core/tools: token-ify per-stream caps and resume memory remainders

src/plyngent/tools/file/get_truncated.py

@@ -8,24 +8,46 @@ from plyngent.agent import ToolTag, tool
 from plyngent.agent.budget import DEFAULT_TOOL_RESULT_MAX_CHARS
 from plyngent.tools.file.read import line_range_label, read_raw_text
 from plyngent.tools.net.fetch import fetch
-from plyngent.tools.truncate_token import decode_truncate_token, truncate_with_token
+from plyngent.tools.truncate_token import (
+    decode_truncate_token,
+    get_remainder,
+    truncate_with_token,
+)
 
 
 @tool(tags=ToolTag.LOCAL | ToolTag.INSTANCE_STATE)
 async def get_truncated(token: str, *, max_chars: int = DEFAULT_TOOL_RESULT_MAX_CHARS) -> str:
-    """Fetch the next chunk of a truncated result using its ``TRUNCATE_TOKEN``.
+    """Fetch the next chunk of a truncated result using its ``truncate_token``.
 
-    Pass the token shown at the end of a truncated ``read_file``, ``fetch``, or
-    earlier ``get_truncated`` result to keep reading without re-requesting the
-    whole source or raising limits. Truncated output carries a fresh token, so
-    chunks chain indefinitely. File chunks start with a 1-based ``L{begin}-{end}``
-    line range like ``read_file``.
+    Pass the token shown at the end of a truncated ``read_file``, ``fetch``,
+    ``run_command``, or earlier ``get_truncated`` result to keep reading without
+    re-requesting the whole source or raising limits. Truncated output carries a
+    fresh token, so chunks chain indefinitely. File chunks start with a 1-based
+    ``L{begin}-{end}`` line range like ``read_file``; memory chunks (generic
+    tool output) are served from a short-lived in-memory store that is forgotten
+    when the agent exits.
     """
     parsed = decode_truncate_token(token)
     if parsed is None:
         return "error: invalid truncate token"
     if parsed.kind == "http":
         return await fetch.handler(parsed.location, offset=parsed.offset, max_chars=parsed.limit)
+    if parsed.kind == "memory":
+        remainder = get_remainder(parsed.location)
+        if remainder is None:
+            return "error: truncate token expired (no longer in memory); re-run the tool"
+        start = parsed.offset
+        segment = remainder[start : start + max_chars]
+        chunk, _ = truncate_with_token(
+            segment,
+            max_chars,
+            kind="memory",
+            location=parsed.location,
+            offset=start,
+            limit=max_chars,
+            total_len=len(remainder),
+        )
+        return chunk
     text, err = read_raw_text(parsed.location)
     if err:
         return err
@@ -41,6 +63,6 @@ async def get_truncated(token: str, *, max_chars: int = DEFAULT_TOOL_RESULT_MAX_
         limit=max_chars,
         total_len=len(text),
     )
-    content_len = len(chunk.split("\n...[", 1)[0]) if "\n...[" in chunk else len(chunk)
+    content_len = len(chunk.split("\n[Truncated", 1)[0]) if "\n[Truncated" in chunk else len(chunk)
     header = line_range_label(text, start, start + content_len)
     return f"{header}\n{chunk}"

src/plyngent/tools/process/command_exec.py

@@ -22,9 +22,19 @@ DEFAULT_MAX_BATCH_STEPS = 20
 
 
 def truncate_output(text: str, label: str, max_chars: int = DEFAULT_MAX_OUTPUT_CHARS) -> str:
-    if len(text) <= max_chars:
+    """Cap a per-stream output block; embed a truncate token when cut.
+
+    ``label`` (stdout/stderr/batch) is kept for call-site clarity but the
+    marker itself is the uniform ``[Truncated (N chars max.; M omitted).
+    truncate_token=...]`` (no label), matching every other truncation site.
+    Returns ``text`` unchanged when it fits.
+    """
+    del label
+    if max_chars < 1 or len(text) <= max_chars:
         return text
-    return text[:max_chars] + f"\n...[{label} truncated]"
+    from plyngent.tools.truncate_token import truncate_generic
+
+    return truncate_generic(text, max_chars)
 
 
 def format_command_result(

tests/test_tools/test_fetch.py

@@ -246,9 +246,9 @@ async def test_fetch_char_truncation_embeds_token(workspace: Path, http_server:
     out = await call_async(fetch, f"{http_server}/big", max_chars=1000)
     assert "truncated=true" in out
     body = out.split("--- body ---", 1)[-1]
-    assert "TRUNCATE_TOKEN:" in body
-    token_line = next(ln for ln in body.splitlines() if "TRUNCATE_TOKEN:" in ln)
-    token_str = token_line.split("[TRUNCATE_TOKEN: ", 1)[1].rstrip("]")
+    assert "truncate_token=" in body
+    token_line = next(ln for ln in body.splitlines() if "truncate_token=" in ln)
+    token_str = token_line.split("truncate_token=", 1)[1].rstrip("]")
     token = decode_truncate_token(token_str)
     assert token is not None
     assert token.kind == "http"
@@ -269,7 +269,7 @@ async def test_fetch_offset_skips_body(workspace: Path, http_server: str) -> Non
     out = await call_async(fetch, f"{http_server}/big", max_chars=200, offset=4900)
     body = out.split("--- body ---", 1)[-1]
     assert body.strip() == "x" * 100
-    assert "TRUNCATE_TOKEN:" not in out
+    assert "truncate_token=" not in out
 
