = Metadata;
/// Determines whether an agent may execute a tool immediately or must pause.pub const ToolExecution = enum { immediate, requires_approval, external,};
/// Encoded result from a tool plus user messages to append after the protocol/// tool-result message.pub const ToolOutput = struct { content: []const u8, follow_up_messages: []const RequestMessage = &.{},};
/// Resource limits for local tool execution. An agent supplies the run-wide/// policy; `Tool.limits` may tighten it for one tool.pub const ToolLimits = struct { /// Maximum wall-clock duration for one call. Requires an agent `io`. timeout_ms: ?u64 = null, /// Maximum simultaneously executing calls. max_concurrency: usize = 8, /// Maximum accepted calls waiting for an execution slot. max_queue_size: usize = 64, /// Maximum bytes in one encoded tool result. max_result_bytes: usize = 1024 * 1024, /// Maximum follow-up messages returned by one tool call. max_follow_up_messages: usize = 16, /// Maximum aggregate string and binary bytes in follow-up messages. max_follow_up_bytes: usize = 1024 * 1024,};
/// A typed reflected-tool return with optional model-visible follow-up/// messages. `reflect.tool` derives its return schema from `Value`.pub fn ToolReturn(comptime Value: type) type { return struct { value: Value, follow_up_messages: []const RequestMessage = &.{},
pub const zigai_tool_return = true; pub const ValueType = Value; };}
pub const Tool = struct { definition: ToolDefinition, /// Metadata for application policy and observability; providers do not receive it. metadata: []const ToolMetadata = &.{}, execution: ToolExecution = .immediate, /// Prevents this call from overlapping any other local function tool. sequential: bool = false, context: *anyopaque, /// Overrides `Agent.max_tool_retries` for this tool when non-null. max_retries: ?usize = null, /// Tightens the agent's local execution limits for this tool when non-null. limits: ?ToolLimits = null, validateFn: ?*const fn ( context: *anyopaque, allocator: std.mem.Allocator, arguments_json: []const u8, ) anyerror!void = null, executeFn: ?*const fn (context: *anyopaque, allocator: std.mem.Allocator, arguments_json: []const u8) anyerror![]const u8 = null, executeWithContextFn: ?*const fn ( context: *anyopaque, allocator: std.mem.Allocator, run_context: ToolRunContext, arguments_json: []const u8, ) anyerror![]const u8 = null, executeOutputFn: ?*const fn ( context: *anyopaque, allocator: std.mem.Allocator, arguments_json: []const u8, ) anyerror!ToolOutput = null, executeOutputWithContextFn: ?*const fn ( context: *anyopaque, allocator: std.mem.Allocator, run_context: ToolRunContext, arguments_json: []const u8, ) anyerror!ToolOutput = null, /// Classifies failures that are safe to show to the model for correction. /// By default, only allocation and cancellation failures are fatal. isRecoverableFn: ?*const fn (context: *anyopaque, failure: anyerror) bool = null,
/// Validates one JSON argument document, then executes this tool. pub fn execute(self: Tool, allocator: std.mem.Allocator, arguments_json: []const u8) ![]const u8 { try validateToolArgumentsJson(allocator, arguments_json); return self.executePrepared(allocator, arguments_json); }
fn executePrepared(self: Tool, allocator: std.mem.Allocator, arguments_json: []const u8) ![]const u8 { if (self.executeFn) |execute_fn| return execute_fn(self.context, allocator, arguments_json); if (self.executeOutputFn) |execute_output| { const output = try execute_output(self.context, allocator, arguments_json); return output.content; } return error.MissingToolExecutor; }
/// Validates one bounded JSON argument document and any tool-specific rules. pub fn validate(self: Tool, allocator: std.mem.Allocator, arguments_json: []const u8) !void { try self.validateJson(allocator, arguments_json); return self.validateRules(allocator, arguments_json); }
/// Validates only the bounded JSON envelope before argument policies run. pub fn validateJson(_: Tool, allocator: std.mem.Allocator, arguments_json: []const u8) !void { return validateToolArgumentsJson(allocator, arguments_json); }
