bytedance/deer-flow · error · ValueError

mem0 max_injection_chars must be positive

Error message

mem0 max_injection_chars must be positive

What it means

Raised by Mem0Config.from_backend_config when memory.backend_config.max_injection_chars is <= 0 after int() coercion. This is a hard cap on the injection text returned by get_context; memories that do not fit whole are skipped (truncation happens on entry boundaries). Zero or negative would disable injection in an undocumented way, so it is rejected.

Source

Thrown at backend/packages/harness/deerflow/agents/memory/backends/mem0/config.py:107

            score_threshold=float(cfg.get("score_threshold", 0.1)),
            max_injection_chars=int(cfg.get("max_injection_chars", 12000)),
            timeout_seconds=float(cfg.get("timeout_seconds", 10.0)),
            startup_policy=str(cfg.get("startup_policy", "fail_fast")),
            read_policy=str(failure_policy.get("read", "fail_open")),
            write_policy=str(failure_policy.get("write", "log_and_drop")),
        )
        if config.startup_policy not in _STARTUP_POLICIES:
            raise ValueError(f"mem0 startup_policy must be one of {sorted(_STARTUP_POLICIES)}")
        if config.read_policy not in _READ_POLICIES:
            raise ValueError(f"mem0 failure_policy.read must be one of {sorted(_READ_POLICIES)}")
        if config.write_policy not in _WRITE_POLICIES:
            raise ValueError(f"mem0 failure_policy.write must be one of {sorted(_WRITE_POLICIES)}")
        if not 1 <= config.top_k <= 1000:
            raise ValueError("mem0 top_k must be in [1, 1000]")
        if not 0.0 <= config.score_threshold <= 1.0:
            raise ValueError("mem0 score_threshold must be in [0, 1]")
        if config.max_injection_chars <= 0:
            raise ValueError("mem0 max_injection_chars must be positive")
        if config.timeout_seconds <= 0:
            raise ValueError("mem0 timeout_seconds must be positive")
        if not config.api_key_env.strip():
            raise ValueError("mem0 api_key_env must be a non-empty env var name")
        parsed_base_url = urlsplit(config.base_url)
        if parsed_base_url.scheme not in {"http", "https"} or not parsed_base_url.netloc:
            raise ValueError("mem0 base_url must be an absolute http:// or https:// URL")
        if parsed_base_url.scheme == "http" and not config.allow_insecure_http:
            raise ValueError("mem0 base_url must use https:// because it carries the API key; set allow_insecure_http: true only for trusted local development")
        return config

    def resolve_api_key(self) -> str:
        """Read the API key from the configured environment variable."""
        key = os.environ.get(self.api_key_env, "").strip()
        if not key:
            raise ValueError(f"mem0 API key missing: environment variable {self.api_key_env} is unset or empty")
        return key

View on GitHub (pinned to 1dd6ba1acb)

Solutions

1. Set max_injection_chars to a positive budget (default 12000)
2. To stop injecting memory text, use memory.injection_enabled: false
3. If reducing prompt size, pick a small positive value (e.g. 2000) and let whole-entry truncation shed the rest

Example fix

# before (config.yaml)
memory:
  backend_config:
    max_injection_chars: 0   # must be positive

# after
memory:
  injection_enabled: false   # or a positive cap:
  backend_config:
    max_injection_chars: 4000

def max_injection_chars_ok(backend_config: dict) -> bool:
    try:
        return int((backend_config or {}).get("max_injection_chars", 12000)) > 0
    except (TypeError, ValueError):
        return False

def is_positive_int(v: object) -> bool:
    return isinstance(v, int) and not isinstance(v, bool) and v > 0

When it happens

Trigger: max_injection_chars: 0 (attempting to disable injection via the cap), a negative value, or a templated empty default coercing to 0.

Common situations: Trying to turn off memory injection by zeroing the budget instead of memory.injection_enabled: false; decreasing the cap aggressively to save tokens and overshooting to 0.

Related errors

• mem0 top_k must be in [1, 1000]
• mem0 score_threshold must be in [0, 1]
• mem0 backend_config has unknown keys: {sorted(unknown)}
• mem0 failure_policy must be a mapping {read, write}
• mem0 failure_policy has unknown keys: {sorted(unknown_fp)}

AI-assisted analysis of bytedance/deer-flow@1dd6ba1acb (2026-08-14). Data as JSON: /api/errors/632cb0df77397541. Report an issue: GitHub.