 
 async def test_fetch_private_denied_without_grant(workspace: Path, http_server: str) -> None:

tests/test_tools/test_file.py

@@ -11,8 +11,8 @@ get_truncated_module = importlib.import_module("plyngent.tools.file.get_truncate
 
 def _extract_token(out: str) -> str | None:
     for line in out.splitlines():
-        if "TRUNCATE_TOKEN:" in line:
-            return line.split("[TRUNCATE_TOKEN: ", 1)[1].rstrip("]")
+        if "truncate_token=" in line:
+            return line.split("truncate_token=", 1)[1].rstrip("]")
     return None
 
 
@@ -33,10 +33,10 @@ def test_read_file_max_chars_embeds_token(workspace: Path) -> None:
     out = call_sync(read_file, "big.txt", max_chars=200)
     header, _, rest = out.partition("\n")
     assert header.startswith("L1-")  # 1-based range of the raw slice read
-    content, _, marker = rest.partition("\n...[")
+    content, _, marker = rest.partition("\n[Truncated")
     assert content == "a" * len(content)
     assert len(content) < 200
-    assert "TRUNCATE_TOKEN:" in marker
+    assert "truncate_token=" in marker
     token = _extract_token(out)
     assert token is not None
     parsed = get_truncated_module.decode_truncate_token(token)
@@ -49,7 +49,7 @@ def test_read_file_max_chars_small_file_untouched(workspace: Path) -> None:
     (workspace / "small.txt").write_text("tiny", encoding="utf-8")
     out = call_sync(read_file, "small.txt", max_chars=200)
     assert out == "L1-1\ntiny"
-    assert "TRUNCATE_TOKEN:" not in out
+    assert "truncate_token=" not in out
 
 
 def test_edit_replace_first_only(workspace: object) -> None:

tests/test_tools/test_get_truncated.py

@@ -12,8 +12,8 @@ get_truncated = get_truncated_module.get_truncated
 
 def _extract_token(out: str) -> str | None:
     for line in out.splitlines():
-        if "TRUNCATE_TOKEN:" in line:
-            return line.split("[TRUNCATE_TOKEN: ", 1)[1].rstrip("]")
+        if "truncate_token=" in line:
+            return line.split("truncate_token=", 1)[1].rstrip("]")
     return None
 
 
@@ -29,7 +29,7 @@ async def test_get_truncated_file_chains_without_gap(workspace: Path) -> None:
     total_read = 0
     for _ in range(20):
         out = await call_async(get_truncated, token, max_chars=200)
-        body, _, _ = out.partition("\n...[")
+        body, _, _ = out.partition("\n[Truncated")
         header, _, content = body.partition("\n")
         assert header.startswith("L") and "-" in header
         assert content == "a" * len(content)
@@ -62,3 +62,42 @@ async def test_get_truncated_http_passthrough(monkeypatch) -> None:
     out = await call_async(get_truncated, token, max_chars=200)
     assert out == "body-from-500"
     assert calls == [("https://example.com/x", 500, 400)]
+
+
+async def test_get_truncated_memory_chains() -> None:
+    from plyngent.tools.truncate_token import truncate_generic
+
+    bounded = truncate_generic("m" * 1000, 200)
+    assert "truncate_token=" in bounded
+    token = bounded.split("truncate_token=", 1)[1].rstrip("]")
+    parsed = decode_truncate_token(token)
+    assert parsed is not None
+    assert parsed.kind == "memory"
+    cursor = parsed.offset  # chars already delivered by truncate_generic
+    delivered = cursor
+    for _ in range(20):
+        out = await call_async(get_truncated, token, max_chars=200)
+        content, _, _ = out.partition("\n[Truncated")
+        assert content == "m" * len(content)
+        delivered += len(content)
+        next_token = _extract_token(out)
+        if next_token is None:
+            break  # source exhausted → no token, no marker
+        parsed = decode_truncate_token(next_token)
+        assert parsed is not None
+        assert parsed.kind == "memory"
+        # No gap: the next cursor is exactly where this chunk ended.
+        assert parsed.offset == delivered
+        token = next_token
+    assert delivered == 1000
+
+
+async def test_get_truncated_memory_expired() -> None:
+    from plyngent.tools.truncate_token import _MEMORY_REMAINDERS, store_remainder
+
+    key = store_remainder("x" * 500)
+    del _MEMORY_REMAINDERS[key]
+    token = encode_truncate_token(TruncateToken(kind="memory", location=key, offset=0, limit=200))
+    out = await call_async(get_truncated, token, max_chars=200)
+    assert out.startswith("error:")
+    assert "expired" in out