/// Applies tool-specific argument rules after policy transformation. pub fn validateRules(self: Tool, allocator: std.mem.Allocator, arguments_json: []const u8) !void { const validate_arguments = self.validateFn orelse return; return validate_arguments(self.context, allocator, arguments_json); }
/// Validates and executes this tool with the current agent run context. pub fn executeWithContext(self: Tool, allocator: std.mem.Allocator, run_context: ToolRunContext, arguments_json: []const u8) ![]const u8 { try validateToolArgumentsJson(allocator, arguments_json); if (self.executeWithContextFn) |contextual| return contextual(self.context, allocator, run_context, arguments_json); // kcov-ignore if (self.executeOutputWithContextFn) |execute_output| return (try execute_output(self.context, allocator, run_context, arguments_json)).content; // kcov-ignore return self.executePrepared(allocator, arguments_json); }
/// Validates and executes this tool while preserving rich output metadata. pub fn executeOutput(self: Tool, allocator: std.mem.Allocator, arguments_json: []const u8) !ToolOutput { try validateToolArgumentsJson(allocator, arguments_json); return self.executeOutputPrepared(allocator, arguments_json); }
fn executeOutputPrepared(self: Tool, allocator: std.mem.Allocator, arguments_json: []const u8) !ToolOutput { if (self.executeOutputFn) |execute_output| return execute_output(self.context, allocator, arguments_json); return .{ .content = try self.executePrepared(allocator, arguments_json) }; }
/// Validates and executes this contextual tool with rich output metadata. pub fn executeOutputWithContext( self: Tool, allocator: std.mem.Allocator, run_context: ToolRunContext, arguments_json: []const u8, ) !ToolOutput { try validateToolArgumentsJson(allocator, arguments_json); if (self.executeOutputWithContextFn) |execute_output| return execute_output(self.context, allocator, run_context, arguments_json); // kcov-ignore if (self.executeWithContextFn) |execute_context| return .{ .content = try execute_context(self.context, allocator, run_context, arguments_json), }; return self.executeOutputPrepared(allocator, arguments_json); }
/// Returns whether `failure` can be safely exposed to the model. pub fn isRecoverable(self: Tool, failure: anyerror) bool { if (self.isRecoverableFn) |classify| return classify(self.context, failure); return switch (failure) { error.OutOfMemory, error.Cancelled, error.RequestCancelled, error.RunTimedOut, error.RunControlRequiresIo, error.RunControlConcurrencyUnavailable, error.ToolConcurrencyUnavailable, error.ToolIsolationRequiresIo, => false, else => true, }; }};
fn validateToolArgumentsJson(allocator: std.mem.Allocator, arguments_json: []const u8) !void { try json_limits.validateAs(allocator, arguments_json, json_limits.defaults.tool_payload, error.InvalidToolArguments);}
/// Per-run state made available to contextual tools. `dependency` provides a/// checked-at-the-call-site cast while keeping Agent itself non-generic.pub const ToolRunContext = struct { dependencies: ?*anyopaque = null, /// Canonical conversation through the model response containing this call. messages: []const Message = &.{}, usage: RunUsage = .{}, model_requests: usize = 0, /// Capability state that a nested agent may use to construct inherited layers. capabilities: capability_types.Snapshot = .{}, /// Shared cooperative cancellation state for the run. cancellation: ?*const CancellationToken = null, /// Runtime available to tools for cancellable I/O. io: ?std.Io = null, /// Absolute monotonic deadline shared by the complete agent invocation. deadline: ?std.Io.Clock.Timestamp = null,
pub fn dependency(self: ToolRunContext, comptime T: type) ?*T { const pointer = self.dependencies orelse return null; return @ptrCast(@alignCast(pointer)); }};
