diff options
Diffstat (limited to 'libpanto/src/anthropic_messages_json.zig')
| -rw-r--r-- | libpanto/src/anthropic_messages_json.zig | 52 |
1 files changed, 50 insertions, 2 deletions
diff --git a/libpanto/src/anthropic_messages_json.zig b/libpanto/src/anthropic_messages_json.zig index 708ede5..46ec17c 100644 --- a/libpanto/src/anthropic_messages_json.zig +++ b/libpanto/src/anthropic_messages_json.zig @@ -232,9 +232,31 @@ pub const StreamEventTag = enum { pub const ContentBlockKind = enum { text, thinking, tool_use, unknown }; +/// Partial token-count snapshot emitted in `message_start` and +/// `message_delta`. Field semantics follow Anthropic's wire format: +/// +/// - `input_tokens`: prompt tokens billed at the base rate. +/// - `cache_creation_input_tokens`: prompt tokens written to a new +/// cache entry (1.25× base). +/// - `cache_read_input_tokens`: prompt tokens served from cache +/// (0.1× base). +/// - `output_tokens`: response tokens billed at the output rate. +/// +/// `message_start.usage` carries the initial input-side counts (output +/// will be 0 or absent); `message_delta.usage` carries the final +/// `output_tokens` and may repeat the input-side counts. The provider +/// merges them — "missing" means "unchanged," not "reset to zero." +pub const StreamUsage = struct { + input_tokens: ?u64 = null, + output_tokens: ?u64 = null, + cache_creation_input_tokens: ?u64 = null, + cache_read_input_tokens: ?u64 = null, +}; + pub const StreamEvent = union(StreamEventTag) { message_start: struct { role: ?[]const u8 = null, + usage: StreamUsage = .{}, }, content_block_start: struct { index: usize, @@ -255,6 +277,7 @@ pub const StreamEvent = union(StreamEventTag) { }, message_delta: struct { stop_reason: ?[]const u8 = null, + usage: StreamUsage = .{}, }, message_stop: void, ping: void, @@ -287,14 +310,18 @@ pub fn parseStreamEvent(allocator: Allocator, payload: []const u8) !ParsedStream const ty = type_v.string; if (std.mem.eql(u8, ty, "message_start")) { var role: ?[]const u8 = null; + var usage: StreamUsage = .{}; if (root.object.get("message")) |m| { if (m == .object) { if (m.object.get("role")) |r| { if (r == .string) role = r.string; } + if (m.object.get("usage")) |u| { + if (u == .object) usage = parseStreamUsage(u.object); + } } } - return .{ .parsed = parsed, .event = .{ .message_start = .{ .role = role } } }; + return .{ .parsed = parsed, .event = .{ .message_start = .{ .role = role, .usage = usage } } }; } if (std.mem.eql(u8, ty, "content_block_start")) { @@ -380,6 +407,7 @@ pub fn parseStreamEvent(allocator: Allocator, payload: []const u8) !ParsedStream if (std.mem.eql(u8, ty, "message_delta")) { var stop_reason: ?[]const u8 = null; + var usage: StreamUsage = .{}; if (root.object.get("delta")) |d| { if (d == .object) { if (d.object.get("stop_reason")) |sr| { @@ -387,7 +415,11 @@ pub fn parseStreamEvent(allocator: Allocator, payload: []const u8) !ParsedStream } } } - return .{ .parsed = parsed, .event = .{ .message_delta = .{ .stop_reason = stop_reason } } }; + // `usage` is on the message_delta event itself, not under `delta`. + if (root.object.get("usage")) |u| { + if (u == .object) usage = parseStreamUsage(u.object); + } + return .{ .parsed = parsed, .event = .{ .message_delta = .{ .stop_reason = stop_reason, .usage = usage } } }; } if (std.mem.eql(u8, ty, "message_stop")) { @@ -417,6 +449,22 @@ pub fn parseStreamEvent(allocator: Allocator, payload: []const u8) !ParsedStream return .{ .parsed = parsed, .event = .unknown }; } +fn parseStreamUsage(obj: std.json.ObjectMap) StreamUsage { + return .{ + .input_tokens = readOptionalU64(obj, "input_tokens"), + .output_tokens = readOptionalU64(obj, "output_tokens"), + .cache_creation_input_tokens = readOptionalU64(obj, "cache_creation_input_tokens"), + .cache_read_input_tokens = readOptionalU64(obj, "cache_read_input_tokens"), + }; +} + +fn readOptionalU64(obj: std.json.ObjectMap, name: []const u8) ?u64 { + const v = obj.get(name) orelse return null; + if (v != .integer) return null; + if (v.integer < 0) return null; + return @intCast(v.integer); +} + fn readIndex(root: std.json.Value) ?usize { const v = root.object.get("index") orelse return null; if (v != .integer) return null; |