| 1 | package tool |
| 2 | |
| 3 | import "context" |
| 4 | |
| 5 | // CompressRequest describes one explicit, model-requested context fold. |
| 6 | type CompressRequest struct { |
| 7 | Direction string |
| 8 | Anchor string |
| 9 | Focus string |
| 10 | } |
| 11 | |
| 12 | // CompressResult is the stable model-facing outcome of a context fold. |
| 13 | type CompressResult struct { |
| 14 | Status string `json:"status"` |
| 15 | Direction string `json:"direction"` |
| 16 | Anchor string `json:"anchor"` |
| 17 | Messages int `json:"messages"` |
| 18 | SourceTokens int `json:"source_tokens"` |
| 19 | ProjectionTokens int `json:"projection_tokens"` |
| 20 | Mode string `json:"mode"` |
| 21 | Reason string `json:"reason"` |
| 22 | } |
| 23 | |
| 24 | // ContextCompressor is supplied by the Agent that owns the active session. |
| 25 | // Keeping the binding on the call context lets parent and child agents share a |
| 26 | // stable tool schema without sharing projection state. |
| 27 | type ContextCompressor interface { |
| 28 | CompressContext(context.Context, CompressRequest) (CompressResult, error) |
| 29 | } |
| 30 | |
| 31 | type contextCompressorKey struct{} |
| 32 | |
| 33 | // WithContextCompressor binds the active session's compressor to a tool call. |
| 34 | func WithContextCompressor(ctx context.Context, compressor ContextCompressor) context.Context { |
| 35 | if compressor == nil { |
| 36 | return ctx |
| 37 | } |
| 38 | return context.WithValue(ctx, contextCompressorKey{}, compressor) |
| 39 | } |
| 40 | |
| 41 | // ContextCompressorFromContext returns the compressor bound to this tool call. |
| 42 | func ContextCompressorFromContext(ctx context.Context) (ContextCompressor, bool) { |
| 43 | compressor, ok := ctx.Value(contextCompressorKey{}).(ContextCompressor) |
| 44 | return compressor, ok && compressor != nil |
| 45 | } |
| 46 |