/// Capabilities belong to the model, not the provider transport. Keeping this/// separate lets callers reject an unsupported feature before making a paid/// network request.pub const ModelProfile = struct { supports_tools: bool = true, supports_parallel_tool_calls: bool = true, supports_json_schema_output: bool = false, supports_json_object_output: bool = false, supports_system_messages: bool = true, supports_thinking: bool = false, supports_streaming: bool = false, supports_temperature: bool = false, supports_max_tokens: bool = true, supports_stop_sequences: bool = false, supports_seed: bool = false, supports_top_p: bool = false, supports_top_k: bool = false, supports_presence_penalty: bool = false, supports_frequency_penalty: bool = false, supports_logprobs: bool = false, supports_tool_choice: bool = false, supports_parallel_tool_call_setting: bool = false, supports_thinking_budget: bool = false, supports_truncation: bool = false, supports_request_headers: bool = false, extra_body_kind: ?ExtraBodyKind = null, /// The adapter can attach a caller-supplied key to retry attempts. supports_idempotency_key: bool = false, reasoning_efforts: ReasoningEffortSet = ReasoningEffortSet.empty, service_tiers: ServiceTierSet = ServiceTierSet.empty, builtin_tools: BuiltinToolSet = BuiltinToolSet.empty, content_types: ContentTypeSet = ContentTypeSet.empty,
pub const ReasoningEffortSet = std.EnumSet(ReasoningEffort); pub const ServiceTierSet = std.EnumSet(ServiceTier); pub const BuiltinToolSet = std.EnumSet(BuiltinToolKind); pub const ContentTypeSet = std.EnumSet(ContentType);
pub fn supportsReasoningEffort(self: ModelProfile, effort: ReasoningEffort) bool { return self.reasoning_efforts.contains(effort); }
pub fn supportsServiceTier(self: ModelProfile, tier: ServiceTier) bool { return self.service_tiers.contains(tier); }
pub fn supportsBuiltinTool(self: ModelProfile, kind: BuiltinToolKind) bool { return self.builtin_tools.contains(kind); }
pub fn supportsContentType(self: ModelProfile, kind: ContentType) bool { return self.content_types.contains(kind); }};
pub const ContentType = enum { image, audio, video, document, binary, thinking,};
pub const BuiltinToolKind = enum { web_search, web_fetch, x_search, code_execution, file_search, remote_mcp,};
/// A provider-managed tool. The provider executes it inside the model request;/// it never enters the application's local tool dispatcher.pub const BuiltinTool = union(BuiltinToolKind) { web_search: WebSearch, web_fetch: WebFetch, x_search: XSearch, code_execution: CodeExecution, file_search: FileSearch, remote_mcp: RemoteMcp,
pub const WebSearch = struct { allowed_domains: ?[]const []const u8 = null, excluded_domains: ?[]const []const u8 = null, enable_image_understanding: ?bool = null, enable_image_search: ?bool = null, }; pub const WebFetch = struct {}; pub const XSearch = struct { allowed_x_handles: ?[]const []const u8 = null, excluded_x_handles: ?[]const []const u8 = null, from_date: ?[]const u8 = null, to_date: ?[]const u8 = null, enable_image_understanding: ?bool = null, enable_video_understanding: ?bool = null, }; pub const CodeExecution = struct {}; pub const FileSearch = struct { vector_store_ids: []const []const u8, max_num_results: ?u32 = null, }; pub const RemoteMcp = struct { server_url: []const u8, server_label: []const u8, server_description: ?[]const u8 = null, allowed_tools: ?[]const []const u8 = null, authorization: ?[]const u8 = null, headers: ?[]const RequestHeader = null, };
pub fn kind(self: BuiltinTool) BuiltinToolKind { return std.meta.activeTag(self); }
/// Whether two declarations would create the same provider-visible tool. /// Remote MCP servers are keyed by label; all other built-ins are singletons. pub fn conflictsWith(self: BuiltinTool, other: BuiltinTool) bool { if (self.kind() != other.kind()) return false; return switch (self) { .remote_mcp => |server| std.mem.eql(u8, server.server_label, other.remote_mcp.server_label), else => true, }; }};
pub const ReasoningEffort = settings_types.ReasoningEffort;pub const ServiceTier = settings_types.ServiceTier;pub const Truncation = settings_types.Truncation;pub const Logprobs = settings_types.Logprobs;pub const ToolChoice = settings_types.ToolChoice;pub const RequestHeader = settings_types.RequestHeader;pub const ExtraBodyKind = settings_types.ExtraBodyKind;pub const ProviderExtraBody = settings_types.ProviderExtraBody;pub const ModelSettings = settings_types.ModelSettings;
/// Stable error categories emitted by provider adapters. Agents can make retry/// decisions from these without depending on a provider's private error JSON.pub const ProviderRequestError = error{ /// A known DNS, connect, socket, or connection-lifetime failure occurred. ProviderConnectionError, /// The provider returned a success payload that its adapter could not decode. ProviderResponseDecodeError, /// The provider rejected the request for rate limiting. ProviderRateLimited, /// The provider returned a retryable 5xx response. ProviderServerError, /// The provider returned another non-success HTTP response. ProviderRequestFailed,};
pub const ProviderError = struct { provider: []const u8, status: u16, code: ?[]const u8 = null, message: []const u8, /// Empty unless `ProviderErrorPolicy.capture_body` is enabled. body: []const u8, body_truncated: bool = false, /// A configured credential appeared in observer-visible details and was suppressed. sensitive_data_redacted: bool = false, /// Borrowed provider correlation ID, when supplied in response headers. request_id: ?[]const u8 = null, retry_after_seconds: ?u64 = null, rate_limit_remaining_requests: ?u64 = null, rate_limit_remaining_tokens: ?u64 = null,};
/// Controls the bounded provider details exposed to error observers.pub const ProviderErrorPolicy = struct { /// Makes the raw response body visible to observers. Disabled by default. capture_body: bool = false, /// Maximum captured body bytes. Exact-limit bodies are not truncated. max_body_bytes: usize = 16 * 1024, /// Maximum provider message bytes exposed regardless of body capture. max_message_bytes: usize = 4 * 1024, /// Maximum provider error-code bytes exposed to observers. max_code_bytes: usize = 256,};
/// Receives a borrowed error view synchronously. Copy fields in the callback if/// they need to outlive the request.pub const ProviderErrorObserver = struct { context: *anyopaque, observeFn: *const fn (context: *anyopaque, provider_error: ProviderError) void,
pub fn observe(self: ProviderErrorObserver, provider_error: ProviderError) void { self.observeFn(self.context, provider_error); }};
pub const ModelRequest = struct { messages: []const Message, /// Current-run instructions. Providers encode these as their native /// instruction or system-message representation; agents do not retain /// them in reusable message history. instructions: []const []const u8 = &.{}, tools: []const ToolDefinition = &.{}, builtin_tools: []const BuiltinTool = &.{}, output: OutputFormat = .text, error_observer: ?ProviderErrorObserver = null, error_policy: ProviderErrorPolicy = .{}, /// Outbound provider and remote-content URL policy for this logical call. url_policy: security.UrlPolicy = .{}, /// Caller correlation ID. Supporting providers forward it unchanged. request_id: ?[]const u8 = null, /// Stable across retries of this logical request. Ignored unless supported. idempotency_key: ?[]const u8 = null, timeout_ms: ?u64 = null, cancellation: ?*const CancellationToken = null, settings: ModelSettings = .{},};
pub const OutputFormat = union(enum) { text, json_object, json_schema: JsonSchema,
pub const JsonSchema = struct { name: []const u8, schema: []const u8, strict: bool = true, };};
/// Provider response data allocated by the allocator passed to `Model.request`/// or `Model.stream`. Direct callers should normally use an arena allocator;/// `Agent` copies the response into its own owned result arena.pub const ModelResponse = ResponseMessage;
/// A text fragment for one response part.pub const TextPartDelta = struct { content_delta: []const u8, provider: ProviderPart = .{},};
/// A reasoning fragment. Providers may deliver content and signature bytes in/// separate events, so either field can be empty.pub const ThinkingPartDelta = struct { content_delta: []const u8 = "", signature_delta: []const u8 = "", provider: ProviderPart = .{},};
/// A function-tool fragment. IDs and names are optional because some provider/// protocols deliver arguments before the remaining fields.pub const ToolCallPartDelta = struct { id: ?[]const u8 = null, name: ?[]const u8 = null, arguments_delta: []const u8 = "", provider: ProviderPart = .{},};
/// Compatibility alias; new code should use `ToolCallPartDelta`.pub const ToolCallDelta = ToolCallPartDelta;
/// A provider-executed tool fragment.pub const NativeToolCallPartDelta = ToolCallPartDelta;
/// A fragment of a provider-executed tool result.pub const NativeToolReturnPartDelta = struct { content_delta: []const u8 = "", provider: ProviderPart = .{},};
/// The semantic kind of streamed media bytes.pub const MediaKind = enum { image, audio, video, document, binary,};
/// A binary media fragment. Bytes are borrowed for the duration of the sink/// callback and are not necessarily a complete file.pub const MediaPartDelta = struct { kind: MediaKind, bytes_delta: []const u8, media_type: ?[]const u8 = null, identifier: ?[]const u8 = null, provider: ProviderPart = .{},};
/// A streaming speech fragment. Audio and transcript fragments may arrive/// independently.pub const SpeechPartDelta = struct { speaker: ?SpeechPart.Speaker = null, transcript_delta: []const u8 = "", audio_delta: []const u8 = "", provider: ProviderPart = .{},};
/// A provider-generated history-compaction fragment.pub const CompactionPartDelta = struct { content_delta: []const u8, provider: ProviderPart = .{},};
/// Provider-neutral fragments for every response part that can arrive/// incrementally.pub const ResponsePartDelta = union(enum) { text: TextPartDelta, thinking: ThinkingPartDelta, tool_call: ToolCallPartDelta, native_tool_call: NativeToolCallPartDelta, native_tool_return: NativeToolReturnPartDelta, media: MediaPartDelta, speech: SpeechPartDelta, compaction: CompactionPartDelta,};
/// Starts one response part. `part` is a borrowed initial snapshot and `index`/// remains stable for all subsequent events for that part.pub const PartStartEvent = struct { index: usize, part: ResponsePart,};
/// Applies one borrowed fragment to the part at `index`.pub const PartDeltaEvent = struct { index: usize, delta: ResponsePartDelta,};
/// Ends one response part with its complete borrowed value.pub const PartEndEvent = struct { index: usize, part: ResponsePart,};
/// Borrowed events emitted synchronously while a model response is arriving./// A part has exactly one start and at most one end, and its index never changes/// during the stream. Providers return the same accumulated `ModelResponse`/// used by buffered requests after all part events.pub const ModelStreamEvent = union(enum) { part_start: PartStartEvent, part_delta: PartDeltaEvent, part_end: PartEndEvent, usage: Usage,};
pub const ModelStreamSink = struct { context: *anyopaque, eventFn: *const fn (context: *anyopaque, event: ModelStreamEvent) anyerror!void,
pub fn emit(self: ModelStreamSink, event: ModelStreamEvent) !void { return self.eventFn(self.context, event); }};
/// Emits a complete part through the same lifecycle used by incremental/// providers. Text and thinking include a delta; atomic parts emit start/end.pub fn emitCompletePart(sink: ModelStreamSink, index: usize, part: ResponsePart) !void { const initial: ResponsePart = switch (part) { .text => .{ .text = "" }, .text_part => |value| .{ .text_part = .{ .content = "", .provider = value.provider } }, .thinking => |value| .{ .thinking = .{ .content = "", .provider = value.provider } }, else => part, }; try sink.emit(.{ .part_start = .{ .index = index, .part = initial } }); switch (part) { .text => |content| try sink.emit(.{ .part_delta = .{ .index = index, .delta = .{ .text = .{ .content_delta = content } }, } }), .text_part => |value| try sink.emit(.{ .part_delta = .{ .index = index, .delta = .{ .text = .{ .content_delta = value.content, .provider = value.provider } }, } }), .thinking => |value| try sink.emit(.{ .part_delta = .{ .index = index, .delta = .{ .thinking = .{ .content_delta = value.content, .signature_delta = value.signature orelse "", .provider = value.provider, } }, } }), else => {}, } try sink.emit(.{ .part_end = .{ .index = index, .part = part } });}
/// A small Zig vtable keeps the agent independent from every provider package/// without forcing provider implementations to allocate wrapper objects.pub const Model = struct { context: *anyopaque, profile: ModelProfile, /// Provider identity used by telemetry and application policy. provider_name: ?[]const u8 = null, /// Provider model identifier used by telemetry and application policy. model_name: ?[]const u8 = null, settings: ModelSettings = .{}, requestFn: *const fn (context: *anyopaque, allocator: std.mem.Allocator, request: ModelRequest) anyerror!ModelResponse, streamFn: ?*const fn ( context: *anyopaque, allocator: std.mem.Allocator, request: ModelRequest, sink: ModelStreamSink, ) anyerror!ModelResponse = null,
pub fn request(self: Model, allocator: std.mem.Allocator, value: ModelRequest) !ModelResponse { var response = try self.requestFn(self.context, allocator, value); response.provider_name = response.provider_name orelse self.provider_name; response.model_name = response.model_name orelse self.model_name; return response; }
pub fn stream(self: Model, allocator: std.mem.Allocator, value: ModelRequest, sink: ModelStreamSink) !ModelResponse { const stream_request = self.streamFn orelse return error.StreamingNotSupported; var response = try stream_request(self.context, allocator, value, sink); response.provider_name = response.provider_name orelse self.provider_name; response.model_name = response.model_name orelse self.model_name; return response; }};
test "run control shares one deadline and drains interrupted work" { const State = struct { active: std.atomic.Value(bool) = .init(false),
fn slow(self: *@This(), io: std.Io) !u8 { self.active.store(true, .seq_cst); defer self.active.store(false, .seq_cst); while (true) try (std.Io.Timeout{ .duration = .{ .raw = .fromMilliseconds(100), .clock = .awake, } }).sleep(io); } };
try std.testing.expectError( error.RunControlRequiresIo, RunControl.init(null, null, 1), ); try (RunControl{}).invoke(void, struct { fn call() !void { try std.testing.expect(true); } }.call, .{});
var unavailable = std.Io.Threaded.init(std.testing.allocator, .{ .concurrent_limit = .nothing }); defer unavailable.deinit(); const unavailable_control = try RunControl.init(unavailable.io(), null, 10); try std.testing.expectError( error.RunControlConcurrencyUnavailable, unavailable_control.invoke(void, struct { fn call() !void { // unreachable: concurrency is unavailable before this callback unreachable; } }.call, .{}), );
var threaded = std.Io.Threaded.init(std.testing.allocator, .{}); defer threaded.deinit(); const io = threaded.io(); var state: State = .{}; const control = try RunControl.init(io, null, 100); const first_remaining = (try control.remainingMilliseconds()).?; try std.testing.expect(first_remaining > 0 and first_remaining <= 100); try std.testing.expectEqual(@as(?u64, 1), try control.timeoutMilliseconds(1)); try std.testing.expectError(error.RunTimedOut, control.invoke(u8, State.slow, .{ &state, io })); try std.testing.expect(!state.active.load(.seq_cst)); try std.testing.expectError(error.RunTimedOut, control.check());}
test "run control drains cancellation and supports cooperative fallback" { const State = struct { active: std.atomic.Value(bool) = .init(false), started: std.atomic.Value(bool) = .init(false),
fn slow(self: *@This(), io: std.Io) !void { self.started.store(true, .seq_cst); self.active.store(true, .seq_cst); defer self.active.store(false, .seq_cst); while (true) try (std.Io.Timeout{ .duration = .{ .raw = .fromSeconds(10), .clock = .awake, } }).sleep(io); }
fn cancelAfter(io: std.Io, token: *CancellationToken) !void { const delay: std.Io.Timeout = .{ .duration = .{ .raw = .fromMilliseconds(50), .clock = .awake, } }; try delay.sleep(io); token.cancel(); }
fn cancelCooperatively(token: *CancellationToken) !u8 { token.cancel(); return 1; }
fn succeed() !void { try std.testing.expect(true); } };
var threaded = std.Io.Threaded.init(std.testing.allocator, .{}); defer threaded.deinit(); const io = threaded.io(); var token: CancellationToken = .{}; var state: State = .{}; var cancel_runtime = std.Io.Threaded.init(std.testing.allocator, .{}); defer cancel_runtime.deinit(); var canceller = try cancel_runtime.io().concurrent(State.cancelAfter, .{ cancel_runtime.io(), &token }); try std.testing.expectError( error.Cancelled, (RunControl{ .io = io, .cancellation = &token }).invoke(void, State.slow, .{ &state, io }), ); try canceller.await(cancel_runtime.io()); try std.testing.expect(state.started.load(.seq_cst)); try std.testing.expect(!state.active.load(.seq_cst));
var polling_token: CancellationToken = .{}; var polling_canceller = try cancel_runtime.io().concurrent(State.cancelAfter, .{ cancel_runtime.io(), &polling_token }); try RunControl.waitForCancellation(io, &polling_token); try polling_canceller.await(cancel_runtime.io());
var live_token: CancellationToken = .{}; var success_runtime = std.Io.Threaded.init(std.testing.allocator, .{}); defer success_runtime.deinit(); const success_io = success_runtime.io(); const success_control = RunControl{ .io = success_io, .deadline = std.Io.Clock.Timestamp.fromNow(success_io, .{ .raw = .fromSeconds(10), .clock = .awake, }), }; try success_control.invoke(void, State.succeed, .{}); try (RunControl{ .cancellation = &live_token }).invoke(void, State.succeed, .{});
var cooperative_token: CancellationToken = .{}; try std.testing.expectError( error.Cancelled, (RunControl{ .cancellation = &cooperative_token }).invoke( u8, State.cancelCooperatively, .{&cooperative_token}, ), );}
test "tool run context casts optional dependencies" { var value: u32 = 42; const context = ToolRunContext{ .dependencies = &value }; try std.testing.expectEqual(@as(u32, 42), context.dependency(u32).?.*); try std.testing.expect((ToolRunContext{}).dependency(u32) == null);}
test "model stream sinks propagate events and unsupported models fail" { const Capture = struct { called: bool = false, requests: usize = 0, fn event(context: *anyopaque, value: ModelStreamEvent) !void { const self: *@This() = @ptrCast(@alignCast(context)); self.called = value == .part_delta and value.part_delta.delta == .text and std.mem.eql(u8, value.part_delta.delta.text.content_delta, "hello"); } fn request(context: *anyopaque, _: std.mem.Allocator, _: ModelRequest) !ModelResponse { const self: *@This() = @ptrCast(@alignCast(context)); self.requests += 1; return .{ .parts = &.{} }; } }; var capture: Capture = .{}; const sink = ModelStreamSink{ .context = &capture, .eventFn = Capture.event }; try sink.emit(.{ .part_delta = .{ .index = 0, .delta = .{ .text = .{ .content_delta = "hello" } }, } }); try std.testing.expect(capture.called); const value = Model{ .context = &capture, .profile = .{}, .requestFn = Capture.request }; const response = try value.request(std.testing.allocator, .{ .messages = &.{} }); try std.testing.expectEqual(@as(usize, 0), response.parts.len); try std.testing.expectEqual(@as(usize, 1), capture.requests); try std.testing.expectError(error.StreamingNotSupported, value.stream(std.testing.allocator, .{ .messages = &.{} }, sink));}
test "complete parts use stable start delta end indexes" { const Capture = struct { sequence: [9]u8 = undefined, indexes: [9]usize = undefined, count: usize = 0,
fn event(context: *anyopaque, value: ModelStreamEvent) !void { const self: *@This() = @ptrCast(@alignCast(context)); const index = switch (value) { .part_start => |event_value| event_value.index, .part_delta => |event_value| event_value.index, .part_end => |event_value| event_value.index, .usage => return error.UnexpectedUsage, }; self.indexes[self.count] = index; self.sequence[self.count] = switch (value) { .part_start => 1, .part_delta => 2, .part_end => 3, .usage => unreachable, }; self.count += 1; } }; var capture: Capture = .{}; const sink = ModelStreamSink{ .context = &capture, .eventFn = Capture.event }; try emitCompletePart(sink, 4, .{ .text = "hello" }); try emitCompletePart(sink, 5, .{ .text_part = .{ .content = "world" } }); try emitCompletePart(sink, 6, .{ .thinking = .{ .content = "reason", .signature = "sig" } }); try std.testing.expectError(error.UnexpectedUsage, sink.emit(.{ .usage = .{} })); try std.testing.expectEqualSlices(u8, &.{ 1, 2, 3, 1, 2, 3, 1, 2, 3 }, &capture.sequence); try std.testing.expectEqualSlices(usize, &.{ 4, 4, 4, 5, 5, 5, 6, 6, 6 }, &capture.indexes);}
test "stream delta vocabulary covers thinking media native tools speech and compaction" { const Capture = struct { seen: std.EnumSet(std.meta.Tag(ResponsePartDelta)) = .empty,
fn event(context: *anyopaque, value: ModelStreamEvent) !void { const self: *@This() = @ptrCast(@alignCast(context)); switch (value) { .part_delta => |event_value| self.seen.insert(std.meta.activeTag(event_value.delta)), else => return error.ExpectedPartDelta, } } }; var capture: Capture = .{}; const sink = ModelStreamSink{ .context = &capture, .eventFn = Capture.event }; const deltas = [_]ResponsePartDelta{ .{ .text = .{ .content_delta = "text" } }, .{ .thinking = .{ .content_delta = "thought", .signature_delta = "signature" } }, .{ .tool_call = .{ .id = "call", .name = "tool", .arguments_delta = "{}" } }, .{ .native_tool_call = .{ .id = "native", .name = "search", .arguments_delta = "{}" } }, .{ .native_tool_return = .{ .content_delta = "result" } }, .{ .media = .{ .kind = .audio, .bytes_delta = "bytes", .media_type = "audio/pcm" } }, .{ .speech = .{ .speaker = .assistant, .transcript_delta = "hello", .audio_delta = "audio" } }, .{ .compaction = .{ .content_delta = "summary" } }, }; for (deltas, 0..) |delta, index| try sink.emit(.{ .part_delta = .{ .index = index, .delta = delta } }); try std.testing.expectEqual(@typeInfo(ResponsePartDelta).@"union".field_names.len, capture.seen.count());}
test "tool execution adapters preserve rich outputs" { const Executor = struct { fn output(_: *anyopaque, allocator: std.mem.Allocator, arguments_json: []const u8) !ToolOutput { return .{ .content = try allocator.dupe(u8, arguments_json) }; }
fn contextual( _: *anyopaque, allocator: std.mem.Allocator, run_context: ToolRunContext, _: []const u8, ) !ToolOutput { return .{ .content = try std.fmt.allocPrint(allocator, "{d}", .{run_context.model_requests}) }; } }; var context: u8 = 0; const output_tool = Tool{ .definition = .{ .name = "output", .description = "", .parameters_json_schema = "{}" }, .context = &context, .executeOutputFn = Executor.output, }; const plain = try output_tool.execute(std.testing.allocator, "\"result\""); defer std.testing.allocator.free(plain); try std.testing.expectEqualStrings("\"result\"", plain); try std.testing.expectError(error.InvalidToolArguments, output_tool.execute(std.testing.allocator, "result")); const deeply_nested = @as([65]u8, @splat('[')) ++ "0" ++ @as([65]u8, @splat(']')); try std.testing.expectError(error.InvalidToolArguments, output_tool.execute(std.testing.allocator, deeply_nested));
const contextual_tool = Tool{ .definition = .{ .name = "contextual", .description = "", .parameters_json_schema = "{}" }, .context = &context, .executeOutputWithContextFn = Executor.contextual, }; const contextual = try contextual_tool.executeWithContext( std.testing.allocator, .{ .model_requests = 7 }, "{}", ); defer std.testing.allocator.free(contextual); try std.testing.expectEqualStrings("7", contextual);
const rich = try contextual_tool.executeOutputWithContext( std.testing.allocator, .{ .model_requests = 9 }, "{}", ); defer std.testing.allocator.free(rich.content); try std.testing.expectEqualStrings("9", rich.content);
const missing = Tool{ .definition = .{ .name = "missing", .description = "", .parameters_json_schema = "{}" }, .context = &context, }; try std.testing.expectError(error.MissingToolExecutor, missing.execute(std.testing.allocator, "{}")); try std.testing.expectError(error.MissingToolExecutor, missing.executeWithContext(std.testing.allocator, .{}, "{}"));}